Trying to draw a colored coordinate system ...

data/shaders/fs_simple.glsl

@@ -1,9 +1,18 @@
-#version 330 core
+#version 150 core
-
-layout(location = 0) out vec3 outColor;
 
 uniform vec4 uColor;
 
+in vec3 fragmentColor;
+
+out vec3 outColor;
+
 void main() {
-	outColor = uColor.rgb; 
+	outColor = vec3(
+		uColor.r * fragmentColor.r,
+		uColor.g * fragmentColor.g,
+		uColor.b * fragmentColor.b
+		);
+
+	outColor = max(uColor.rgb, fragmentColor);
+//outColor = fragmentColor + uColor.rgb - uColor.rgb;
 }

data/shaders/vs_simple.glsl

@@ -1,10 +1,14 @@
 #version 150 core
-#extension GL_ARB_explicit_uniform_location : require
+#extension GL_ARB_explicit_attrib_location : require
 
-in vec3 inVertex;
+layout(location = 0) in vec3 inCoord;
+layout(location = 1) in vec3 inColor;
 
 uniform mat4 uModelViewProj;
 
+out vec3 fragmentColor;
+
 void main() {
-	gl_Position = uModelViewProj * vec4(inVertex, 1);
+	gl_Position = uModelViewProj * vec4(inCoord, 1);
+	fragmentColor = inColor;
 }

src/main.cc

@@ -161,13 +161,6 @@ int main(void)
 		glfwPollEvents();
 		ImGui_ImplGlfwGL3_NewFrame();
 
-//		imguiBeginFrame (gGuiInputState->mouseX,
-//				gGuiInputState->mouseY,
-//				gGuiInputState->mouseButton,
-//				gGuiInputState->mouseScroll,
-//				width,
-//				height);
-
 		if (module_manager.CheckModulesChanged()) {
 			gLog("Detected module update at frame %d. Unloading all modules.", frame_counter);
 			module_manager.UnloadModules();

src/modules/RenderModule.cc

@@ -41,6 +41,15 @@ static const GLfloat g_textured_quad_vertex_buffer_data[] = {
 	1.0f, 1.0f, 0.0f,		1.0f, 0.0f,
 };
 
+static const GLfloat g_coordinate_system_vertex_buffer_data[] = {
+	0.0f, 0.0f, 0.0f,		1.0f, 0.0f, 0.0f,
+	1.0f, 0.0f, 0.0f,		1.0f, 0.0f, 0.0f,
+	0.0f, 0.0f, 0.0f,		0.0f, 1.0f, 0.0f,
+	0.0f, 1.0f, 0.0f,		0.0f, 1.0f, 0.0f,
+	0.0f, 0.0f, 0.0f,		0.0f, 0.0f, 1.0f,
+	0.0f, 0.0f, 1.0f,		0.0f, 0.0f, 1.0f
+};
+
 //
 // Module
 //
@@ -186,6 +195,13 @@ void Renderer::Initialize(int width, int height) {
 	glBindBuffer(GL_ARRAY_BUFFER, mPlane.mVertexBuffer);
 	glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);
 
+	// Coordinate System
+	glGenVertexArrays(1, &mCoordinateSystem.mVertexArrayId);
+	glBindVertexArray(mCoordinateSystem.mVertexArrayId);
+	glGenBuffers(1, &mCoordinateSystem.mVertexBuffer);
+	glBindBuffer(GL_ARRAY_BUFFER, mCoordinateSystem.mVertexBuffer);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(g_coordinate_system_vertex_buffer_data), g_coordinate_system_vertex_buffer_data, GL_STATIC_DRAW);
+
 	// Simple Shader
 	mDefaultProgram = RenderProgram("data/shaders/vs_simple.glsl", "data/shaders/fs_simple.glsl");
 	bool load_result = mDefaultProgram.Load();
@@ -230,6 +246,8 @@ void Renderer::Shutdown() {
 	glDeleteBuffers(1, &mMesh.mVertexBuffer);
 	glDeleteVertexArrays(1, &mPlane.mVertexArrayId);
 	glDeleteBuffers(1, &mPlane.mVertexBuffer);
+	glDeleteVertexArrays(1, &mCoordinateSystem.mVertexArrayId);
+	glDeleteBuffers(1, &mCoordinateSystem.mVertexBuffer);
 }
 
 
@@ -275,7 +293,31 @@ void Renderer::RenderGl() {
 			(void*)0	// offset
 			);
 
-	glDrawArrays(GL_TRIANGLES, 0, 3);	// starting from vertex 0; 3 vertices total
+//	glDrawArrays(GL_TRIANGLES, 0, 3);	// starting from vertex 0; 3 vertices total
+	glDisableVertexAttribArray(0);
+
+	// Coordinate system
+	glBindVertexArray(mCoordinateSystem.mVertexArrayId);
+	glEnableVertexAttribArray(0);
+	glUniform4fv(muDefaultColor, 1, Vector4f(1.0f, 0.0f, 1.0f, 1.0f).data());
+	glBindBuffer(GL_ARRAY_BUFFER, mCoordinateSystem.mVertexBuffer);
+	glVertexAttribPointer(
+			0,
+			3,
+			GL_FLOAT,
+			GL_FALSE,
+			(sizeof(float[6])),
+			(void*)0
+			);
+	glVertexAttribPointer(
+			1,
+			3,
+			GL_FLOAT,
+			GL_FALSE,
+			(sizeof(float[6])),
+			(void*) (sizeof(float[3]))
+			);
+	glDrawArrays(GL_LINES, 0, 6);
 
 	if (mSettings->DrawDepth) {
 		mRenderTarget.RenderToLinearizedDepth(true);

src/modules/RenderModule.h

@@ -102,11 +102,6 @@ struct Light {
 	}
 };
 
-struct Mesh {
-	GLuint mVertexArrayId = -1;
-	GLuint mVertexBuffer = -1;
-};
-
 struct RendererSettings;
 
 struct Renderer {
@@ -119,6 +114,7 @@ struct Renderer {
 	Camera mCamera;
 	Mesh mMesh;
 	Mesh mPlane;
+	Mesh mCoordinateSystem;
 
 	Texture mDefaultTexture;
 

src/modules/RenderUtils.cc

@@ -323,3 +323,34 @@ bool Texture::Load(const char* filename, int num_components) {
 //	unsigned char* rgb = stbi_load(filename, &mWidth, &mHeight, num_components);
 	assert(false);
 }
+
+void VertexArray::Initialize(const int& size, GLenum usage) {
+	mSize = size;
+	mUsed = 0;
+
+	glGenVertexArrays (1, &mVertexArrayId);
+	glBindVertexArray(mVertexArrayId);
+
+	glGenBuffers(1, &mVertexBuffer);
+	glBindBuffer(GL_ARRAY_BUFFER, mVertexBuffer);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(VertexData) * size, NULL, usage);
+}
+
+GLuint VertexArray::AllocateMesh(const int& size) {
+	GLuint mesh_data_size = size * sizeof(VertexData);
+	if (mUsed + mesh_data_size > mSize) {
+		gLog("Cannot allocate mesh in VertexArray: not enough vertices available");
+		assert(false);
+		return -1;
+	}
+
+	GLuint offset = mUsed;
+	mUsed += mesh_data_size;
+
+	return offset;
+}
+
+void VertexArrayMesh::Initialize(VertexArray &array, const int& size) {
+	mOffset = array.AllocateMesh(size);		
+	assert(mOffset != -1);
+}

src/modules/RenderUtils.h

@@ -186,4 +186,44 @@ struct Texture {
 	bool Load(const char* path, int num_components = 3);
 };
 
+struct Mesh {
+	GLuint mVertexArrayId = -1;
+	GLuint mVertexBuffer = -1;
+};
+
+/**
+ * Multiple VertexArrayMeshes can be stored in a single VertexArray.
+ * Storage order is:
+ *   (VVVV)(NNNN)(UV)(CCCC)
+ */
+struct VertexArray {
+	GLuint mVertexBuffer = -1;
+	GLuint mVertexArrayId = -1;
+	GLuint mSize = -1;
+	GLuint mUsed = -1;
+
+	struct VertexData {
+		float mCoords[4];
+		float mNormals[4];
+		float mTexCoords[2];
+		GLubyte mColor[4];
+	};
+
+	void Initialize(const int& size, GLenum usage);
+	GLuint AllocateMesh(const int& size);
+};
+
+struct VertexArrayMesh {
+	GLuint mOffset;
+
+	void Initialize(VertexArray &array, const int& size);
+	void SetData(
+			const std::vector<Vector4f> &coords,
+			const std::vector<Vector4f> &normals,
+			const std::vector<Vector2f> &uvs,
+			const std::vector<Vector4f> &colors
+			);
+};
+
+
 #endif