protot/3rdparty/bgfx/include/bgfx/bgfx.h

/*
 * Copyright 2011-2016 Branimir Karadzic. All rights reserved.
 * License: https://github.com/bkaradzic/bgfx/blob/master/LICENSE
 */

#ifndef BGFX_H_HEADER_GUARD
#define BGFX_H_HEADER_GUARD

#include <stdarg.h> // va_list
#include <stdint.h> // uint32_t
#include <stdlib.h> // NULL

#include <bgfx/bgfxdefines.h>

///
#define BGFX_HANDLE(_name) \
			struct _name { uint16_t idx; }; \
			inline bool isValid(_name _handle) { return bgfx::invalidHandle != _handle.idx; }

#define BGFX_INVALID_HANDLE { bgfx::invalidHandle }

namespace bx { struct AllocatorI; }

/// BGFX
namespace bgfx
{
	/// Fatal error enum.
	///
	/// @attention C99 equivalent is `bgfx_fatal_t`.
	///
	struct Fatal
	{
		enum Enum
		{
			DebugCheck,
			InvalidShader,
			UnableToInitialize,
			UnableToCreateTexture,
			DeviceLost,

			Count
		};
	};

	/// Renderer backend type enum.
	///
	/// @attention C99 equivalent is `bgfx_renderer_type_t`.
	///
	struct RendererType
	{
		/// Renderer types:
		enum Enum
		{
			Noop,         //!< No rendering.
			Direct3D9,    //!< Direct3D 9.0
			Direct3D11,   //!< Direct3D 11.0
			Direct3D12,   //!< Direct3D 12.0
			Gnm,          //!< GNM
			Metal,        //!< Metal
			OpenGLES,     //!< OpenGL ES 2.0+
			OpenGL,       //!< OpenGL 2.1+
			Vulkan,       //!< Vulkan

			Count
		};
	};

	/// Access mode enum.
	///
	/// @attention C99 equivalent is `bgfx_access_t`.
	///
	struct Access
	{
		/// Access:
		enum Enum
		{
			Read,
			Write,
			ReadWrite,

			Count
		};
	};

	/// Vertex attribute enum.
	///
	/// @attention C99 equivalent is `bgfx_attrib_t`.
	///
	struct Attrib
	{
		/// Corresponds to vertex shader attribute. Attributes:
		enum Enum
		{
			Position,  //!< a_position
			Normal,    //!< a_normal
			Tangent,   //!< a_tangent
			Bitangent, //!< a_bitangent
			Color0,    //!< a_color0
			Color1,    //!< a_color1
			Indices,   //!< a_indices
			Weight,    //!< a_weight
			TexCoord0, //!< a_texcoord0
			TexCoord1, //!< a_texcoord1
			TexCoord2, //!< a_texcoord2
			TexCoord3, //!< a_texcoord3
			TexCoord4, //!< a_texcoord4
			TexCoord5, //!< a_texcoord5
			TexCoord6, //!< a_texcoord6
			TexCoord7, //!< a_texcoord7

			Count
		};
	};

	/// Vertex attribute type enum.
	///
	/// @attention C99 equivalent is `bgfx_attrib_type_t`.
	///
	struct AttribType
	{
		/// Attribute types:
		enum Enum
		{
			Uint8,  //!< Uint8
			Uint10, //!< Uint10, availability depends on: `BGFX_CAPS_VERTEX_ATTRIB_UINT10`.
			Int16,  //!< Int16
			Half,   //!< Half, availability depends on: `BGFX_CAPS_VERTEX_ATTRIB_HALF`.
			Float,  //!< Float

			Count
		};
	};

	/// Texture format enum.
	///
	/// Notation:
	///
	///       RGBA16S
	///       ^   ^ ^
	///       |   | +-- [ ]Unorm
	///       |   |     [F]loat
	///       |   |     [S]norm
	///       |   |     [I]nt
	///       |   |     [U]int
	///       |   +---- Number of bits per component
	///       +-------- Components
	///
	/// @attention Availability depends on Caps (see: formats).
	///
	/// @attention C99 equivalent is `bgfx_texture_format_t`.
	///
	struct TextureFormat
	{
		/// Texture formats:
		enum Enum
		{
			BC1,          //!< DXT1
			BC2,          //!< DXT3
			BC3,          //!< DXT5
			BC4,          //!< LATC1/ATI1
			BC5,          //!< LATC2/ATI2
			BC6H,         //!< BC6H
			BC7,          //!< BC7
			ETC1,         //!< ETC1 RGB8
			ETC2,         //!< ETC2 RGB8
			ETC2A,        //!< ETC2 RGBA8
			ETC2A1,       //!< ETC2 RGB8A1
			PTC12,        //!< PVRTC1 RGB 2BPP
			PTC14,        //!< PVRTC1 RGB 4BPP
			PTC12A,       //!< PVRTC1 RGBA 2BPP
			PTC14A,       //!< PVRTC1 RGBA 4BPP
			PTC22,        //!< PVRTC2 RGBA 2BPP
			PTC24,        //!< PVRTC2 RGBA 4BPP

			Unknown,      // Compressed formats above.

			R1,
			A8,
			R8,
			R8I,
			R8U,
			R8S,
			R16,
			R16I,
			R16U,
			R16F,
			R16S,
			R32I,
			R32U,
			R32F,
			RG8,
			RG8I,
			RG8U,
			RG8S,
			RG16,
			RG16I,
			RG16U,
			RG16F,
			RG16S,
			RG32I,
			RG32U,
			RG32F,
			RGB8,
			RGB8I,
			RGB8U,
			RGB8S,
			RGB9E5F,
			BGRA8,
			RGBA8,
			RGBA8I,
			RGBA8U,
			RGBA8S,
			RGBA16,
			RGBA16I,
			RGBA16U,
			RGBA16F,
			RGBA16S,
			RGBA32I,
			RGBA32U,
			RGBA32F,
			R5G6B5,
			RGBA4,
			RGB5A1,
			RGB10A2,
			R11G11B10F,

			UnknownDepth, // Depth formats below.

			D16,
			D24,
			D24S8,
			D32,
			D16F,
			D24F,
			D32F,
			D0S8,

			Count
		};
	};

	/// Uniform type enum.
	///
	/// @attention C99 equivalent is `bgfx_uniform_type_t`.
	///
	struct UniformType
	{
		/// Uniform types:
		enum Enum
		{
			Int1,
			End,

			Vec4,
			Mat3,
			Mat4,

			Count
		};
	};

	/// Backbuffer ratio enum.
	///
	/// @attention C99 equivalent is `bgfx_backbuffer_ratio_t`.
	///
	struct BackbufferRatio
	{
		/// Backbuffer ratios:
		enum Enum
		{
			Equal,     //!< Equal to backbuffer.
			Half,      //!< One half size of backbuffer.
			Quarter,   //!< One quarter size of backbuffer.
			Eighth,    //!< One eighth size of backbuffer.
			Sixteenth, //!< One sixteenth size of backbuffer.
			Double,    //!< Double size of backbuffer.

			Count
		};
	};

	/// Occlusion query result.
	///
	/// @attention C99 equivalent is `bgfx_occlusion_query_result_t`.
	///
	struct OcclusionQueryResult
	{
		/// Occlusion query results:
		enum Enum
		{
			Invisible, //!< Query failed test.
			Visible,   //!< Query passed test.
			NoResult,  //!< Query result is not available yet.

			Count
		};
	};

	/// Topology conversion function.
	///
	/// @attention C99 equivalent is `bgfx_topology_convert_t`.
	///
	struct TopologyConvert
	{
		/// Topology conversion functions:
		enum Enum
		{
			TriListFlipWinding,  //!< Flip winding order of triangle list.
			TriListToLineList,   //!< Convert triangle list to line list.
			TriStripToTriList,   //!< Convert triangle strip to triangle list.
			LineStripToLineList, //!< Convert line strip to line list.

			Count
		};
	};

	/// Topology sort order.
	///
	/// @attention C99 equivalent is `bgfx_topology_sort_t`.
	///
	struct TopologySort
	{
		/// Topology sort order:
		enum Enum
		{
			DirectionFrontToBackMin, //!<
			DirectionFrontToBackAvg, //!<
			DirectionFrontToBackMax, //!<
			DirectionBackToFrontMin, //!<
			DirectionBackToFrontAvg, //!<
			DirectionBackToFrontMax, //!<
			DistanceFrontToBackMin,  //!<
			DistanceFrontToBackAvg,  //!<
			DistanceFrontToBackMax,  //!<
			DistanceBackToFrontMin,  //!<
			DistanceBackToFrontAvg,  //!<
			DistanceBackToFrontMax,  //!<

			Count
		};
	};

	static const uint16_t invalidHandle = UINT16_MAX;

	BGFX_HANDLE(DynamicIndexBufferHandle);
	BGFX_HANDLE(DynamicVertexBufferHandle);
	BGFX_HANDLE(FrameBufferHandle);
	BGFX_HANDLE(IndexBufferHandle);
	BGFX_HANDLE(IndirectBufferHandle);
	BGFX_HANDLE(OcclusionQueryHandle);
	BGFX_HANDLE(ProgramHandle);
	BGFX_HANDLE(ShaderHandle);
	BGFX_HANDLE(TextureHandle);
	BGFX_HANDLE(UniformHandle);
	BGFX_HANDLE(VertexBufferHandle);
	BGFX_HANDLE(VertexDeclHandle);

	/// Callback interface to implement application specific behavior.
	/// Cached items are currently used for OpenGL and Direct3D 12 binary
	/// shaders.
	///
	/// @remarks
	///   'fatal' and 'trace' callbacks can be called from any thread. Other
	///   callbacks are called from the render thread.
	///
	/// @attention C99 equivalent is `bgfx_callback_interface_t`.
	///
	struct CallbackI
	{
		virtual ~CallbackI() = 0;

		/// If fatal code code is not Fatal::DebugCheck this callback is
		/// called on unrecoverable error. It's not safe to continue, inform
		/// user and terminate application from this call.
		///
		/// @param[in] _code Fatal error code.
		/// @param[in] _str More information about error.
		///
		/// @remarks
		///   Not thread safe and it can be called from any thread.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.fatal`.
		///
		virtual void fatal(Fatal::Enum _code, const char* _str) = 0;

		/// Print debug message.
		///
		/// @param[in] _filePath File path where debug message was generated.
		/// @param[in] _line Line where debug message was generated.
		/// @param[in] _format `printf` style format.
		/// @param[in] _argList Variable arguments list initialized with
		///   `va_start`.
		///
		/// @remarks
		///   Not thread safe and it can be called from any thread.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.trace_vargs`.
		///
		virtual void traceVargs(
			  const char* _filePath
			, uint16_t _line
			, const char* _format
			, va_list _argList
			) = 0;

		/// Return size of for cached item. Return 0 if no cached item was
		/// found.
		///
		/// @param[in] _id Cache id.
		/// @returns Number of bytes to read.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.cache_read_size`.
		///
		virtual uint32_t cacheReadSize(uint64_t _id) = 0;

		/// Read cached item.
		///
		/// @param[in] _id Cache id.
		/// @param[in] _data Buffer where to read data.
		/// @param[in] _size Size of data to read.
		///
		/// @returns True if data is read.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.cache_read`.
		///
		virtual bool cacheRead(uint64_t _id, void* _data, uint32_t _size) = 0;

		/// Write cached item.
		///
		/// @param[in] _id Cache id.
		/// @param[in] _data Data to write.
		/// @param[in] _size Size of data to write.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.cache_write`.
		///
		virtual void cacheWrite(uint64_t _id, const void* _data, uint32_t _size) = 0;

		/// Screenshot captured. Screenshot format is always 4-byte BGRA.
		///
		/// @param[in] _filePath File path.
		/// @param[in] _width Image width.
		/// @param[in] _height Image height.
		/// @param[in] _pitch Number of bytes to skip to next line.
		/// @param[in] _data Image data.
		/// @param[in] _size Image size.
		/// @param[in] _yflip If true image origin is bottom left.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.screen_shot`.
		///
		virtual void screenShot(
			  const char* _filePath
			, uint32_t _width
			, uint32_t _height
			, uint32_t _pitch
			, const void* _data
			, uint32_t _size
			, bool _yflip
			) = 0;

		/// Called when capture begins.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.capture_begin`.
		///
		virtual void captureBegin(
			  uint32_t _width
			, uint32_t _height
			, uint32_t _pitch
			, TextureFormat::Enum _format
			, bool _yflip
			) = 0;

		/// Called when capture ends.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.capture_end`.
		///
		virtual void captureEnd() = 0;

		/// Captured frame.
		///
		/// @param[in] _data Image data.
		/// @param[in] _size Image size.
		///
		/// @attention C99 equivalent is `bgfx_callback_vtbl.capture_frame`.
		///
		virtual void captureFrame(const void* _data, uint32_t _size) = 0;
	};

	inline CallbackI::~CallbackI()
	{
	}

	/// Memory release callback.
	///
	/// @attention C99 equivalent is `bgfx_release_fn_t`.
	///
	typedef void (*ReleaseFn)(void* _ptr, void* _userData);

	/// Memory obtained by calling `bgfx::alloc`, `bgfx::copy`, or `bgfx::makeRef`.
	///
	/// @attention C99 equivalent is `bgfx_memory_t`.
	///
	struct Memory
	{
		uint8_t* data;
		uint32_t size;
	};

	/// Renderer capabilities.
	///
	/// @attention C99 equivalent is `bgfx_caps_t`.
	///
	struct Caps
	{
		/// Renderer backend type. See: `bgfx::RendererType`
		RendererType::Enum rendererType;

		/// Supported functionality.
		///
		/// @attention See BGFX_CAPS_* flags at https://bkaradzic.github.io/bgfx/bgfx.html#available-caps
		///
		uint64_t supported;

		uint16_t vendorId;         //!< Selected GPU vendor PCI id.
		uint16_t deviceId;         //!< Selected GPU device id.
		bool     homogeneousDepth; //!< True when NDC depth is in [-1, 1] range.
		bool     originBottomLeft; //!< True when NDC origin is at bottom left.
		uint8_t  numGPUs;          //!< Number of enumerated GPUs.

		/// GPU info.
		///
		/// @attention C99 equivalent is `bgfx_caps_gpu_t`.
		///
		struct GPU
		{
			uint16_t vendorId; //!< Vendor PCI id. See `BGFX_PCI_ID_*`.
			uint16_t deviceId; //!< Device id.
		};

		GPU gpu[4]; //!< Enumerated GPUs.

		struct Limits
		{
			uint32_t maxDrawCalls;            //!< Maximum draw calls.
			uint32_t maxBlits;                //!< Maximum number of blit calls.
			uint32_t maxTextureSize;          //!< Maximum texture size.
			uint32_t maxViews;                //!< Maximum views.
			uint32_t maxFrameBuffers;         //!< Maximum number of frame buffer handles.
			uint32_t maxFBAttachments;        //!< Maximum frame buffer attachments.
			uint32_t maxPrograms;             //!< Maximum number of program handles.
			uint32_t maxShaders;              //!< Maximum number of shader handles.
			uint32_t maxTextures;             //!< Maximum number of texture handles.
			uint32_t maxTextureSamplers;      //!< Maximum number of texture samplers.
			uint32_t maxVertexDecls;          //!< Maximum number of vertex format declarations.
			uint32_t maxVertexStreams;        //!< Maximum number of vertex streams.
			uint32_t maxIndexBuffers;         //!< Maximum number of index buffer handles.
			uint32_t maxVertexBuffers;        //!< Maximum number of vertex buffer handles.
			uint32_t maxDynamicIndexBuffers;  //!< Maximum number of dynamic index buffer handles.
			uint32_t maxDynamicVertexBuffers; //!< Maximum number of dynamic vertex buffer handles.
			uint32_t maxUniforms;             //!< Maximum number of uniform handles.
			uint32_t maxOcclusionQueries;     //!< Maximum number of occlusion query handles.
		};

		Limits limits;

		/// Supported texture formats.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_NONE` - Texture format is not supported.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_2D` - Texture format is supported.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_2D_SRGB` - Texture as sRGB format is supported.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_2D_EMULATED` - Texture format is emulated.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_3D` - Texture format is supported.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_3D_SRGB` - Texture as sRGB format is supported.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_3D_EMULATED` - Texture format is emulated.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_CUBE` - Texture format is supported.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_CUBE_SRGB` - Texture as sRGB format is supported.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_CUBE_EMULATED` - Texture format is emulated.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_VERTEX` - Texture format can be used from vertex shader.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_IMAGE` - Texture format can be used as image from compute
		///     shader.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_FRAMEBUFFER` - Texture format can be used as frame
		///     buffer.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_FRAMEBUFFER_MSAA` - Texture format can be used as MSAA
		///     frame buffer.
		///   - `BGFX_CAPS_FORMAT_TEXTURE_MSAA` - Texture can be sampled as MSAA.
		uint16_t formats[TextureFormat::Count];
	};

	/// Transient index buffer.
	///
	/// @attention C99 equivalent is `bgfx_transient_index_buffer_t`.
	///
	struct TransientIndexBuffer
	{
		uint8_t* data;            //!< Pointer to data.
		uint32_t size;            //!< Data size.
		uint32_t startIndex;      //!< First index.
		IndexBufferHandle handle; //!< Index buffer handle.
	};

	/// Transient vertex buffer.
	///
	/// @attention C99 equivalent is `bgfx_transient_vertex_buffer_t`.
	///
	struct TransientVertexBuffer
	{
		uint8_t* data;             //!< Pointer to data.
		uint32_t size;             //!< Data size.
		uint32_t startVertex;      //!< First vertex.
		uint16_t stride;           //!< Vertex stride.
		VertexBufferHandle handle; //!< Vertex buffer handle.
		VertexDeclHandle decl;     //!< Vertex declaration handle.
	};

	/// Instance data buffer info.
	///
	/// @attention C99 equivalent is `bgfx_texture_info_t`.
	///
	struct InstanceDataBuffer
	{
		uint8_t* data;             //!< Pointer to data.
		uint32_t size;             //!< Data size.
		uint32_t offset;           //!< Offset in vertex buffer.
		uint32_t num;              //!< Number of instances.
		uint16_t stride;           //!< Vertex buffer stride.
		VertexBufferHandle handle; //!< Vertex buffer object handle.
	};

	/// Texture info.
	///
	/// @attention C99 equivalent is `bgfx_texture_info_t`.
	///
	struct TextureInfo
	{
		TextureFormat::Enum format; //!< Texture format.
		uint32_t storageSize;       //!< Total amount of bytes required to store texture.
		uint16_t width;             //!< Texture width.
		uint16_t height;            //!< Texture height.
		uint16_t depth;             //!< Texture depth.
		uint16_t numLayers;         //!< Number of layers in texture array.
		uint8_t numMips;            //!< Number of MIP maps.
		uint8_t bitsPerPixel;       //!< Format bits per pixel.
		bool    cubeMap;            //!< Texture is cubemap.
	};

	/// Uniform info.
	///
	/// @attention C99 equivalent is `bgfx_uniform_info_t`.
	///
	struct UniformInfo
	{
		char name[256];         //!< Uniform name.
		UniformType::Enum type; //!< Uniform type.
		uint16_t num;           //!< Number of elements in array.
	};

	/// Frame buffer texture attachemnt info.
	///
	/// @attention C99 equivalent is `bgfx_attachment_t`.
	///
	struct Attachment
	{
		TextureHandle handle; //!< Texture handle.
		uint16_t mip;         //!< Mip level.
		uint16_t layer;       //!< Cubemap side or depth layer/slice.
	};

	/// Transform data.
	///
	/// @attention C99 equivalent is `bgfx_transform_t`.
	///
	struct Transform
	{
		float* data;  //!< Pointer to first matrix.
		uint16_t num; //!< Number of matrices.
	};

	/// HMD info.
	///
	/// @attention C99 equivalent is `bgfx_hmd_t`.
	///
	struct HMD
	{
		/// Eye
		///
		/// @attention C99 equivalent is `bgfx_hmd_eye_t`.
		///
		struct Eye
		{
			float rotation[4];          //!< Eye rotation represented as quaternion.
			float translation[3];       //!< Eye translation.
			float fov[4];               //!< Field of view (up, down, left, right).
			float viewOffset[3];        //!< Eye view matrix translation adjustment.
			float projection[16];       //!< Eye projection matrix
			float pixelsPerTanAngle[2]; //!<
		};

		Eye eye[2];
		uint16_t width;        //!< Framebuffer width.
		uint16_t height;       //!< Framebuffer width.
		uint32_t deviceWidth;  //!< Device resolution width
		uint32_t deviceHeight; //!< Device resolution height
		uint8_t flags;         //!< Status flags
	};

	/// Renderer statistics data.
	///
	/// @attention C99 equivalent is `bgfx_stats_t`.
	///
	struct Stats
	{
		uint64_t cpuTimeBegin; //!< CPU frame begin time.
		uint64_t cpuTimeEnd;   //!< CPU frame end time.
		uint64_t cpuTimerFreq; //!< CPU timer frequency.

		uint64_t gpuTimeBegin; //!< GPU frame begin time.
		uint64_t gpuTimeEnd;   //!< GPU frame end time.
		uint64_t gpuTimerFreq; //!< GPU timer frequency.

		int64_t waitRender;    //!< Time spent waiting for render backend thread to finish issuing
		                       //!  draw commands to underlying graphics API.
		int64_t waitSubmit;    //!< Time spent waiting for submit thread to advance to next frame.
	};

	/// Vertex declaration.
	///
	/// @attention C99 equivalent is `bgfx_vertex_decl_t`.
	///
	struct VertexDecl
	{
		VertexDecl();

		/// Start VertexDecl.
		///
		/// @attention C99 equivalent is `bgfx_vertex_decl_begin`.
		///
		VertexDecl& begin(RendererType::Enum _renderer = RendererType::Noop);

		/// End VertexDecl.
		///
		/// @attention C99 equivalent is `bgfx_vertex_decl_end`.
		///
		void end();

		/// Add attribute to VertexDecl.
		///
		/// @param[in] _attrib Attribute semantics. See: `bgfx::Attrib`
		/// @param[in] _num Number of elements 1, 2, 3 or 4.
		/// @param[in] _type Element type.
		/// @param[in] _normalized When using fixed point AttribType (f.e. Uint8)
		///   value will be normalized for vertex shader usage. When normalized
		///   is set to true, AttribType::Uint8 value in range 0-255 will be
		///   in range 0.0-1.0 in vertex shader.
		/// @param[in] _asInt Packaging rule for vertexPack, vertexUnpack, and
		///   vertexConvert for AttribType::Uint8 and AttribType::Int16.
		///   Unpacking code must be implemented inside vertex shader.
		///
		/// @remarks
		///   Must be called between begin/end.
		///
		/// @attention C99 equivalent is `bgfx_vertex_decl_add`.
		///
		VertexDecl& add(
			  Attrib::Enum _attrib
			, uint8_t _num
			, AttribType::Enum _type
			, bool _normalized = false
			, bool _asInt = false
			);

		/// Skip _num bytes in vertex stream.
		///
		/// @attention C99 equivalent is `bgfx_vertex_decl_skip`.
		///
		VertexDecl& skip(uint8_t _num);

		/// Decode attribute.
		///
		/// @attention C99 equivalent is ``.
		///
		void decode(
			  Attrib::Enum _attrib
			, uint8_t& _num
			, AttribType::Enum& _type
			, bool& _normalized
			, bool& _asInt
			) const;

		/// Returns true if VertexDecl contains attribute.
		bool has(Attrib::Enum _attrib) const { return UINT16_MAX != m_attributes[_attrib]; }

		/// Returns relative attribute offset from the vertex.
		uint16_t getOffset(Attrib::Enum _attrib) const { return m_offset[_attrib]; }

		/// Returns vertex stride.
		uint16_t getStride() const { return m_stride; }

		/// Returns size of vertex buffer for number of vertices.
		uint32_t getSize(uint32_t _num) const { return _num*m_stride; }

		uint32_t m_hash;
		uint16_t m_stride;
		uint16_t m_offset[Attrib::Count];
		uint16_t m_attributes[Attrib::Count];
	};

	/// Pack vec4 into vertex stream format.
	///
	/// @attention C99 equivalent is `bgfx_vertex_pack`.
	///
	void vertexPack(
		  const float _input[4]
		, bool _inputNormalized
		, Attrib::Enum _attr
		, const VertexDecl& _decl
		, void* _data
		, uint32_t _index = 0
		);

	/// Unpack vec4 from vertex stream format.
	///
	/// @attention C99 equivalent is `bgfx_vertex_unpack`.
	///
	void vertexUnpack(
		  float _output[4]
		, Attrib::Enum _attr
		, const VertexDecl& _decl
		, const void* _data
		, uint32_t _index = 0
		);

	/// Converts vertex stream data from one vertex stream format to another.
	///
	/// @param[in] _destDecl Destination vertex stream declaration.
	/// @param[in] _destData Destination vertex stream.
	/// @param[in] _srcDecl Source vertex stream declaration.
	/// @param[in] _srcData Source vertex stream data.
	/// @param[in] _num Number of vertices to convert from source to destination.
	///
	/// @attention C99 equivalent is `bgfx_vertex_convert`.
	///
	void vertexConvert(
		  const VertexDecl& _destDecl
		, void* _destData
		, const VertexDecl& _srcDecl
		, const void* _srcData
		, uint32_t _num = 1
		);

	/// Weld vertices.
	///
	/// @param[in] _output Welded vertices remapping table. The size of buffer
	///   must be the same as number of vertices.
	/// @param[in] _decl Vertex stream declaration.
	/// @param[in] _data Vertex stream.
	/// @param[in] _num Number of vertices in vertex stream.
	/// @param[in] _epsilon Error tolerance for vertex position comparison.
	/// @returns Number of unique vertices after vertex welding.
	///
	/// @attention C99 equivalent is `bgfx_weld_vertices`.
	///
	uint16_t weldVertices(
		  uint16_t* _output
		, const VertexDecl& _decl
		, const void* _data
		, uint16_t _num
		, float _epsilon = 0.001f
		);

	/// Convert index buffer for use with different primitive topologies.
	///
	/// @param[in] _conversion Conversion type, see `TopologyConvert::Enum`.
	/// @param[in] _dst Destination index buffer. If this argument it NULL
	///    function will return number of indices after conversion.
	/// @param[in] _dstSize Destination index buffer in bytes. It must be
	///    large enough to contain output indices. If destination size is
	///    insufficient index buffer will be truncated.
	/// @param[in] _indices Source indices.
	/// @param[in] _numIndices Number of input indices.
	/// @param[in] _index32 Set to `true` if input indices are 32-bit.
	///
	/// @returns Number of output indices after conversion.
	///
	/// @attention C99 equivalent is `bgfx_topology_convert`.
	///
	uint32_t topologyConvert(
		  TopologyConvert::Enum _conversion
		, void* _dst
		, uint32_t _dstSize
		, const void* _indices
		, uint32_t _numIndices
		, bool _index32
		);

	/// Sort indices.
	///
	/// @param[in] _sort Sort order, see `TopologySort::Enum`.
	/// @param[in] _dst Destination index buffer.
	/// @param[in] _dstSize Destination index buffer in bytes. It must be
	///    large enough to contain output indices. If destination size is
	///    insufficient index buffer will be truncated.
	/// @param[in] _dir Direction (vector must be normalized).
	/// @param[in] _pos Position.
	/// @param[in] _vertices Pointer to first vertex represented as
	///    float x, y, z. Must contain at least number of vertices
	///    referencende by index buffer.
	/// @param[in] _stride Vertex stride.
	/// @param[in] _indices Source indices.
	/// @param[in] _numIndices Number of input indices.
	/// @param[in] _index32 Set to `true` if input indices are 32-bit.
	///
	/// @attention C99 equivalent is `bgfx_topology_sort_tri_list`.
	///
	void topologySortTriList(
		  TopologySort::Enum _sort
		, void* _dst
		, uint32_t _dstSize
		, const float _dir[3]
		, const float _pos[3]
		, const void* _vertices
		, uint32_t _stride
		, const void* _indices
		, uint32_t _numIndices
		, bool _index32
		);

	/// Swizzle RGBA8 image to BGRA8.
	///
	/// @param[in] _width Width of input image (pixels).
	/// @param[in] _height Height of input image (pixels).
	/// @param[in] _pitch Pitch of input image (bytes).
	/// @param[in] _src Source image.
	/// @param[in] _dst Destination image. Must be the same size as input image.
	///   _dst might be pointer to the same memory as _src.
	///
	/// @attention C99 equivalent is `bgfx_image_swizzle_bgra8`.
	///
	void imageSwizzleBgra8(
		  uint32_t _width
		, uint32_t _height
		, uint32_t _pitch
		, const void* _src
		, void* _dst
		);

	/// Downsample RGBA8 image with 2x2 pixel average filter.
	///
	/// @param[in] _width Width of input image (pixels).
	/// @param[in] _height Height of input image (pixels).
	/// @param[in] _pitch Pitch of input image (bytes).
	/// @param[in] _src Source image.
	/// @param[in] _dst Destination image. Must be at least quarter size of
	///   input image. _dst might be pointer to the same memory as _src.
	///
	/// @attention C99 equivalent is `bgfx_image_rgba8_downsample_2x2`.
	///
	void imageRgba8Downsample2x2(
		  uint32_t _width
		, uint32_t _height
		, uint32_t _pitch
		, const void* _src
		, void* _dst
		);

	/// Returns supported backend API renderers.
	///
	/// @param[in] _max Maximum number of elements in _enum array.
	/// @param[inout] _enum Array where supported renderers will be written.
	///
	/// @returns Number of supported renderers.
	///
	/// @attention C99 equivalent is `bgfx_get_supported_renderers`.
	///
	uint8_t getSupportedRenderers(uint8_t _max = 0, RendererType::Enum* _enum = NULL);

	/// Returns name of renderer.
	///
	/// @attention C99 equivalent is `bgfx_get_renderer_name`.
	///
	const char* getRendererName(RendererType::Enum _type);

	/// Initialize bgfx library.
	///
	/// @param[in] _type Select rendering backend. When set to RendererType::Count
	///   default rendering backend will be selected.
	///   See: `bgfx::RendererType`
	///
	/// @param[in] _vendorId Vendor PCI id. If set to `BGFX_PCI_ID_NONE` it will select the first
	///   device.
	///   - `BGFX_PCI_ID_NONE` - Autoselect adapter.
	///   - `BGFX_PCI_ID_SOFTWARE_RASTERIZER` - Software rasterizer.
	///   - `BGFX_PCI_ID_AMD` - AMD adapter.
	///   - `BGFX_PCI_ID_INTEL` - Intel adapter.
	///   - `BGFX_PCI_ID_NVIDIA` - nVidia adapter.
	///
	/// @param[in] _deviceId Device id. If set to 0 it will select first device, or device with
	///   matching id.
	///
	/// @param[in] _callback Provide application specific callback interface.
	///   See: `bgfx::CallbackI`
	///
	/// @param[in] _allocator Custom allocator. When custom allocator is not
	///   specified, library uses default CRT allocator. The library assumes
	///   custom allocator is thread safe.
	///
	/// @returns `true` if initialization was successful.
	///
	/// @attention C99 equivalent is `bgfx_init`.
	///
	bool init(
		  RendererType::Enum _type = RendererType::Count
		, uint16_t _vendorId = BGFX_PCI_ID_NONE
		, uint16_t _deviceId = 0
		, CallbackI* _callback = NULL
		, bx::AllocatorI* _allocator = NULL
		);

	/// Shutdown bgfx library.
	///
	/// @attention C99 equivalent is `bgfx_shutdown`.
	///
	void shutdown();

	/// Reset graphic settings and back-buffer size.
	///
	/// @param[in] _width Back-buffer width.
	/// @param[in] _height Back-buffer height.
	/// @param[in] _flags See: `BGFX_RESET_*` for more info.
	///   - `BGFX_RESET_NONE` - No reset flags.
	///   - `BGFX_RESET_FULLSCREEN` - Not supported yet.
	///   - `BGFX_RESET_MSAA_X[2/4/8/16]` - Enable 2, 4, 8 or 16 x MSAA.
	///   - `BGFX_RESET_VSYNC` - Enable V-Sync.
	///   - `BGFX_RESET_MAXANISOTROPY` - Turn on/off max anisotropy.
	///   - `BGFX_RESET_CAPTURE` - Begin screen capture.
	///   - `BGFX_RESET_HMD` - HMD stereo rendering.
	///   - `BGFX_RESET_HMD_DEBUG` - HMD stereo rendering debug mode.
	///   - `BGFX_RESET_HMD_RECENTER` - HMD calibration.
	///   - `BGFX_RESET_FLUSH_AFTER_RENDER` - Flush rendering after submitting to GPU.
	///   - `BGFX_RESET_FLIP_AFTER_RENDER` - This flag  specifies where flip
	///     occurs. Default behavior is that flip occurs before rendering new
	///     frame. This flag only has effect when `BGFX_CONFIG_MULTITHREADED=0`.
	///   - `BGFX_RESET_SRGB_BACKBUFFER` - Enable sRGB backbuffer.
	///
	/// @attention This call doesn't actually change window size, it just
	///   resizes back-buffer. Windowing code has to change window size.
	///
	/// @attention C99 equivalent is `bgfx_reset`.
	///
	void reset(uint32_t _width, uint32_t _height, uint32_t _flags = BGFX_RESET_NONE);

	/// Advance to next frame. When using multithreaded renderer, this call
	/// just swaps internal buffers, kicks render thread, and returns. In
	/// singlethreaded renderer this call does frame rendering.
	///
	/// @param[in] _capture Capture frame with graphics debugger.
	///
	/// @returns Current frame number. This might be used in conjunction with
	///   double/multi buffering data outside the library and passing it to
	///   library via `bgfx::makeRef` calls.
	///
	/// @attention C99 equivalent is `bgfx_frame`.
	///
	uint32_t frame(bool _capture = false);

	/// Returns current renderer backend API type.
	///
	/// @remarks
	///   Library must be initialized.
	///
	/// @attention C99 equivalent is `bgfx_get_renderer_type`.
	///
	RendererType::Enum getRendererType();

	/// Returns renderer capabilities.
	///
	/// @returns Pointer to static `bgfx::Caps` structure.
	///
	/// @remarks
	///   Library must be initialized.
	///
	/// @attention C99 equivalent is `bgfx_get_caps`.
	///
	const Caps* getCaps();

	/// Returns HMD info.
	///
	/// @attention C99 equivalent is `bgfx_get_hmd`.
	///
	const HMD* getHMD();

	/// Returns performance counters.
	///
	/// @attention C99 equivalent is `bgfx_get_stats`.
	///
	const Stats* getStats();

	/// Allocate buffer to pass to bgfx calls. Data will be freed inside bgfx.
	///
	/// @attention C99 equivalent is `bgfx_alloc`.
	///
	const Memory* alloc(uint32_t _size);

	/// Allocate buffer and copy data into it. Data will be freed inside bgfx.
	///
	/// @attention C99 equivalent is `bgfx_copy`.
	///
	const Memory* copy(const void* _data, uint32_t _size);

	/// Make reference to data to pass to bgfx. Unlike `bgfx::alloc` this call
	/// doesn't allocate memory for data. It just copies pointer to data. You
	/// can pass `ReleaseFn` function pointer to release this memory after it's
	/// consumed, or you must make sure data is available for at least 2
	/// `bgfx::frame` calls. `ReleaseFn` function must be able to be called
	/// from any thread.
	///
	/// @attention C99 equivalent are `bgfx_make_ref`, `bgfx_make_ref_release`.
	///
	const Memory* makeRef(
		  const void* _data
		, uint32_t _size
		, ReleaseFn _releaseFn = NULL
		, void* _userData = NULL
		);

	/// Set debug flags.
	///
	/// @param[in] _debug Available flags:
	///   - `BGFX_DEBUG_IFH` - Infinitely fast hardware. When this flag is set
	///     all rendering calls will be skipped. It's useful when profiling
	///     to quickly assess bottleneck between CPU and GPU.
	///   - `BGFX_DEBUG_STATS` - Display internal statistics.
	///   - `BGFX_DEBUG_TEXT` - Display debug text.
	///   - `BGFX_DEBUG_WIREFRAME` - Wireframe rendering. All rendering
	///     primitives will be rendered as lines.
	///
	/// @attention C99 equivalent is `bgfx_set_debug`.
	///
	void setDebug(uint32_t _debug);

	/// Clear internal debug text buffer.
	///
	/// @attention C99 equivalent is `bgfx_dbg_text_clear`.
	///
	void dbgTextClear(uint8_t _attr = 0, bool _small = false);

	/// Print into internal debug text character-buffer (VGA-compatible text mode).
	///
	/// @param[in] _x, _y 2D position from top-left.
	/// @param[in] _attr Color palette. Where top 4-bits represent index of background, and bottom
	///   4-bits represent foreground color from standard VGA text palette.
	/// @param[in] _format `printf` style format.
	///
	/// @attention C99 equivalent is `bgfx_dbg_text_printf`.
	///
	void dbgTextPrintf(uint16_t _x, uint16_t _y, uint8_t _attr, const char* _format, ...);

	/// Print into internal debug text character-buffer (VGA-compatible text mode).
	///
	/// @param[in] _x, _y 2D position from top-left.
	/// @param[in] _attr Color palette. Where top 4-bits represent index of background, and bottom
	///   4-bits represent foreground color from standard VGA text palette.
	/// @param[in] _format `printf` style format.
	/// @param[in] _argList additional arguments for format string
	///
	/// @attention C99 equivalent is `bgfx_dbg_text_vprintf`.
	///
	void dbgTextPrintfVargs(uint16_t _x, uint16_t _y, uint8_t _attr, const char* _format, va_list _argList);

	/// Draw image into internal debug text buffer.
	///
	/// @param[in] _x, _y 2D position from top-left.
	/// @param[in] _width, _height  Image width and height.
	/// @param[in] _data  Raw image data (character/attribute raw encoding).
	/// @param[in] _pitch Image pitch in bytes.
	///
	/// @attention C99 equivalent is `bgfx_dbg_text_image`.
	///
	void dbgTextImage(
		  uint16_t _x
		, uint16_t _y
		, uint16_t _width
		, uint16_t _height
		, const void* _data
		, uint16_t _pitch
		);

	/// Create static index buffer.
	///
	/// @param[in] _mem Index buffer data.
	/// @param[in] _flags Buffer creation flags.
	///   - `BGFX_BUFFER_NONE` - No flags.
	///   - `BGFX_BUFFER_COMPUTE_READ` - Buffer will be read from by compute shader.
	///   - `BGFX_BUFFER_COMPUTE_WRITE` - Buffer will be written into by compute shader. When buffer
	///       is created with `BGFX_BUFFER_COMPUTE_WRITE` flag it cannot be updated from CPU.
	///   - `BGFX_BUFFER_COMPUTE_READ_WRITE` - Buffer will be used for read/write by compute shader.
	///   - `BGFX_BUFFER_ALLOW_RESIZE` - Buffer will resize on buffer update if different amount of
	///       data is passed. If this flag is not specified if more data is passed on update buffer
	///       will be trimmed to fit existing buffer size. This flag has effect only on dynamic
	///       buffers.
	///   - `BGFX_BUFFER_INDEX32` - Buffer is using 32-bit indices. This flag has effect only on
	///       index buffers.
	///
	/// @attention C99 equivalent is `bgfx_create_index_buffer`.
	///
	IndexBufferHandle createIndexBuffer(const Memory* _mem, uint16_t _flags = BGFX_BUFFER_NONE);

	/// Destroy static index buffer.
	///
	/// @attention C99 equivalent is `bgfx_destroy_index_buffer`.
	///
	void destroyIndexBuffer(IndexBufferHandle _handle);

	/// Create static vertex buffer.
	///
	/// @param[in] _mem Vertex buffer data.
	/// @param[in] _decl Vertex declaration.
	/// @param[in] _flags Buffer creation flags.
	///   - `BGFX_BUFFER_NONE` - No flags.
	///   - `BGFX_BUFFER_COMPUTE_READ` - Buffer will be read from by compute shader.
	///   - `BGFX_BUFFER_COMPUTE_WRITE` - Buffer will be written into by compute shader. When buffer
	///       is created with `BGFX_BUFFER_COMPUTE_WRITE` flag it cannot be updated from CPU.
	///   - `BGFX_BUFFER_COMPUTE_READ_WRITE` - Buffer will be used for read/write by compute shader.
	///   - `BGFX_BUFFER_ALLOW_RESIZE` - Buffer will resize on buffer update if different amount of
	///       data is passed. If this flag is not specified if more data is passed on update buffer
	///       will be trimmed to fit existing buffer size. This flag has effect only on dynamic
	///       buffers.
	///   - `BGFX_BUFFER_INDEX32` - Buffer is using 32-bit indices. This flag has effect only on
	///       index buffers.
	/// @returns Static vertex buffer handle.
	///
	/// @attention C99 equivalent is `bgfx_create_vertex_buffer`.
	///
	VertexBufferHandle createVertexBuffer(
		  const Memory* _mem
		, const VertexDecl& _decl
		, uint16_t _flags = BGFX_BUFFER_NONE
		);

	/// Destroy static vertex buffer.
	///
	/// @param[in] _handle Static vertex buffer handle.
	///
	/// @attention C99 equivalent is `bgfx_destroy_vertex_buffer`.
	///
	void destroyVertexBuffer(VertexBufferHandle _handle);

	/// Create empty dynamic index buffer.
	///
	/// @param[in] _num Number of indices.
	/// @param[in] _flags Buffer creation flags.
	///   - `BGFX_BUFFER_NONE` - No flags.
	///   - `BGFX_BUFFER_COMPUTE_READ` - Buffer will be read from by compute shader.
	///   - `BGFX_BUFFER_COMPUTE_WRITE` - Buffer will be written into by compute shader. When buffer
	///       is created with `BGFX_BUFFER_COMPUTE_WRITE` flag it cannot be updated from CPU.
	///   - `BGFX_BUFFER_COMPUTE_READ_WRITE` - Buffer will be used for read/write by compute shader.
	///   - `BGFX_BUFFER_ALLOW_RESIZE` - Buffer will resize on buffer update if different amount of
	///       data is passed. If this flag is not specified if more data is passed on update buffer
	///       will be trimmed to fit existing buffer size. This flag has effect only on dynamic
	///       buffers.
	///   - `BGFX_BUFFER_INDEX32` - Buffer is using 32-bit indices. This flag has effect only on
	///       index buffers.
	///
	/// @attention C99 equivalent is `bgfx_create_dynamic_index_buffer`.
	///
	DynamicIndexBufferHandle createDynamicIndexBuffer(
		  uint32_t _num
		, uint16_t _flags = BGFX_BUFFER_NONE
		);

	/// Create dynamic index buffer and initialized it.
	///
	/// @param[in] _mem Index buffer data.
	/// @param[in] _flags Buffer creation flags.
	///   - `BGFX_BUFFER_NONE` - No flags.
	///   - `BGFX_BUFFER_COMPUTE_READ` - Buffer will be read from by compute shader.
	///   - `BGFX_BUFFER_COMPUTE_WRITE` - Buffer will be written into by compute shader. When buffer
	///       is created with `BGFX_BUFFER_COMPUTE_WRITE` flag it cannot be updated from CPU.
	///   - `BGFX_BUFFER_COMPUTE_READ_WRITE` - Buffer will be used for read/write by compute shader.
	///   - `BGFX_BUFFER_ALLOW_RESIZE` - Buffer will resize on buffer update if different amount of
	///       data is passed. If this flag is not specified if more data is passed on update buffer
	///       will be trimmed to fit existing buffer size. This flag has effect only on dynamic
	///       buffers.
	///   - `BGFX_BUFFER_INDEX32` - Buffer is using 32-bit indices. This flag has effect only on
	///       index buffers.
	///
	/// @attention C99 equivalent is `bgfx_create_dynamic_index_buffer_mem`.
	///
	DynamicIndexBufferHandle createDynamicIndexBuffer(
		  const Memory* _mem
		, uint16_t _flags = BGFX_BUFFER_NONE
		);

	/// Update dynamic index buffer.
	///
	/// @param[in] _handle Dynamic index buffer handle.
	/// @param[in] _startIndex Start index.
	/// @param[in] _mem Index buffer data.
	///
	/// @attention C99 equivalent is `bgfx_update_dynamic_index_buffer`.
	///
	void updateDynamicIndexBuffer(
		  DynamicIndexBufferHandle _handle
		, uint32_t _startIndex
		, const Memory* _mem
		);

	/// Destroy dynamic index buffer.
	///
	/// @param[in] _handle Dynamic index buffer handle.
	///
	/// @attention C99 equivalent is `bgfx_destroy_dynamic_index_buffer`.
	///
	void destroyDynamicIndexBuffer(DynamicIndexBufferHandle _handle);

	/// Create empty dynamic vertex buffer.
	///
	/// @param[in] _num Number of vertices.
	/// @param[in] _decl Vertex declaration.
	/// @param[in] _flags Buffer creation flags.
	///   - `BGFX_BUFFER_NONE` - No flags.
	///   - `BGFX_BUFFER_COMPUTE_READ` - Buffer will be read from by compute shader.
	///   - `BGFX_BUFFER_COMPUTE_WRITE` - Buffer will be written into by compute shader. When buffer
	///       is created with `BGFX_BUFFER_COMPUTE_WRITE` flag it cannot be updated from CPU.
	///   - `BGFX_BUFFER_COMPUTE_READ_WRITE` - Buffer will be used for read/write by compute shader.
	///   - `BGFX_BUFFER_ALLOW_RESIZE` - Buffer will resize on buffer update if different amount of
	///       data is passed. If this flag is not specified if more data is passed on update buffer
	///       will be trimmed to fit existing buffer size. This flag has effect only on dynamic
	///       buffers.
	///   - `BGFX_BUFFER_INDEX32` - Buffer is using 32-bit indices. This flag has effect only on
	///       index buffers.
	///
	/// @attention C99 equivalent is `bgfx_create_dynamic_vertex_buffer`.
	///
	DynamicVertexBufferHandle createDynamicVertexBuffer(
		  uint32_t _num
		, const VertexDecl& _decl
		, uint16_t _flags = BGFX_BUFFER_NONE
		);

	/// Create dynamic vertex buffer and initialize it.
	///
	/// @param[in] _mem Vertex buffer data.
	/// @param[in] _decl Vertex declaration.
	/// @param[in] _flags Buffer creation flags.
	///   - `BGFX_BUFFER_NONE` - No flags.
	///   - `BGFX_BUFFER_COMPUTE_READ` - Buffer will be read from by compute shader.
	///   - `BGFX_BUFFER_COMPUTE_WRITE` - Buffer will be written into by compute shader. When buffer
	///       is created with `BGFX_BUFFER_COMPUTE_WRITE` flag it cannot be updated from CPU.
	///   - `BGFX_BUFFER_COMPUTE_READ_WRITE` - Buffer will be used for read/write by compute shader.
	///   - `BGFX_BUFFER_ALLOW_RESIZE` - Buffer will resize on buffer update if different amount of
	///       data is passed. If this flag is not specified if more data is passed on update buffer
	///       will be trimmed to fit existing buffer size. This flag has effect only on dynamic
	///       buffers.
	///   - `BGFX_BUFFER_INDEX32` - Buffer is using 32-bit indices. This flag has effect only on
	///       index buffers.
	///
	/// @attention C99 equivalent is `bgfx_create_dynamic_vertex_buffer_mem`.
	///
	DynamicVertexBufferHandle createDynamicVertexBuffer(
		  const Memory* _mem
		, const VertexDecl& _decl
		, uint16_t _flags = BGFX_BUFFER_NONE
		);

	/// Update dynamic vertex buffer.
	///
	/// @param[in] _handle Dynamic vertex buffer handle.
	/// @param[in] _startVertex Start vertex.
	/// @param[in] _mem Vertex buffer data.
	///
	/// @attention C99 equivalent is `bgfx_update_dynamic_vertex_buffer`.
	///
	void updateDynamicVertexBuffer(
		  DynamicVertexBufferHandle _handle
		, uint32_t _startVertex
		, const Memory* _mem
		);

	/// Destroy dynamic vertex buffer.
	///
	/// @attention C99 equivalent is `bgfx_destroy_dynamic_vertex_buffer`.
	///
	void destroyDynamicVertexBuffer(DynamicVertexBufferHandle _handle);

	/// Returns true if internal transient index buffer has enough space.
	///
	/// @param[in] _num Number of indices.
	///
	/// @attention C99 equivalent is `bgfx_check_avail_transient_index_buffer`.
	///
	bool checkAvailTransientIndexBuffer(uint32_t _num);

	/// Returns true if internal transient vertex buffer has enough space.
	///
	/// @param[in] _num Number of vertices.
	/// @param[in] _decl Vertex declaration.
	///
	/// @attention C99 equivalent is `bgfx_check_avail_transient_vertex_buffer`.
	///
	bool checkAvailTransientVertexBuffer(uint32_t _num, const VertexDecl& _decl);

	/// Returns true if internal instance data buffer has enough space.
	///
	/// @param[in] _num Number of instances.
	/// @param[in] _stride Stride per instance.
	///
	/// @attention C99 equivalent is `bgfx_check_avail_instance_data_buffer`.
	///
	bool checkAvailInstanceDataBuffer(uint32_t _num, uint16_t _stride);

	/// Returns true if both internal transient index and vertex buffer have
	/// enough space.
	///
	/// @param[in] _numVertices Number of vertices.
	/// @param[in] _decl Vertex declaration.
	/// @param[in] _numIndices Number of indices.
	///
	/// @attention C99 equivalent is `bgfx_check_avail_transient_buffers`.
	///
	bool checkAvailTransientBuffers(
		  uint32_t _numVertices
		, const VertexDecl& _decl
		, uint32_t _numIndices
		);

	/// Allocate transient index buffer.
	///
	/// @param[out] _tib TransientIndexBuffer structure is filled and is valid
	///   for the duration of frame, and it can be reused for multiple draw
	///   calls.
	/// @param[in] _num Number of indices to allocate.
	///
	/// @remarks
	///   1. You must call setIndexBuffer after alloc in order to avoid memory
	///      leak.
	///   2. Only 16-bit index buffer is supported.
	///
	/// @attention C99 equivalent is `bgfx_alloc_transient_index_buffer`.
	///
	void allocTransientIndexBuffer(TransientIndexBuffer* _tib, uint32_t _num);

	/// Allocate transient vertex buffer.
	///
	/// @param[out] _tvb TransientVertexBuffer structure is filled and is valid
	///   for the duration of frame, and it can be reused for multiple draw
	///   calls.
	/// @param[in] _num Number of vertices to allocate.
	/// @param[in] _decl Vertex declaration.
	///
	/// @remarks
	///   You must call setVertexBuffer after alloc in order to avoid memory
	///   leak.
	///
	/// @attention C99 equivalent is `bgfx_alloc_transient_vertex_buffer`.
	///
	void allocTransientVertexBuffer(TransientVertexBuffer* _tvb
		, uint32_t _num
		, const VertexDecl& _decl
		);

	/// Check for required space and allocate transient vertex and index
	/// buffers. If both space requirements are satisfied function returns
	/// true.
	///
	/// @remarks
	///   Only 16-bit index buffer is supported.
	///
	/// @attention C99 equivalent is `bgfx_alloc_transient_buffers`.
	///
	bool allocTransientBuffers(TransientVertexBuffer* _tvb
		, const VertexDecl& _decl
		, uint32_t _numVertices
		, TransientIndexBuffer* _tib
		, uint32_t _numIndices
		);

	/// Allocate instance data buffer.
	///
	/// @remarks
	///   You must call setInstanceDataBuffer after alloc in order to avoid
	///   memory leak.
	///
	/// @attention C99 equivalent is `bgfx_alloc_instance_data_buffer`.
	///
	const InstanceDataBuffer* allocInstanceDataBuffer(uint32_t _num, uint16_t _stride);

	/// Create draw indirect buffer.
	///
	/// @attention C99 equivalent is `bgfx_create_indirect_buffer`.
	///
	IndirectBufferHandle createIndirectBuffer(uint32_t _num);

	/// Destroy draw indirect buffer.
	///
	/// @attention C99 equivalent is `bgfx_destroy_indirect_buffer`.
	///
	void destroyIndirectBuffer(IndirectBufferHandle _handle);

	/// Create shader from memory buffer.
	///
	/// @attention C99 equivalent is `bgfx_create_shader`.
	///
	ShaderHandle createShader(const Memory* _mem);

	/// Returns num of uniforms, and uniform handles used inside shader.
	///
	/// @param[in] _handle Shader handle.
	/// @param[in] _uniforms UniformHandle array where data will be stored.
	/// @param[in] _max Maximum capacity of array.
	/// @returns Number of uniforms used by shader.
	///
	/// @remarks
	///   Only non-predefined uniforms are returned.
	///
	/// @attention C99 equivalent is `bgfx_get_shader_uniforms`.
	///
	uint16_t getShaderUniforms(
		  ShaderHandle _handle
		, UniformHandle* _uniforms = NULL
		, uint16_t _max = 0
		);

	/// Destroy shader. Once program is created with shader it is safe to
	/// destroy shader.
	///
	/// @attention C99 equivalent is `bgfx_destroy_shader`.
	///
	void destroyShader(ShaderHandle _handle);

	/// Create program with vertex and fragment shaders.
	///
	/// @param[in] _vsh Vertex shader.
	/// @param[in] _fsh Fragment shader.
	/// @param[in] _destroyShaders If true, shaders will be destroyed when
	///   program is destroyed.
	/// @returns Program handle if vertex shader output and fragment shader
	///   input are matching, otherwise returns invalid program handle.
	///
	/// @attention C99 equivalent is `bgfx_create_program`.
	///
	ProgramHandle createProgram(
		  ShaderHandle _vsh
		, ShaderHandle _fsh
		, bool _destroyShaders = false
		);

	/// Create program with compute shader.
	///
	/// @param[in] _csh Compute shader.
	/// @param[in] _destroyShader If true, shader will be destroyed when
	///   program is destroyed.
	/// @returns Program handle.
	///
	/// @attention C99 equivalent is `bgfx_create_compute_program`.
	///
	ProgramHandle createProgram(
		  ShaderHandle _csh
		, bool _destroyShader = false
		);

	/// Destroy program.
	///
	/// @attention C99 equivalent is `bgfx_destroy_program`.
	///
	void destroyProgram(ProgramHandle _handle);

	/// Calculate amount of memory required for texture.
	///
	/// @param[out] _info Resulting texture info structure.
	/// @param[in] _width Width.
	/// @param[in] _height Height.
	/// @param[in] _depth Depth.
	/// @param[in] _cubeMap Indicates that texture contains cubemap.
	/// @param[in] _hasMips Indicates that texture contains full mip-map chain.
	/// @param[in] _numLayers Number of layers in texture array.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_calc_texture_size`.
	///
	void calcTextureSize(
		  TextureInfo& _info
		, uint16_t _width
		, uint16_t _height
		, uint16_t _depth
		, bool _cubeMap
		, bool _hasMips
		, uint16_t _numLayers
		, TextureFormat::Enum _format
		);

	/// Create texture from memory buffer.
	///
	/// @param[in] _mem DDS, KTX or PVR texture data.
	/// @param[in] _flags Default texture sampling mode is linear, and wrap mode
	///   is repeat.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @param[in] _skip Skip top level mips when parsing texture.
	/// @param[out] _info When non-`NULL` is specified it returns parsed texture information.
	/// @returns Texture handle.
	///
	/// @attention C99 equivalent is `bgfx_create_texture`.
	///
	TextureHandle createTexture(
		  const Memory* _mem
		, uint32_t _flags = BGFX_TEXTURE_NONE
		, uint8_t _skip = 0
		, TextureInfo* _info = NULL
		);

	/// Create 2D texture.
	///
	/// @param[in] _width Width.
	/// @param[in] _height Height.
	/// @param[in] _hasMips Indicates that texture contains full mip-map chain.
	/// @param[in] _numLayers Number of layers in texture array. Must be 1 if caps
	///   `BGFX_CAPS_TEXTURE_2D_ARRAY` flag is not set.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	/// @param[in] _flags Default texture sampling mode is linear, and wrap mode
	///   is repeat.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @param[in] _mem Texture data. If `_mem` is non-NULL, created texture will be immutable.
	///   When `_numLayers` is more than 1, expected memory layout is texture and all mips together
	///   for each array element.
	///
	/// @attention C99 equivalent is `bgfx_create_texture_2d`.
	///
	TextureHandle createTexture2D(
		  uint16_t _width
		, uint16_t _height
		, bool     _hasMips
		, uint16_t _numLayers
		, TextureFormat::Enum _format
		, uint32_t _flags = BGFX_TEXTURE_NONE
		, const Memory* _mem = NULL
		);

	/// Create frame buffer with size based on backbuffer ratio. Frame buffer will maintain ratio
	/// if back buffer resolution changes.
	///
	/// @param[in] _ratio Frame buffer size in respect to back-buffer size. See:
	///   `BackbufferRatio::Enum`.
	/// @param[in] _hasMips Indicates that texture contains full mip-map chain.
	/// @param[in] _numLayers Number of layers in texture array. Must be 1 if caps
	///   `BGFX_CAPS_TEXTURE_2D_ARRAY` flag is not set.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	/// @param[in] _flags Default texture sampling mode is linear, and wrap mode
	///   is repeat.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @attention C99 equivalent is `bgfx_create_texture_2d_scaled`.
	///
	TextureHandle createTexture2D(
		  BackbufferRatio::Enum _ratio
		, bool _hasMips
		, uint16_t _numLayers
		, TextureFormat::Enum _format
		, uint32_t _flags = BGFX_TEXTURE_NONE
		);

	/// Create 3D texture.
	///
	/// @param[in] _width Width.
	/// @param[in] _height Height.
	/// @param[in] _depth Depth.
	/// @param[in] _hasMips Indicates that texture contains full mip-map chain.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	/// @param[in] _flags Default texture sampling mode is linear, and wrap mode
	///   is repeat.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @param[in] _mem Texture data. If `_mem` is non-NULL, created texture will be immutable.
	///
	/// @attention C99 equivalent is `bgfx_create_texture_3d`.
	///
	TextureHandle createTexture3D(
		  uint16_t _width
		, uint16_t _height
		, uint16_t _depth
		, bool _hasMips
		, TextureFormat::Enum _format
		, uint32_t _flags = BGFX_TEXTURE_NONE
		, const Memory* _mem = NULL
		);

	/// Create Cube texture.
	///
	/// @param[in] _size Cube side size.
	/// @param[in] _hasMips Indicates that texture contains full mip-map chain.
	/// @param[in] _numLayers Number of layers in texture array. Must be 1 if caps
	///   `BGFX_CAPS_TEXTURE_CUBE_ARRAY` flag is not set.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	/// @param[in] _flags Default texture sampling mode is linear, and wrap mode
	///   is repeat.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @param[in] _mem Texture data. If `_mem` is non-NULL, created texture will be immutable.
	///   When `_numLayers` is more than 1, expected memory layout is cubemap texture and all mips
	///   together for each array element.
	///
	/// @attention C99 equivalent is `bgfx_create_texture_cube`.
	///
	TextureHandle createTextureCube(
		  uint16_t _size
		, bool _hasMips
		, uint16_t _numLayers
		, TextureFormat::Enum _format
		, uint32_t _flags = BGFX_TEXTURE_NONE
		, const Memory* _mem = NULL
		);

	/// Update 2D texture.
	///
	/// @param[in] _handle Texture handle.
	/// @param[in] _layer Layers in texture array.
	/// @param[in] _mip Mip level.
	/// @param[in] _x X offset in texture.
	/// @param[in] _y Y offset in texture.
	/// @param[in] _width Width of texture block.
	/// @param[in] _height Height of texture block.
	/// @param[in] _mem Texture update data.
	/// @param[in] _pitch Pitch of input image (bytes). When _pitch is set to
	///   UINT16_MAX, it will be calculated internally based on _width.
	///
	/// @attention C99 equivalent is `bgfx_update_texture_2d`.
	///
	void updateTexture2D(
		  TextureHandle _handle
		, uint16_t _layer
		, uint8_t _mip
		, uint16_t _x
		, uint16_t _y
		, uint16_t _width
		, uint16_t _height
		, const Memory* _mem
		, uint16_t _pitch = UINT16_MAX
		);

	/// Update 3D texture.
	///
	/// @param[in] _handle Texture handle.
	/// @param[in] _mip Mip level.
	/// @param[in] _x X offset in texture.
	/// @param[in] _y Y offset in texture.
	/// @param[in] _z Z offset in texture.
	/// @param[in] _width Width of texture block.
	/// @param[in] _height Height of texture block.
	/// @param[in] _depth Depth of texture block.
	/// @param[in] _mem Texture update data.
	///
	/// @attention C99 equivalent is `bgfx_update_texture_3d`.
	///
	void updateTexture3D(
		  TextureHandle _handle
		, uint8_t _mip
		, uint16_t _x
		, uint16_t _y
		, uint16_t _z
		, uint16_t _width
		, uint16_t _height
		, uint16_t _depth
		, const Memory* _mem
		);

	/// Update Cube texture.
	///
	/// @param[in] _handle Texture handle.
	/// @param[in] _layer Layers in texture array.
	/// @param[in] _side Cubemap side `BGFX_CUBE_MAP_<POSITIVE or NEGATIVE>_<X, Y or Z>`,
	///   where 0 is +X, 1 is -X, 2 is +Y, 3 is -Y, 4 is +Z, and 5 is -Z.
	///
	///                  +----------+
	///                  |-z       2|
	///                  | ^  +y    |
	///                  | |        |
	///                  | +---->+x |
	///       +----------+----------+----------+----------+
	///       |+y       1|+y       4|+y       0|+y       5|
	///       | ^  -x    | ^  +z    | ^  +x    | ^  -z    |
	///       | |        | |        | |        | |        |
	///       | +---->+z | +---->+x | +---->-z | +---->-x |
	///       +----------+----------+----------+----------+
	///                  |+z       3|
	///                  | ^  -y    |
	///                  | |        |
	///                  | +---->+x |
	///                  +----------+
	///
	/// @param[in] _mip Mip level.
	/// @param[in] _x X offset in texture.
	/// @param[in] _y Y offset in texture.
	/// @param[in] _width Width of texture block.
	/// @param[in] _height Height of texture block.
	/// @param[in] _mem Texture update data.
	/// @param[in] _pitch Pitch of input image (bytes). When _pitch is set to
	///   UINT16_MAX, it will be calculated internally based on _width.
	///
	/// @attention C99 equivalent is `bgfx_update_texture_cube`.
	///
	void updateTextureCube(
		  TextureHandle _handle
		, uint16_t _layer
		, uint8_t _side
		, uint8_t _mip
		, uint16_t _x
		, uint16_t _y
		, uint16_t _width
		, uint16_t _height
		, const Memory* _mem
		, uint16_t _pitch = UINT16_MAX
		);

	/// Read back texture content.
	///
	/// @param[in] _handle Texture handle.
	/// @param[in] _data Destination buffer.
	/// @param[in] _mip Mip level.
	///
	/// @returns Frame number when the result will be available. See: `bgfx::frame`.
	///
	/// @attention Texture must be created with `BGFX_TEXTURE_READ_BACK` flag.
	/// @attention Availability depends on: `BGFX_CAPS_TEXTURE_READ_BACK`.
	/// @attention C99 equivalent is `bgfx_read_texture`.
	///
	uint32_t readTexture(TextureHandle _handle, void* _data, uint8_t _mip = 0);

	/// Read back texture content.
	///
	/// @param[in] _handle Frame buffer handle.
	/// @param[in] _attachment Frame buffer attachment index.
	/// @param[in] _data Destination buffer.
	///
	/// @returns Frame number when the result will be available. See: `bgfx::frame`.
	///
	/// @attention Texture must be created with `BGFX_TEXTURE_READ_BACK` flag.
	/// @attention Availability depends on: `BGFX_CAPS_TEXTURE_READ_BACK`.
	/// @attention C99 equivalent is `bgfx_read_frame_buffer`.
	///
	uint32_t readTexture(FrameBufferHandle _handle, uint8_t _attachment, void* _data);

	/// Destroy texture.
	///
	/// @param[in] _handle Texture handle.
	///
	/// @attention C99 equivalent is `bgfx_destroy_texture`.
	///
	void destroyTexture(TextureHandle _handle);

	/// Create frame buffer (simple).
	///
	/// @param[in] _width Texture width.
	/// @param[in] _height Texture height.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	/// @param[in] _textureFlags Default texture sampling mode is linear, and wrap mode
	///   is repeat.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @returns Handle to frame buffer object.
	///
	/// @attention C99 equivalent is `bgfx_create_frame_buffer`.
	///
	FrameBufferHandle createFrameBuffer(
		  uint16_t _width
		, uint16_t _height
		, TextureFormat::Enum _format
		, uint32_t _textureFlags = BGFX_TEXTURE_U_CLAMP|BGFX_TEXTURE_V_CLAMP
		);

	/// Create frame buffer with size based on backbuffer ratio. Frame buffer will maintain ratio
	/// if back buffer resolution changes.
	///
	/// @param[in] _ratio Frame buffer size in respect to back-buffer size. See:
	///   `BackbufferRatio::Enum`.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	/// @param[in] _textureFlags Default texture sampling mode is linear, and wrap mode
	///   is repeat.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @returns Handle to frame buffer object.
	///
	/// @attention C99 equivalent is `bgfx_create_frame_buffer_scaled`.
	///
	FrameBufferHandle createFrameBuffer(
		  BackbufferRatio::Enum _ratio
		, TextureFormat::Enum _format
		, uint32_t _textureFlags = BGFX_TEXTURE_U_CLAMP|BGFX_TEXTURE_V_CLAMP
		);

	/// Create frame buffer.
	///
	/// @param[in] _num Number of texture attachments.
	/// @param[in] _handles Texture attachments.
	/// @param[in] _destroyTextures If true, textures will be destroyed when
	///   frame buffer is destroyed.
	///
	/// @returns Handle to frame buffer object.
	///
	/// @attention C99 equivalent is `bgfx_create_frame_buffer_from_handles`.
	///
	FrameBufferHandle createFrameBuffer(
		  uint8_t _num
		, const TextureHandle* _handles
		, bool _destroyTextures = false
		);

	/// Create frame buffer.
	///
	/// @param[in] _num Number of texture attachments.
	/// @param[in] _attachment Attachment texture info. See: `Attachment`.
	/// @param[in] _destroyTextures If true, textures will be destroyed when
	///   frame buffer is destroyed.
	///
	/// @returns Handle to frame buffer object.
	///
	/// @attention C99 equivalent is `bgfx_create_frame_buffer_from_attachment`.
	///
	FrameBufferHandle createFrameBuffer(
		  uint8_t _num
		, const Attachment* _attachment
		, bool _destroyTextures = false
		);

	/// Create frame buffer for multiple window rendering.
	///
	/// @param[in] _nwh OS' target native window handle.
	/// @param[in] _width Window back buffer width.
	/// @param[in] _height Window back buffer height.
	/// @param[in] _depthFormat Window back buffer depth format.
	///
	/// @returns Handle to frame buffer object.
	///
	/// @remarks
	///   Frame buffer cannot be used for sampling.
	///
	/// @attention C99 equivalent is `bgfx_create_frame_buffer_from_nwh`.
	///
	FrameBufferHandle createFrameBuffer(
		  void* _nwh
		, uint16_t _width
		, uint16_t _height
		, TextureFormat::Enum _depthFormat = TextureFormat::UnknownDepth
		);

	/// Destroy frame buffer.
	///
	/// @attention C99 equivalent is `bgfx_destroy_frame_buffer`.
	///
	void destroyFrameBuffer(FrameBufferHandle _handle);

	/// Create shader uniform parameter.
	///
	/// @param[in] _name Uniform name in shader.
	/// @param[in] _type Type of uniform (See: `bgfx::UniformType`).
	/// @param[in] _num Number of elements in array.
	///
	/// @returns Handle to uniform object.
	///
	/// @remarks
	/// Predefined uniforms (declared in `bgfx_shader.sh`):
	///   - `u_viewRect vec4(x, y, width, height)` - view rectangle for current
	///     view.
	///   - `u_viewTexel vec4(1.0/width, 1.0/height, undef, undef)` - inverse
	///     width and height
	///   - `u_view mat4` - view matrix
	///   - `u_invView mat4` - inverted view matrix
	///   - `u_proj mat4` - projection matrix
	///   - `u_invProj mat4` - inverted projection matrix
	///   - `u_viewProj mat4` - concatenated view projection matrix
	///   - `u_invViewProj mat4` - concatenated inverted view projection matrix
	///   - `u_model mat4[BGFX_CONFIG_MAX_BONES]` - array of model matrices.
	///   - `u_modelView mat4` - concatenated model view matrix, only first
	///     model matrix from array is used.
	///   - `u_modelViewProj mat4` - concatenated model view projection matrix.
	///   - `u_alphaRef float` - alpha reference value for alpha test.
	///
	/// @attention C99 equivalent is `bgfx_create_uniform`.
	///
	UniformHandle createUniform(const char* _name, UniformType::Enum _type, uint16_t _num = 1);

	/// Retrieve uniform info.
	///
	/// @param[in] _handle Handle to uniform object.
	/// @param[out] _info Uniform info.
	///
	/// @attention C99 equivalent is `bgfx_get_uniform_info`.
	///
	void getUniformInfo(UniformHandle _handle, UniformInfo& _info);

	/// Destroy shader uniform parameter.
	///
	/// @param[in] _handle Handle to uniform object.
	///
	/// @attention C99 equivalent is `bgfx_destroy_uniform`.
	///
	void destroyUniform(UniformHandle _handle);

	/// Create occlusion query.
	///
	/// @returns Handle to occlusion query object.
	///
	/// @attention C99 equivalent is `bgfx_create_occlusion_query`.
	///
	OcclusionQueryHandle createOcclusionQuery();

	/// Retrieve occlusion query result from previous frame.
	///
	/// @param[in] _handle Handle to occlusion query object.
	/// @returns Occlusion query result.
	///
	/// @attention C99 equivalent is `bgfx_get_result`.
	///
	OcclusionQueryResult::Enum getResult(OcclusionQueryHandle _handle);

	/// Destroy occlusion query.
	///
	/// @param[in] _handle Handle to occlusion query object.
	///
	/// @attention C99 equivalent is `bgfx_destroy_occlusion_query`.
	///
	void destroyOcclusionQuery(OcclusionQueryHandle _handle);

	/// Set palette color value.
	///
	/// @param[in] _index Index into palette.
	/// @param[in] _rgba Packed 32-bit RGBA value.
	///
	/// @attention C99 equivalent is `bgfx_set_palette_color`.
	///
	void setPaletteColor(uint8_t _index, uint32_t _rgba);

	/// Set palette color value.
	///
	/// @param[in] _index Index into palette.
	/// @param[in] _r, _g, _b, _a RGBA floating point values.
	///
	/// @attention C99 equivalent is `bgfx_set_palette_color`.
	///
	void setPaletteColor(uint8_t _index, float _r, float _g, float _b, float _a);

	/// Set palette color value.
	///
	/// @param[in] _index Index into palette.
	/// @param[in] _rgba RGBA floating point value.
	///
	/// @attention C99 equivalent is `bgfx_set_palette_color`.
	///
	void setPaletteColor(uint8_t _index, const float _rgba[4]);

	/// Set view name.
	///
	/// @param[in] _id View id.
	/// @param[in] _name View name.
	///
	/// @remarks
	///   This is debug only feature.
	///
	///   In graphics debugger view name will appear as:
	///
	///       "nnnce <view name>"
	///        ^  ^^ ^
	///        |  |+-- eye (L/R)
	///        |  +--- compute (C)
	///        +------ view id
	///
	/// @attention C99 equivalent is `bgfx_set_view_name`.
	///
	void setViewName(uint8_t _id, const char* _name);

	/// Set view rectangle. Draw primitive outside view will be clipped.
	///
	/// @param[in] _id View id.
	/// @param[in] _x Position x from the left corner of the window.
	/// @param[in] _y Position y from the top corner of the window.
	/// @param[in] _width Width of view port region.
	/// @param[in] _height Height of view port region.
	///
	/// @attention C99 equivalent is `bgfx_set_view_rect`.
	///
	void setViewRect(uint8_t _id, uint16_t _x, uint16_t _y, uint16_t _width, uint16_t _height);

	/// @attention C99 equivalent is `bgfx_set_view_rect_auto`.
	///
	void setViewRect(uint8_t _id, uint16_t _x, uint16_t _y, BackbufferRatio::Enum _ratio);

	/// Set view scissor. Draw primitive outside view will be clipped. When
	/// _x, _y, _width and _height are set to 0, scissor will be disabled.
	///
	/// @param[in] _id View id.
	/// @param[in] _x Position x from the left corner of the window.
	/// @param[in] _y Position y from the top corner of the window.
	/// @param[in] _width Width of scissor region.
	/// @param[in] _height Height of scissor region.
	///
	/// @attention C99 equivalent is `bgfx_set_view_scissor`.
	///
	void setViewScissor(
		  uint8_t _id
		, uint16_t _x = 0
		, uint16_t _y = 0
		, uint16_t _width = 0
		, uint16_t _height = 0
		);

	/// Set view clear flags.
	///
	/// @param[in] _id View id.
	/// @param[in] _flags Clear flags. Use `BGFX_CLEAR_NONE` to remove any clear
	///   operation. See: `BGFX_CLEAR_*`.
	/// @param[in] _rgba Color clear value.
	/// @param[in] _depth Depth clear value.
	/// @param[in] _stencil Stencil clear value.
	///
	/// @attention C99 equivalent is `bgfx_set_view_clear`.
	///
	void setViewClear(
		  uint8_t _id
		, uint16_t _flags
		, uint32_t _rgba = 0x000000ff
		, float _depth = 1.0f
		, uint8_t _stencil = 0
		);

	/// Set view clear flags with different clear color for each
	/// frame buffer texture. Must use setClearColor to setup clear color
	/// palette.
	///
	/// @param[in] _id View id.
	/// @param[in] _flags Clear flags. Use `BGFX_CLEAR_NONE` to remove any clear
	///   operation. See: `BGFX_CLEAR_*`.
	/// @param[in] _depth Depth clear value.
	/// @param[in] _stencil Stencil clear value.
	/// @param[in] _0 Palette index for frame buffer attachment 0.
	/// @param[in] _1 Palette index for frame buffer attachment 1.
	/// @param[in] _2 Palette index for frame buffer attachment 2.
	/// @param[in] _3 Palette index for frame buffer attachment 3.
	/// @param[in] _4 Palette index for frame buffer attachment 4.
	/// @param[in] _5 Palette index for frame buffer attachment 5.
	/// @param[in] _6 Palette index for frame buffer attachment 6.
	/// @param[in] _7 Palette index for frame buffer attachment 7.
	///
	/// @attention C99 equivalent is `bgfx_set_view_clear_mrt`.
	///
	void setViewClear(
		  uint8_t _id
		, uint16_t _flags
		, float _depth
		, uint8_t _stencil
		, uint8_t _0 = UINT8_MAX
		, uint8_t _1 = UINT8_MAX
		, uint8_t _2 = UINT8_MAX
		, uint8_t _3 = UINT8_MAX
		, uint8_t _4 = UINT8_MAX
		, uint8_t _5 = UINT8_MAX
		, uint8_t _6 = UINT8_MAX
		, uint8_t _7 = UINT8_MAX
		);

	/// Set view into sequential mode. Draw calls will be sorted in the same
	/// order in which submit calls were called.
	///
	/// @attention C99 equivalent is `bgfx_set_view_seq`.
	///
	void setViewSeq(uint8_t _id, bool _enabled);

	/// Set view frame buffer.
	///
	/// @param[in] _id View id.
	/// @param[in] _handle Frame buffer handle. Passing `BGFX_INVALID_HANDLE` as
	///   frame buffer handle will draw primitives from this view into
	///   default back buffer.
	///
	/// @remarks
	///   Not persistent after `bgfx::reset` call.
	///
	/// @attention C99 equivalent is `bgfx_set_view_frame_buffer`.
	///
	void setViewFrameBuffer(uint8_t _id, FrameBufferHandle _handle);

	/// Set view view and projection matrices, all draw primitives in this
	/// view will use these matrices.
	///
	/// @param[in] _id View id.
	/// @param[in] _view View matrix.
	/// @param[in] _projL Projection matrix. When using stereo rendering this projection matrix
	///   represent projection matrix for left eye.
	/// @param[in] _flags View flags. Use
	///   - `BGFX_VIEW_NONE` - View will be rendered only once if stereo mode is enabled.
	///   - `BGFX_VIEW_STEREO` - View will be rendered for both eyes if stereo mode is enabled. When
	///     stereo mode is disabled this flag doesn't have effect.
	/// @param[in] _projR Projection matrix for right eye in stereo mode.
	///
	/// @attention C99 equivalent are `bgfx_set_view_transform`, `bgfx_set_view_transform_stereo`.
	///
	void setViewTransform(
		  uint8_t _id
		, const void* _view
		, const void* _projL
		, uint8_t _flags = BGFX_VIEW_STEREO
		, const void* _projR = NULL
		);

	/// Post submit view reordering.
	///
	/// @param[in] _id First view id.
	/// @param[in] _num Number of views to remap.
	/// @param[in] _remap View remap id table. Passing `NULL` will reset view ids
	///   to default state.
	///
	/// @attention C99 equivalent is `bgfx_set_view_remap`.
	///
	void setViewRemap(uint8_t _id = 0, uint8_t _num = UINT8_MAX, const void* _remap = NULL);

	/// Reset all view settings to default.
	///
	/// @param[in] _id View id.
	///
	/// @attention C99 equivalent is `bgfx_reset_view`.
	///
	void resetView(uint8_t _id);

	/// Sets debug marker.
	///
	/// @attention C99 equivalent is `bgfx_set_marker`.
	///
	void setMarker(const char* _marker);

	/// Set render states for draw primitive.
	///
	/// @param[in] _state State flags. Default state for primitive type is
	///   triangles. See: `BGFX_STATE_DEFAULT`.
	///   - `BGFX_STATE_ALPHA_WRITE` - Enable alpha write.
	///   - `BGFX_STATE_DEPTH_WRITE` - Enable depth write.
	///   - `BGFX_STATE_DEPTH_TEST_*` - Depth test function.
	///   - `BGFX_STATE_BLEND_*` - See remark 1 about BGFX_STATE_BLEND_FUNC.
	///   - `BGFX_STATE_BLEND_EQUATION_*` - See remark 2.
	///   - `BGFX_STATE_CULL_*` - Backface culling mode.
	///   - `BGFX_STATE_RGB_WRITE` - Enable RGB write.
	///   - `BGFX_STATE_MSAA` - Enable MSAA.
	///   - `BGFX_STATE_PT_[TRISTRIP/LINES/POINTS]` - Primitive type.
	///
	/// @param[in] _rgba Sets blend factor used by `BGFX_STATE_BLEND_FACTOR` and
	///   `BGFX_STATE_BLEND_INV_FACTOR` blend modes.
	///
	/// @remarks
	///   1. Use `BGFX_STATE_ALPHA_REF`, `BGFX_STATE_POINT_SIZE` and
	///      `BGFX_STATE_BLEND_FUNC` macros to setup more complex states.
	///   2. `BGFX_STATE_BLEND_EQUATION_ADD` is set when no other blend
	///      equation is specified.
	///
	/// @attention C99 equivalent is `bgfx_set_state`.
	///
	void setState(uint64_t _state, uint32_t _rgba = 0);

	/// Set condition for rendering.
	///
	/// @param[in] _handle Occlusion query handle.
	/// @param[in] _visible Render if occlusion query is visible.
	///
	/// @attention C99 equivalent is `bgfx_set_condition`.
	///
	void setCondition(OcclusionQueryHandle _handle, bool _visible);

	/// Set stencil test state.
	///
	/// @param[in] _fstencil Front stencil state.
	/// @param[in] _bstencil Back stencil state. If back is set to `BGFX_STENCIL_NONE`
	///   _fstencil is applied to both front and back facing primitives.
	///
	/// @attention C99 equivalent is `bgfx_set_stencil`.
	///
	void setStencil(uint32_t _fstencil, uint32_t _bstencil = BGFX_STENCIL_NONE);

	/// Set scissor for draw primitive. For scissor for all primitives in
	/// view see `bgfx::setViewScissor`.
	///
	/// @param[in] _x Position x from the left corner of the window.
	/// @param[in] _y Position y from the top corner of the window.
	/// @param[in] _width Width of scissor region.
	/// @param[in] _height Height of scissor region.
	/// @returns Scissor cache index.
	///
	/// @attention C99 equivalent is `bgfx_set_scissor`.
	///
	uint16_t setScissor(uint16_t _x, uint16_t _y, uint16_t _width, uint16_t _height);

	/// Set scissor from cache for draw primitive.
	///
	/// @param[in] _cache Index in scissor cache. Passing UINT16_MAX unset primitive
	///   scissor and primitive will use view scissor instead.
	///
	/// @attention C99 equivalent is `bgfx_set_scissor_cached`.
	///
	void setScissor(uint16_t _cache = UINT16_MAX);

	/// Set model matrix for draw primitive. If it is not called model will
	/// be rendered with identity model matrix.
	///
	/// @param[in] _mtx Pointer to first matrix in array.
	/// @param[in] _num Number of matrices in array.
	/// @returns index into matrix cache in case the same model matrix has
	///   to be used for other draw primitive call.
	///
	/// @attention C99 equivalent is `bgfx_set_transform`.
	///
	uint32_t setTransform(const void* _mtx, uint16_t _num = 1);

	/// Reserve `_num` matrices in internal matrix cache. Pointer returned
	/// can be modifed until `bgfx::frame` is called.
	///
	/// @param[in] _transform Pointer to `Transform` structure.
	/// @param[in] _num Number of matrices.
	/// @returns index into matrix cache.
	///
	/// @attention C99 equivalent is `bgfx_alloc_transform`.
	///
	uint32_t allocTransform(Transform* _transform, uint16_t _num);

	/// Set model matrix from matrix cache for draw primitive.
	///
	/// @param[in] _cache Index in matrix cache.
	/// @param[in] _num Number of matrices from cache.
	///
	/// @attention C99 equivalent is `bgfx_set_transform_cached`.
	///
	void setTransform(uint32_t _cache, uint16_t _num = 1);

	/// Set shader uniform parameter for draw primitive.
	///
	/// @param[in] _handle Uniform.
	/// @param[in] _value Pointer to uniform data.
	/// @param[in] _num Number of elements. Passing `UINT16_MAX` will
	///   use the _num passed on uniform creation.
	///
	/// @attention C99 equivalent is `bgfx_set_uniform`.
	///
	void setUniform(UniformHandle _handle, const void* _value, uint16_t _num = 1);

	/// Set index buffer for draw primitive.
	///
	/// @param[in] _handle Index buffer.
	///
	/// @attention C99 equivalent is `bgfx_set_index_buffer`.
	///
	void setIndexBuffer(IndexBufferHandle _handle);

	/// Set index buffer for draw primitive.
	///
	/// @param[in] _handle Index buffer.
	/// @param[in] _firstIndex First index to render.
	/// @param[in] _numIndices Number of indices to render.
	///
	/// @attention C99 equivalent is `bgfx_set_index_buffer`.
	///
	void setIndexBuffer(IndexBufferHandle _handle, uint32_t _firstIndex, uint32_t _numIndices);

	/// Set index buffer for draw primitive.
	///
	/// @param[in] _handle Dynamic index buffer.
	///
	/// @attention C99 equivalent is `bgfx_set_dynamic_index_buffer`.
	///
	void setIndexBuffer(DynamicIndexBufferHandle _handle);

	/// Set index buffer for draw primitive.
	///
	/// @param[in] _handle Dynamic index buffer.
	/// @param[in] _firstIndex First index to render.
	/// @param[in] _numIndices Number of indices to render.
	///
	/// @attention C99 equivalent is `bgfx_set_dynamic_index_buffer`.
	///
	void setIndexBuffer(
		  DynamicIndexBufferHandle _handle
		, uint32_t _firstIndex
		, uint32_t _numIndices
		);

	/// Set index buffer for draw primitive.
	///
	/// @param[in] _tib Transient index buffer.
	///
	/// @attention C99 equivalent is `bgfx_set_transient_index_buffer`.
	///
	void setIndexBuffer(const TransientIndexBuffer* _tib);

	/// Set index buffer for draw primitive.
	///
	/// @param[in] _tib Transient index buffer.
	/// @param[in] _firstIndex First index to render.
	/// @param[in] _numIndices Number of indices to render.
	///
	/// @attention C99 equivalent is `bgfx_set_transient_index_buffer`.
	///
	void setIndexBuffer(
		  const TransientIndexBuffer* _tib
		, uint32_t _firstIndex
		, uint32_t _numIndices
		);

	/// Set vertex buffer for draw primitive.
	///
	/// @param[in] _handle Vertex buffer.
	///
	/// @attention C99 equivalent is `bgfx_set_vertex_buffer`.
	///
	void setVertexBuffer(VertexBufferHandle _handle);

	/// Set vertex buffer for draw primitive.
	///
	/// @param[in] _handle Vertex buffer.
	/// @param[in] _startVertex First vertex to render.
	/// @param[in] _numVertices Number of vertices to render.
	///
	/// @attention C99 equivalent is `bgfx_set_vertex_buffer`.
	///
	void setVertexBuffer(VertexBufferHandle _handle, uint32_t _startVertex, uint32_t _numVertices);

	/// Set vertex buffer for draw primitive.
	///
	/// @param[in] _handle Dynamic vertex buffer.
	///
	/// @attention C99 equivalent is `bgfx_set_dynamic_vertex_buffer`.
	///
	void setVertexBuffer(DynamicVertexBufferHandle _handle);

	/// Set vertex buffer for draw primitive.
	///
	/// @param[in] _handle Dynamic vertex buffer.
	/// @param[in] _startVertex First vertex to render.
	/// @param[in] _numVertices Number of vertices to render.
	///
	/// @attention C99 equivalent is `bgfx_set_dynamic_vertex_buffer`.
	///
	void setVertexBuffer(
		  DynamicVertexBufferHandle _handle
		, uint32_t _startVertex
		, uint32_t _numVertices
		);

	/// Set vertex buffer for draw primitive.
	///
	/// @param[in] _tvb Transient vertex buffer.
	///
	/// @attention C99 equivalent is `bgfx_set_transient_vertex_buffer`.
	///
	void setVertexBuffer(const TransientVertexBuffer* _tvb);

	/// Set vertex buffer for draw primitive.
	///
	/// @param[in] _tvb Transient vertex buffer.
	/// @param[in] _startVertex First vertex to render.
	/// @param[in] _numVertices Number of vertices to render.
	///
	/// @attention C99 equivalent is `bgfx_set_transient_vertex_buffer`.
	///
	void setVertexBuffer(
		  const TransientVertexBuffer* _tvb
		, uint32_t _startVertex
		, uint32_t _numVertices
		);

	/// Set instance data buffer for draw primitive.
	///
	/// @attention C99 equivalent is `bgfx_set_instance_data_buffer`.
	///
	void setInstanceDataBuffer(const InstanceDataBuffer* _idb, uint32_t _num = UINT32_MAX);

	/// Set instance data buffer for draw primitive.
	///
	/// @attention C99 equivalent is `bgfx_set_instance_data_from_vertex_buffer`.
	///
	void setInstanceDataBuffer(VertexBufferHandle _handle, uint32_t _startVertex, uint32_t _num);

	/// Set instance data buffer for draw primitive.
	///
	/// @attention C99 equivalent is `bgfx_set_instance_data_from_dynamic_vertex_buffer`.
	///
	void setInstanceDataBuffer(
		  DynamicVertexBufferHandle _handle
		, uint32_t _startVertex
		, uint32_t _num
		);

	/// Set texture stage for draw primitive.
	///
	/// @param[in] _stage Texture unit.
	/// @param[in] _sampler Program sampler.
	/// @param[in] _handle Texture handle.
	/// @param[in] _flags Texture sampling mode. Default value UINT32_MAX uses
	///   texture sampling settings from the texture.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @param[in] _flags Texture sampler filtering flags. UINT32_MAX use the
	///   sampler filtering mode set by texture.
	///
	/// @attention C99 equivalent is `bgfx_set_texture`.
	///
	void setTexture(
		  uint8_t _stage
		, UniformHandle _sampler
		, TextureHandle _handle
		, uint32_t _flags = UINT32_MAX
		);

	/// Set texture stage for draw primitive.
	///
	/// @param[in] _stage Texture unit.
	/// @param[in] _sampler Program sampler.
	/// @param[in] _handle Frame buffer handle.
	/// @param[in] _attachment Frame buffer attachment index.
	/// @param[in] _flags Texture sampling mode. Default value UINT32_MAX uses
	///   texture sampling settings from the texture.
	///   - `BGFX_TEXTURE_[U/V/W]_[MIRROR/CLAMP]` - Mirror or clamp to edge wrap
	///     mode.
	///   - `BGFX_TEXTURE_[MIN/MAG/MIP]_[POINT/ANISOTROPIC]` - Point or anisotropic
	///     sampling.
	///
	/// @attention C99 equivalent is `bgfx_set_texture_from_frame_buffer`.
	///
	void setTexture(
		  uint8_t _stage
		, UniformHandle _sampler
		, FrameBufferHandle _handle
		, uint8_t _attachment = 0
		, uint32_t _flags = UINT32_MAX
		);

	/// Submit an empty primitive for rendering. Uniforms and draw state
	/// will be applied but no geometry will be submitted.
	///
	/// These empty draw calls will sort before ordinary draw calls.
	///
	/// @param[in] _id View id.
	/// @returns Number of draw calls.
	///
	uint32_t touch(uint8_t _id);

	/// Submit primitive for rendering.
	///
	/// @param[in] _id View id.
	/// @param[in] _program Program.
	/// @param[in] _depth Depth for sorting.
	/// @param[in] _preserveState Preserve internal draw state for next draw
	///   call submit.
	/// @returns Number of draw calls.
	///
	/// @attention C99 equivalent is `bgfx_submit`.
	///
	uint32_t submit(
		  uint8_t _id
		, ProgramHandle _program
		, int32_t _depth = 0
		, bool _preserveState = false
		);

	/// Submit primitive with occlusion query for rendering.
	///
	/// @param[in] _id View id.
	/// @param[in] _program Program.
	/// @param[in] _occlusionQuery Occlusion query.
	/// @param[in] _depth Depth for sorting.
	/// @param[in] _preserveState Preserve internal draw state for next draw
	///   call submit.
	/// @returns Number of draw calls.
	///
	/// @attention C99 equivalent is `bgfx_submit_occlusion_query`.
	///
	uint32_t submit(
		  uint8_t _id
		, ProgramHandle _program
		, OcclusionQueryHandle _occlusionQuery
		, int32_t _depth = 0
		, bool _preserveState = false
		);

	/// Submit primitive for rendering with index and instance data info from
	/// indirect buffer.
	///
	/// @param[in] _id View id.
	/// @param[in] _program Program.
	/// @param[in] _indirectHandle Indirect buffer.
	/// @param[in] _start First element in indirect buffer.
	/// @param[in] _num Number of dispatches.
	/// @param[in] _depth Depth for sorting.
	/// @param[in] _preserveState Preserve internal draw state for next draw
	///   call submit.
	/// @returns Number of draw calls.
	///
	/// @attention C99 equivalent is `bgfx_submit_indirect`.
	///
	uint32_t submit(
		  uint8_t _id
		, ProgramHandle _program
		, IndirectBufferHandle _indirectHandle
		, uint16_t _start = 0
		, uint16_t _num = 1
		, int32_t _depth = 0
		, bool _preserveState = false
		);

	/// Set compute index buffer.
	///
	/// @param[in] _stage Compute stage.
	/// @param[in] _handle Index buffer handle.
	/// @param[in] _access Buffer access. See `Access::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_set_compute_index_buffer`.
	///
	void setBuffer(uint8_t _stage, IndexBufferHandle _handle, Access::Enum _access);

	/// Set compute vertex buffer.
	///
	/// @param[in] _stage Compute stage.
	/// @param[in] _handle Vertex buffer handle.
	/// @param[in] _access Buffer access. See `Access::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_set_compute_vertex_buffer`.
	///
	void setBuffer(uint8_t _stage, VertexBufferHandle _handle, Access::Enum _access);

	/// Set compute dynamic index buffer.
	///
	/// @param[in] _stage Compute stage.
	/// @param[in] _handle Dynamic index buffer handle.
	/// @param[in] _access Buffer access. See `Access::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_set_compute_dynamic_index_buffer`.
	///
	void setBuffer(uint8_t _stage, DynamicIndexBufferHandle _handle, Access::Enum _access);

	/// Set compute dynamic vertex buffer.
	///
	/// @param[in] _stage Compute stage.
	/// @param[in] _handle Dynamic vertex buffer handle.
	/// @param[in] _access Buffer access. See `Access::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_set_compute_dynamic_vertex_buffer`.
	///
	void setBuffer(uint8_t _stage, DynamicVertexBufferHandle _handle, Access::Enum _access);

	/// Set compute indirect buffer.
	///
	/// @param[in] _stage Compute stage.
	/// @param[in] _handle Indirect buffer handle.
	/// @param[in] _access Buffer access. See `Access::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_set_compute_indirect_buffer`.
	///
	void setBuffer(uint8_t _stage, IndirectBufferHandle _handle, Access::Enum _access);

	/// Set compute image from texture.
	///
	/// @param[in] _stage Texture unit.
	/// @param[in] _sampler Program sampler.
	/// @param[in] _handle Texture handle.
	/// @param[in] _mip Mip level.
	/// @param[in] _access Texture access. See `Access::Enum`.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_set_image`.
	///
	void setImage(
		  uint8_t _stage
		, UniformHandle _sampler
		, TextureHandle _handle
		, uint8_t _mip
		, Access::Enum _access
		, TextureFormat::Enum _format = TextureFormat::Count
		);

	/// Set compute image from frame buffer texture.
	///
	/// @param[in] _stage Texture unit.
	/// @param[in] _sampler Program sampler.
	/// @param[in] _handle Frame buffer handle.
	/// @param[in] _attachment Frame buffer attachment index.
	/// @param[in] _access Texture access. See `Access::Enum`.
	/// @param[in] _format Texture format. See: `TextureFormat::Enum`.
	///
	/// @attention C99 equivalent is `bgfx_set_image_from_frame_buffer`.
	///
	void setImage(
		  uint8_t _stage
		, UniformHandle _sampler
		, FrameBufferHandle _handle
		, uint8_t _attachment
		, Access::Enum _access
		, TextureFormat::Enum _format = TextureFormat::Count
		);

	/// Dispatch compute.
	///
	/// @param[in] _id View id.
	/// @param[in] _handle Compute program.
	/// @param[in] _numX Number of groups X.
	/// @param[in] _numY Number of groups Y.
	/// @param[in] _numZ Number of groups Z.
	/// @param[in] _flags View flags. Use
	///   - `BGFX_VIEW_NONE` - View will be rendered only once if stereo mode is enabled.
	///   - `BGFX_VIEW_STEREO` - View will be rendered for both eyes if stereo mode is enabled. When
	///     stereo mode is disabled this flag doesn't have effect.
	///
	/// @attention C99 equivalent is `bgfx_dispatch`.
	///
	uint32_t dispatch(
		  uint8_t _id
		, ProgramHandle _handle
		, uint16_t _numX = 1
		, uint16_t _numY = 1
		, uint16_t _numZ = 1
		, uint8_t _flags = BGFX_SUBMIT_EYE_FIRST
		);

	/// Dispatch compute indirect.
	///
	/// @param[in] _id View id.
	/// @param[in] _handle Compute program.
	/// @param[in] _indirectHandle Indirect buffer.
	/// @param[in] _start First element in indirect buffer.
	/// @param[in] _num Number of dispatches.
	/// @param[in] _flags View flags. Use
	///   - `BGFX_VIEW_NONE` - View will be rendered only once if stereo mode is enabled.
	///   - `BGFX_VIEW_STEREO` - View will be rendered for both eyes if stereo mode is enabled. When
	///     stereo mode is disabled this flag doesn't have effect.
	///
	/// @attention C99 equivalent is `bgfx_dispatch_indirect`.
	///
	uint32_t dispatch(
		  uint8_t _id
		, ProgramHandle _handle
		, IndirectBufferHandle _indirectHandle
		, uint16_t _start = 0
		, uint16_t _num = 1
		, uint8_t _flags = BGFX_SUBMIT_EYE_FIRST
		);

	/// Discard all previously set state for draw or compute call.
	///
	/// @attention C99 equivalent is `bgfx_discard`.
	///
	void discard();

	/// Blit texture 2D region between two 2D textures.
	///
	/// @param[in] _id View id.
	/// @param[in] _dst Destination texture handle.
	/// @param[in] _dstX Destination texture X position.
	/// @param[in] _dstY Destination texture Y position.
	/// @param[in] _src Source texture handle.
	/// @param[in] _srcX Source texture X position.
	/// @param[in] _srcY Source texture Y position.
	/// @param[in] _width Width of region.
	/// @param[in] _height Height of region.
	///
	/// @attention Destination texture must be create with `BGFX_TEXTURE_BLIT_DST` flag.
	/// @attention Availability depends on: `BGFX_CAPS_TEXTURE_BLIT`.
	/// @attention C99 equivalent is `bgfx_blit`.
	///
	void blit(
		  uint8_t _id
		, TextureHandle _dst
		, uint16_t _dstX
		, uint16_t _dstY
		, TextureHandle _src
		, uint16_t _srcX = 0
		, uint16_t _srcY = 0
		, uint16_t _width = UINT16_MAX
		, uint16_t _height = UINT16_MAX
		);

	/// Blit texture 2D region between 2D frame buffer and 2D texture.
	///
	/// @param[in] _id View id.
	/// @param[in] _dst Destination texture handle.
	/// @param[in] _dstX Destination texture X position.
	/// @param[in] _dstY Destination texture Y position.
	/// @param[in] _src Source frame buffer handle.
	/// @param[in] _attachment Source frame buffer attachment index.
	/// @param[in] _srcX Source texture X position.
	/// @param[in] _srcY Source texture Y position.
	/// @param[in] _width Width of region.
	/// @param[in] _height Height of region.
	///
	/// @attention Destination texture must be create with `BGFX_TEXTURE_BLIT_DST` flag.
	/// @attention Availability depends on: `BGFX_CAPS_TEXTURE_BLIT`.
	/// @attention C99 equivalent is `bgfx_blit`.
	///
	void blit(
		  uint8_t _id
		, TextureHandle _dst
		, uint16_t _dstX
		, uint16_t _dstY
		, FrameBufferHandle _src
		, uint8_t _attachment = 0
		, uint16_t _srcX = 0
		, uint16_t _srcY = 0
		, uint16_t _width = UINT16_MAX
		, uint16_t _height = UINT16_MAX
		);

	/// Blit texture region between two textures.
	///
	/// @param[in] _id View id.
	/// @param[in] _dst Destination texture handle.
	/// @param[in] _dstMip Destination texture mip level.
	/// @param[in] _dstX Destination texture X position.
	/// @param[in] _dstY Destination texture Y position.
	/// @param[in] _dstZ If texture is 2D this argument should be 0. If destination texture is cube
	///   this argument represent destination texture cube face. For 3D texture this argument
	///   represent destination texture Z position.
	/// @param[in] _src Source texture handle.
	/// @param[in] _srcMip Source texture mip level.
	/// @param[in] _srcX Source texture X position.
	/// @param[in] _srcY Source texture Y position.
	/// @param[in] _srcZ If texture is 2D this argument should be 0. If source texture is cube
	///   this argument represent source texture cube face. For 3D texture this argument
	///   represent source texture Z position.
	/// @param[in] _width Width of region.
	/// @param[in] _height Height of region.
	/// @param[in] _depth If texture is 3D this argument represent depth of region, otherwise is
	///   unused.
	///
	/// @attention Destination texture must be create with `BGFX_TEXTURE_BLIT_DST` flag.
	/// @attention Availability depends on: `BGFX_CAPS_TEXTURE_BLIT`.
	/// @attention C99 equivalent is `bgfx_blit`.
	///
	void blit(
		  uint8_t _id
		, TextureHandle _dst
		, uint8_t _dstMip
		, uint16_t _dstX
		, uint16_t _dstY
		, uint16_t _dstZ
		, TextureHandle _src
		, uint8_t _srcMip = 0
		, uint16_t _srcX = 0
		, uint16_t _srcY = 0
		, uint16_t _srcZ = 0
		, uint16_t _width = UINT16_MAX
		, uint16_t _height = UINT16_MAX
		, uint16_t _depth = UINT16_MAX
		);

	/// Blit texture region between frame buffer and texture.
	///
	/// @param[in] _id View id.
	/// @param[in] _dst Destination texture handle.
	/// @param[in] _dstMip Destination texture mip level.
	/// @param[in] _dstX Destination texture X position.
	/// @param[in] _dstY Destination texture Y position.
	/// @param[in] _dstZ If texture is 2D this argument should be 0. If destination texture is cube
	///   this argument represent destination texture cube face. For 3D texture this argument
	///   represent destination texture Z position.
	/// @param[in] _src Source frame buffer handle.
	/// @param[in] _attachment Source frame buffer attachment index.
	/// @param[in] _srcMip Source texture mip level.
	/// @param[in] _srcX Source texture X position.
	/// @param[in] _srcY Source texture Y position.
	/// @param[in] _srcZ If texture is 2D this argument should be 0. If source texture is cube
	///   this argument represent source texture cube face. For 3D texture this argument
	///   represent source texture Z position.
	/// @param[in] _width Width of region.
	/// @param[in] _height Height of region.
	/// @param[in] _depth If texture is 3D this argument represent depth of region, otherwise is
	///   unused.
	///
	/// @attention Destination texture must be create with `BGFX_TEXTURE_BLIT_DST` flag.
	/// @attention Availability depends on: `BGFX_CAPS_TEXTURE_BLIT`.
	/// @attention C99 equivalent is `bgfx_blit`.
	///
	void blit(
		  uint8_t _id
		, TextureHandle _dst
		, uint8_t _dstMip
		, uint16_t _dstX
		, uint16_t _dstY
		, uint16_t _dstZ
		, FrameBufferHandle _src
		, uint8_t _attachment = 0
		, uint8_t _srcMip = 0
		, uint16_t _srcX = 0
		, uint16_t _srcY = 0
		, uint16_t _srcZ = 0
		, uint16_t _width = UINT16_MAX
		, uint16_t _height = UINT16_MAX
		, uint16_t _depth = UINT16_MAX
		);

	/// Request screen shot.
	///
	/// @param[in] _filePath Will be passed to `bgfx::CallbackI::screenShot` callback.
	///
	/// @remarks
	///   `bgfx::CallbackI::screenShot` must be implemented.
	///
	/// @attention C99 equivalent is `bgfx_save_screen_shot`.
	///
	void saveScreenShot(const char* _filePath);

} // namespace bgfx

#endif // BGFX_H_HEADER_GUARD