//========= Copyright Valve Corporation, All rights reserved. ============//
//                       TOGL CODE LICENSE
//
//  Copyright 2011-2014 Valve Corporation
//  All Rights Reserved.
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
//
// cglmprogram.cpp
//
//===============================================================================

#include "togl/rendermechanism.h"

#include "filesystem.h"
#include "tier1/fmtstr.h"
#include "tier1/KeyValues.h"
#include "tier0/fasttimer.h"

#if GLMDEBUG && defined( _MSC_VER )
#include <direct.h>
#endif

// memdbgon -must- be the last include file in a .cpp file.
#include "tier0/memdbgon.h"

#if GLMDEBUG
#define GLM_FREE_SHADER_TEXT 0
#else
#define GLM_FREE_SHADER_TEXT 1
#endif

//===============================================================================

ConVar	gl_shaderpair_cacherows_lg2( "gl_paircache_rows_lg2", "10");		// 10 is minimum
ConVar	gl_shaderpair_cacheways_lg2( "gl_paircache_ways_lg2", "5");		// 5 is minimum
ConVar	gl_shaderpair_cachelog( "gl_shaderpair_cachelog", "0" );

static CCycleCount	gShaderCompileTime;
static int			gShaderCompileCount = 0;
static CCycleCount	gShaderCompileQueryTime;
static CCycleCount	gShaderLinkTime;
static int			gShaderLinkCount = 0;
static CCycleCount	gShaderLinkQueryTime;
CON_COMMAND( gl_shader_compile_time_dump, "Dump  stats shader compile time." )
{
	ConMsg( "Shader Compile Time: %u ms (Count: %d) / Query: %u ms \n", (uint32)gShaderCompileTime.GetMilliseconds(), gShaderCompileCount, (uint32)gShaderCompileQueryTime.GetMilliseconds() );
	ConMsg( "Shader Link Time   : %u ms (Count: %d) / Query: %u ms \n", (uint32)gShaderLinkTime.GetMilliseconds(), gShaderLinkCount, (uint32)gShaderLinkQueryTime.GetMilliseconds() );
}

//===============================================================================


GLenum	GLMProgTypeToARBEnum( EGLMProgramType type )
{
	GLenum	result = 0;
	switch(type)
	{
		case	kGLMVertexProgram:		result = GL_VERTEX_PROGRAM_ARB; break;
		case	kGLMFragmentProgram:	result = GL_FRAGMENT_PROGRAM_ARB; break;
		default:	Assert( !"bad program type"); result = 0; break;
	}
	return result;
}

GLenum	GLMProgTypeToGLSLEnum( EGLMProgramType type )
{
	GLenum	result = 0;
	switch(type)
	{
		case	kGLMVertexProgram:		result = GL_VERTEX_SHADER_ARB; break;
		case	kGLMFragmentProgram:	result = GL_FRAGMENT_SHADER_ARB; break;
		default:	Assert( !"bad program type"); result = 0; break;
	}
	return result;
}

CGLMProgram::CGLMProgram( GLMContext *ctx, EGLMProgramType type )
{
	m_ctx = ctx;
	m_ctx->CheckCurrent();

	m_type		= type;
	m_nHashTag	= rand() ^ ( rand() << 15 );
	m_text		= NULL;	// no text yet
	
#if GLMDEBUG
	m_editable	= NULL;
#endif

	memset( &m_descs, 0, sizeof( m_descs ) );

	m_samplerMask    = 0;	// dxabstract sets this field later
	m_samplerTypes   = 0;
	m_fragDataMask   = 0;
	m_numDrawBuffers = 0;
	memset( &m_drawBuffers, 0, sizeof( m_drawBuffers ) );

	m_maxSamplers    = GLM_SAMPLER_COUNT;
	m_nNumUsedSamplers = GLM_SAMPLER_COUNT;
	m_maxVertexAttrs = kGLMVertexAttributeIndexMax;

	// create an ARB vp/fp program object name.  No need to bind it yet.
	GLMShaderDesc *arbDesc = &m_descs[ kGLMARB ];
	Assert(gGL);
	gGL->glGenProgramsARB( 1, &arbDesc->m_object.arb );

	// create a GLSL shader object.
	GLMShaderDesc *glslDesc = &m_descs[ kGLMGLSL ];
	GLenum glslStage = GLMProgTypeToGLSLEnum( m_type );

	glslDesc->m_object.glsl = gGL->glCreateShaderObjectARB( glslStage );;

	m_shaderName[0] = '\0';

	m_bTranslatedProgram = false;

	m_nCentroidMask = 0;
	m_nShadowDepthSamplerMask = 0;

	m_labelName[0]	= '\0';
	m_labelIndex	= -1;
	m_labelCombo	= -1;

	// no text has arrived yet.  That's done in SetProgramText.
}

CGLMProgram::~CGLMProgram( )
{
	m_ctx->CheckCurrent();
	
	// if there is an arb program, delete it
	GLMShaderDesc *arbDesc = &m_descs[ kGLMARB ];
	if (arbDesc->m_object.arb)
	{
		gGL->glDeleteProgramsARB( 1, &arbDesc->m_object.arb );
		arbDesc->m_object.arb = 0;
	}
	
	// if there is a GLSL shader, delete it
	GLMShaderDesc *glslDesc = &m_descs[kGLMGLSL];
	if (glslDesc->m_object.glsl)
	{
		gGL->glDeleteShader( (uint)glslDesc->m_object.glsl );	// why do I need a cast here again ?
		glslDesc->m_object.glsl = 0;
	}

#if GLMDEBUG
	if (m_editable)
	{
		delete m_editable;
		m_editable = NULL;
	}
#endif

	if (m_text)
	{
		free( m_text );
		m_text = NULL;
	}
	m_ctx = NULL;
}

enum EShaderSection
{
	kGLMARBVertex,		kGLMARBVertexDisabled,
	kGLMARBFragment,	kGLMARBFragmentDisabled,
	kGLMGLSLVertex,		kGLMGLSLVertexDisabled,
	kGLMGLSLFragment,	kGLMGLSLFragmentDisabled,

};

const char *g_shaderSectionMarkers[] =	// match ordering of enum
{
	"!!ARBvp",	"-!!ARBvp",			// enabled and disabled markers.  so you can have multiple flavors in a blob and activate the one you want.
	"!!ARBfp",	"-!!ARBfp",
	"//GLSLvp",	"-//GLSLvp",
	"//GLSLfp",	"-//GLSLfp",
	NULL
};

void	CGLMProgram::SetShaderName( const char *name )
{
	V_strncpy( m_shaderName, name, sizeof( m_shaderName ) );
}

void	CGLMProgram::SetProgramText( char *text )
{
	// free old text if any
	// clone new text
	// scan newtext to find sections
	// walk sections, and mark descs to indicate where text is at
	
	if (m_text)
	{
		free( m_text );
		m_text = NULL;
	}
	
	// scrub desc text references
	for( int i=0; i<kGLMNumProgramTypes; i++)
	{
		GLMShaderDesc	*desc = &m_descs[i];
		
		desc->m_textPresent = false;
		desc->m_textOffset	= 0;
		desc->m_textLength	= 0;
	}
	
	m_text = strdup( text );
	Assert( m_text != NULL );	

	#if GLMDEBUG
		// create editable text item, if it does not already exist
		if (!m_editable)
		{
			char	*suffix = "";

			switch(m_type)
			{
				case	kGLMVertexProgram:		suffix = ".vsh"; break;
				case	kGLMFragmentProgram:	suffix = ".fsh"; break;
				default:	GLMDebugger();
			}

#ifdef POSIX
            CFmtStr debugShaderPath( "%s/debugshaders/", getenv( "HOME" ) );
#else
			CFmtStr debugShaderPath( "debugshaders/" );
#endif
			_mkdir( debugShaderPath.Access() );
			m_editable = new CGLMEditableTextItem( m_text, strlen(m_text), false, debugShaderPath.Access(), suffix );
			
			// pull our string back from the editable (it has probably munged it)
			if (m_editable->HasData())
			{
				ReloadStringFromEditable();
			}
		}
	#endif

	
	// scan the text and find sections
	CGLMTextSectioner		sections( m_text, strlen( m_text ), g_shaderSectionMarkers );
	
	int sectionCount = sections.Count();
	for( int i=0; i < sectionCount; i++ )
	{
		uint subtextOffset	= 0;
		uint subtextLength	= 0;
		int markerIndex		= 0;
		
		sections.GetSection( i, &subtextOffset, &subtextLength, &markerIndex );

		// act on the section
		GLMShaderDesc *desc = NULL;
		switch( m_type )
		{
			case kGLMVertexProgram:
				switch( markerIndex )
				{
					case	kGLMARBVertex:
					case	kGLMGLSLVertex:
						desc = &m_descs[ (markerIndex==kGLMARBVertex) ? kGLMARB : kGLMGLSL];

						// these steps are generic across both langs
						desc->m_textPresent	= true;
						desc->m_textOffset	= subtextOffset;
						desc->m_textLength	= subtextLength;
						desc->m_compiled	= false;
						desc->m_valid		= false;
					break;

					case	kGLMARBVertexDisabled:
					case	kGLMGLSLVertexDisabled:
						// ignore quietly
					break;
					
					default: Assert(!"Mismatched section marker seen in SetProgramText (VP)"); break;
				}
			break;
			
			case kGLMFragmentProgram:
				switch( markerIndex )
				{
					case	kGLMARBFragment:
					case	kGLMGLSLFragment:
						desc = &m_descs[ (markerIndex==kGLMARBFragment) ? kGLMARB : kGLMGLSL];

						// these steps are generic across both langs
						desc->m_textPresent	= true;
						desc->m_textOffset	= subtextOffset;
						desc->m_textLength	= subtextLength;
						desc->m_compiled	= false;
						desc->m_valid		= false;
					break;

					case	kGLMARBFragmentDisabled:
					case	kGLMGLSLFragmentDisabled:
						// ignore quietly
					break;
					
					default: Assert(!"Mismatched section marker seen in SetProgramText (VP)"); break;
				}
			break;			
		}
	}

	// find the label string
	// example:
	// trans#2871 label:vs-file vertexlit_and_unlit_generic_vs20 vs-index 294912 vs-combo 1234

	char *lineStr = strstr( m_text, "// trans#" );
	if (lineStr)
	{
		int		scratch = -1;
		
		if (this->m_type == kGLMVertexProgram)
		{
			sscanf( lineStr, "// trans#%d label:vs-file %s vs-index %d vs-combo %d", &scratch, m_labelName, &m_labelIndex, &m_labelCombo );
		}
		else
		{
			sscanf( lineStr, "// trans#%d label:ps-file %s ps-index %d ps-combo %d", &scratch, m_labelName, &m_labelIndex, &m_labelCombo );
		}
	}
}

void	CGLMProgram::CompileActiveSources	( void )
{
	// compile everything we have text for
	for( int i=0; i<kGLMNumProgramTypes; i++)
	{
		if (m_descs[i].m_textPresent)
		{
			Compile( (EGLMProgramLang)i );
		}
	}
}

void	CGLMProgram::Compile( EGLMProgramLang lang )
{
	bool bTimeShaderCompiles = (CommandLine()->FindParm( "-gl_time_shader_compiles" ) != 0);
	// If using "-gl_time_shader_compiles", keeps track of total cycle count spent on shader compiles.
	CFastTimer shaderCompileTimer;
	if (bTimeShaderCompiles)
	{
		shaderCompileTimer.Start();
	}
	
	bool noisy = false; noisy;
	int loglevel = gl_shaderpair_cachelog.GetInt();
	
	switch( lang )
	{
		case kGLMARB:
		{
			GLMShaderDesc *arbDesc;
			
			arbDesc = &m_descs[ kGLMARB ];
			
			// make sure no GLSL program is set up
			gGL->glUseProgram(0);
			// bind our program container to context
			GLenum arbTarget = GLMProgTypeToARBEnum( m_type );

			glSetEnable( arbTarget, true );							// unclear if I need this to compile or just to draw...

			gGL->glBindProgramARB( arbTarget, arbDesc->m_object.arb );	// object created or just re-bound

			char *section = m_text + arbDesc->m_textOffset;
			char *lastCharOfSection = section + arbDesc->m_textLength;	// actually it's one past the last textual character
			lastCharOfSection;

			#if GLMDEBUG				
				if(noisy)
				{
					GLMPRINTF((">-D- CGLMProgram::Compile submitting following text for ARB %s program (name %d) ---------------------",
						arbTarget == GL_FRAGMENT_PROGRAM_ARB ? "fragment" : "vertex",
						arbDesc->m_object.arb ));

					// we don't have a "print this many chars" call yet
					// just temporarily null terminate the text we want to print
					
					char saveChar = *lastCharOfSection;
					
					*lastCharOfSection= 0;
					GLMPRINTTEXT(( section, eDebugDump ));
					*lastCharOfSection= saveChar;

					GLMPRINTF(("<-D- CGLMProgram::Compile ARB EOT--" ));
				}
			#endif

			gGL->glProgramStringARB( arbTarget, GL_PROGRAM_FORMAT_ASCII_ARB, arbDesc->m_textLength, section );
			arbDesc->m_compiled = true;	// compiled but not necessarily valid
			
			CheckValidity( lang );
			// leave it bound n enabled, don't care (draw will sort it all out)
		}
		break;

		case kGLMGLSL:
		{
			GLMShaderDesc *glslDesc;
			
			glslDesc = &m_descs[ kGLMGLSL ];

			GLenum glslStage = GLMProgTypeToGLSLEnum( m_type );
			glslStage;
			
			// there's no binding to do for GLSL.  but make sure no ARB stuff is bound for tidiness.
			glSetEnable( GL_VERTEX_PROGRAM_ARB, false );
			glSetEnable( GL_FRAGMENT_PROGRAM_ARB, false );	// add check errors on these
			
			gGL->glBindProgramARB( GL_VERTEX_PROGRAM_ARB, 0 );
			gGL->glBindProgramARB( GL_FRAGMENT_PROGRAM_ARB, 0 );

			// no GLSL program either
			gGL->glUseProgram(0);
			
			// pump text into GLSL shader object

			char *section = m_text + glslDesc->m_textOffset;
			char *lastCharOfSection = section + glslDesc->m_textLength;	// actually it's one past the last textual character
			lastCharOfSection;

			#if GLMDEBUG
				if(noisy)
				{
					GLMPRINTF((">-D- CGLMProgram::Compile submitting following text for GLSL %s program (name %d) ---------------------",
						glslStage == GL_FRAGMENT_SHADER_ARB ? "fragment" : "vertex",
						glslDesc->m_object.glsl ));

					// we don't have a "print this many chars" call yet
					// just temporarily null terminate the text we want to print
					
					char saveChar = *lastCharOfSection;
					
					*lastCharOfSection= 0;
					GLMPRINTTEXT(( section, eDebugDump ));
					*lastCharOfSection= saveChar;

					GLMPRINTF(("<-D- CGLMProgram::Compile GLSL EOT--" ));
				}
			#endif

			gGL->glShaderSourceARB( glslDesc->m_object.glsl, 1, (const GLchar **)&section, &glslDesc->m_textLength);	

#if GLM_FREE_SHADER_TEXT
			// Free the shader program text - not needed anymore (GL has its own copy)
			if ( m_text && !m_descs[kGLMARB].m_textPresent )
			{
				free( m_text );
				m_text = NULL;
			}
#endif

			// compile
			gGL->glCompileShaderARB( glslDesc->m_object.glsl );
			glslDesc->m_compiled = true;	// compiled but not necessarily valid

			// Check shader validity at creation time.  This will cause the driver to not be able to
			// multi-thread/defer shader compiles, but it is useful for getting error messages on the
			// shader when it is compiled
			bool bValidateShaderEarly = (CommandLine()->FindParm( "-gl_validate_shader_early" ) != 0);
			if (bValidateShaderEarly)
			{
				CheckValidity( lang );
			}

			if (loglevel>=2)
			{
				char tempname[128];
				//int tempindex = -1;
				//int tempcombo = -1;

				//GetLabelIndexCombo( tempname, sizeof(tempname), &tempindex, &tempcombo );
				//printf("\ncompile: - [ %s/%d/%d ] on GL name %d ", tempname, tempindex, tempcombo, glslDesc->m_object.glsl );
				

				GetComboIndexNameString( tempname, sizeof(tempname) );
				printf("\ncompile: %s on GL name %d ", tempname, glslDesc->m_object.glsl );
			}
		}
		break;
	}

	if (bTimeShaderCompiles)
	{
		shaderCompileTimer.End();
		gShaderCompileTime += shaderCompileTimer.GetDuration();
		gShaderCompileCount++;
	}
}

#if GLMDEBUG

	bool CGLMProgram::PollForChanges( void )
	{
		bool result = false;
		if (m_editable)
		{
			result = m_editable->PollForChanges();
		}
		return result;
	}

	void	CGLMProgram::ReloadStringFromEditable( void )
	{
		uint	dataSize=0;
		char	*data=NULL;
		
		m_editable->GetCurrentText( &data, &dataSize );
		
		char *buf = (char *)malloc( dataSize+1 );	// we will NULL terminate it, since the mirror copy might not be
		memcpy( buf, data, dataSize );
		buf[dataSize] = 0;
		
		SetProgramText( buf );
		
		free( buf );
	}

	bool	CGLMProgram::SyncWithEditable( void )
	{
		bool result = false;
		
		if (m_editable->PollForChanges())
		{
			ReloadStringFromEditable();

			CompileActiveSources();
			
			// invalidate shader pair cache entries using this shader..
			m_ctx->m_pairCache->PurgePairsWithShader( this );
			
			result = true;	// result true means "it changed"
		}
		return result;
	}
	
#endif


// attributes which are general to both stages
//	VP and FP:
//	
//	0x88A0         PROGRAM_INSTRUCTIONS_ARB                         VP  FP
//	0x88A1         MAX_PROGRAM_INSTRUCTIONS_ARB                     VP  FP
//	0x88A2         PROGRAM_NATIVE_INSTRUCTIONS_ARB                  VP  FP
//	0x88A3         MAX_PROGRAM_NATIVE_INSTRUCTIONS_ARB              VP  FP
//	
//	0x88A4         PROGRAM_TEMPORARIES_ARB                          VP  FP
//	0x88A5         MAX_PROGRAM_TEMPORARIES_ARB                      VP  FP
//	0x88A6         PROGRAM_NATIVE_TEMPORARIES_ARB                   VP  FP
//	0x88A7         MAX_PROGRAM_NATIVE_TEMPORARIES_ARB               VP  FP
//	
//	0x88A8         PROGRAM_PARAMETERS_ARB                           VP  FP
//	0x88A9         MAX_PROGRAM_PARAMETERS_ARB                       VP  FP
//	0x88AA         PROGRAM_NATIVE_PARAMETERS_ARB                    VP  FP
//	0x88AB         MAX_PROGRAM_NATIVE_PARAMETERS_ARB                VP  FP
//	
//	0x88AC         PROGRAM_ATTRIBS_ARB                              VP  FP
//	0x88AD         MAX_PROGRAM_ATTRIBS_ARB                          VP  FP
//	0x88AE         PROGRAM_NATIVE_ATTRIBS_ARB                       VP  FP
//	0x88AF         MAX_PROGRAM_NATIVE_ATTRIBS_ARB                   VP  FP
//	
//	0x88B4         MAX_PROGRAM_LOCAL_PARAMETERS_ARB                 VP  FP
//	0x88B5         MAX_PROGRAM_ENV_PARAMETERS_ARB                   VP  FP
//	0x88B6         PROGRAM_UNDER_NATIVE_LIMITS_ARB                  VP  FP
//
//	VP only:
//	
//	0x88B0         PROGRAM_ADDRESS_REGISTERS_ARB                    VP
//	0x88B1         MAX_PROGRAM_ADDRESS_REGISTERS_ARB                VP
//	0x88B2         PROGRAM_NATIVE_ADDRESS_REGISTERS_ARB             VP
//	0x88B3         MAX_PROGRAM_NATIVE_ADDRESS_REGISTERS_ARB         VP
//	
//	FP only:
//	
//	0x8805         PROGRAM_ALU_INSTRUCTIONS_ARB                         FP
//	0x880B         MAX_PROGRAM_ALU_INSTRUCTIONS_ARB                     FP
//	0x8808         PROGRAM_NATIVE_ALU_INSTRUCTIONS_ARB                  FP
//	0x880E         MAX_PROGRAM_NATIVE_ALU_INSTRUCTIONS_ARB              FP

//	0x8806         PROGRAM_TEX_INSTRUCTIONS_ARB                         FP
//	0x880C         MAX_PROGRAM_TEX_INSTRUCTIONS_ARB                     FP
//	0x8809         PROGRAM_NATIVE_TEX_INSTRUCTIONS_ARB                  FP
//	0x880F         MAX_PROGRAM_NATIVE_TEX_INSTRUCTIONS_ARB              FP

//	0x8807         PROGRAM_TEX_INDIRECTIONS_ARB                         FP
//	0x880D         MAX_PROGRAM_TEX_INDIRECTIONS_ARB                     FP
//	0x880A         PROGRAM_NATIVE_TEX_INDIRECTIONS_ARB                  FP
//	0x8810         MAX_PROGRAM_NATIVE_TEX_INDIRECTIONS_ARB              FP

struct GLMShaderLimitDesc
{
	GLenum	m_valueEnum;
	GLenum	m_limitEnum;
	const char	*m_debugName;
	char	m_flags;
	// m_flags - 0x01 for VP, 0x02 for FP, or set both if applicable to both
};

// macro to help make the table of what to check
#ifndef	LMD
#define	LMD( val, flags )	{ GL_PROGRAM_##val##_ARB, GL_MAX_PROGRAM_##val##_ARB, #val, flags }
#else
#error you need to use a different name for this macro.
#endif

GLMShaderLimitDesc	g_glmShaderLimitDescs[] = 
{
	// VP and FP..
	LMD( INSTRUCTIONS,				3 ),
	LMD( NATIVE_INSTRUCTIONS,		3 ),
	LMD( NATIVE_TEMPORARIES,		3 ),
	LMD( PARAMETERS,				3 ),
	LMD( NATIVE_PARAMETERS,			3 ),
	LMD( ATTRIBS,					3 ),
	LMD( NATIVE_ATTRIBS,			3 ),

	// VP only..
	LMD( ADDRESS_REGISTERS,			1 ),
	LMD( NATIVE_ADDRESS_REGISTERS,	1 ),

	// FP only..
	LMD( ALU_INSTRUCTIONS,			2 ),
	LMD( NATIVE_ALU_INSTRUCTIONS,	2 ),
	LMD( TEX_INSTRUCTIONS,			2 ),
	LMD( NATIVE_TEX_INSTRUCTIONS,	2 ),
	LMD( TEX_INDIRECTIONS,			2 ),
	LMD( NATIVE_TEX_INDIRECTIONS,	2 ),
	
	{ 0, 0, NULL, 0 }
};

#undef LMD

bool CGLMProgram::CheckValidity( EGLMProgramLang lang )
{
	static char *targnames[] = { "vertex", "fragment" };

	bool bTimeShaderCompiles = (CommandLine()->FindParm( "-gl_time_shader_compiles" ) != 0);
	// If using "-gl_time_shader_compiles", keeps track of total cycle count spent on shader compiles.
	CFastTimer shaderCompileTimer;
	if (bTimeShaderCompiles)
	{
		shaderCompileTimer.Start();
	}

	bool bValid = false;

	switch(lang)
	{
		case kGLMARB:
		{
			GLMShaderDesc *arbDesc;
			arbDesc = &m_descs[ kGLMARB ];
			
			GLenum arbTarget = GLMProgTypeToARBEnum( m_type );

			Assert( arbDesc->m_compiled );
			
			arbDesc->m_valid = true;	// assume success til we see otherwise

			// assume program is bound.  is there anything wrong with it ?

			GLint isNative=0;
			gGL->glGetProgramivARB( arbTarget, GL_PROGRAM_UNDER_NATIVE_LIMITS_ARB, &isNative );
			
			// If the program is over the hardware's limits, print out some information
			if (isNative!=1)
			{
				arbDesc->m_valid = false;
				
				// check everything we can check
				char checkmask = (1<<m_type);	// 1 for VP, 2 for FP
				
				for( GLMShaderLimitDesc *desc = g_glmShaderLimitDescs; desc->m_valueEnum !=0; desc++ )
				{
					if ( desc->m_flags & checkmask )
					{
						// test it
						GLint value = 0;
						GLint limit = 0;
						gGL->glGetProgramivARB(arbTarget, desc->m_valueEnum, &value);
						
						gGL->glGetProgramivARB(arbTarget, desc->m_limitEnum, &limit);
						
						if (value > limit)
						{
							GLMPRINTF(("-D- Invalid %s program: program has %d %s; limit is %d", targnames[ m_type ], value, desc->m_debugName, limit ));
						}
					}
				}
			}

			// syntax error check
			GLint errorLine;
			gGL->glGetIntegerv( GL_PROGRAM_ERROR_POSITION_ARB, &errorLine );

			if ( errorLine!=-1 )
			{
				const GLubyte* errorString = gGL->glGetString(GL_PROGRAM_ERROR_STRING_ARB); errorString;
				GLMPRINTF(( "-D- Syntax error in ARB %s program: %s",targnames[ m_type ], errorString ));
				arbDesc->m_valid = false;
			}
			if (!arbDesc->m_valid)
			{
				char *temp = strdup(m_text);
				temp[ arbDesc->m_textOffset + arbDesc->m_textLength ] = 0;
				GLMPRINTF(("-D- ----- ARB compile failed; bad source follows -----" ));
				GLMPRINTTEXT(( temp + arbDesc->m_textOffset, eDebugDump, GLMPRINTTEXT_NUMBEREDLINES ));
				GLMPRINTF(("-D- -----end-----" ));
				free( temp );
			}
			
			bValid = arbDesc->m_valid;
		}
		break;
		
		case kGLMGLSL:
		{
			GLMShaderDesc *glslDesc;
			GLcharARB *logString = NULL;
			glslDesc = &m_descs[ kGLMGLSL ];
			
			GLenum glslStage = GLMProgTypeToGLSLEnum( m_type ); glslStage;

			Assert( glslDesc->m_compiled );
			
			glslDesc->m_valid = true;	// assume success til we see otherwise

			// GLSL error check
			int compiled = 0, length = 0, laux = 0;

			gGL->glGetObjectParameterivARB( (GLhandleARB)glslDesc->m_object.glsl, GL_OBJECT_COMPILE_STATUS_ARB, &compiled);
			gGL->glGetObjectParameterivARB( (GLhandleARB)glslDesc->m_object.glsl, GL_OBJECT_INFO_LOG_LENGTH_ARB, &length);
            if ( length > 0 )
            {
                logString = (GLcharARB *)malloc(length * sizeof(GLcharARB));
                gGL->glGetInfoLogARB((GLhandleARB)glslDesc->m_object.glsl, length, &laux, logString);	
			}
			// we may not be able to check "native limits" stuff until link time. meh

			if (!compiled)
			{
				glslDesc->m_valid = false;
			}
			
			if (!glslDesc->m_valid)
			{
				GLMPRINTF(("-D- ----- GLSL compile failed: \n %s \n",logString ));
#if !GLM_FREE_SHADER_TEXT
				char *temp = strdup(m_text);
				temp[ glslDesc->m_textOffset + glslDesc->m_textLength ] = 0;
				GLMPRINTTEXT(( temp + glslDesc->m_textOffset, eDebugDump, GLMPRINTTEXT_NUMBEREDLINES ));
				free( temp );
#endif
				GLMPRINTF(("-D- -----end-----" ));
			}
			
            if ( logString )
                free( logString );

			bValid = glslDesc->m_valid;
		}
		break;
	}

	if ( !bValid )
	{
		GLMDebugPrintf( "Compile of \"%s\" Failed:\n%s\n", m_shaderName, m_text ? m_text : "" );
	}
	AssertOnce( bValid );

	if (bTimeShaderCompiles)
	{
		shaderCompileTimer.End();
		gShaderCompileQueryTime += shaderCompileTimer.GetDuration();
	}

	return bValid;
}

void	CGLMProgram::LogSlow( EGLMProgramLang lang )
{
	// find the desc, see if it's marked
	GLMShaderDesc *desc = &m_descs[ lang ];

	if (!desc->m_slowMark)
	{
#if !GLM_FREE_SHADER_TEXT
		// log it
		printf(	"\n-------------- Slow %s ( CGLMProgram @ %p, lang %s, name %d ) : \n%s \n",
				m_type==kGLMVertexProgram ? "VS" : "FS",
				this,
				lang==kGLMGLSL ? "GLSL" : "ARB",
				(int)(lang==kGLMGLSL ? (int)desc->m_object.glsl : (int)desc->m_object.arb),
				m_text
		);
#endif
	}
	else	// complain on a decreasing basis (powers of two)
	{
		if ( (desc->m_slowMark & (desc->m_slowMark-1)) == 0 )
		{
			// short blurb
			printf(	"\n               Slow %s ( CGLMProgram @ %p, lang %s, name %d ) (%d times)",
					m_type==kGLMVertexProgram ? "VS" : "FS",
					this,
					lang==kGLMGLSL ? "GLSL" : "ARB",
					(int)(lang==kGLMGLSL ? (int)desc->m_object.glsl : (int)desc->m_object.arb),
					desc->m_slowMark+1
			);
		}
	}

	// mark it
	desc->m_slowMark++;
		

}

void	CGLMProgram::GetLabelIndexCombo		( char *labelOut, int labelOutMaxChars, int *indexOut, int *comboOut )
{
	// find the label string
	// example:
	// trans#2871 label:vs-file vertexlit_and_unlit_generic_vs20 vs-index 294912 vs-combo 1234
	// Done in SetProgramText
	
	*labelOut = 0;
	*indexOut = -1;

	if ((strlen( m_labelName ) != 0))
	{
		Q_strncpy( labelOut, m_labelName, labelOutMaxChars );
		*indexOut = m_labelIndex;
		*comboOut = m_labelCombo;
	}
}

void	CGLMProgram::GetComboIndexNameString	( char *stringOut, int stringOutMaxChars )		// mmmmmmmm-nnnnnnnn-filename
{
	// find the label string
	// example:
	// trans#2871 label:vs-file vertexlit_and_unlit_generic_vs20 vs-index 294912 vs-combo 1234
	// Done in SetProgramText
	
	*stringOut = 0;

	int len = strlen( m_labelName );
		
	if ( (len+20) < stringOutMaxChars )
	{
		// output formatted version
		sprintf( stringOut, "%08X-%08X-%s", m_labelCombo, m_labelIndex, m_labelName );
	}
}

//===============================================================================


CGLMShaderPair::CGLMShaderPair( GLMContext *ctx  )
{
	m_ctx = ctx;
	m_vertexProg = m_fragmentProg = NULL;

	m_program = gGL->glCreateProgramObjectARB();

	m_locVertexParams = -1;
	m_locVertexBoneParams = -1;
	m_locVertexScreenParams = -1;
	m_nScreenWidthHeight = 0xFFFFFFFF;
	m_locVertexInteger0 = -1;	// "i0"
	memset( m_locVertexBool, 0xFF, sizeof( m_locVertexBool ) );
	memset( m_locFragmentBool, 0xFF, sizeof( m_locFragmentBool ) );
	m_bHasBoolOrIntUniforms = false;
	
	m_locFragmentParams = -1;
	
	m_locFragmentFakeSRGBEnable = -1;
	m_fakeSRGBEnableValue = -1.0f;
	
	memset( m_locSamplers, 0xFF, sizeof( m_locSamplers ) );
	
	m_valid = false;
	m_bCheckLinkStatus = false;
	m_revision = 0;				// bumps to 1 once linked
}

CGLMShaderPair::~CGLMShaderPair( )
{
	if (m_program)
	{
		gGL->glDeleteObjectARB( (GLhandleARB)m_program );
		m_program = 0;
	}
}

bool CGLMShaderPair::ValidateProgramPair()
{
	if ( m_vertexProg && m_vertexProg->m_descs[kGLMGLSL].m_textPresent && !m_vertexProg->m_descs[kGLMGLSL].m_valid )
	{
		m_vertexProg->CheckValidity( kGLMGLSL );
	}
	if (m_fragmentProg && m_fragmentProg->m_descs[kGLMGLSL].m_textPresent && !m_fragmentProg->m_descs[kGLMGLSL].m_valid)
	{
		m_fragmentProg->CheckValidity( kGLMGLSL );
	}
	
	if ( !m_valid && m_bCheckLinkStatus )
	{
		bool bTimeShaderCompiles = (CommandLine()->FindParm( "-gl_time_shader_compiles" ) != 0);
		// If using "-gl_time_shader_compiles", keeps track of total cycle count spent on shader compiles.
		CFastTimer shaderCompileTimer;
		if (bTimeShaderCompiles)
		{
			shaderCompileTimer.Start();
		}

		// check for success
		GLint result = 0;
		gGL->glGetObjectParameterivARB( m_program, GL_OBJECT_LINK_STATUS_ARB, &result );	// want GL_TRUE
		m_bCheckLinkStatus = false;

		if (result == GL_TRUE)
		{
			// success

			m_valid = true;
			m_revision++;
		}
		else
		{
			GLint length = 0;
			GLint laux = 0;

			// do some digging
			gGL->glGetObjectParameterivARB( m_program, GL_OBJECT_INFO_LOG_LENGTH_ARB, &length );

			GLcharARB *logString = (GLcharARB *)malloc( length * sizeof(GLcharARB) );
			gGL->glGetInfoLogARB( m_program, length, &laux, logString );

			GLMPRINTF( ("-D- ----- GLSL link failed: \n %s ", logString) );
#if !GLM_FREE_SHADER_TEXT
			char *vtemp = strdup( m_vertexProg->m_text );
			vtemp[m_vertexProg->m_descs[kGLMGLSL].m_textOffset + m_vertexProg->m_descs[kGLMGLSL].m_textLength] = 0;

			char *ftemp = strdup( m_fragmentProg->m_text );
			ftemp[m_fragmentProg->m_descs[kGLMGLSL].m_textOffset + m_fragmentProg->m_descs[kGLMGLSL].m_textLength] = 0;

			GLMPRINTF( ("-D- ----- GLSL vertex program selected: %08x (handle %08x)", m_vertexProg, m_vertexProg->m_descs[kGLMGLSL].m_object.glsl) );
			GLMPRINTTEXT( (vtemp + m_vertexProg->m_descs[kGLMGLSL].m_textOffset, eDebugDump, GLMPRINTTEXT_NUMBEREDLINES) );

			GLMPRINTF( ("-D- ----- GLSL fragment program selected: %08x (handle %08x)", m_fragmentProg, m_fragmentProg->m_descs[kGLMGLSL].m_object.glsl) );
			GLMPRINTTEXT( (ftemp + m_fragmentProg->m_descs[kGLMGLSL].m_textOffset, eDebugDump, GLMPRINTTEXT_NUMBEREDLINES) );

			free( ftemp );
			free( vtemp );
#endif
			free( logString );

			GLMPRINTF( ("-D- -----end-----") );
		}

		if (m_valid)
		{
			gGL->glUseProgram( m_program );

			m_ctx->NewLinkedProgram();

			m_locVertexParams = gGL->glGetUniformLocationARB( m_program, "vc" );
			m_locVertexBoneParams = gGL->glGetUniformLocationARB( m_program, "vcbones" );
			m_locVertexScreenParams = gGL->glGetUniformLocationARB( m_program, "vcscreen" );
			m_nScreenWidthHeight = 0xFFFFFFFF;

			m_locVertexInteger0 = gGL->glGetUniformLocationARB( m_program, "i0" );

			m_bHasBoolOrIntUniforms = false;
			if (m_locVertexInteger0 >= 0)
				m_bHasBoolOrIntUniforms = true;

			for (uint i = 0; i < cMaxVertexShaderBoolUniforms; i++)
			{
				char buf[256];
				V_snprintf( buf, sizeof(buf), "b%d", i );
				m_locVertexBool[i] = gGL->glGetUniformLocationARB( m_program, buf );
				if (m_locVertexBool[i] != -1)
					m_bHasBoolOrIntUniforms = true;
			}

			for (uint i = 0; i < cMaxFragmentShaderBoolUniforms; i++)
			{
				char buf[256];
				V_snprintf( buf, sizeof(buf), "fb%d", i );
				m_locFragmentBool[i] = gGL->glGetUniformLocationARB( m_program, buf );
				if (m_locFragmentBool[i] != -1)
					m_bHasBoolOrIntUniforms = true;
			}

			m_locFragmentParams = gGL->glGetUniformLocationARB( m_program, "pc" );

			for (uint i = 0; i < kGLMNumProgramTypes; i++)
			{
				m_NumUniformBufferParams[i] = 0;

				if (i == kGLMVertexProgram)
				{
					if (m_locVertexParams < 0)
						continue;
				}
				else if (m_locFragmentParams < 0)
					continue;

				const uint nNum = (i == kGLMVertexProgram) ? m_vertexProg->m_descs[kGLMGLSL].m_highWater : m_fragmentProg->m_descs[kGLMGLSL].m_highWater;

				uint j;
				for (j = 0; j < nNum; j++)
				{
					char buf[256];
					V_snprintf( buf, sizeof(buf), "%cc[%i]", "vp"[i], j );
					// Grab the handle of each array element, so we can more efficiently update array elements in the middle.
					int l = m_UniformBufferParams[i][j] = gGL->glGetUniformLocationARB( m_program, buf );
					if (l < 0)
						break;
				}

				m_NumUniformBufferParams[i] = j;
			}

			m_locFragmentFakeSRGBEnable = gGL->glGetUniformLocationARB( m_program, "flSRGBWrite" );
			m_fakeSRGBEnableValue = -1.0f;

			for (int sampler = 0; sampler < 16; sampler++)
			{
				char tmp[16];
				sprintf( tmp, "sampler%d", sampler );	// sampler0 .. sampler1.. etc

				GLint nLoc = gGL->glGetUniformLocationARB( m_program, tmp );
				m_locSamplers[sampler] = nLoc;
				if (nLoc >= 0)
				{
					gGL->glUniform1iARB( nLoc, sampler );
				}
			}
		}
		else
		{
			m_locVertexParams = -1;
			m_locVertexBoneParams = -1;
			m_locVertexScreenParams = -1;
			m_nScreenWidthHeight = 0xFFFFFFFF;

			m_locVertexInteger0 = -1;
			memset( m_locVertexBool, 0xFF, sizeof(m_locVertexBool) );
			memset( m_locFragmentBool, 0xFF, sizeof(m_locFragmentBool) );
			m_bHasBoolOrIntUniforms = false;

			m_locFragmentParams = -1;
			m_locFragmentFakeSRGBEnable = -1;
			m_fakeSRGBEnableValue = -999;

			memset( m_locSamplers, 0xFF, sizeof(m_locSamplers) );

			m_revision = 0;
		}

		if (bTimeShaderCompiles)
		{
			shaderCompileTimer.End();
			gShaderLinkQueryTime += shaderCompileTimer.GetDuration();
		}
	}
	
	return m_valid;
}

// glUseProgram() will be called as a side effect!
bool CGLMShaderPair::SetProgramPair( CGLMProgram *vp, CGLMProgram *fp )
{
	bool bTimeShaderCompiles = (CommandLine()->FindParm( "-gl_time_shader_compiles" ) != 0);
	// If using "-gl_time_shader_compiles", keeps track of total cycle count spent on shader compiles.
	CFastTimer shaderCompileTimer;
	if (bTimeShaderCompiles)
	{
		shaderCompileTimer.Start();
	}
	
	m_valid	= false;			// assume failure
	
	// No need to check that vp and fp are valid at this point (ie shader compile succeed)
	// It is permissible to attach a shader object to a program before source code has been loaded
	// into the shader object or before the shader object has been compiled. The program won't 
	// link if one or more of the shader objects has not been successfully compiled.
	// (Defer querying the compile and link status to take advantage of GLSL shaders
	// building in parallels)
	bool vpgood = (vp != NULL);
	bool fpgood = (fp != NULL);
	
	if ( !fpgood )
	{
		// fragment side allowed to be "null".
		fp = m_ctx->m_pNullFragmentProgram;
	}

	if ( vpgood && fpgood )
	{
		if ( vp->m_nCentroidMask != fp->m_nCentroidMask )
		{
			Warning( "CGLMShaderPair::SetProgramPair: Centroid masks differ at link time of vertex shader %s and pixel shader %s!\n", 
				vp->m_shaderName, fp->m_shaderName );
		}

		// attempt link. but first, detach any previously attached programs
		if (m_vertexProg)
		{
			gGL->glDetachObjectARB(m_program, m_vertexProg->m_descs[kGLMGLSL].m_object.glsl);
			m_vertexProg = NULL;			
		}
		
		if (m_fragmentProg)
		{
			gGL->glDetachObjectARB(m_program, m_fragmentProg->m_descs[kGLMGLSL].m_object.glsl);
			m_fragmentProg = NULL;			
		}
		
		// now attach
		
		gGL->glAttachObjectARB( m_program, vp->m_descs[kGLMGLSL].m_object.glsl );
		m_vertexProg = vp;

		gGL->glAttachObjectARB( m_program, fp->m_descs[kGLMGLSL].m_object.glsl );
		m_fragmentProg = fp;
	
		// force the locations for input attributes v0-vN to be at locations 0-N
		// use the vertex attrib map to know which slots are live or not... oy!  we don't have that map yet... but it's OK.
		// fallback - just force v0-v15 to land in locations 0-15 as a standard.
		
		for( int i = 0; i < 16; i++ )
		{
			char tmp[16];
			sprintf(tmp, "v%d", i);	// v0 v1 v2 ... et al
				
			gGL->glBindAttribLocationARB( m_program, i, tmp );
		}
#if !GLM_FREE_SHADER_TEXT
		if (CommandLine()->CheckParm("-dumpallshaders"))
		{
			// Dump all shaders, for debugging.
			FILE* pFile = fopen("shaderdump.txt", "a+");
			if (pFile)
			{
				fprintf(pFile, "--------------VP:%s\n%s\n", vp->m_shaderName, vp->m_text);
				fprintf(pFile, "--------------FP:%s\n%s\n", fp->m_shaderName, fp->m_text);
				fclose(pFile);
			}
		}
#endif
			
		// now link
		gGL->glLinkProgramARB( m_program );
		m_bCheckLinkStatus = true;
	}
	else
	{
		// fail
		Assert(!"Can't link these programs");
	}

	// Check shader validity at creation time.  This will cause the driver to not be able to
	// multi-thread/defer shader compiles, but it is useful for getting error messages on the
	// shader when it is compiled
	bool bValidateShaderEarly = (CommandLine()->FindParm( "-gl_validate_shader_early" ) != 0);
	if (bValidateShaderEarly)
	{
		ValidateProgramPair();
	}

	if (bTimeShaderCompiles)
	{
		shaderCompileTimer.End();
		gShaderLinkTime += shaderCompileTimer.GetDuration();
		gShaderLinkCount++;
	}

	return m_valid;
}


bool	CGLMShaderPair::RefreshProgramPair		( void )
{
	// re-link and re-query the uniforms.
	
	// since SetProgramPair knows how to detach previously attached shader objects, just pass the same ones in again.
	CGLMProgram	*vp = m_vertexProg;
	CGLMProgram	*fp = m_fragmentProg;
	
	bool vpgood = (vp!=NULL) && (vp->m_descs[ kGLMGLSL ].m_valid);
	bool fpgood = (fp!=NULL) && (fp->m_descs[ kGLMGLSL ].m_valid);

	if (vpgood && fpgood)
	{
		SetProgramPair( vp, fp );
	}
	else
	{
		DebuggerBreak();
		return false;
	}
	
	return false;
}


//===============================================================================

CGLMShaderPairCache::CGLMShaderPairCache( GLMContext *ctx  )
{
	m_ctx = ctx;
	
	m_mark = 1;
	
	m_rowsLg2 = gl_shaderpair_cacherows_lg2.GetInt();
	if (m_rowsLg2 < 10)
			m_rowsLg2 = 10;
	m_rows = 1<<m_rowsLg2;
	m_rowsMask = m_rows - 1;

	m_waysLg2 = gl_shaderpair_cacheways_lg2.GetInt();
	if (m_waysLg2 < 5)
		m_waysLg2 = 5;
	m_ways = 1<<m_waysLg2;

	m_entryCount = m_rows * m_ways;
	
	uint entryTableSize = m_rows * m_ways * sizeof(CGLMPairCacheEntry);
	m_entries = (CGLMPairCacheEntry*)malloc( entryTableSize );				// array[ m_rows ][ m_ways ]
	memset( m_entries, 0, entryTableSize );
	
	uint evictTableSize = m_rows * sizeof(uint);
	m_evictions = (uint*)malloc( evictTableSize );
	memset (m_evictions, 0, evictTableSize);

#if GL_SHADER_PAIR_CACHE_STATS
	// hit counter table is same size
	m_hits = (uint*)malloc( evictTableSize );
	memset (m_hits, 0, evictTableSize);
#endif
}

CGLMShaderPairCache::~CGLMShaderPairCache( )
{
	if (gl_shaderpair_cachelog.GetInt())
	{
		DumpStats();
	}

	// free all the built pairs
	// free the entry table
	bool purgeResult = this->Purge();
	(void)purgeResult;
	Assert( !purgeResult );
	
	if (m_entries)
	{
		free( m_entries );
		m_entries = NULL;
	}

	if (m_evictions)
	{
		free( m_evictions );
		m_evictions = NULL;
	}

#if GL_SHADER_PAIR_CACHE_STATS
	if (m_hits)
	{
		free( m_hits );
		m_hits = NULL;
	}
#endif
}

// Set this convar internally to build or add to the shader pair cache file (link hints)
// We really only expect this to work on POSIX
static ConVar glm_cacheprograms( "glm_cacheprograms", "0", FCVAR_DEVELOPMENTONLY );

#define PROGRAM_CACHE_FILE "program_cache.cfg"

static void WriteToProgramCache( CGLMShaderPair *pair )
{
	KeyValues *pProgramCache = new KeyValues( "programcache" );
	pProgramCache->LoadFromFile( g_pFullFileSystem, PROGRAM_CACHE_FILE, "MOD" );

	if ( !pProgramCache )
	{
		Warning( "Could not write to program cache file!\n" );
		return;
	}

	// extract values of interest which represent a pair of shaders
	
	char	vprogramName[128];
	int		vprogramStaticIndex = -1;
	int		vprogramDynamicIndex = -1;
	pair->m_vertexProg->GetLabelIndexCombo( vprogramName, sizeof(vprogramName), &vprogramStaticIndex, &vprogramDynamicIndex );

	
	char	pprogramName[128];
	int		pprogramStaticIndex = -1;
	int		pprogramDynamicIndex = -1;
	pair->m_fragmentProg->GetLabelIndexCombo( pprogramName, sizeof(pprogramName), &pprogramStaticIndex, &pprogramDynamicIndex );

	// make up a key - this thing is really a list of tuples, so need not be keyed by anything particular
	KeyValues *pProgramKey = pProgramCache->CreateNewKey();
	Assert( pProgramKey );

	pProgramKey->SetString	( "vs", vprogramName );
	pProgramKey->SetString	( "ps", pprogramName );

	pProgramKey->SetInt		( "vs_static", vprogramStaticIndex );
	pProgramKey->SetInt		( "ps_static", pprogramStaticIndex );

	pProgramKey->SetInt		( "vs_dynamic", vprogramDynamicIndex );
	pProgramKey->SetInt		( "ps_dynamic", pprogramDynamicIndex );

	pProgramCache->SaveToFile( g_pFullFileSystem, PROGRAM_CACHE_FILE, "MOD" );
	pProgramCache->deleteThis();
}

// Calls glUseProgram() as a side effect
CGLMShaderPair	*CGLMShaderPairCache::SelectShaderPairInternal( CGLMProgram *vp, CGLMProgram *fp, uint extraKeyBits, int rowIndex )
{
	CGLMShaderPair	*result = NULL;
		
#if GLMDEBUG
	int loglevel = gl_shaderpair_cachelog.GetInt();
#else
	const int loglevel = 0;
#endif

	char vtempname[128];
	int vtempindex = -1; vtempindex;
	int vtempcombo = -1; vtempcombo;

	char ptempname[128];
	int ptempindex = -1; ptempindex;
	int ptempcombo = -1; ptempcombo;
	
	CGLMPairCacheEntry *row = HashRowPtr( rowIndex );
	
	// Re-probe to find the oldest and first unoccupied entry (this func should be very rarely called if the cache is properly configured so re-scanning shouldn't matter).
	int hitway, emptyway, oldestway;
	HashRowProbe( row, vp, fp, extraKeyBits, hitway, emptyway, oldestway );
	Assert( hitway == -1 );

	// we missed.  if there is no empty way, then somebody's getting evicted.
	int destway = -1;
		
	if (emptyway>=0)
	{			
		destway = emptyway;

		if (loglevel >= 2)  // misses logged at level 3 and higher
		{
			printf("\nSSP: miss - row %05d - ", rowIndex );
		}
	}
	else
	{
		// evict the oldest way
		Assert( oldestway >= 0);	// better not come back negative
			
		CGLMPairCacheEntry *evict = row + oldestway;
			
		Assert( evict->m_pair != NULL );
		Assert( evict->m_pair != m_ctx->m_pBoundPair );	// just check
			
		///////////////////////FIXME may need to do a shoot-down if the pair being evicted is currently active in the context
			
		m_evictions[ rowIndex ]++;

		// log eviction if desired
		if (loglevel >= 2)  // misses logged at level 3 and higher
		{
			//evict->m_vertexProg->GetLabelIndexCombo( vtempname, sizeof(vtempname), &vtempindex, &vtempcombo );
			//evict->m_fragmentProg->GetLabelIndexCombo( ptempname, sizeof(ptempname), &ptempindex, &ptempcombo );
			//printf("\nSSP: miss - row %05d - [ %s/%d/%d %s/%d/%d ]'s %d'th eviction - ", rowIndex, vtempname, vtempindex, vtempcombo, ptempname, ptempindex, ptempcombo, m_evictions[ rowIndex ] );

			evict->m_vertexProg->GetComboIndexNameString( vtempname, sizeof(vtempname) );
			evict->m_fragmentProg->GetComboIndexNameString( ptempname, sizeof(ptempname) );				
			printf("\nSSP: miss - row %05d - [ %s + %s ]'s %d'th eviction - ", rowIndex, vtempname, ptempname, m_evictions[ rowIndex ] );
		}

		delete evict->m_pair;	evict->m_pair = NULL;
		memset( evict, 0, sizeof(*evict) );
			
		destway = oldestway;
	}

	// make the new entry
	CGLMPairCacheEntry *newentry = row + destway;
		
	newentry->m_lastMark = m_mark;
	newentry->m_vertexProg = vp;
	newentry->m_fragmentProg = fp;
	newentry->m_extraKeyBits = extraKeyBits;
	newentry->m_pair = new CGLMShaderPair( m_ctx );
	Assert( newentry->m_pair );
	newentry->m_pair->SetProgramPair( vp, fp );

	if (loglevel >= 2)  // say a little bit more
	{
		//newentry->m_vertexProg->GetLabelIndexCombo( vtempname, sizeof(vtempname), &vtempindex, &vtempcombo );
		//newentry->m_fragmentProg->GetLabelIndexCombo( ptempname, sizeof(ptempname), &ptempindex, &ptempcombo );			
		//printf("new [ %s/%d/%d %s/%d/%d ]", vtempname, vtempindex, vtempcombo, ptempname, ptempindex, ptempcombo );

		newentry->m_vertexProg->GetComboIndexNameString( vtempname, sizeof(vtempname) );
		newentry->m_fragmentProg->GetComboIndexNameString( ptempname, sizeof(ptempname) );				
		printf("new [ %s + %s ]", vtempname, ptempname );
	}

	m_mark = m_mark+1;
	if (!m_mark)		// somewhat unlikely this will ever be reached.. but we need to avoid zero as a mark value
	{
		m_mark = 1;
	}

	result = newentry->m_pair;

	if (glm_cacheprograms.GetInt())
	{
		WriteToProgramCache( newentry->m_pair );
	}
		
	return result;
}

void	CGLMShaderPairCache::QueryShaderPair( int index, GLMShaderPairInfo *infoOut )
{
	if ( (index<0) || ( static_cast<uint>(index) >= (m_rows*m_ways) ) )
	{
		// no such location
		memset( infoOut, 0, sizeof(*infoOut) );
		
		infoOut->m_status = -1;
	}
	else
	{
		// locate the entry, and see if an active pair is present.
		// if so, extract info and return with m_status=1.
		// if not, exit with m_status = 0.

		CGLMPairCacheEntry *entry = &m_entries[index];
		
		if (entry->m_pair)
		{
			// live
			// extract values of interest for caller

			entry->m_pair->m_vertexProg->GetLabelIndexCombo		( infoOut->m_vsName, sizeof(infoOut->m_vsName), &infoOut->m_vsStaticIndex, &infoOut->m_vsDynamicIndex );
			entry->m_pair->m_fragmentProg->GetLabelIndexCombo	( infoOut->m_psName, sizeof(infoOut->m_psName), &infoOut->m_psStaticIndex, &infoOut->m_psDynamicIndex );

			infoOut->m_status = 1;
		}
		else
		{
			// not
			memset( infoOut, 0, sizeof(*infoOut) );
			infoOut->m_status = 0;
		}
	}
}

bool CGLMShaderPairCache::PurgePairsWithShader( CGLMProgram *prog )
{
	bool result = false;
	
	// walk all rows*ways
	int limit = m_rows * m_ways;
	for( int i=0; i < limit; i++)
	{
		CGLMPairCacheEntry *entry = &m_entries[i];
		
		if (entry->m_pair)
		{
			//scrub it, if not currently bound, and if the supplied shader matches either stage
			if ( (entry->m_vertexProg==prog) || (entry->m_fragmentProg==prog) )
			{
				// found it, but does it conflict with bound pair ?
				if (entry->m_pair == m_ctx->m_pBoundPair)
				{
					m_ctx->m_pBoundPair = NULL;
					m_ctx->m_bDirtyPrograms = true;
				}
				delete entry->m_pair;
				memset( entry, 0, sizeof(*entry) );
			}
		}
	}
	return result;
}

bool CGLMShaderPairCache::Purge( void )
{
	bool result = false;
	
	// walk all rows*ways
	int limit = m_rows * m_ways;
	for( int i=0; i < limit; i++)
	{
		CGLMPairCacheEntry *entry = &m_entries[i];
		
		if (entry->m_pair)
		{
			//scrub it, unless the pair is the currently bound pair in our parent glm context
			if (entry->m_pair != m_ctx->m_pBoundPair)
			{
				delete entry->m_pair;
				memset( entry, 0, sizeof(*entry) );
			}
			else
			{
				result = true;
			}
		}
	}
	return result;
}
	
void			CGLMShaderPairCache::DumpStats			( void )
{
#if GL_SHADER_PAIR_CACHE_STATS
	printf("\n------------------\npair cache stats");
	int total = 0;
	for( uint row=0; row < m_rows; row++ )
	{
		if ( (m_evictions[row] != 0) || (m_hits[row] != 0) )
		{
			printf("\n row %d : %d evictions, %d hits",row,m_evictions[row], m_hits[row]);
			total += m_evictions[row];
		}
	}
	printf("\n\npair cache evictions: %d\n-----------------------\n",total );
#endif
}
	
	//===============================