// Copyright (C) 2003 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/

#include "Globals.h"
#include "Profiler.h"

#include "GLUtil.h"

#include <cmath>

#include "Statistics.h"
#include "VideoConfig.h"
#include "ImageWrite.h"
#include "Common.h"
#include "Render.h"
#include "VertexShaderGen.h"
#include "PixelShaderCache.h"
#include "PixelShaderManager.h"
#include "FileUtil.h"

static int s_nMaxPixelInstructions;
static GLuint s_ColorMatrixProgram = 0;
static GLuint s_DepthMatrixProgram = 0;
PixelShaderCache::PSCache PixelShaderCache::pshaders;
PIXELSHADERUID PixelShaderCache::s_curuid;
bool PixelShaderCache::s_displayCompileAlert;
GLuint PixelShaderCache::CurrentShader;
bool PixelShaderCache::ShaderEnabled;

static FRAGMENTSHADER* pShaderLast = NULL;

GLuint PixelShaderCache::GetDepthMatrixProgram()
{
	return s_DepthMatrixProgram;
}

GLuint PixelShaderCache::GetColorMatrixProgram()
{
	return s_ColorMatrixProgram;
}

void SetPSConstant4f(unsigned int const_number, float f1, float f2, float f3, float f4)
{
	float f[4] = { f1, f2, f3, f4 };
	glProgramEnvParameter4fvARB(GL_FRAGMENT_PROGRAM_ARB, const_number, f);
}

void SetPSConstant4fv(unsigned int const_number, const float *f)
{
	glProgramEnvParameter4fvARB(GL_FRAGMENT_PROGRAM_ARB, const_number, f);
}

void SetMultiPSConstant4fv(unsigned int const_number, unsigned int count, const float *f)
{
	for (unsigned int i = 0; i < count; i++,f+=4)
		glProgramEnvParameter4fvARB(GL_FRAGMENT_PROGRAM_ARB, const_number + i, f);
}

void PixelShaderCache::Init()
{
	glEnable(GL_FRAGMENT_PROGRAM_ARB);
	ShaderEnabled = true;
	CurrentShader = 0;
	GL_REPORT_ERRORD();

	memset(&last_pixel_shader_uid, 0xFF, sizeof(last_pixel_shader_uid));

	s_displayCompileAlert = true;

	glGetProgramivARB(GL_FRAGMENT_PROGRAM_ARB, GL_MAX_PROGRAM_NATIVE_ALU_INSTRUCTIONS_ARB, (GLint *)&s_nMaxPixelInstructions);
#if CG_VERSION_NUM == 2100
	if (strstr((const char*)glGetString(GL_VENDOR), "ATI") != NULL)
	{
		s_nMaxPixelInstructions = 4096;
	}
#endif

	int maxinst, maxattribs;
	glGetProgramivARB(GL_FRAGMENT_PROGRAM_ARB, GL_MAX_PROGRAM_NATIVE_INSTRUCTIONS_ARB, (GLint *)&maxinst);
	glGetProgramivARB(GL_FRAGMENT_PROGRAM_ARB, GL_MAX_PROGRAM_NATIVE_ATTRIBS_ARB, (GLint *)&maxattribs);
	INFO_LOG(VIDEO, "pixel max_alu=%d, max_inst=%d, max_attrib=%d", s_nMaxPixelInstructions, maxinst, maxattribs);
	
	char pmatrixprog[1024];
	sprintf(pmatrixprog, "!!ARBfp1.0"
						"TEMP R0;\n"
						"TEMP R1;\n"
						"TEX R0, fragment.texcoord[0], texture[0], RECT;\n"
						"DP4 R1.w, R0, program.env[%d];\n"
						"DP4 R1.z, R0, program.env[%d];\n"
						"DP4 R1.x, R0, program.env[%d];\n"
						"DP4 R1.y, R0, program.env[%d];\n"
						"ADD result.color, R1, program.env[%d];\n"
						"END\n", C_COLORMATRIX+3, C_COLORMATRIX+2, C_COLORMATRIX, C_COLORMATRIX+1, C_COLORMATRIX+4);
	glGenProgramsARB(1, &s_ColorMatrixProgram);
	SetCurrentShader(s_ColorMatrixProgram);
	glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB, (GLsizei)strlen(pmatrixprog), pmatrixprog);

	GLenum err = GL_REPORT_ERROR();
	if (err != GL_NO_ERROR) {
		ERROR_LOG(VIDEO, "Failed to create color matrix fragment program");
		glDeleteProgramsARB(1, &s_ColorMatrixProgram);
		s_ColorMatrixProgram = 0;
	}

    sprintf(pmatrixprog, "!!ARBfp1.0\n"
						"TEMP R0;\n"
						"TEMP R1;\n"
                        "TEMP R2;\n"
                        //16777215/16777216*256, 1/255, 256, 0
                        "PARAM K0 = { 255.99998474121, 0.003921568627451, 256.0, 0.0};\n" 
                        //sample the depth value
						"TEX R2, fragment.texcoord[0], texture[0], RECT;\n"

                        //scale from [0*16777216..1*16777216] to
                        //[0*16777215..1*16777215], multiply by 256
						"MUL R0, R2.x, K0.x;\n" // *16777215/16777216*256

                        //It is easy to get bad results due to low precision
                        //here, for example converting like this:
                        //MUL R0,R0,{ 65536, 256, 1, 16777216 }
                        //FRC R0,R0
                        //gives {?, 128/255, 254/255, ?} for depth value 254/255
                        //on some gpus

                        "FLR R0.z,R0;\n"        //bits 31..24

                        "SUB R0.xyw,R0,R0.z;\n" //subtract bits 31..24 from rest
                        "MUL R0.xyw,R0,K0.z;\n" // *256
                        "FLR R0.y,R0;\n"        //bits 23..16

                        "SUB R0.xw,R0,R0.y;\n"  //subtract bits 23..16 from rest
                        "MUL R0.xw,R0,K0.z;\n"  // *256
                        "FLR R0.x,R0;\n"        //bits 15..8

                        "SUB R0.w,R0,R0.x;\n"   //subtract bits 15..8 from rest
                        "MUL R0.w,R0,K0.z;\n"   // *256
                        "FLR R0.w,R0;\n"        //bits 7..0

                        "MUL R0,R0,K0.y;\n"     // /255

						"DP4 R1.x, R0, program.env[%d];\n"
						"DP4 R1.y, R0, program.env[%d];\n"
                        "DP4 R1.z, R0, program.env[%d];\n"
                        "DP4 R1.w, R0, program.env[%d];\n"
						"ADD result.color, R1, program.env[%d];\n"
						"END\n", C_COLORMATRIX, C_COLORMATRIX+1, C_COLORMATRIX+2, C_COLORMATRIX+3, C_COLORMATRIX+4);
	glGenProgramsARB(1, &s_DepthMatrixProgram);
	SetCurrentShader(s_DepthMatrixProgram);
	glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB, (GLsizei)strlen(pmatrixprog), pmatrixprog);

	err = GL_REPORT_ERROR();
	if (err != GL_NO_ERROR) {
		ERROR_LOG(VIDEO, "Failed to create depth matrix fragment program");
		glDeleteProgramsARB(1, &s_DepthMatrixProgram);
		s_DepthMatrixProgram = 0;
	}
	
}

void PixelShaderCache::Shutdown()
{
	glDeleteProgramsARB(1, &s_ColorMatrixProgram);
	s_ColorMatrixProgram = 0;
    glDeleteProgramsARB(1, &s_DepthMatrixProgram);
	s_DepthMatrixProgram = 0;
	PSCache::iterator iter = pshaders.begin();
	for (; iter != pshaders.end(); iter++)
		iter->second.Destroy();
	pshaders.clear();
}

FRAGMENTSHADER* PixelShaderCache::SetShader(bool dstAlphaEnable,u32 components)
{
	DVSTARTPROFILE();
	PIXELSHADERUID uid;
	GetPixelShaderId(&uid, dstAlphaEnable ? 1 : 0);
	if (uid == last_pixel_shader_uid && pshaders[uid].frameCount == frameCount)
	{
		return pShaderLast;
	}

	memcpy(&last_pixel_shader_uid, &uid, sizeof(PIXELSHADERUID));

	PSCache::iterator iter = pshaders.find(uid);

	if (iter != pshaders.end()) {
		iter->second.frameCount = frameCount;
		PSCacheEntry &entry = iter->second;
		if (&entry.shader != pShaderLast)
		{
			pShaderLast = &entry.shader;
		}

		return pShaderLast;
	}

	//Make an entry in the table
	PSCacheEntry& newentry = pshaders[uid];
	newentry.frameCount = frameCount;
	pShaderLast = &newentry.shader;
	const char *code = GeneratePixelShaderCode(dstAlphaEnable,API_OPENGL,components);

#if defined(_DEBUG) || defined(DEBUGFAST)
	if (g_ActiveConfig.iLog & CONF_SAVESHADERS && code) {	
		static int counter = 0;
		char szTemp[MAX_PATH];
		sprintf(szTemp, "%sps_%04i.txt", File::GetUserPath(D_DUMP_IDX), counter++);
		
		SaveData(szTemp, code);
	}
#endif

	//	printf("Compiling pixel shader. size = %i\n", strlen(code));
	if (!code || !CompilePixelShader(newentry.shader, code)) {
		ERROR_LOG(VIDEO, "failed to create pixel shader");
		static int counter = 0;
		char szTemp[MAX_PATH];
		sprintf(szTemp, "%sBADps_%04i.txt", File::GetUserPath(D_DUMP_IDX), counter++);			
		SaveData(szTemp, code);
		return NULL;
	}
	
	INCSTAT(stats.numPixelShadersCreated);
	SETSTAT(stats.numPixelShadersAlive, pshaders.size());
	return pShaderLast;
}

bool PixelShaderCache::CompilePixelShader(FRAGMENTSHADER& ps, const char* pstrprogram)
{
	GLenum err = GL_REPORT_ERROR();
	if (err != GL_NO_ERROR)
	{
		ERROR_LOG(VIDEO, "glError %08x before PS!", err);
	}

#if defined HAVE_CG && HAVE_CG
	char stropt[128];
	sprintf(stropt, "MaxLocalParams=32,NumInstructionSlots=%d", s_nMaxPixelInstructions);
	const char *opts[] = {"-profileopts", stropt, "-O2", "-q", NULL};
	CGprogram tempprog = cgCreateProgram(g_cgcontext, CG_SOURCE, pstrprogram, g_cgfProf, "main", opts);

	// handle errors
	if (!cgIsProgram(tempprog)) {
			cgDestroyProgram(tempprog);
			ERROR_LOG(VIDEO, "Failed to compile ps %s:", cgGetLastListing(g_cgcontext));
			ERROR_LOG(VIDEO, pstrprogram);
			return false;
	}

	// handle warnings
	if (cgGetError() != CG_NO_ERROR)
	{
			WARN_LOG(VIDEO, "Warnings on compile ps %s:", cgGetLastListing(g_cgcontext));
			WARN_LOG(VIDEO, pstrprogram);
	}

	// This looks evil - we modify the program through the const char * we got from cgGetProgramString!
	// It SHOULD not have any nasty side effects though - but you never know...
	char *pcompiledprog = (char*)cgGetProgramString(tempprog, CG_COMPILED_PROGRAM);
	char *plocal = strstr(pcompiledprog, "program.local");
	while (plocal != NULL) {
		const char *penv = "  program.env";
		memcpy(plocal, penv, 13);
		plocal = strstr(plocal+13, "program.local");
	}

	glGenProgramsARB(1, &ps.glprogid);
	SetCurrentShader(ps.glprogid);	
	glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB, (GLsizei)strlen(pcompiledprog), pcompiledprog);

	err = GL_REPORT_ERROR();
	if (err != GL_NO_ERROR)
	{
		GLint error_pos, native_limit;
		glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &error_pos);
		glGetProgramivARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_UNDER_NATIVE_LIMITS_ARB, &native_limit);
		// Error occur
		if (error_pos != -1) {
			const char *program_error = (const char *)glGetString(GL_PROGRAM_ERROR_STRING_ARB);
			char line[256];
			strncpy(line, (const char *)pcompiledprog + error_pos, 255);
			line[255] = 0;
			ERROR_LOG(VIDEO, "Error at %i: %s", error_pos, program_error);
			ERROR_LOG(VIDEO, "Line dump: \n%s", line);
		} else if (native_limit != -1) {
			ERROR_LOG(VIDEO, "Hit limit? %i", native_limit);
			// TODO
		}
		ERROR_LOG(VIDEO, pstrprogram);
		ERROR_LOG(VIDEO, pcompiledprog);
	}

	cgDestroyProgram(tempprog);
#endif

#if defined(_DEBUG) || defined(DEBUGFAST) 
	ps.strprog = pstrprogram;
#endif
	return true;
}

//Disable Fragment programs and reset the selected Program
void PixelShaderCache::DisableShader()
{
	if(ShaderEnabled)
	{		
		glDisable(GL_FRAGMENT_PROGRAM_ARB);
		ShaderEnabled = false;
	}	
}


//bind a program if is diferent from the binded oone
void PixelShaderCache::SetCurrentShader(GLuint Shader)
{
	if(!ShaderEnabled)
	{
		glEnable(GL_FRAGMENT_PROGRAM_ARB);
		ShaderEnabled = true;
	}
	if(CurrentShader != Shader)
	{
		if(Shader != 0)
			CurrentShader = Shader;
		glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, CurrentShader);
	}
}