// Copyright (C) 2003-2008 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/


// Preliminary non-working code.

#include "Globals.h"
#include "GLUtil.h"
#include "MemoryUtil.h"
#include "Render.h"
#include "TextureMngr.h"
#include "VertexShaderManager.h"
#include "XFBConvert.h"
#include "TextureConverter.h"

#define XFB_USE_SHADERS 1

enum {
	XFB_WIDTH = 640,
	XFB_HEIGHT = 480, // 528 is max height.
	XFB_BUF_HEIGHT = 538, //480,
	// TODO: figure out what to do with PAL
};


#if XFB_USE_SHADERS

static GLuint xfb_decoded_texture;

void XFB_Init()
{
	glGenTextures(1, &xfb_decoded_texture);
	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, xfb_decoded_texture);
	glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, 4, XFB_WIDTH, XFB_BUF_HEIGHT, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
}

void XFB_Shutdown()
{
	glDeleteTextures(1, &xfb_decoded_texture);
}


void XFB_Write(u8 *xfb_in_ram, const TRectangle& sourceRc, u32 dstWd, u32 dstHt)
{
    u32 nBackbufferHeight = OpenGL_GetHeight();
	TRectangle renderSrcRc;
	renderSrcRc.left = sourceRc.left;
	renderSrcRc.right = sourceRc.right;
	renderSrcRc.top = nBackbufferHeight - sourceRc.top;
	renderSrcRc.bottom = nBackbufferHeight - sourceRc.bottom; 
	TextureConverter::EncodeToRam(Renderer::GetRenderTarget(), renderSrcRc, xfb_in_ram, dstWd, dstHt);
}

void XFB_Draw(u8 *xfb_in_ram, u32 width, u32 height, s32 yOffset)
{
	TextureConverter::DecodeToTexture(xfb_in_ram, width, height, xfb_decoded_texture);

	OpenGL_Update(); // just updates the render window position and the backbuffer size

	Renderer::ResetGLState();

	TextureMngr::EnableTexRECT(0);

	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); // switch to the backbuffer

	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, xfb_decoded_texture);

	glViewport(OpenGL_GetXoff(), OpenGL_GetYoff(),
		   (int)OpenGL_GetWidth(), (int)OpenGL_GetHeight);
	GL_REPORT_ERRORD();

	float w = (float)width;
	float h = (float)height;
	float yOff = (float)yOffset;

    glBegin(GL_QUADS);
	glTexCoord2f(w, 0 - yOff);  glVertex2f(1, -1);
	glTexCoord2f(w, h - yOff);  glVertex2f(1, 1);
	glTexCoord2f(0, h - yOff);  glVertex2f(-1, 1);
	glTexCoord2f(0, 0 - yOff);  glVertex2f(-1,-1);
    glEnd();	

	TextureMngr::DisableStage(0);

	Renderer::SwapBuffers();

	Renderer::RestoreGLState();
	GL_REPORT_ERRORD();
}

#else

static GLuint xfb_texture;
static u8 *xfb_buffer = 0;
static u8 *efb_buffer = 0;
static GLuint s_xfbFrameBuffer = 0;
static GLuint s_xfbRenderBuffer = 0;

void XFB_Init()
{
	// used to render XFB
	xfb_buffer = new u8[XFB_WIDTH * XFB_BUF_HEIGHT * 4];
	memset(xfb_buffer, 0, XFB_WIDTH * XFB_BUF_HEIGHT * 4);
    glGenTextures(1, &xfb_texture);
	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, xfb_texture);
    glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, 4, XFB_WIDTH, XFB_HEIGHT, 0, GL_BGRA, GL_UNSIGNED_BYTE, xfb_buffer);

	// used to render EFB
	glGenFramebuffersEXT( 1, &s_xfbFrameBuffer);
	glGenRenderbuffersEXT(1, &s_xfbRenderBuffer);
	glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, s_xfbRenderBuffer);
	glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGBA, nBackbufferWidth, nBackbufferHeight);

	// Ensure efb_buffer is aligned.
	efb_buffer = (u8 *)AllocateMemoryPages(nBackbufferWidth * nBackbufferHeight * 4);
}

void XFB_Shutdown()
{
	glDeleteFramebuffersEXT(1, &s_xfbFrameBuffer);

	glDeleteTextures(1, &xfb_texture);
	xfb_texture = 0;
	delete [] xfb_buffer;
	xfb_buffer = 0;
	FreeMemoryPages(efb_buffer, nBackbufferWidth * nBackbufferHeight * 4);
}


void XFB_Write(u8 *xfb_in_ram, const TRectangle& sourceRc, u32 dstWd, u32 dstHt)
{
	Renderer::SetRenderMode(Renderer::RM_Normal);

	Renderer::ResetGLState();

	 // switch to XFB frame buffer
	Renderer::SetFramebuffer(s_xfbFrameBuffer);
	glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, s_xfbRenderBuffer);
	glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_RENDERBUFFER_EXT, s_xfbRenderBuffer);
	GL_REPORT_ERRORD();

	glViewport(nXoff, nYoff, nBackbufferWidth, nBackbufferHeight);

	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, Renderer::GetRenderTarget());
    TextureMngr::EnableTexRECT(0);
	for (int i = 1; i < 8; ++i)
		TextureMngr::DisableStage(i);	
	GL_REPORT_ERRORD();

	glBegin(GL_QUADS);
    glTexCoord2f(0, nBackbufferHeight); glVertex2f(-1,-1);
	glTexCoord2f(0, 0); glVertex2f(-1,1);
    glTexCoord2f(nBackbufferWidth, 0); glVertex2f(1,1);
    glTexCoord2f(nBackbufferWidth, nBackbufferHeight); glVertex2f(1,-1);
    glEnd();
	GL_REPORT_ERRORD();

	int width = sourceRc.right - sourceRc.left;
	int height = sourceRc.bottom - sourceRc.top;	
	glReadPixels(sourceRc.left, sourceRc.top, width, height, GL_RGBA, GL_UNSIGNED_BYTE, efb_buffer);
	GL_REPORT_ERRORD();

	Renderer::SetFramebuffer(0);
    Renderer::RestoreGLState();
    VertexShaderMngr::SetViewportChanged();
	
	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
    TextureMngr::DisableStage(0);

	Renderer::RestoreGLState();
    GL_REPORT_ERRORD();

	// TODO - use shader for conversion
	ConvertToXFB((u32 *)xfb_in_ram, efb_buffer, dstWd, dstHt);
}

void XFB_Draw(u8 *xfb_in_ram, u32 width, u32 height, s32 yOffset)
{
	OpenGL_Update(); // just updates the render window position and the backbuffer size

    Renderer::SetRenderMode(Renderer::RM_Normal);

    // render to the real buffer now 
    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); // switch to the backbuffer
    glViewport(nXoff, nYoff, nBackbufferWidth, nBackbufferHeight);

	Renderer::ResetGLState();

	// TODO - use shader for conversion
	ConvertFromXFB((u32 *)xfb_buffer, xfb_in_ram, width, height);

	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, xfb_texture);	
    glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, 4, width, height, 0, GL_BGRA, GL_UNSIGNED_BYTE, xfb_buffer);
    TextureMngr::EnableTexRECT(0);
    for (int i = 1; i < 8; ++i)
		TextureMngr::DisableStage(i);

	GL_REPORT_ERRORD();

    glBegin(GL_QUADS);
	glTexCoord2f(width, height + yOffset); glVertex2f(1,-1);
	glTexCoord2f(width, 0 + yOffset); glVertex2f(1,1);
	glTexCoord2f(0, 0 + yOffset); glVertex2f(-1,1);
	glTexCoord2f(0, height + yOffset); glVertex2f(-1,-1);
    glEnd();

	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
    TextureMngr::DisableStage(0);

	Renderer::SwapBuffers();	

	Renderer::RestoreGLState();
    GL_REPORT_ERRORD();
}

#endif