#include "ViewBase.h"

#include "ModelBase.h"
#include "ControllerBase.h"
#include "CameraBase.h"
#include "OverlayBase.h"

#include "SimpleConsoleOverlay.h"
#include "OGLFT.h"

#include <GL/gl.h>
#include <GL/glu.h>

#include "OBJModel.h"

#include "DrawingsGL.h"

using namespace std;

namespace Engine {

static ViewBase* ViewInstance = NULL;

void InitGL () {
	glClearColor(0.3f, 0.3f, 0.3f, 1.0f);
	glClearDepth(1.0);
	glDepthFunc(GL_LEQUAL);
	glEnable(GL_DEPTH_TEST);
	glShadeModel(GL_SMOOTH);
	glEnable (GL_CULL_FACE);
	glDisable (GL_FOG);

	glMatrixMode (GL_PROJECTION);
	glLoadIdentity ();
	glMatrixMode (GL_MODELVIEW);
	glLoadIdentity ();
}

/*
 * Inherited Module functions
 */
int ViewBase::OnInit (int argc, char* argv[]) {
	LogMessage ("View Init");

	mWindowHeight = VIEW_DEFAULT_HEIGHT;
	mWindowWidth = VIEW_DEFAULT_WIDTH;

	// get and save the screen resolution
	mScreenHeight = SDL_GetVideoInfo()->current_h;
	mScreenWidth = SDL_GetVideoInfo()->current_w;

	mDrawFullscreen = false;

	SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

	if( SDL_SetVideoMode( mWindowWidth, mWindowHeight, 16, SDL_OPENGL ) == 0 ) {
		LogError ("Video mode set failed: %s", SDL_GetError ());
		exit (-1);
	}

	LogMessage ("Resolution is %dx%d", SDL_GetVideoInfo()->current_w, SDL_GetVideoInfo()->current_h);

	InitGL ();
	Resize (mWindowWidth, mWindowHeight);

	// Initialize GLEW and check for anything we need
	GLenum err = glewInit();
	if (GLEW_OK != err) {
		LogError ("Could not init GLEW properly: %s", glewGetErrorString(err));
	}

	LogDebug ("Using GLEW version %s", glewGetString(GLEW_VERSION));
	if (glewIsExtensionSupported("GL_ARB_vertex_buffer_object")) {
	} else {
		LogError ("VBOs are not supported!");
	}

	// read OpenGL version
	std::string gl_version (reinterpret_cast<const char*>(glGetString(GL_VERSION)));
	if (gl_version.size() == 0)
		LogError ("Could not retrieve GL version!");

	std::string major_number_str = gl_version.substr(0, gl_version.find('.'));
	std::string minor_number_str = gl_version.substr(major_number_str.size() + 1, gl_version.find_first_of(". ", major_number_str.size()));

	mGLVersionInfo.GLMajor = atoi (major_number_str.c_str());
	mGLVersionInfo.GLMinor = atoi (minor_number_str.c_str());

	// read GLSL version
	std::string glsl_version (reinterpret_cast<const char*>(glGetString(GL_SHADING_LANGUAGE_VERSION)));
	if (glsl_version.size() == 0)
		LogError ("Could not retrieve GLSL version!");

	major_number_str = glsl_version.substr(0, glsl_version.find('.'));
	minor_number_str = glsl_version.substr(major_number_str.size() + 1, glsl_version.find_first_of(". ", major_number_str.size()));

	mGLVersionInfo.GLSLMajor = atoi (major_number_str.c_str());
	mGLVersionInfo.GLSLMinor = atoi (minor_number_str.c_str());

	LogMessage ("GL Version = %s, gl_major = %d, gl_minor = %d", gl_version.c_str(), mGLVersionInfo.GLMajor, mGLVersionInfo.GLMinor);
	LogMessage ("GLSL Version = %s, gl_major = %d, gl_minor = %d", gl_version.c_str(), mGLVersionInfo.GLSLMajor, mGLVersionInfo.GLSLMinor);

	if (mGLVersionInfo.GLMajor >= 2 && mGLVersionInfo.GLMinor >= 0)
		mUseShaders = true;
	else
		mUseShaders = false;

	// load the shaders if possible
	if (mUseShaders) {
		mBlinnPhongShader = LoadShaderProgram (GetResourceFullPath("/data/shaders/blinn_phong.glsl"));
		mNormalMappingShader = LoadShaderProgram (GetResourceFullPath("/data/shaders/normal_mapping.glsl"));
	} else {
		mBlinnPhongShader = 0;
		mNormalMappingShader = 0;
	}

	// Create a null texture that can be used for objects without textures
	// taken from http://www.dhpoware.com/demos/glslNormalMapping.html
	int pitch = ((2 * 32 + 31) & ~31) >> 3; // align to 4-byte boundaries
	std::vector<GLubyte> pixels(pitch * 2, 255);
	mNullTexture = 0;

	glGenTextures(1, &mNullTexture);
	glBindTexture(GL_TEXTURE_2D, mNullTexture);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 2, 2, 0, GL_BGRA,
			GL_UNSIGNED_BYTE, &pixels[0]);

	// Load fonts etc.
	LoadFont ("console.ttf");
	mCurrentFont = mFonts["console.ttf"];

	// Overlays
	OverlayBasePtr console_overlay(new SimpleConsoleOverlay);
	mOverlayManager.Register (console_overlay, 0);
	//AddOverlay (console_overlay);

	mDrawGrid = false;
	mGridSizeX = 8;
	mGridSizeZ = 8;

	ViewInstance = this;

	return 0;
}

void ViewBase::OnDestroy () {
	std::map<std::string, OGLFT::Monochrome*>::iterator iter;

	for (iter = mFonts.begin(); iter != mFonts.end(); ++iter) {
		delete iter->second;
	}
	mFonts.clear();

	ViewInstance = NULL;

	LogDebug ("View Destroy");
}

void ViewBase::CalcWorldCoordinates (int screen_x, int screen_y, float world_y, float *pos_out) {
	GLdouble modelMatrix[16], projMatrix[16];
	GLint viewport[4];
	GLdouble wx, wy, wz;

	glGetIntegerv (GL_VIEWPORT, viewport);
	glGetDoublev(GL_MODELVIEW_MATRIX, modelMatrix);
	glGetDoublev(GL_PROJECTION_MATRIX, projMatrix);

	int realy = viewport[3] - screen_y - 1;

	gluUnProject ((GLdouble) screen_x, (GLdouble) realy, 1.,
			modelMatrix, projMatrix, viewport, &wx, &wy, &wz);

	GLdouble t;
	GLdouble d[3];
	float	eye[3];

	mCamera->GetEye (&eye[0]);

	d[0] = wx - eye[0];
	d[1] = wy - eye[1];
	d[2] = wz - eye[2];

	assert (fabs (d[1]) >= 1.0e-3);
	t = -eye[1]/d[1]  + world_y;

	pos_out[0] = eye[0] + t * d[0];
	pos_out[1] = eye[1] + t * d[1];
	pos_out[2] = eye[2] + t * d[2];
}

/*
 * Module specific functions
 */
void ViewBase::UpdateCamera () {
	EntityPhysicState* player_ent = GetEntityPhysicState (GetPlayerEntityId());

	if (!player_ent) {
		LogError ("Could not call Model::PositionCamera(): player entity not found!");
		exit (-1);
	}
	vector3d entity_camera_distance (-2, 3, 0);
	vector3d entity_position = player_ent->GetPosition();
	player_ent->Globalize (entity_camera_distance);

	mCamera->SetEye (
			entity_camera_distance[0],
			entity_camera_distance[1],
			entity_camera_distance[2]
			);
	mCamera->SetPointOfIntrest (
			entity_position[0],
			entity_position[1],
			entity_position[2]
			);

	mCamera->Update ();
}

void ViewBase::PreDraw() {
	// Clear the screen
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	// update the frame rate counter
	static Uint32 this_frame_ticks;
	static Uint32 last_frame_ticks = 0;
	static Uint32 last_fps_update = 0;
	static int frame_counter = 0;

  this_frame_ticks = SDL_GetTicks ();
	last_fps_update += this_frame_ticks - last_frame_ticks;
	last_frame_ticks = this_frame_ticks;
	frame_counter++;

	if (last_fps_update > 1000) {
		mFrameRate = frame_counter;
		last_fps_update = 0;
		frame_counter = 0;
	}
}

void ViewBase::Draw () {
	// Perform pre-Draw actions
	PreDraw ();

	// Actual Drawing
	UpdateCamera ();

	if (mDrawGrid)
		DrawGrid ();

	DrawWorld ();

	mOverlayManager.Draw();

	// Perform post-Draw actions
	PostDraw();
}

void ViewBase::PostDraw() {
	SDL_GL_SwapBuffers ();
}

void ViewBase::SetFullscreen (bool fullscreen) {
	if (fullscreen && mDrawFullscreen)
		return;

	if (!fullscreen && !mDrawFullscreen)
		return;

	if (mDrawFullscreen) {
		mWindowHeight = VIEW_DEFAULT_HEIGHT;
		mWindowWidth = VIEW_DEFAULT_WIDTH;

		mDrawFullscreen = false;
	} else {
		mWindowWidth = mScreenWidth;
		mWindowHeight = mScreenHeight;

		mDrawFullscreen = true;
	}

	Resize (mWindowWidth, mWindowHeight);
}

/* Fonts */

/** \brief Parses font specifications strings into its values
 *
 * Fonts can be specified by strings such as
 *   name=default.ttf color=#ff0000 size=12
 *   color=#ff00ff size=12 otherfont.ttf
 *   myfont.ttf
 * for which the appropriate values will be parsed. Default size is 12 and
 * default color is white (#ffffff)
 */
void parse_font_spec_string (const std::string &spec_string,
		std::string &font_name,
		float font_color[3],
		float *font_size) {
	// set default values
	font_name = "default.ttf";
	font_color[0] = 1.f;
	font_color[1] = 1.f;
	font_color[2] = 1.f;
	*font_size = 12.f;

	// perform the actual parsing
	std::string::size_type pos = 0;

	while (pos < spec_string.size()) {
		std::string::size_type next_start = spec_string.find_first_not_of(" \t", pos);
		// if we don't find anything we break out of this loop
		if (next_start == std::string::npos)
			break;

		// find the next token
		std::string::size_type next_end = spec_string.find_first_of("\t ", next_start);
		std::string token (spec_string.substr(next_start, next_end - next_start));

		// If no id was given it is automatically set to name
		std::string id("name");
		std::string value(token);

		// Split the token into id and value if there is an '=' sign.
		if (token.find('=', 0) != std::string::npos) {
			id = token.substr(0, token.find('=',0));
			value = token.substr(id.size() + 1, token.size());
		}

		// std::cout << "id = " << id << " value = " << value << std::endl;

		if (id == "name")
			font_name = value;
		else if (id == "size") {
			std::istringstream istr(value);
			istr >> *font_size;	
		} else if (id == "color") {
			// we assume #RRGGBB specification
			if (value[0] != '#' || value.size() != 7)
				LogError ("Invalid font color specification '%s'. Please specify as #rrggbb!", value.c_str());

			// convert the color string to float values
			int num;
			std::istringstream istr(value.substr(1, 2));
			istr >> std::hex >> num;
			font_color[0] = static_cast<float>(num) / 255.;

			istr.clear();
			istr.str(value.substr(3,2));
			istr >> std::hex >> num;
			font_color[1] = static_cast<float>(num) / 255.;

			istr.clear();
			istr.str(value.substr(5,2));
			istr >> std::hex >> num;
			font_color[2] = static_cast<float>(num) / 255.;
		}

		pos = next_end;
	}
}

bool ViewBase::LoadFont (const std::string &font_spec_string) {
	// font_spec_string can be of the form
	// (name=)<name> (color=<color>) (size=<size>)

	std::string font_name;
	float font_size = 12.;
	float font_color[3] = {1., 1., 1.};

	parse_font_spec_string(font_spec_string, font_name, font_color, &font_size);	

	std::string font_path (GetResourceFullPath("/data/fonts/"));
	font_path += font_name;

	LogDebug ("Loading font %s color (%1.2f, %1.2f, %1.2f) size %f from %s", font_name.c_str(), font_color[0], font_color[1], font_color[2], font_size, font_path.c_str());

	OGLFT::Monochrome *font = new OGLFT::Monochrome (font_path.c_str(), font_size);
	if ( font == 0 || !font->isValid() ) {
		LogError ("Could not load font %s! (ptr=%x", font_path.c_str(), (void*)font);
		return false;
	}

	font->setForegroundColor(font_color[0], font_color[1], font_color[2], 1.);
	font->setBackgroundColor(0., 0., 0., 0.);

	mFonts.insert(std::make_pair<std::string, OGLFT::Monochrome*>(font_spec_string, font));
	LogDebug ("Loading font %s successful!", font_name.c_str());
	return true;
}

void ViewBase::SelectFont (const char *font) {
	std::map<std::string, OGLFT::Monochrome*>::iterator font_iter;

	font_iter = mFonts.find(font);

	if (font_iter != mFonts.end()) {
		mCurrentFont = font_iter->second;
		return;
	}

	LogDebug ("Selecting font %s failed, trying to load it", font);

	if (LoadFont (font)) {
		LogDebug ("font count = %d", mFonts.size());
		font_iter = mFonts.find(font);

		assert (mFonts.find(font) != mFonts.end());

		mCurrentFont = font_iter->second;

		return;
	}

	LogError("Error trying to load font %s", font);
}

float ViewBase::GetCurrentFontSize() {
	if (mCurrentFont == NULL) {
		LogError ("Could not get current font size: no font selected!");
		return 0.;
	}

	return mCurrentFont->pointSize();
}

void ViewBase::SetFontJustification (FontJustification justification) {
	assert (mCurrentFont != NULL);

	if (justification == FontJustificationRight)
		mCurrentFont->setHorizontalJustification(OGLFT::Face::RIGHT);
	else if (justification == FontJustificationCenter) 
		mCurrentFont->setHorizontalJustification(OGLFT::Face::CENTER);
	else mCurrentFont->setHorizontalJustification(OGLFT::Face::LEFT);
}

void ViewBase::DrawGLString (float x, float y, const char* str) {
	glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
	mCurrentFont->draw (x, y, str);
}

void ViewBase::DrawGLStringMeasure (const char* str, float *width, float *height) {
	OGLFT::BBox bbox = mCurrentFont->measure (str);
	*width = bbox.x_max_ - bbox.x_min_;
	*height = bbox.y_max_ - bbox.y_min_;
//	LogDebug ("measure bbox '%s' = %f,%f %f,%f",str, bbox.x_min_, bbox.y_min_, bbox.x_max_, bbox.y_max_);
}

GLuint ViewBase::LoadTextureFromPNG (const std::string &filename) {
	std::map<std::string, GLuint>::iterator texture_iterator = mGLTextures.find(filename);

	if (texture_iterator != mGLTextures.end()) {
		return texture_iterator->second;
	}

	Sprite temp_sprite;
	temp_sprite.LoadFromPNG (filename.c_str());

	// register the texture in the View
	mGLTextures[filename] = temp_sprite.GetGLTextureName();

	return temp_sprite.GetGLTextureName();
}

/*
 * OBJModel loading and drawing
 */


OBJModelPtr ViewBase::LoadOBJModel (const std::string &model_filename) {
	LogDebug ("Loading OBJ model %s", model_filename.c_str());

	OBJModelPtr result_model (new OBJModel);

	if(!result_model->import (model_filename.c_str(), true)) {
		LogError("Could not load model %s", model_filename.c_str());
		return result_model;
	}

	result_model->normalize();
	result_model->reverseWinding();

	// Load any associated textures.
	// Note the path where the textures are assumed to be located.

	const OBJModel::Material *pMaterial = 0;
	GLuint textureId = 0;
	std::string::size_type offset = 0;
	std::string filename;

	for (int i = 0; i < result_model->getNumberOfMaterials(); ++i)
	{
		pMaterial = &result_model->getMaterial(i);

		// Look for and load any diffuse color map textures.
		if (!pMaterial->colorMapFilename.empty()) {
			// Try load the texture using the path in the .MTL file.
			textureId = LoadTextureFromPNG(pMaterial->colorMapFilename.c_str());

			if (!textureId)
			{
				offset = pMaterial->colorMapFilename.find_last_of('\\');

				if (offset != std::string::npos)
					filename = pMaterial->colorMapFilename.substr(++offset);
				else
					filename = pMaterial->colorMapFilename;

				// Try loading the texture from the same directory as the OBJ file.
				textureId = LoadTextureFromPNG((filename).c_str());
			}
		} else {
			LogMessage ("No diffuse color map found!");
		}
		
		// Look for and load any normal map textures.
		if (!pMaterial->bumpMapFilename.empty()) {

			// Try load the texture using the path in the .MTL file.
			textureId = LoadTextureFromPNG((pMaterial->bumpMapFilename).c_str());

			if (!textureId)
			{
				offset = pMaterial->bumpMapFilename.find_last_of('\\');

				if (offset != std::string::npos)
					filename = pMaterial->bumpMapFilename.substr(++offset);
				else
					filename = pMaterial->bumpMapFilename;

				// Try loading the texture from the same directory as the OBJ file.
				textureId = LoadTextureFromPNG((result_model->getPath() + filename).c_str());
			}
		} else {
			LogMessage ("Material has no bumpmap!");
			continue;
		}

	}

	// Update the window caption.

	LogMessage ("Loaded model %s successful, dimensions (whl): %f, %f, %f meshes %d vertices %d triangles: %d", 
			model_filename.c_str(), 
			result_model->getWidth(),
			result_model->getHeight(),
			result_model->getLength(),
			result_model->getNumberOfMeshes(),
			result_model->getNumberOfVertices(),
			result_model->getNumberOfTriangles()
			);

	return result_model;
}

void ViewBase::DrawOBJModel (OBJModelPtr obj_model) {
	if (mUseShaders) {
		DrawOBJModelShaded(obj_model);
	} else {
		DrawOBJModelSolid (obj_model);
	}
}

void ViewBase::DrawOBJModelSolid (OBJModelPtr obj_model) {
	const OBJModel::Mesh *pMesh = 0;
	const OBJModel::Material *pMaterial = 0;
	const OBJModel::Vertex *pVertices = 0;
	std::map<std::string, GLuint>::const_iterator iter;

	for (int i = 0; i < obj_model->getNumberOfMeshes(); ++i)
	{
		pMesh = &obj_model->getMesh(i);
		pMaterial = pMesh->pMaterial;
		pVertices = obj_model->getVertexBuffer();

		glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT,  pMaterial->ambient);
		glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE,  pMaterial->diffuse);
		glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, pMaterial->specular);

		glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, pMaterial->shininess * 128.0f);

		if (pMaterial->colorMapFilename.size() > 0)
		{
			iter = mGLTextures.find(pMaterial->colorMapFilename);

			if (iter == mGLTextures.end())
			{
				LogError ("Could not find required colormap '%s'", pMaterial->colorMapFilename.c_str());
				glDisable(GL_TEXTURE_2D);
			}
			else
			{
				glEnable(GL_TEXTURE_2D);
				glBindTexture(GL_TEXTURE_2D, iter->second);
			}
		}
		else
		{
			glDisable(GL_TEXTURE_2D);
		}

		if (obj_model->hasPositions())
		{
			glEnableClientState(GL_VERTEX_ARRAY);
			glVertexPointer(3, GL_FLOAT, obj_model->getVertexSize(),
					obj_model->getVertexBuffer()->position);
		}

		if (obj_model->hasTextureCoords())
		{
			glEnableClientState(GL_TEXTURE_COORD_ARRAY);
			glTexCoordPointer(2, GL_FLOAT, obj_model->getVertexSize(),
					obj_model->getVertexBuffer()->texCoord);
		}

		if (obj_model->hasNormals())
		{
			glEnableClientState(GL_NORMAL_ARRAY);
			glNormalPointer(GL_FLOAT, obj_model->getVertexSize(),
					obj_model->getVertexBuffer()->normal);
		}

		glDrawElements(GL_TRIANGLES, pMesh->triangleCount * 3, GL_UNSIGNED_INT,
				obj_model->getIndexBuffer() + pMesh->startIndex);

		if (obj_model->hasNormals())
			glDisableClientState(GL_NORMAL_ARRAY);

		if (obj_model->hasTextureCoords())
			glDisableClientState(GL_TEXTURE_COORD_ARRAY);

		if (obj_model->hasPositions())
			glDisableClientState(GL_VERTEX_ARRAY);

		// disable texture drawing if active
		if (pMaterial->colorMapFilename.size() > 0)
			glDisable(GL_TEXTURE_2D);
	}
}

void ViewBase::DrawOBJModelShaded (OBJModelPtr obj_model) {
	const OBJModel::Mesh *pMesh = 0;
	const OBJModel::Material *pMaterial = 0;
	const OBJModel::Vertex *pVertices = 0;
	std::map<std::string, GLuint>::const_iterator iter;
	GLuint texture = 0;

	for (int i = 0; i < obj_model->getNumberOfMeshes(); ++i)
	{
		pMesh = &obj_model->getMesh(i);
		pMaterial = pMesh->pMaterial;
		pVertices = obj_model->getVertexBuffer();

		glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, pMaterial->ambient);
		glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, pMaterial->diffuse);
		glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, pMaterial->specular);
		glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, pMaterial->shininess * 128.0f);

		// if there is no bumpmap we will simply use a blinn phong shader and draw
		// the color map onto our model
		if (pMaterial->bumpMapFilename.empty())
		{
			// LogMessage ("using Blinn Phong shader");
			// Per fragment Blinn-Phong code path.
			glUseProgram(mBlinnPhongShader);

			// Bind the color map texture.

			texture = mNullTexture;

			if (pMaterial->colorMapFilename.size() > 0) {
				iter = mGLTextures.find(pMaterial->colorMapFilename);

				if (iter != mGLTextures.end())
					texture = iter->second;

			} else {
//				LogMessage ("Disabling textures");
			}

			glActiveTexture(GL_TEXTURE0);
			glEnable(GL_TEXTURE_2D);
			glBindTexture(GL_TEXTURE_2D, texture);

			// Update shader parameters.
			assert (glIsProgram (mBlinnPhongShader) == GL_TRUE);
			assert (glGetUniformLocation(mBlinnPhongShader, "materialAlpha") != -1);
			assert (glGetUniformLocation(mBlinnPhongShader, "colorMap") != -1);
			glUniform1i(glGetUniformLocation(
						mBlinnPhongShader, "colorMap"), 0);
			glUniform1f(glGetUniformLocation(
						mBlinnPhongShader, "materialAlpha"), pMaterial->alpha);
		}
		else
		{
			// if there is a bumpmap we use both the bump map and the color map and
			// apply it on our model
			
			// LogMessage ("using Normal Mapping Shader");
			// Normal mapping code path.

			glUseProgram(mNormalMappingShader);

			// Bind the normal map texture.

			iter = mGLTextures.find(pMaterial->bumpMapFilename);

			if (iter != mGLTextures.end()) {
				texture = iter->second;

				glActiveTexture(GL_TEXTURE1);
				glEnable(GL_TEXTURE_2D);
				glBindTexture(GL_TEXTURE_2D, texture);
			} else {
				LogError ("bumpmap %s not found", pMaterial->bumpMapFilename.c_str());
			}

			// Bind the color map texture.

			texture = mNullTexture;

			if (pMaterial->colorMapFilename.size() > 0)
			{
				iter = mGLTextures.find(pMaterial->colorMapFilename);

				if (iter != mGLTextures.end()) {
					texture = iter->second;
				}	else {
					LogError ("color map %s not found", pMaterial->colorMapFilename.c_str());
				}
			}

			glActiveTexture(GL_TEXTURE0);
			glEnable(GL_TEXTURE_2D);
			glBindTexture(GL_TEXTURE_2D, texture);
	
			// Update shader parameters.
			assert (glGetUniformLocation(mNormalMappingShader, "colorMap") != -1);
			assert (glGetUniformLocation(mNormalMappingShader, "normalMap") != -1);
			assert (glGetUniformLocation(mNormalMappingShader, "materialAlpha") != -1);

			glUniform1i(glGetUniformLocation(
						mNormalMappingShader, "colorMap"), 0);
			glUniform1i(glGetUniformLocation(
						mNormalMappingShader, "normalMap"), 1);
			glUniform1f(glGetUniformLocation(
						mNormalMappingShader, "materialAlpha"), pMaterial->alpha);
		}        

		// Render mesh.

		if (obj_model->hasPositions())
		{
			glEnableClientState(GL_VERTEX_ARRAY);
			glVertexPointer(3, GL_FLOAT, obj_model->getVertexSize(),
					obj_model->getVertexBuffer()->position);
		}

		if (obj_model->hasTextureCoords())
		{
			glClientActiveTexture(GL_TEXTURE0);
			glEnableClientState(GL_TEXTURE_COORD_ARRAY);
			glTexCoordPointer(2, GL_FLOAT, obj_model->getVertexSize(),
					obj_model->getVertexBuffer()->texCoord);
		}

		if (obj_model->hasNormals())
		{
			glEnableClientState(GL_NORMAL_ARRAY);
			glNormalPointer(GL_FLOAT, obj_model->getVertexSize(),
					obj_model->getVertexBuffer()->normal);
		}

		if (obj_model->hasTangents())
		{
			glClientActiveTexture(GL_TEXTURE1);
			glEnableClientState(GL_TEXTURE_COORD_ARRAY);
			glTexCoordPointer(4, GL_FLOAT, obj_model->getVertexSize(),
					obj_model->getVertexBuffer()->tangent);
		}

		glDrawElements(GL_TRIANGLES, pMesh->triangleCount * 3, GL_UNSIGNED_INT,
				obj_model->getIndexBuffer() + pMesh->startIndex);

		if (obj_model->hasTangents())
		{
			glClientActiveTexture(GL_TEXTURE1);
			glDisableClientState(GL_TEXTURE_COORD_ARRAY);
		}

		if (obj_model->hasNormals())
			glDisableClientState(GL_NORMAL_ARRAY);

		if (obj_model->hasTextureCoords())
		{
			glClientActiveTexture(GL_TEXTURE0);
			glDisableClientState(GL_TEXTURE_COORD_ARRAY);
		}

		if (obj_model->hasPositions())
			glDisableClientState(GL_VERTEX_ARRAY);
	}

	// as we might be using multiple textures (at least for the normal mapping
	// case) we have to disable both textures
	glActiveTexture(GL_TEXTURE1);
	glBindTexture(GL_TEXTURE_2D, 0);

	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, 0);
	
	glUseProgram(0);
}

/*
 * Shader loading, compiling, linking
 */
/** Compiles a shader program
 *
 * This function contains code mainly taken from dhpowares excellent
 * objviewer example (see http://www.dhpoware.com/demos/gl3NormalMapping.html ).
 */
GLuint ViewBase::CompileShader (GLenum type, const GLchar *source, GLint length) {
	GLuint shader = glCreateShader(type);

	if (shader) {
		GLint compiled = 0;

		glShaderSource (shader, 1, &source, &length);
		glCompileShader(shader);
		glGetShaderiv (shader, GL_COMPILE_STATUS, &compiled);

		if (!compiled) {
			GLsizei info_log_size = 0;
			std::string info_log;

			glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &info_log_size);
			info_log.resize (info_log_size);
			glGetShaderInfoLog (shader, info_log_size, &info_log_size, &info_log[0]);

			LogError ("Error compiling shader: %s", info_log.c_str());
		}
	}

	return shader;
}

/** Links the given shader programs
 *
 * This function contains code mainly taken from dhpowares excellent
 * objviewer example (see http://www.dhpoware.com/demos/gl3NormalMapping.html ).
 */
GLuint ViewBase::LinkShaders (GLuint vertex_shader, GLuint fragment_shader) {
	GLuint program = glCreateProgram();

	if (program) {
		GLint linked = 0;

		if (vertex_shader)
			glAttachShader (program, vertex_shader);

		if (fragment_shader)
			glAttachShader (program, fragment_shader);

		glLinkProgram (program);
		glGetProgramiv (program, GL_LINK_STATUS, &linked);

		if (!linked) {
			GLsizei info_log_size = 0;
			std::string info_log;

			glGetProgramiv(program, GL_INFO_LOG_LENGTH, &info_log_size);
			info_log.resize (info_log_size);
			glGetProgramInfoLog (program, info_log_size, &info_log_size, &info_log[0]);

			LogError ("Error linking shaders vert: %d, frag: %d", vertex_shader, fragment_shader);
		}

		if (vertex_shader)
			glDeleteShader (vertex_shader);

		if (fragment_shader)
			glDeleteShader (fragment_shader);
	}

	return program;
}


/** Loads a vertex or fragment shader program 
 *
 * This function contains code mainly taken from dhpowares excellent
 * objviewer example (see http://www.dhpoware.com/demos/gl3NormalMapping.html ).
 */
GLuint ViewBase::LoadShaderProgram (const std::string &filename) {
	LogDebug ("Loading shader program %s", filename.c_str());
	
	std::ifstream program_file (filename.c_str());
	if (!program_file) {
		LogError ("Could not open file '%s' while loading shader program", filename.c_str());
	}

	// read the whole file into a string
	std::string shader_program ((std::istreambuf_iterator<char>(program_file)), std::istreambuf_iterator<char>());

	program_file.close();

	GLuint program = 0;

	if (shader_program.size() > 0) {
		const GLchar *source;
		GLint length = 0;
		GLuint vertex_shader = 0;
		GLuint fragment_shader = 0;

		std::string::size_type vertex_shader_offset = shader_program.find("[vert]");
		std::string::size_type fragment_shader_offset = shader_program.find("[frag]");

		if (vertex_shader_offset != std::string::npos) {
			// skip over the [vert] tag
			vertex_shader_offset += 6;
			source = reinterpret_cast<const GLchar *> (&shader_program[vertex_shader_offset]);
			length = static_cast<GLint>(fragment_shader_offset - vertex_shader_offset);
			vertex_shader = CompileShader (GL_VERTEX_SHADER, source, length);

			LogMessage ("Compiled vertex shader with id %d", vertex_shader);
		}

		if (fragment_shader_offset != std::string::npos) {
			// skip over the [vert] tag
			fragment_shader_offset += 6;
			source = reinterpret_cast<const GLchar *> (&shader_program[fragment_shader_offset]);
			length = static_cast<GLint>(shader_program.length() - fragment_shader_offset - 1);
			fragment_shader = CompileShader (GL_FRAGMENT_SHADER, source, length);

			LogMessage ("Compiled fragment shader with id %d", fragment_shader);
		}

		program = LinkShaders (vertex_shader, fragment_shader);

		LogMessage ("Successfully linked shaders vert: %d frag: %d from file %s into program %d", vertex_shader, fragment_shader, filename.c_str(), program);
	}

	mShaderPrograms[filename] = program;

	return program;
}

/*
 * Camera and other auxillary functions
 */

void ViewBase::GetCamereEye (float *eye_out) {
	assert (mCamera);
	mCamera->GetEye (eye_out);
}

void ViewBase::DrawGrid () {
	float xmin, xmax, xstep, zmin, zmax, zstep;
	int i, count_x, count_z;

	xmin = -mGridSizeX;
	xmax = mGridSizeX;
	zmin = -mGridSizeZ;
	zmax = mGridSizeZ;

	count_x = mGridSizeX * 2;
	count_z = mGridSizeZ * 2;

	xstep = 1.;
	zstep = 1.;

	glColor3f (0.8, 0.8, 0.8);
	glLineWidth(1.);
	glBegin (GL_LINES);
	for (i = 0; i <= count_x; i++) {
		glVertex3f (i * xstep + xmin, 0., zmin);
		glVertex3f (i * xstep + xmin, 0., zmax);
	}
	for (i = 0; i <= count_z; i++) {
		glVertex3f (xmin, 0, i * zstep + zmin);
		glVertex3f (xmax, 0, i * zstep + zmin);
	}
	glEnd ();
}

void ViewBase::DrawWorld () {
}

void ViewBase::Resize (int width, int height) {
	if (height == 0)
		height = 1;

	mWindowWidth = static_cast<unsigned int> (width);
	mWindowHeight = static_cast<unsigned int> (height);

	glViewport(0, 0, width, height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(mCamera->GetFOVY (), float (width) / float (height), 0., 100);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity ();

	LogDebug ("Resize to: %d x %d", mWindowWidth,mWindowHeight);

	/** \warning
	 * This call has to be made for SDL 1.2 for 1.3 there seems to be a
	 * workaround, however since I do not yet run SDL 1.3 I hold on to this.
	 * See http://lists.libsdl.org/pipermail/sdl-libsdl.org/2008-November/067306.html
	 */
	Uint32 video_flags = SDL_OPENGL;

	if (mDrawFullscreen)
		video_flags = video_flags | SDL_FULLSCREEN;

	if( SDL_SetVideoMode( mWindowWidth, mWindowHeight, 16, video_flags) == 0 ) {
		LogError ("Video mode set failed: %s", SDL_GetError ());
		exit (-1);
	}
}

/*
bool ViewBase::SendKeyDown (const SDL_keysym &keysym) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnKeyDown (keysym))
			return true;
	}

	return false;
}

bool ViewBase::SendKeyUp (const SDL_keysym &keysym) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnKeyUp (keysym))
			return true;
	}

	return false;
}

bool ViewBase::SendMouseButtonUp (Uint8 button, Uint16 xpos, Uint16 ypos) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnMouseButtonUp (button, xpos, ypos))
			return true;
	}

	return false;
}

bool ViewBase::SendMouseButtonDown (Uint8 button, Uint16 xpos, Uint16 ypos) {
	std::vector<OverlayBasePtr>::iterator overlay_iter;
	for (overlay_iter = mOverlays.begin(); overlay_iter != mOverlays.end(); overlay_iter++) {
		if ( (*overlay_iter)->OnMouseButtonDown (button, xpos, ypos))
			return true;
	}

	return false;
}
*/

/*
 * Global functions
 */
void DrawGLString (float x, float y, const char* str) {
	if (!ViewInstance) {
		LogError ("Cannot Draw GL String: View not yet initialized!");
		return;
	}
	ViewInstance->DrawGLString (x, y, str);
}

void SelectFont (const char* font) {
	if (!ViewInstance) {
		LogError ("Cannot select font: View not yet initialized!");
		return;
	}
	ViewInstance->SelectFont(font);
}

void SetFontJustification (FontJustification justification) {
	if (!ViewInstance) {
		LogError ("Cannot select font: View not yet initialized!");
		return;
	}
	ViewInstance->SetFontJustification (justification);
}

float GetCurrentFontSize() {
	if (!ViewInstance) {
		LogError ("Cannot get font size: View not yet initialized!");
		return 0.;
	}
	return ViewInstance->GetCurrentFontSize();
}

unsigned int GetWindowWidth() {
	return ViewInstance->GetWindowWidth ();
}

unsigned int GetWindowHeight() {
	return ViewInstance->GetWindowHeight ();
}

int GetFrameRate () {
	return ViewInstance->GetFrameRate ();
}

}