code/renderer/tr_shade.c - sourcetech - noire-dev/SourceTech

code/renderer/tr_shade.c
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noire-dev
Update: 2025-12-17 10:42 clean
17 дек 2025, 01:42
17 дек 2025, 01:426071f1a
/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code 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; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code 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 for more details.

You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// tr_shade.c

#include "tr_local.h"

/*

  THIS ENTIRE FILE IS BACK END

  This file deals with applying shaders to surface data in the tess struct.
*/


/*
==================
R_DrawElements
==================
*/
void R_DrawElements( int numIndexes, const glIndex_t *indexes ) {
	qglDrawElements( GL_TRIANGLES, numIndexes, GL_INDEX_TYPE, indexes );
}


/*
=============================================================

SURFACE SHADERS

=============================================================
*/

shaderCommands_t	tess;
static qboolean	setArraysOnce;

/*
=================
R_BindAnimatedImage
=================
*/
void R_BindAnimatedImage( const textureBundle_t *bundle ) {
	int64_t index;
	double	v;

	if ( bundle->isScreenMap && backEnd.viewParms.frameSceneNum == 1 ) {
		GL_BindTexNum( FBO_ScreenTexture() );
		return;
	}

	if ( bundle->numImageAnimations <= 1 ) {
		GL_Bind( bundle->image[0] );
		return;
	}

	// it is necessary to do this messy calc to make sure animations line up
	// exactly with waveforms of the same frequency
	//v = tess.shaderTime * bundle->imageAnimationSpeed * FUNCTABLE_SIZE;
	//index = v;
	//index >>= FUNCTABLE_SIZE2;

	v = tess.shaderTime * bundle->imageAnimationSpeed; // fix for frameloss bug -EC-
	index = v;

	if ( index < 0 ) {
		index = 0;	// may happen with shader time offsets
	}
	index %= bundle->numImageAnimations;

	GL_Bind( bundle->image[ index ] );
}


/*
================
DrawTris

Draws triangle outlines for debugging
================
*/
static void DrawTris( const shaderCommands_t *input ) {

	if ( r_showtris->integer == 1 && backEnd.drawConsole )
		return;

	if ( tess.numIndexes == 0 )
		return;

	GL_ProgramDisable();

	tess.dlightUpdateParams = qtrue;

	GL_ClientState( 0, CLS_NONE );
	qglDisable( GL_TEXTURE_2D );

	if ( tess.dlightPass )
		qglColor4f( 1.0f, 0.33f, 0.2f, 1.0f );
	else
	qglColor4f( 1, 1, 1, 1 );

	GL_State( GLS_POLYMODE_LINE | GLS_DEPTHMASK_TRUE );
	qglDepthRange( 0, 0 );

	qglVertexPointer( 3, GL_FLOAT, sizeof( input->xyz[0] ), input->xyz );

	if ( qglLockArraysEXT ) {
		qglLockArraysEXT( 0, input->numVertexes );
	}

	R_DrawElements( input->numIndexes, input->indexes );

	if ( qglUnlockArraysEXT ) {
		qglUnlockArraysEXT();
	}

	qglEnable( GL_TEXTURE_2D );

	qglDepthRange( 0, 1 );
}

/*
==============
RB_BeginSurface

We must set some things up before beginning any tesselation,
because a surface may be forced to perform a RB_End due
to overflow.
==============
*/
void RB_BeginSurface( shader_t *shader, int fogNum ) {

	shader_t *state;

	if ( !tess.dlightPass && shader->isStaticShader && !shader->remappedShader )
		tess.allowVBO = qtrue;
	else
		tess.allowVBO = qfalse;

	if ( shader->remappedShader ) {
		state = shader->remappedShader;
	} else {
		state = shader;
	}

	if ( tess.fogNum != fogNum || tess.cullType != state->cullType ) {
		tess.dlightUpdateParams = qtrue;
	}

#ifdef USE_TESS_NEEDS_NORMAL
	tess.needsNormal = state->needsNormal || tess.dlightPass;
#endif

#ifdef USE_TESS_NEEDS_ST2
	tess.needsST2 = state->needsST2;
#endif

	tess.numIndexes = 0;
	tess.numVertexes = 0;
	tess.shader = state;
	tess.fogNum = fogNum;

	tess.xstages = state->stages;
	tess.numPasses = state->numUnfoggedPasses;

	tess.shaderTime = backEnd.refdef.floatTime - tess.shader->timeOffset;
	if ( tess.shader->clampTime && tess.shaderTime >= tess.shader->clampTime ) {
		tess.shaderTime = tess.shader->clampTime;
	}
}


/*
===================
DrawMultitextured

output = t0 * t1 or t0 + t1

t0 = most upstream according to spec
t1 = most downstream according to spec
===================
*/
static void DrawMultitextured( const shaderCommands_t *input, int stage ) {
	const shaderStage_t *pStage;

	pStage = tess.xstages[ stage ];

	GL_State( pStage->stateBits );

	if ( !setArraysOnce ) {
		R_ComputeColors( pStage );
		R_ComputeTexCoords( 0, &pStage->bundle[0] );
		R_ComputeTexCoords( 1, &pStage->bundle[1] );
		GL_ClientState( 0, CLS_TEXCOORD_ARRAY | CLS_COLOR_ARRAY );

		qglTexCoordPointer( 2, GL_FLOAT, 0, input->svars.texcoordPtr[0] );
		qglColorPointer( 4, GL_UNSIGNED_BYTE, 0, input->svars.colors[0].rgba );

		GL_ClientState( 1, CLS_TEXCOORD_ARRAY );
		qglTexCoordPointer( 2, GL_FLOAT, 0, input->svars.texcoordPtr[1] );
	}

	//
	// base
	//
	GL_SelectTexture( 0 );
	R_BindAnimatedImage( &pStage->bundle[0] );

	//
	// lightmap/secondary pass
	//
	GL_SelectTexture( 1 );
	qglEnable( GL_TEXTURE_2D );
	R_BindAnimatedImage( &pStage->bundle[1] );
	GL_TexEnv( pStage->mtEnv );

	R_DrawElements( input->numIndexes, input->indexes );

	//
	// disable texturing on TEXTURE1, then select TEXTURE0
	//

	qglDisable( GL_TEXTURE_2D );

	GL_SelectTexture( 0 );
}

/*
===================
RB_FogPass

Blends a fog texture on top of everything else
===================
*/
static void RB_FogPass( void ) {
	const fog_t *fog = tr.world->fogs + tess.fogNum;
	int i;

	for ( i = 0; i < tess.numVertexes; i++ ) {
		tess.svars.colors[i] = fog->colorInt;
	}

	RB_CalcFogTexCoords( ( float * ) tess.svars.texcoords[0] );

	GL_ClientState( 1, CLS_NONE );
	GL_ClientState( 0, CLS_TEXCOORD_ARRAY | CLS_COLOR_ARRAY );

	qglColorPointer( 4, GL_UNSIGNED_BYTE, 0, tess.svars.colors[0].rgba );
	qglTexCoordPointer( 2, GL_FLOAT, 0, tess.svars.texcoords[0] );

	GL_SelectTexture( 0 );
	GL_Bind( tr.fogImage );

	if ( tess.shader->fogPass == FP_EQUAL ) {
		GL_State( GLS_SRCBLEND_SRC_ALPHA | GLS_DSTBLEND_ONE_MINUS_SRC_ALPHA | GLS_DEPTHFUNC_EQUAL );
	} else {
		GL_State( GLS_SRCBLEND_SRC_ALPHA | GLS_DSTBLEND_ONE_MINUS_SRC_ALPHA );
	}

	R_DrawElements( tess.numIndexes, tess.indexes );
}


/*
===============
R_ComputeColors
===============
*/
void R_ComputeColors( const shaderStage_t *pStage )
{
	int		i;

	if ( tess.numVertexes == 0 )
		return;

	//
	// rgbGen
	//
	switch ( pStage->rgbGen )
	{
		case CGEN_IDENTITY:
			Com_Memset( tess.svars.colors, 0xff, tess.numVertexes * 4 );
			break;
		default:
		case CGEN_IDENTITY_LIGHTING:
			Com_Memset( tess.svars.colors, tr.identityLightByte, tess.numVertexes * 4 );
			break;
		case CGEN_LIGHTING_DIFFUSE:
			RB_CalcDiffuseColor( ( unsigned char * ) tess.svars.colors );
			break;
		case CGEN_EXACT_VERTEX:
			Com_Memcpy( tess.svars.colors, tess.vertexColors, tess.numVertexes * sizeof( tess.vertexColors[0] ) );
			break;
		case CGEN_CONST:
			for ( i = 0; i < tess.numVertexes; i++ ) {
				tess.svars.colors[i] = pStage->constantColor;
			}
			break;
		case CGEN_VERTEX:
			if ( tr.identityLight == 1 )
			{
				Com_Memcpy( tess.svars.colors, tess.vertexColors, tess.numVertexes * sizeof( tess.vertexColors[0] ) );
			}
			else
			{
				for ( i = 0; i < tess.numVertexes; i++ )
				{
					tess.svars.colors[i].rgba[0] = tess.vertexColors[i].rgba[0] * tr.identityLight;
					tess.svars.colors[i].rgba[1] = tess.vertexColors[i].rgba[1] * tr.identityLight;
					tess.svars.colors[i].rgba[2] = tess.vertexColors[i].rgba[2] * tr.identityLight;
					tess.svars.colors[i].rgba[3] = tess.vertexColors[i].rgba[3];
				}
			}
			break;
		case CGEN_ONE_MINUS_VERTEX:
			if ( tr.identityLight == 1 )
			{
				for ( i = 0; i < tess.numVertexes; i++ )
				{
					tess.svars.colors[i].rgba[0] = 255 - tess.vertexColors[i].rgba[0];
					tess.svars.colors[i].rgba[1] = 255 - tess.vertexColors[i].rgba[1];
					tess.svars.colors[i].rgba[2] = 255 - tess.vertexColors[i].rgba[2];
				}
			}
			else
			{
				for ( i = 0; i < tess.numVertexes; i++ )
				{
					tess.svars.colors[i].rgba[0] = ( 255 - tess.vertexColors[i].rgba[0] ) * tr.identityLight;
					tess.svars.colors[i].rgba[1] = ( 255 - tess.vertexColors[i].rgba[1] ) * tr.identityLight;
					tess.svars.colors[i].rgba[2] = ( 255 - tess.vertexColors[i].rgba[2] ) * tr.identityLight;
				}
			}
			break;
		case CGEN_FOG:
			{
				const fog_t *fog;

				fog = tr.world->fogs + tess.fogNum;

				for ( i = 0; i < tess.numVertexes; i++ ) {
					tess.svars.colors[i] = fog->colorInt;
				}
			}
			break;
		case CGEN_WAVEFORM:
			RB_CalcWaveColor( &pStage->rgbWave, tess.svars.colors[0].rgba );
			break;
		case CGEN_ENTITY:
			RB_CalcColorFromEntity( tess.svars.colors[0].rgba );
			break;
		case CGEN_ONE_MINUS_ENTITY:
			RB_CalcColorFromOneMinusEntity( tess.svars.colors[0].rgba );
			break;
	}

	//
	// alphaGen
	//
	switch ( pStage->alphaGen )
	{
	case AGEN_SKIP:
		break;
	case AGEN_IDENTITY:
		if ( ( pStage->rgbGen == CGEN_VERTEX && tr.identityLight != 1 ) ||
			 pStage->rgbGen != CGEN_VERTEX ) {
			for ( i = 0; i < tess.numVertexes; i++ ) {
				tess.svars.colors[i].rgba[3] = 255;
			}
		}
		break;
	case AGEN_CONST:
		for ( i = 0; i < tess.numVertexes; i++ ) {
			tess.svars.colors[i].rgba[3] = pStage->constantColor.rgba[3];
		}
		break;
	case AGEN_WAVEFORM:
		RB_CalcWaveAlpha( &pStage->alphaWave, tess.svars.colors[0].rgba );
		break;
	case AGEN_LIGHTING_SPECULAR:
		RB_CalcSpecularAlpha( tess.svars.colors[0].rgba );
		break;
	case AGEN_ENTITY:
		RB_CalcAlphaFromEntity( tess.svars.colors[0].rgba );
		break;
	case AGEN_ONE_MINUS_ENTITY:
		RB_CalcAlphaFromOneMinusEntity( tess.svars.colors[0].rgba );
		break;
	case AGEN_VERTEX:
		for ( i = 0; i < tess.numVertexes; i++ ) {
			tess.svars.colors[i].rgba[3] = tess.vertexColors[i].rgba[3];
		}
		break;
	case AGEN_ONE_MINUS_VERTEX:
		for ( i = 0; i < tess.numVertexes; i++ )
		{
			tess.svars.colors[i].rgba[3] = 255 - tess.vertexColors[i].rgba[3];
		}
		break;
	case AGEN_PORTAL:
		{
			for ( i = 0; i < tess.numVertexes; i++ )
			{
				unsigned char alpha;
				float len;
				vec3_t v;

				VectorSubtract( tess.xyz[i], backEnd.viewParms.or.origin, v );
				len = VectorLength( v ) * tess.shader->portalRangeR;

				if ( len > 1 )
				{
					alpha = 0xff;
				}
				else
				{
					alpha = len * 0xff;
				}

				tess.svars.colors[i].rgba[3] = alpha;
			}
		}
		break;
	}

	//
	// fog adjustment for colors to fade out as fog increases
	//
	if ( tess.fogNum )
	{
		switch ( pStage->adjustColorsForFog )
		{
		case ACFF_MODULATE_RGB:
			RB_CalcModulateColorsByFog( tess.svars.colors[0].rgba );
			break;
		case ACFF_MODULATE_ALPHA:
			RB_CalcModulateAlphasByFog( tess.svars.colors[0].rgba );
			break;
		case ACFF_MODULATE_RGBA:
			RB_CalcModulateRGBAsByFog( tess.svars.colors[0].rgba );
			break;
		case ACFF_NONE:
			break;
		}
	}
}


/*
===============
R_ComputeTexCoords
===============
*/
void R_ComputeTexCoords( const int b, const textureBundle_t *bundle ) {
	int	i;
	int tm;
	vec2_t *src, *dst;

	if ( !tess.numVertexes )
		return;

	src = dst = tess.svars.texcoords[b];

	//
	// generate the texture coordinates
	//
	switch ( bundle->tcGen )
	{
	case TCGEN_IDENTITY:
		src = tess.texCoords00;
		break;
	case TCGEN_TEXTURE:
		src = tess.texCoords[0];
		break;
	case TCGEN_LIGHTMAP:
		src = tess.texCoords[1];
		break;
	case TCGEN_VECTOR:
		for ( i = 0 ; i < tess.numVertexes ; i++ ) {
			dst[i][0] = DotProduct( tess.xyz[i], bundle->tcGenVectors[0] );
			dst[i][1] = DotProduct( tess.xyz[i], bundle->tcGenVectors[1] );
		}
		break;
	case TCGEN_FOG:
		RB_CalcFogTexCoords( ( float * ) dst );
		break;
	case TCGEN_ENVIRONMENT_MAPPED:
		RB_CalcEnvironmentTexCoords( ( float * ) dst );
		break;
	case TCGEN_ENVIRONMENT_MAPPED_FP:
		RB_CalcEnvironmentTexCoordsFP( ( float * ) dst, bundle->isScreenMap );
		break;
	case TCGEN_BAD:
		return;
	}

	//
	// alter texture coordinates
	//
	for ( tm = 0; tm < bundle->numTexMods ; tm++ ) {
		switch ( bundle->texMods[tm].type )
		{
		case TMOD_NONE:
			tm = TR_MAX_TEXMODS; // break out of for loop
			break;

		case TMOD_TURBULENT:
			RB_CalcTurbulentTexCoords( &bundle->texMods[tm].wave, (float *)src, (float *) dst );
			src = dst;
			break;

		case TMOD_ENTITY_TRANSLATE:
			RB_CalcScrollTexCoords( backEnd.currentEntity->e.shaderTexCoord, (float *)src, (float *) dst );
			src = dst;
			break;

		case TMOD_SCROLL:
			RB_CalcScrollTexCoords( bundle->texMods[tm].scroll, (float *)src, (float *) dst );
			src = dst;
			break;

		case TMOD_SCALE:
			RB_CalcScaleTexCoords( bundle->texMods[tm].scale, (float *) src, (float *) dst );
			src = dst;
			break;

		case TMOD_OFFSET:
			for ( i = 0; i < tess.numVertexes; i++ ) {
				dst[i][0] = src[i][0] + bundle->texMods[tm].offset[0];
				dst[i][1] = src[i][1] + bundle->texMods[tm].offset[1];
			}
			src = dst;
			break;

		case TMOD_SCALE_OFFSET:
			for ( i = 0; i < tess.numVertexes; i++ ) {
				dst[i][0] = (src[i][0] * bundle->texMods[tm].scale[0] ) + bundle->texMods[tm].offset[0];
				dst[i][1] = (src[i][1] * bundle->texMods[tm].scale[1] ) + bundle->texMods[tm].offset[1];
			}
			src = dst;
			break;

		case TMOD_OFFSET_SCALE:
			for ( i = 0; i < tess.numVertexes; i++ ) {
				dst[i][0] = (src[i][0] + bundle->texMods[tm].offset[0]) * bundle->texMods[tm].scale[0];
				dst[i][1] = (src[i][1] + bundle->texMods[tm].offset[1]) * bundle->texMods[tm].scale[1];
			}
			src = dst;
			break;

		case TMOD_STRETCH:
			RB_CalcStretchTexCoords( &bundle->texMods[tm].wave, (float *)src, (float *) dst );
			src = dst;
			break;

		case TMOD_TRANSFORM:
			RB_CalcTransformTexCoords( &bundle->texMods[tm], (float *)src, (float *) dst );
			src = dst;
			break;

		case TMOD_ROTATE:
			RB_CalcRotateTexCoords( bundle->texMods[tm].rotateSpeed, (float *) src, (float *) dst );
			src = dst;
			break;

		default:
			ri.Error( ERR_DROP, "ERROR: unknown texmod '%d' in shader '%s'", bundle->texMods[tm].type, tess.shader->name );
			break;
		}
	}

	tess.svars.texcoordPtr[ b ] = src;
}


/*
** RB_IterateStagesGeneric
*/
static void RB_IterateStagesGeneric( const shaderCommands_t *input )
{
	const shaderStage_t *pStage;
	int stage;

	for ( stage = 0; stage < MAX_SHADER_STAGES; stage++ )
	{
		pStage = tess.xstages[ stage ];
		if ( !pStage )
			break;

		//
		// do multitexture
		//
		if ( pStage->mtEnv )
		{
			DrawMultitextured( input, stage );
		}
		else
		{
			if ( !setArraysOnce )
			{
				R_ComputeTexCoords( 0, &pStage->bundle[0] );
				R_ComputeColors( pStage );

				GL_ClientState( 1, CLS_NONE );
				GL_ClientState( 0, CLS_TEXCOORD_ARRAY | CLS_COLOR_ARRAY );

				qglTexCoordPointer( 2, GL_FLOAT, 0, input->svars.texcoordPtr[0] );
				qglColorPointer( 4, GL_UNSIGNED_BYTE, 0, input->svars.colors[0].rgba );
			}

			//
			// set state
			//
			R_BindAnimatedImage( &pStage->bundle[0] );

			GL_State( pStage->stateBits );

			//
			// draw
			//
			R_DrawElements( input->numIndexes, input->indexes );
			if ( pStage->depthFragment )
			{
				GL_State( pStage->stateBits | GLS_DEPTHMASK_TRUE );
				GL_ProgramEnable();
				R_DrawElements( input->numIndexes, input->indexes );
				GL_ProgramDisable();
			}
		}
	}
}


/*
** RB_StageIteratorGeneric
*/
void RB_StageIteratorGeneric( void )
{
	const shaderCommands_t *input;
	shader_t		*shader;

	if ( tess.dlightPass ) {
		ARB_LightingPass();
		return;
	}

	GL_ProgramDisable();

	if ( tess.vboIndex )
	{
		RB_StageIteratorVBO();
		return;
	}

	VBO_UnBind();

	input = &tess;
	shader = input->shader;

	RB_DeformTessGeometry();

	//
	// set face culling appropriately
	//
	GL_Cull( shader->cullType );

	// set polygon offset if necessary
	if ( shader->polygonOffset ) {
		qglEnable( GL_POLYGON_OFFSET_FILL );
		qglPolygonOffset( -1, -2 );
	}

	//
	// if there is only a single pass then we can enable color
	// and texture arrays before we compile, otherwise we need
	// to avoid compiling those arrays since they will change
	// during multipass rendering
	//
	if ( tess.numPasses > 1 )
	{
		setArraysOnce = qfalse;

		GL_ClientState( 1, CLS_NONE );
		GL_ClientState( 0, CLS_NONE );
	}
	else
	{
		// FIXME: we can't do that if going to lighting/fog later?
		setArraysOnce = qtrue;

		GL_ClientState( 0, CLS_COLOR_ARRAY | CLS_TEXCOORD_ARRAY );

		if ( tess.xstages[0] )
		{
			R_ComputeColors( tess.xstages[0] );
			qglColorPointer( 4, GL_UNSIGNED_BYTE, 0, tess.svars.colors[0].rgba );
			R_ComputeTexCoords( 0, &tess.xstages[0]->bundle[0] );
			qglTexCoordPointer( 2, GL_FLOAT, 0, tess.svars.texcoordPtr[0] );
			if ( shader->multitextureEnv )
			{
				GL_ClientState( 1, CLS_TEXCOORD_ARRAY );
				R_ComputeTexCoords( 1, &tess.xstages[0]->bundle[1] );
				qglTexCoordPointer( 2, GL_FLOAT, 0, tess.svars.texcoordPtr[1] );
			}
			else
			{
				GL_ClientState( 1, CLS_NONE );
			}
		}
	}

	qglVertexPointer( 3, GL_FLOAT, sizeof( input->xyz[0] ), input->xyz ); // padded for SIMD

	//
	// lock XYZ
	//
	if ( qglLockArraysEXT )
	{
		qglLockArraysEXT( 0, input->numVertexes );
	}

	//
	// call shader function
	//
	RB_IterateStagesGeneric( input );

	//
	// now do fog
	//
	if ( tess.fogNum && tess.shader->fogPass )
	{
		RB_FogPass();
	}

	//
	// unlock arrays
	//
	if ( qglUnlockArraysEXT )
	{
		qglUnlockArraysEXT();
	}

	GL_ClientState( 1, CLS_NONE );

	//
	// reset polygon offset
	//
	if ( shader->polygonOffset )
	{
		qglDisable( GL_POLYGON_OFFSET_FILL );
	}
}


/*
** RB_EndSurface
*/
void RB_EndSurface( void ) {
	const shaderCommands_t *input;

	input = &tess;

	if ( input->numIndexes == 0 ) {
		VBO_UnBind();
		return;
	}

	if ( input->numIndexes > SHADER_MAX_INDEXES ) {
		ri.Error( ERR_DROP, "RB_EndSurface() - SHADER_MAX_INDEXES hit" );
	}

	if ( input->numVertexes > SHADER_MAX_VERTEXES ) {
		ri.Error( ERR_DROP, "RB_EndSurface() - SHADER_MAX_VERTEXES hit" );
	}

	//
	// call off to shader specific tess end function
	//
	tess.shader->optimalStageIteratorFunc();

	//
	// draw debugging stuff
	//
	if ( !VBO_Active() ) {
		if ( r_showtris->integer ) {
			DrawTris( input );
		}
	}

	// clear shader so we can tell we don't have any unclosed surfaces
	tess.numIndexes = 0;
	tess.numVertexes = 0;
}