#include <iostream>
#include "FrameBufferObject.h"
#include "glInterface.h"

using namespace std;


namespace CHCDemoEngine
{

GLenum color_attachment[] = {GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT, GL_COLOR_ATTACHMENT2_EXT, GL_COLOR_ATTACHMENT3_EXT};

void PrintFBOStatus(GLenum status)
{
	switch(status)
	{
	case GL_FRAMEBUFFER_COMPLETE_EXT:
		//cout << "frame buffer object complete" << endl;
		break;
	case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:
		cerr << "incomplete attachment" << endl;
		break;
	case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
		cerr << "missing attachment" << endl;
		break;
	case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
		cerr << "incomplete dimensions" << endl;
		break;
	case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
		cerr << "incomplete formats" << endl;
		break;
	case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
		cerr << "incomplete draw buffer" << endl;
		break;
	case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
		cerr << "incomplete read buffer" << endl;
		break;
	case GL_FRAMEBUFFER_UNSUPPORTED_EXT:
		cerr << "framebuffer unsupported" << endl;
		break;
	default:
		cerr << "unknown status code " << status << endl;
	}
}


ColorBufferObject::ColorBufferObject(int w, int h, 
									 FORMAT format, 
									 WRAP_TYPE wrapType, 
									 FILTER_TYPE filterType, 
									 bool useMipMap, 
									 int attachment_idx)
{
	GLuint glformat, internalFormat;


	switch (format)
	{
	case BUFFER_UBYTE:
		glformat = GL_UNSIGNED_BYTE; internalFormat = GL_RGBA8; break;
	case BUFFER_FLOAT_16:
		glformat = GL_FLOAT; internalFormat = GL_RGBA16F_ARB; break;
	case BUFFER_FLOAT_32: 
		glformat = GL_FLOAT; internalFormat = GL_RGBA32F_ARB; break;
	default:
		glformat = GL_UNSIGNED_BYTE; internalFormat = GL_RGBA8;
		cerr << "should not come here" << endl;
	}


	glGenRenderbuffersEXT(1, &mId);
	glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, mId);
	
	glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, internalFormat, w, h);
	glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, color_attachment[attachment_idx], GL_RENDERBUFFER_EXT, mId);


	glGenTextures(1, &mTexId);
	glBindTexture(GL_TEXTURE_2D, mTexId);
	glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, w, h, 0, GL_RGBA, glformat, NULL);

	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, color_attachment[attachment_idx], GL_TEXTURE_2D, mTexId, 0);

	GLuint minfilterParam;
	GLuint magfilterParam;

	switch (filterType)
	{
	case FILTER_NEAREST:
		minfilterParam = GL_NEAREST;
		magfilterParam = GL_NEAREST; break;
	case FILTER_LINEAR:
		minfilterParam = GL_LINEAR;
		magfilterParam = GL_LINEAR; break;
	case FILTER_MIPMAP_LINEAR: 
		minfilterParam = GL_NEAREST_MIPMAP_NEAREST;
		magfilterParam = GL_NEAREST; 

		//minfilterParam = GL_LINEAR_MIPMAP_NEAREST;
		//magfilterParam = GL_LINEAR; 
		break;
	default:
		minfilterParam = GL_NEAREST;
		magfilterParam = GL_NEAREST;

		cerr << "should not come here" << endl;
	}

	
	GLuint wrapParam;

	switch (wrapType)
	{
	case WRAP_REPEAT:
		wrapParam = GL_REPEAT; break;
	case WRAP_CLAMP_TO_EDGE:
		wrapParam = GL_CLAMP_TO_EDGE; break;
	}

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magfilterParam);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minfilterParam);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapParam);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapParam);

	if (useMipMap) glGenerateMipmapEXT(GL_TEXTURE_2D);

	// print status
	PrintFBOStatus(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT));
}


ColorBufferObject::~ColorBufferObject()
{
	glDeleteRenderbuffersEXT(1, &mId);
	glDeleteTextures(1, &mTexId);
}


FrameBufferObject::FrameBufferObject(int w, int h, DEPTH_FORMAT d, bool useDepthTex)
: mWidth(w), mHeight(h), mDepthTexId(0)
{
	glGenFramebuffersEXT(1, &mId);
	
	Bind();

	///////////
	//-- create depth buffer

	if (d != DEPTH_NONE)
	{
		glGenRenderbuffersEXT(1, &mDepthId);	
		glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, mDepthId);

		GLuint depthFormat;

		switch (d)
		{
		case DEPTH_16:
			depthFormat = GL_DEPTH_COMPONENT16; break;
		case DEPTH_24:
			depthFormat = GL_DEPTH_COMPONENT24; break;
		case DEPTH_32: 
			depthFormat = GL_DEPTH_COMPONENT32; break;
		default:	
			cerr << "should not come here" << endl;
		}

		glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, depthFormat, w, h);
		

		glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, mDepthId);

		if (useDepthTex)
		{
			glGenTextures(1, &mDepthTexId);
			glBindTexture(GL_TEXTURE_2D, mDepthTexId);

			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
			
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
			glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

			glTexImage2D(GL_TEXTURE_2D, 0, depthFormat, mWidth, mHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);

			glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, mDepthTexId, 0);
		}
	}

	Release();
}


FrameBufferObject::~FrameBufferObject()
{
	glDeleteFramebuffersEXT(1, &mId);
	glDeleteRenderbuffersEXT(1, &mDepthId);

	if (mDepthTexId) glDeleteTextures(1, &mDepthTexId);

	CLEAR_CONTAINER(mColorBuffers);
}


int FrameBufferObject::AddColorBuffer(ColorBufferObject::FORMAT col, 
									  ColorBufferObject::WRAP_TYPE wrapType, 
									  ColorBufferObject::FILTER_TYPE filterType, 
									  bool useMipMap)
{
	Bind();

	const int idx = (int)mColorBuffers.size();

	ColorBufferObject *colorBuf = 
		new ColorBufferObject(mWidth, mHeight, col, wrapType, filterType, useMipMap, idx);

	mColorBuffers.push_back(colorBuf);

	Release();

	return idx;
}


void FrameBufferObject::Bind() const
{
	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, mId);
}


void FrameBufferObject::Release()
{
	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}


} // namespace