tr_shade.c

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		origin0 = dl->transformed[0];
		origin1 = dl->transformed[1];
		origin2 = dl->transformed[2];
#else
		VectorCopy( dl->transformed, origin );
#endif
		radius = dl->radius;
		scale = 1.0f / radius;

		floatColor[0] = dl->color[0] * 255.0f;
		floatColor[1] = dl->color[1] * 255.0f;
		floatColor[2] = dl->color[2] * 255.0f;
#if idppc_altivec
		floatColorVec0 = vec_ld(0, floatColor);
		floatColorVec1 = vec_ld(11, floatColor);
		floatColorVec0 = vec_perm(floatColorVec0,floatColorVec0,floatColorVecPerm);
#endif
		for ( i = 0 ; i < tess.numVertexes ; i++, texCoords += 2, colors += 4 ) {
#if idppc_altivec
			vec_t dist0, dist1, dist2;
#else
			vec3_t	dist;
#endif
			int		clip;

			backEnd.pc.c_dlightVertexes++;

#if idppc_altivec
			//VectorSubtract( origin, tess.xyz[i], dist );
			dist0 = origin0 - tess.xyz[i][0];
			dist1 = origin1 - tess.xyz[i][1];
			dist2 = origin2 - tess.xyz[i][2];
			texCoords0 = 0.5f + dist0 * scale;
			texCoords1 = 0.5f + dist1 * scale;

			clip = 0;
			if ( texCoords0 < 0.0f ) {
				clip |= 1;
			} else if ( texCoords0 > 1.0f ) {
				clip |= 2;
			}
			if ( texCoords1 < 0.0f ) {
				clip |= 4;
			} else if ( texCoords1 > 1.0f ) {
				clip |= 8;
			}
			texCoords[0] = texCoords0;
			texCoords[1] = texCoords1;
			
			// modulate the strength based on the height and color
			if ( dist2 > radius ) {
				clip |= 16;
				modulate = 0.0f;
			} else if ( dist2 < -radius ) {
				clip |= 32;
				modulate = 0.0f;
			} else {
				dist2 = Q_fabs(dist2);
				if ( dist2 < radius * 0.5f ) {
					modulate = 1.0f;
				} else {
					modulate = 2.0f * (radius - dist2) * scale;
				}
			}
			clipBits[i] = clip;

			modulateVec = vec_ld(0,(float *)&modulate);
			modulateVec = vec_perm(modulateVec,modulateVec,modulatePerm);
			colorVec = vec_madd(floatColorVec0,modulateVec,zero);
			colorInt = vec_cts(colorVec,0);	// RGBx
			colorShort = vec_pack(colorInt,colorInt);		// RGBxRGBx
			colorChar = vec_packsu(colorShort,colorShort);	// RGBxRGBxRGBxRGBx
			colorChar = vec_sel(colorChar,vSel,vSel);		// RGBARGBARGBARGBA replace alpha with 255
			vec_ste((vector unsigned int)colorChar,0,(unsigned int *)colors);	// store color
#else
			VectorSubtract( origin, tess.xyz[i], dist );
			texCoords[0] = 0.5f + dist[0] * scale;
			texCoords[1] = 0.5f + dist[1] * scale;

			clip = 0;
			if ( texCoords[0] < 0.0f ) {
				clip |= 1;
			} else if ( texCoords[0] > 1.0f ) {
				clip |= 2;
			}
			if ( texCoords[1] < 0.0f ) {
				clip |= 4;
			} else if ( texCoords[1] > 1.0f ) {
				clip |= 8;
			}
			// modulate the strength based on the height and color
			if ( dist[2] > radius ) {
				clip |= 16;
				modulate = 0.0f;
			} else if ( dist[2] < -radius ) {
				clip |= 32;
				modulate = 0.0f;
			} else {
				dist[2] = Q_fabs(dist[2]);
				if ( dist[2] < radius * 0.5f ) {
					modulate = 1.0f;
				} else {
					modulate = 2.0f * (radius - dist[2]) * scale;
				}
			}
			clipBits[i] = clip;

			colors[0] = myftol(floatColor[0] * modulate);
			colors[1] = myftol(floatColor[1] * modulate);
			colors[2] = myftol(floatColor[2] * modulate);
			colors[3] = 255;
#endif
		}

		// build a list of triangles that need light
		numIndexes = 0;
		for ( i = 0 ; i < tess.numIndexes ; i += 3 ) {
			int		a, b, c;

			a = tess.indexes[i];
			b = tess.indexes[i+1];
			c = tess.indexes[i+2];
			if ( clipBits[a] & clipBits[b] & clipBits[c] ) {
				continue;	// not lighted
			}
			hitIndexes[numIndexes] = a;
			hitIndexes[numIndexes+1] = b;
			hitIndexes[numIndexes+2] = c;
			numIndexes += 3;
		}

		if ( !numIndexes ) {
			continue;
		}

		qglEnableClientState( GL_TEXTURE_COORD_ARRAY );
		qglTexCoordPointer( 2, GL_FLOAT, 0, texCoordsArray[0] );

		qglEnableClientState( GL_COLOR_ARRAY );
		qglColorPointer( 4, GL_UNSIGNED_BYTE, 0, colorArray );

		GL_Bind( tr.dlightImage );
		// include GLS_DEPTHFUNC_EQUAL so alpha tested surfaces don't add light
		// where they aren't rendered
		if ( dl->additive ) {
			GL_State( GLS_SRCBLEND_ONE | GLS_DSTBLEND_ONE | GLS_DEPTHFUNC_EQUAL );
		}
		else {
			GL_State( GLS_SRCBLEND_DST_COLOR | GLS_DSTBLEND_ONE | GLS_DEPTHFUNC_EQUAL );
		}
		R_DrawElements( numIndexes, hitIndexes );
		backEnd.pc.c_totalIndexes += numIndexes;
		backEnd.pc.c_dlightIndexes += numIndexes;
	}
}


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

Blends a fog texture on top of everything else
===================
*/
static void RB_FogPass( void ) {
	fog_t		*fog;
	int			i;

	qglEnableClientState( GL_COLOR_ARRAY );
	qglColorPointer( 4, GL_UNSIGNED_BYTE, 0, tess.svars.colors );

	qglEnableClientState( GL_TEXTURE_COORD_ARRAY);
	qglTexCoordPointer( 2, GL_FLOAT, 0, tess.svars.texcoords[0] );

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

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

	RB_CalcFogTexCoords( ( float * ) tess.svars.texcoords[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 );
}

/*
===============
ComputeColors
===============
*/
static void ComputeColors( shaderStage_t *pStage )
{
	int		i;

	//
	// 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++ ) {
				*(int *)tess.svars.colors[i] = *(int *)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][0] = tess.vertexColors[i][0] * tr.identityLight;
					tess.svars.colors[i][1] = tess.vertexColors[i][1] * tr.identityLight;
					tess.svars.colors[i][2] = tess.vertexColors[i][2] * tr.identityLight;
					tess.svars.colors[i][3] = tess.vertexColors[i][3];
				}
			}
			break;
		case CGEN_ONE_MINUS_VERTEX:
			if ( tr.identityLight == 1 )
			{
				for ( i = 0; i < tess.numVertexes; i++ )
				{
					tess.svars.colors[i][0] = 255 - tess.vertexColors[i][0];
					tess.svars.colors[i][1] = 255 - tess.vertexColors[i][1];
					tess.svars.colors[i][2] = 255 - tess.vertexColors[i][2];
				}
			}
			else
			{
				for ( i = 0; i < tess.numVertexes; i++ )
				{
					tess.svars.colors[i][0] = ( 255 - tess.vertexColors[i][0] ) * tr.identityLight;
					tess.svars.colors[i][1] = ( 255 - tess.vertexColors[i][1] ) * tr.identityLight;
					tess.svars.colors[i][2] = ( 255 - tess.vertexColors[i][2] ) * tr.identityLight;
				}
			}
			break;
		case CGEN_FOG:
			{
				fog_t		*fog;

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

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

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

			for ( i = 0; i < tess.numVertexes; i++ )
			{
				float len;
				vec3_t v;

				VectorSubtract( tess.xyz[i], backEnd.viewParms.or.origin, v );
				len = VectorLength( v );

				len /= tess.shader->portalRange;

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

				tess.svars.colors[i][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( ( unsigned char * ) tess.svars.colors );
			break;
		case ACFF_MODULATE_ALPHA:
			RB_CalcModulateAlphasByFog( ( unsigned char * ) tess.svars.colors );
			break;
		case ACFF_MODULATE_RGBA:
			RB_CalcModulateRGBAsByFog( ( unsigned char * ) tess.svars.colors );
			break;
		case ACFF_NONE:
			break;
		}
	}
}

/*
===============
ComputeTexCoords
===============
*/
static void ComputeTexCoords( shaderStage_t *pStage ) {
	int		i;
	int		b;

	for ( b = 0; b < NUM_TEXTURE_BUNDLES; b++ ) {
		int tm;

		//
		// generate the texture coordinates
		//
		switch ( pStage->bundle[b].tcGen )
		{
		case TCGEN_IDENTITY:
			Com_Memset( tess.svars.texcoords[b], 0, sizeof( float ) * 2 * tess.numVertexes );
			break;
		case TCGEN_TEXTURE:
			for ( i = 0 ; i < tess.numVertexes ; i++ ) {
				tess.svars.texcoords[b][i][0] = tess.texCoords[i][0][0];
				tess.svars.texcoords[b][i][1] = tess.texCoords[i][0][1];
			}
			break;
		case TCGEN_LIGHTMAP:
			for ( i = 0 ; i < tess.numVertexes ; i++ ) {
				tess.svars.texcoords[b][i][0] = tess.texCoords[i][1][0];
				tess.svars.texcoords[b][i][1] = tess.texCoords[i][1][1];
			}
			break;
		case TCGEN_VECTOR:
			for ( i = 0 ; i < tess.numVertexes ; i++ ) {
				tess.svars.texcoords[b][i][0] = DotProduct( tess.xyz[i], pStage->bundle[b].tcGenVectors[0] );
				tess.svars.texcoords[b][i][1] = DotProduct( tess.xyz[i], pStage->bundle[b].tcGenVectors[1] );
			}
			break;
		case TCGEN_FOG:
			RB_CalcFogTexCoords( ( float * ) tess.svars.texcoords[b] );
			break;
		case TCGEN_ENVIRONMENT_MAPPED:
			RB_CalcEnvironmentTexCoords( ( float * ) tess.svars.texcoords[b] );
			break;
		case TCGEN_BAD:
			return;
		}

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

			case TMOD_TURBULENT:
				RB_CalcTurbulentTexCoords( &pStage->bundle[b].texMods[tm].wave, 
						                 ( float * ) tess.svars.texcoords[b] );
				break;

			case TMOD_ENTITY_TRANSLATE:
				RB_CalcScrollTexCoords( backEnd.currentEntity->e.shaderTexCoord,
									 ( float * ) tess.svars.texcoords[b] );
				break;