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

Wolfenstein: Enemy Territory GPL Source Code
Copyright (C) 1999-2010 id Software LLC, a ZeniMax Media company. 

This file is part of the Wolfenstein: Enemy Territory GPL Source Code (Wolf ET Source Code).  

Wolf ET 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 3 of the License, or
(at your option) any later version.

Wolf ET 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 Wolf ET Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Wolf: ET Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Wolf ET Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

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

// tr_shade_calc.c

#include "tr_local.h"


#define WAVEVALUE( table, base, amplitude, phase, freq )  ( ( base ) + table[ myftol( ( ( ( phase ) + tess.shaderTime * ( freq ) ) * FUNCTABLE_SIZE ) ) & FUNCTABLE_MASK ] * ( amplitude ) )

static float *TableForFunc( genFunc_t func ) {
	switch ( func )
	{
	case GF_SIN:
		return tr.sinTable;
	case GF_TRIANGLE:
		return tr.triangleTable;
	case GF_SQUARE:
		return tr.squareTable;
	case GF_SAWTOOTH:
		return tr.sawToothTable;
	case GF_INVERSE_SAWTOOTH:
		return tr.inverseSawToothTable;
	case GF_NONE:
	default:
		break;
	}

	ri.Error( ERR_DROP, "TableForFunc called with invalid function '%d' in shader '%s'\n", func, tess.shader->name );
	return NULL;
}

/*
** EvalWaveForm
**
** Evaluates a given waveForm_t, referencing backEnd.refdef.time directly
*/
static float EvalWaveForm( const waveForm_t *wf ) {
	float   *table;

	table = TableForFunc( wf->func );

	return WAVEVALUE( table, wf->base, wf->amplitude, wf->phase, wf->frequency );
}

static float EvalWaveFormClamped( const waveForm_t *wf ) {
	float glow  = EvalWaveForm( wf );

	if ( glow < 0 ) {
		return 0;
	}

	if ( glow > 1 ) {
		return 1;
	}

	return glow;
}

/*
** RB_CalcStretchTexCoords
*/
void RB_CalcStretchTexCoords( const waveForm_t *wf, float *st ) {
	float p;
	texModInfo_t tmi;

	p = 1.0f / EvalWaveForm( wf );

	tmi.matrix[0][0] = p;
	tmi.matrix[1][0] = 0;
	tmi.translate[0] = 0.5f - 0.5f * p;

	tmi.matrix[0][1] = 0;
	tmi.matrix[1][1] = p;
	tmi.translate[1] = 0.5f - 0.5f * p;

	RB_CalcTransformTexCoords( &tmi, st );
}

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

DEFORMATIONS

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

/*
========================
RB_CalcDeformVertexes

========================
*/
void RB_CalcDeformVertexes( deformStage_t *ds ) {
	int i;
	vec3_t offset;
	float scale;
	float   *xyz = ( float * ) tess.xyz;
	float   *normal = ( float * ) tess.normal;
	float   *table;

	// Ridah
	if ( ds->deformationWave.frequency < 0 ) {
		qboolean inverse = qfalse;
		vec3_t worldUp;
		//static vec3_t up = {0,0,1};

		if ( VectorCompare( backEnd.currentEntity->e.fireRiseDir, vec3_origin ) ) {
			VectorSet( backEnd.currentEntity->e.fireRiseDir, 0, 0, 1 );
		}

		// get the world up vector in local coordinates
		if ( backEnd.currentEntity->e.hModel ) {  // world surfaces dont have an axis
			VectorRotate( backEnd.currentEntity->e.fireRiseDir, backEnd.currentEntity->e.axis, worldUp );
		} else {
			VectorCopy( backEnd.currentEntity->e.fireRiseDir, worldUp );
		}
		// don't go so far if sideways, since they must be moving
		VectorScale( worldUp, 0.4 + 0.6 * Q_fabs( backEnd.currentEntity->e.fireRiseDir[2] ), worldUp );

		ds->deformationWave.frequency *= -1;
		if ( ds->deformationWave.frequency > 999 ) {  // hack for negative Z deformation (ack)
			inverse = qtrue;
			ds->deformationWave.frequency -= 999;
		}

		table = TableForFunc( ds->deformationWave.func );

		for ( i = 0; i < tess.numVertexes; i++, xyz += 4, normal += 4 )
		{
			float off = ( xyz[0] + xyz[1] + xyz[2] ) * ds->deformationSpread;
			float dot;

			scale = WAVEVALUE( table, ds->deformationWave.base,
							   ds->deformationWave.amplitude,
							   ds->deformationWave.phase + off,
							   ds->deformationWave.frequency );

			dot = DotProduct( worldUp, normal );

			if ( dot * scale > 0 ) {
				if ( inverse ) {
					scale *= -1;
				}
				VectorMA( xyz, dot * scale, worldUp, xyz );
			}
		}

		if ( inverse ) {
			ds->deformationWave.frequency += 999;
		}
		ds->deformationWave.frequency *= -1;
	}
	// done.
	else if ( ds->deformationWave.frequency == 0 ) {
		scale = EvalWaveForm( &ds->deformationWave );

		for ( i = 0; i < tess.numVertexes; i++, xyz += 4, normal += 4 )
		{
			VectorScale( normal, scale, offset );

			xyz[0] += offset[0];
			xyz[1] += offset[1];
			xyz[2] += offset[2];
		}
	} else
	{
		table = TableForFunc( ds->deformationWave.func );

		for ( i = 0; i < tess.numVertexes; i++, xyz += 4, normal += 4 )
		{
			float off = ( xyz[0] + xyz[1] + xyz[2] ) * ds->deformationSpread;

			scale = WAVEVALUE( table, ds->deformationWave.base,
							   ds->deformationWave.amplitude,
							   ds->deformationWave.phase + off,
							   ds->deformationWave.frequency );

			VectorScale( normal, scale, offset );

			xyz[0] += offset[0];
			xyz[1] += offset[1];
			xyz[2] += offset[2];
		}
	}
}

/*
=========================
RB_CalcDeformNormals

Wiggle the normals for wavy environment mapping
=========================
*/
void RB_CalcDeformNormals( deformStage_t *ds ) {
	int i;
	float scale;
	float   *xyz = ( float * ) tess.xyz;
	float   *normal = ( float * ) tess.normal;

	for ( i = 0; i < tess.numVertexes; i++, xyz += 4, normal += 4 ) {
		scale = 0.98f;
		scale = R_NoiseGet4f( xyz[0] * scale, xyz[1] * scale, xyz[2] * scale,
							  tess.shaderTime * ds->deformationWave.frequency );
		normal[ 0 ] += ds->deformationWave.amplitude * scale;

		scale = 0.98f;
		scale = R_NoiseGet4f( 100 + xyz[0] * scale, xyz[1] * scale, xyz[2] * scale,
							  tess.shaderTime * ds->deformationWave.frequency );
		normal[ 1 ] += ds->deformationWave.amplitude * scale;

		scale = 0.98f;
		scale = R_NoiseGet4f( 200 + xyz[0] * scale, xyz[1] * scale, xyz[2] * scale,
							  tess.shaderTime * ds->deformationWave.frequency );
		normal[ 2 ] += ds->deformationWave.amplitude * scale;

		VectorNormalizeFast( normal );
	}
}

/*
========================
RB_CalcBulgeVertexes

========================
*/
void RB_CalcBulgeVertexes( deformStage_t *ds ) {
	int i;
	const float *st = ( const float * ) tess.texCoords0;
	float       *xyz = ( float * ) tess.xyz;
	float       *normal = ( float * ) tess.normal;
	float now;

	now = backEnd.refdef.time * ds->bulgeSpeed * 0.001f;

	for ( i = 0; i < tess.numVertexes; i++, xyz += 4, st += 4, normal += 4 ) {
		int off;
		float scale;

		off = (float)( FUNCTABLE_SIZE / ( M_PI * 2 ) ) * ( st[0] * ds->bulgeWidth + now );

		scale = tr.sinTable[ off & FUNCTABLE_MASK ] * ds->bulgeHeight;

		xyz[0] += normal[0] * scale;
		xyz[1] += normal[1] * scale;
		xyz[2] += normal[2] * scale;
	}
}


/*
======================
RB_CalcMoveVertexes

A deformation that can move an entire surface along a wave path
======================
*/
void RB_CalcMoveVertexes( deformStage_t *ds ) {
	int i;
	float       *xyz;
	float       *table;
	float scale;
	vec3_t offset;

	table = TableForFunc( ds->deformationWave.func );

	scale = WAVEVALUE( table, ds->deformationWave.base,
					   ds->deformationWave.amplitude,
					   ds->deformationWave.phase,
					   ds->deformationWave.frequency );

	VectorScale( ds->moveVector, scale, offset );

	xyz = ( float * ) tess.xyz;
	for ( i = 0; i < tess.numVertexes; i++, xyz += 4 ) {
		VectorAdd( xyz, offset, xyz );
	}
}


/*
=============
DeformText

Change a polygon into a bunch of text polygons
=============
*/
void DeformText( const char *text ) {
	int i;
	vec3_t origin, width, height;
	int len;
	int ch;
	byte color[4];
	float bottom, top;
	vec3_t mid;

	height[0] = 0;
	height[1] = 0;
	height[2] = -1;
	CrossProduct( tess.normal[0].v, height, width );

	// find the midpoint of the box
	VectorClear( mid );
	bottom = 999999;
	top = -999999;
	for ( i = 0 ; i < 4 ; i++ ) {
		VectorAdd( tess.xyz[i].v, mid, mid );
		if ( tess.xyz[i].v[2] < bottom ) {
			bottom = tess.xyz[i].v[2];
		}
		if ( tess.xyz[i].v[2] > top ) {
			top = tess.xyz[i].v[2];
		}
	}
	VectorScale( mid, 0.25f, origin );

	// determine the individual character size
	height[0] = 0;
	height[1] = 0;
	height[2] = ( top - bottom ) * 0.5f;

	VectorScale( width, height[2] * -0.75f, width );

	// determine the starting position
	len = strlen( text );
	VectorMA( origin, ( len - 1 ), width, origin );

	// clear the shader indexes
	tess.numIndexes = 0;
	tess.numVertexes = 0;

	color[0] = color[1] = color[2] = color[3] = 255;

	// draw each character
	for ( i = 0 ; i < len ; i++ ) {
		ch = text[i];
		ch &= 255;

		if ( ch != ' ' ) {
			int row, col;
			float frow, fcol, size;

			row = ch >> 4;
			col = ch & 15;

			frow = row * 0.0625f;
			fcol = col * 0.0625f;
			size = 0.0625f;

			RB_AddQuadStampExt( origin, width, height, color, fcol, frow, fcol + size, frow + size );
		}
		VectorMA( origin, -2, width, origin );
	}
}

/*
==================
GlobalVectorToLocal
==================
*/
void GlobalVectorToLocal( const vec3_t in, vec3_t out ) {
	out[0] = DotProduct( in, backEnd.orientation.axis[0] );
	out[1] = DotProduct( in, backEnd.orientation.axis[1] );
	out[2] = DotProduct( in, backEnd.orientation.axis[2] );
}

/*
=====================
AutospriteDeform

Assuming all the triangles for this shader are independant
quads, rebuild them as forward facing sprites
=====================
*/
static void AutospriteDeform( void ) {
	int i;
	int oldVerts;
	float   *xyz;
	vec3_t mid, delta;
	float radius;
	vec3_t left, up;
	vec3_t leftDir, upDir;

	if ( tess.numVertexes & 3 ) {
		ri.Printf( PRINT_WARNING, "Autosprite shader %s had odd vertex count", tess.shader->name );
	}
	if ( tess.numIndexes != ( tess.numVertexes >> 2 ) * 6 ) {
		ri.Printf( PRINT_WARNING, "Autosprite shader %s had odd index count", tess.shader->name );
	}

	oldVerts = tess.numVertexes;
	tess.numVertexes = 0;
	tess.numIndexes = 0;

	if ( backEnd.currentEntity != &tr.worldEntity ) {
		GlobalVectorToLocal( backEnd.viewParms.orientation.axis[1], leftDir );
		GlobalVectorToLocal( backEnd.viewParms.orientation.axis[2], upDir );
	} else {
		VectorCopy( backEnd.viewParms.orientation.axis[1], leftDir );
		VectorCopy( backEnd.viewParms.orientation.axis[2], upDir );
	}

	for ( i = 0 ; i < oldVerts ; i += 4 ) {
		// find the midpoint
		xyz = tess.xyz[i].v;

		mid[0] = 0.25f * ( xyz[0] + xyz[4] + xyz[8] + xyz[12] );
		mid[1] = 0.25f * ( xyz[1] + xyz[5] + xyz[9] + xyz[13] );
		mid[2] = 0.25f * ( xyz[2] + xyz[6] + xyz[10] + xyz[14] );

		VectorSubtract( xyz, mid, delta );
		radius = VectorLength( delta ) * 0.707f;        // / sqrt(2)

		VectorScale( leftDir, radius, left );
		VectorScale( upDir, radius, up );

		if ( backEnd.viewParms.isMirror ) {
			VectorSubtract( vec3_origin, left, left );
		}

		// compensate for scale in the axes if necessary
		if ( backEnd.currentEntity->e.nonNormalizedAxes ) {
			float axisLength;
			axisLength = VectorLength( backEnd.currentEntity->e.axis[0] );
			if ( !axisLength ) {
				axisLength = 0;
			} else {
				axisLength = 1.0f / axisLength;
			}
			VectorScale( left, axisLength, left );
			VectorScale( up, axisLength, up );
		}

		RB_AddQuadStamp( mid, left, up, tess.vertexColors[i].v );
	}
}


/*
=====================
Autosprite2Deform

Autosprite2 will pivot a rectangular quad along the center of its long axis
=====================
*/
int edgeVerts[6][2] = {
	{ 0, 1 },
	{ 0, 2 },
	{ 0, 3 },
	{ 1, 2 },
	{ 1, 3 },
	{ 2, 3 }
};

static void Autosprite2Deform( void ) {
	int i, j, k;
	int indexes;
	float   *xyz;
	vec3_t forward;

	if ( tess.numVertexes & 3 ) {
		ri.Printf( PRINT_WARNING, "Autosprite2 shader %s had odd vertex count", tess.shader->name );
	}
	if ( tess.numIndexes != ( tess.numVertexes >> 2 ) * 6 ) {
		ri.Printf( PRINT_WARNING, "Autosprite2 shader %s had odd index count", tess.shader->name );
	}

	if ( backEnd.currentEntity != &tr.worldEntity ) {
		GlobalVectorToLocal( backEnd.viewParms.orientation.axis[0], forward );
	} else {
		VectorCopy( backEnd.viewParms.orientation.axis[0], forward );
	}

	// this is a lot of work for two triangles...
	// we could precalculate a lot of it is an issue, but it would mess up
	// the shader abstraction
	for ( i = 0, indexes = 0 ; i < tess.numVertexes ; i += 4, indexes += 6 ) {
		float lengths[2];
		int nums[2];
		vec3_t mid[2];
		vec3_t major, minor;
		float   *v1, *v2;

		// find the midpoint
		xyz = tess.xyz[i].v;

		// identify the two shortest edges
		nums[0] = nums[1] = 0;
		lengths[0] = lengths[1] = 999999;

		for ( j = 0 ; j < 6 ; j++ ) {
			float l;
			vec3_t temp;

			v1 = xyz + 4 * edgeVerts[j][0];
			v2 = xyz + 4 * edgeVerts[j][1];

			VectorSubtract( v1, v2, temp );

			l = DotProduct( temp, temp );
			if ( l < lengths[0] ) {
				nums[1] = nums[0];
				lengths[1] = lengths[0];
				nums[0] = j;
				lengths[0] = l;
			} else if ( l < lengths[1] ) {
				nums[1] = j;
				lengths[1] = l;
			}
		}

		for ( j = 0 ; j < 2 ; j++ ) {
			v1 = xyz + 4 * edgeVerts[nums[j]][0];
			v2 = xyz + 4 * edgeVerts[nums[j]][1];

			mid[j][0] = 0.5f * ( v1[0] + v2[0] );
			mid[j][1] = 0.5f * ( v1[1] + v2[1] );
			mid[j][2] = 0.5f * ( v1[2] + v2[2] );
		}

		// find the vector of the major axis
		VectorSubtract( mid[1], mid[0], major );

		// cross this with the view direction to get minor axis
		CrossProduct( major, forward, minor );
		VectorNormalize( minor );

		// re-project the points
		for ( j = 0 ; j < 2 ; j++ ) {
			float l;

			v1 = xyz + 4 * edgeVerts[nums[j]][0];
			v2 = xyz + 4 * edgeVerts[nums[j]][1];

			l = 0.5f * sqrt( lengths[j] );

			// we need to see which direction this edge
			// is used to determine direction of projection
			for ( k = 0 ; k < 5 ; k++ ) {
				if ( tess.indexes[ indexes + k ] == i + edgeVerts[nums[j]][0]
					 && tess.indexes[ indexes + k + 1 ] == i + edgeVerts[nums[j]][1] ) {
					break;
				}
			}

			if ( k == 5 ) {
				VectorMA( mid[j], l, minor, v1 );
				VectorMA( mid[j], -l, minor, v2 );
			} else {
				VectorMA( mid[j], -l, minor, v1 );
				VectorMA( mid[j], l, minor, v2 );
			}
		}
	}
}


/*
=====================
RB_DeformTessGeometry

=====================
*/
void RB_DeformTessGeometry( void ) {
	int i;
	deformStage_t   *ds;

	for ( i = 0 ; i < tess.shader->numDeforms ; i++ ) {
		ds = &tess.shader->deforms[ i ];

		switch ( ds->deformation ) {
		case DEFORM_NONE:
			break;
		case DEFORM_NORMALS:
			RB_CalcDeformNormals( ds );
			break;
		case DEFORM_WAVE:
			RB_CalcDeformVertexes( ds );
			break;
		case DEFORM_BULGE:
			RB_CalcBulgeVertexes( ds );
			break;
		case DEFORM_MOVE:
			RB_CalcMoveVertexes( ds );
			break;
		case DEFORM_PROJECTION_SHADOW:
			RB_ProjectionShadowDeform();
			break;
		case DEFORM_AUTOSPRITE:
			AutospriteDeform();
			break;
		case DEFORM_AUTOSPRITE2:
			Autosprite2Deform();
			break;
		case DEFORM_TEXT0:
		case DEFORM_TEXT1:
		case DEFORM_TEXT2:
		case DEFORM_TEXT3:
		case DEFORM_TEXT4:
		case DEFORM_TEXT5:
		case DEFORM_TEXT6:
		case DEFORM_TEXT7:
			DeformText( backEnd.refdef.text[ds->deformation - DEFORM_TEXT0] );
			break;
		}
	}
}

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

COLORS

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


/*
** RB_CalcColorFromEntity
*/
void RB_CalcColorFromEntity( unsigned char *dstColors ) {
	int i;
	int *pColors = ( int * ) dstColors;
	int c;

	if ( !backEnd.currentEntity ) {
		return;
	}

	c = *( int * ) backEnd.currentEntity->e.shaderRGBA;

	for ( i = 0; i < tess.numVertexes; i++, pColors++ )
	{
		*pColors = c;
	}
}

/*
** RB_CalcColorFromOneMinusEntity
*/
void RB_CalcColorFromOneMinusEntity( unsigned char *dstColors ) {
	int i;
	int *pColors = ( int * ) dstColors;
	unsigned char invModulate[3];
	int c;

	if ( !backEnd.currentEntity ) {
		return;
	}

	invModulate[0] = 255 - backEnd.currentEntity->e.shaderRGBA[0];
	invModulate[1] = 255 - backEnd.currentEntity->e.shaderRGBA[1];
	invModulate[2] = 255 - backEnd.currentEntity->e.shaderRGBA[2];
	invModulate[3] = 255 - backEnd.currentEntity->e.shaderRGBA[3];  // this trashes alpha, but the AGEN block fixes it

	c = *( int * ) invModulate;

	for ( i = 0; i < tess.numVertexes; i++, pColors++ )
	{
		*pColors = *( int * ) invModulate;
	}
}

/*
** RB_CalcAlphaFromEntity
*/
void RB_CalcAlphaFromEntity( unsigned char *dstColors ) {
	int i;

	if ( !backEnd.currentEntity ) {
		return;
	}

	dstColors += 3;

	for ( i = 0; i < tess.numVertexes; i++, dstColors += 4 )
	{
		*dstColors = backEnd.currentEntity->e.shaderRGBA[3];
	}
}

/*
** RB_CalcAlphaFromOneMinusEntity
*/
void RB_CalcAlphaFromOneMinusEntity( unsigned char *dstColors ) {
	int i;

	if ( !backEnd.currentEntity ) {
		return;
	}

	dstColors += 3;

	for ( i = 0; i < tess.numVertexes; i++, dstColors += 4 )
	{
		*dstColors = 0xff - backEnd.currentEntity->e.shaderRGBA[3];
	}
}

/*
** RB_CalcWaveColor
*/
void RB_CalcWaveColor( const waveForm_t *wf, unsigned char *dstColors ) {
	int i;
	int v;
	float glow;
	int *colors = ( int * ) dstColors;
	byte color[4];


	if ( wf->func == GF_NOISE ) {
		glow = wf->base + R_NoiseGet4f( 0, 0, 0, ( tess.shaderTime + wf->phase ) * wf->frequency ) * wf->amplitude;
	} else {
		glow = EvalWaveForm( wf ) * tr.identityLight;
	}

	if ( glow < 0 ) {
		glow = 0;
	} else if ( glow > 1 )   {
		glow = 1;
	}

	v = myftol( 255 * glow );
	color[0] = color[1] = color[2] = v;
	color[3] = 255;
	v = *(int *)color;

	for ( i = 0; i < tess.numVertexes; i++, colors++ ) {
		*colors = v;
	}
}

/*
** RB_CalcWaveAlpha
*/
void RB_CalcWaveAlpha( const waveForm_t *wf, unsigned char *dstColors ) {
	int i;
	int v;
	float glow;


	// ydnar: added alphaGen noise support
	if ( wf->func == GF_NOISE ) {
		glow = wf->base + R_NoiseGet4f( 0, 0, 0, ( tess.shaderTime + wf->phase ) * wf->frequency ) * wf->amplitude;
	} else {
		glow = EvalWaveFormClamped( wf );
	}

	v = 255 * glow;

	for ( i = 0; i < tess.numVertexes; i++, dstColors += 4 )
	{
		dstColors[3] = v;
	}
}

/*
** RB_CalcModulateAlphasByFog
*/
void RB_CalcModulateAlphasByFog( unsigned char *colors ) {
	int i;
	float f, texCoords[ SHADER_MAX_VERTEXES ][ 2 ];


	// ydnar: no world, no fogging
	if ( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) {
		return;
	}

	// calculate texcoords so we can derive density
	// this is not wasted, because it would only have
	// been previously called if the surface was opaque
	RB_CalcFogTexCoords( texCoords[ 0 ] );

	for ( i = 0; i < tess.numVertexes; i++, colors += 4 )
	{
		//%	float f = 1.0 - R_FogFactor( texCoords[i][0], texCoords[i][1] );'
		if ( texCoords[ i ][ 0 ] <= 0.0f || texCoords[ i ][ 1 ] <= 0.0f ) {
			continue;
		} else {
			f = 1.0f - ( texCoords[ i ][ 0 ] * texCoords[ i ][ 1 ] );
		}
		if ( f <= 0.0f ) {
			colors[ 3 ] = 0;
		} else {
			colors[ 3 ] *= f;
		}
	}
}

/*
** RB_CalcModulateColorsByFog
*/
void RB_CalcModulateColorsByFog( unsigned char *colors ) {
	int i;
	float f, texCoords[ SHADER_MAX_VERTEXES ][ 2 ];


	// ydnar: no world, no fogging
	if ( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) {
		return;
	}

	// calculate texcoords so we can derive density
	// this is not wasted, because it would only have
	// been previously called if the surface was opaque
	RB_CalcFogTexCoords( texCoords[ 0 ] );

	for ( i = 0; i < tess.numVertexes; i++, colors += 4 ) {
		//%	float f = 1.0 - R_FogFactor( texCoords[i][0], texCoords[i][1] );
		if ( texCoords[ i ][ 0 ] <= 0.0f || texCoords[ i ][ 1 ] <= 0.0f ) {
			continue;
		} else {
			f = 1.0f - ( texCoords[ i ][ 0 ] * texCoords[ i ][ 1 ] );
		}
		if ( f <= 0.0f ) {
			colors[ 0 ] = 0;
			colors[ 1 ] = 0;
			colors[ 2 ] = 0;
		} else
		{
			colors[ 0 ] *= f;
			colors[ 1 ] *= f;
			colors[ 2 ] *= f;
		}
	}
}

/*
** RB_CalcModulateRGBAsByFog
*/
void RB_CalcModulateRGBAsByFog( unsigned char *colors ) {
	int i;
	float f, texCoords[ SHADER_MAX_VERTEXES ][ 2 ];


	// ydnar: no world, no fogging
	if ( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) {
		return;
	}

	// calculate texcoords so we can derive density
	// this is not wasted, because it would only have
	// been previously called if the surface was opaque
	RB_CalcFogTexCoords( texCoords[ 0 ] );

	for ( i = 0; i < tess.numVertexes; i++, colors += 4 ) {
		//%	float f = 1.0 - R_FogFactor( texCoords[i][0], texCoords[i][1] );
		if ( texCoords[ i ][ 0 ] <= 0.0f || texCoords[ i ][ 1 ] <= 0.0f ) {
			continue;
		} else {
			f = 1.0f - ( texCoords[ i ][ 0 ] * texCoords[ i ][ 1 ] );
		}
		if ( f <= 0.0f ) {
			colors[ 0 ] = 0;
			colors[ 1 ] = 0;
			colors[ 2 ] = 0;
			colors[ 3 ] = 0;
		} else
		{
			colors[ 0 ] *= f;
			colors[ 1 ] *= f;
			colors[ 2 ] *= f;
			colors[ 3 ] *= f;
		}
	}
}


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

TEX COORDS

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

/*
========================
RB_CalcFogTexCoords

To do the clipped fog plane really correctly, we should use
projected textures, but I don't trust the drivers and it
doesn't fit our shader data.
========================
*/

void RB_CalcFogTexCoords( float *st ) {
	int i;
	float       *v;
	float s, t;
	float eyeT;
	qboolean eyeInside;
	fog_t       *fog;
	vec3_t local, viewOrigin;
	vec4_t fogSurface, fogDistanceVector, fogDepthVector;
	bmodel_t    *bmodel;


	// Gordon: rarrrrr, stop stupid msvc debug thing
	fogDepthVector[ 0 ] = 0;
	fogDepthVector[ 1 ] = 0;
	fogDepthVector[ 2 ] = 0;
	fogDepthVector[ 3 ] = 0;

	// get fog stuff
	fog = tr.world->fogs + tess.fogNum;
	bmodel = tr.world->bmodels + fog->modelNum;

	// if the brush model containing the fog volume wasn't in the scene, then don't bother rendering the fog
//	if( bmodel->visible[ backEnd.smpFrame ] == qfalse )
//		return;

	// all fogging distance is based on world Z units
	VectorSubtract( backEnd.orientation.origin, backEnd.viewParms.orientation.origin, local );
	//%	VectorSubtract( local, bmodel->origin[ backEnd.smpFrame ], local );
	fogDistanceVector[ 0 ] = -backEnd.orientation.modelMatrix[ 2 ];
	fogDistanceVector[ 1 ] = -backEnd.orientation.modelMatrix[ 6 ];
	fogDistanceVector[ 2 ] = -backEnd.orientation.modelMatrix[ 10 ];
	fogDistanceVector[ 3 ] = DotProduct( local, backEnd.viewParms.orientation.axis[ 0 ] );

	// scale the fog vectors based on the fog's thickness
	fogDistanceVector[ 0 ] *= fog->shader->fogParms.tcScale * 1.0;
	fogDistanceVector[ 1 ] *= fog->shader->fogParms.tcScale * 1.0;
	fogDistanceVector[ 2 ] *= fog->shader->fogParms.tcScale * 1.0;
	fogDistanceVector[ 3 ] *= fog->shader->fogParms.tcScale * 1.0;

	// offset view origin by fog brush origin (fixme: really necessary?)
	//%	VectorSubtract( backEnd.orientation.viewOrigin, bmodel->origin[ backEnd.smpFrame ], viewOrigin );
	VectorCopy( backEnd.orientation.viewOrigin, viewOrigin );

	// offset fog surface
	VectorCopy( fog->surface, fogSurface );
	fogSurface[ 3 ] = fog->surface[ 3 ] + DotProduct( fogSurface, bmodel->orientation[ backEnd.smpFrame ].origin );

	// ydnar: general fog case
	if ( fog->originalBrushNumber >= 0 ) {
		// rotate the gradient vector for this orientation
		if ( fog->hasSurface ) {
			fogDepthVector[ 0 ] = fogSurface[ 0 ] * backEnd.orientation.axis[ 0 ][ 0 ] +
								  fogSurface[ 1 ] * backEnd.orientation.axis[ 0 ][ 1 ] + fogSurface[ 2 ] * backEnd.orientation.axis[ 0 ][ 2 ];
			fogDepthVector[ 1 ] = fogSurface[ 0 ] * backEnd.orientation.axis[ 1 ][ 0 ] +
								  fogSurface[ 1 ] * backEnd.orientation.axis[ 1 ][ 1 ] + fogSurface[ 2 ] * backEnd.orientation.axis[ 1 ][ 2 ];
			fogDepthVector[ 2 ] = fogSurface[ 0 ] * backEnd.orientation.axis[ 2 ][ 0 ] +
								  fogSurface[ 1 ] * backEnd.orientation.axis[ 2 ][ 1 ] + fogSurface[ 2 ] * backEnd.orientation.axis[ 2 ][ 2 ];
			fogDepthVector[ 3 ] = -fogSurface[ 3 ] + DotProduct( backEnd.orientation.origin, fogSurface );

			// scale the fog vectors based on the fog's thickness
			fogDepthVector[ 0 ] *= fog->shader->fogParms.tcScale * 1.0;
			fogDepthVector[ 1 ] *= fog->shader->fogParms.tcScale * 1.0;
			fogDepthVector[ 2 ] *= fog->shader->fogParms.tcScale * 1.0;
			fogDepthVector[ 3 ] *= fog->shader->fogParms.tcScale * 1.0;

			eyeT = DotProduct( viewOrigin, fogDepthVector ) + fogDepthVector[ 3 ];
		} else {
			eyeT = 1;   // non-surface fog always has eye inside

		}
		// see if the viewpoint is outside
		eyeInside = eyeT < 0 ? qfalse : qtrue;

		// calculate density for each point
		for ( i = 0, v = tess.xyz[ 0 ].v ; i < tess.numVertexes; i++, v += 4 )
		{
			// calculate the length in fog
			s = DotProduct( v, fogDistanceVector ) + fogDistanceVector[ 3 ];
			t = DotProduct( v, fogDepthVector ) + fogDepthVector[ 3 ];

			if ( eyeInside ) {
				t += eyeT;
			}

			//%	t *= fog->shader->fogParms.tcScale;

			st[0] = s;
			st[1] = t;
			st += 2;
		}
	}
	// ydnar: optimized for level-wide fogging
	else
	{
		// calculate density for each point
		for ( i = 0, v = tess.xyz[ 0 ].v; i < tess.numVertexes; i++, v += 4 )
		{
			// calculate the length in fog (t is always 0 if eye is in fog)
			st[ 0 ] = DotProduct( v, fogDistanceVector ) + fogDistanceVector[ 3 ];
			st[ 1 ] = 1.0;
			st += 2;
		}
	}
}



/*
** RB_CalcEnvironmentTexCoords
*/

#if 1

void RB_CalcEnvironmentTexCoords( float *st ) {
	int i;
	float d2, *v, *normal, sAdjust, tAdjust;
	vec3_t viewOrigin, ia1, ia2, viewer, reflected;


	// setup
	v = tess.xyz[ 0 ].v;
	normal = tess.normal[ 0 ].v;
	VectorCopy( backEnd.orientation.viewOrigin, viewOrigin );

	// ydnar: origin of entity affects its environment map (every 256 units)
	// this is similar to racing game hacks where the env map seems to move
	// as the car passes through the world
	sAdjust = VectorLength( backEnd.orientation.origin ) * 0.00390625;
	//%	 sAdjust = backEnd.orientation.origin[ 0 ] * 0.00390625;
	sAdjust = 0.5 -  ( sAdjust - floor( sAdjust ) );

	tAdjust = backEnd.orientation.origin[ 2 ] * 0.00390625;
	tAdjust = 0.5 - ( tAdjust - floor( tAdjust ) );

	// ydnar: the final reflection vector must be converted into world-space again
	// we just assume here that all transformations are rotations, so the inverse
	// of the transform matrix (the 3x3 part) is just the transpose
	// additionally, we don't need all 3 rows, so we just calculate 2
	// and we also scale by 0.5 to eliminate two per-vertex multiplies
	ia1[ 0 ] = backEnd.orientation.axis[ 0 ][ 1 ] * 0.5;
	ia1[ 1 ] = backEnd.orientation.axis[ 1 ][ 1 ] * 0.5;
	ia1[ 2 ] = backEnd.orientation.axis[ 2 ][ 1 ] * 0.5;
	ia2[ 0 ] = backEnd.orientation.axis[ 0 ][ 2 ] * 0.5;
	ia2[ 1 ] = backEnd.orientation.axis[ 1 ][ 2 ] * 0.5;
	ia2[ 2 ] = backEnd.orientation.axis[ 2 ][ 2 ] * 0.5;

	// walk verts
	for ( i = 0; i < tess.numVertexes; i++, v += 4, normal += 4, st += 2 )
	{
		VectorSubtract( viewOrigin, v, viewer );
		VectorNormalizeFast( viewer );

		d2 = 2.0 * DotProduct( normal, viewer );

		reflected[ 0 ] = normal[ 0 ] * d2 - viewer[ 0 ];
		reflected[ 1 ] = normal[ 1 ] * d2 - viewer[ 1 ];
		reflected[ 2 ] = normal[ 2 ] * d2 - viewer[ 2 ];

		st[ 0 ] = sAdjust + DotProduct( reflected, ia1 );
		st[ 1 ] = tAdjust - DotProduct( reflected, ia2 );
	}
}

#else

void RB_CalcEnvironmentTexCoords( float *st ) {
	int i;
	float       *v, *normal;
	vec3_t viewOrigin, viewer, reflected, reflectedTransformed;
	float d;


	// ydnar: optimization
	VectorCopy( backEnd.orientation.viewOrigin, viewOrigin );

	// debug
	#undef DEBUG_ENVMAPPING
	#ifdef DEBUG_ENVMAPPING
	GL_Bind( tr.whiteImage );
	GL_State( GLS_DEPTHMASK_TRUE );
	qglLineWidth( 2 );
	qglBegin( GL_LINES );
	qglColor3f( 0.3, 0.4, 1 );
	#endif


	// setup
	v = tess.xyz[0].v;
	normal = tess.normal[0].v;

	// walk verts
	for ( i = 0 ; i < tess.numVertexes ; i++, v += 4, normal += 4, st += 2 )
	{
		VectorSubtract( viewOrigin, v, viewer );
		VectorNormalizeFast( viewer );

		d = DotProduct( normal, viewer );

		reflected[0] = normal[0] * 2 * d - viewer[0];
		reflected[1] = normal[1] * 2 * d - viewer[1];
		reflected[2] = normal[2] * 2 * d - viewer[2];

		reflectedTransformed[0] = reflected[0] * backEnd.orientation.axis[0][0] + reflected[1] * backEnd.orientation.axis[1][0] + reflected[2] * backEnd.orientation.axis[2][0];
		reflectedTransformed[1] = reflected[0] * backEnd.orientation.axis[0][1] + reflected[1] * backEnd.orientation.axis[1][1] + reflected[2] * backEnd.orientation.axis[2][1];
		reflectedTransformed[2] = reflected[0] * backEnd.orientation.axis[0][2] + reflected[1] * backEnd.orientation.axis[1][2] + reflected[2] * backEnd.orientation.axis[2][2];

		VectorCopy( reflectedTransformed, reflected );

		st[0] = 0.5 + reflectedTransformed[ 1 ] * 0.5;
		st[1] = 0.5 - reflectedTransformed[ 2 ] * 0.5;

		#ifdef DEBUG_ENVMAPPING
		qglVertex3f( v[ 0 ], v[ 1 ], v[ 2 ] );
		qglVertex3f( v[ 0 ] + reflected[ 0 ] * 2, v[ 1 ] + reflected[ 1 ] * 2, v[ 2 ] + reflected[ 2 ] * 2 );
		#endif
	}

	#ifdef DEBUG_ENVMAPPING
	qglEnd();
	qglLineWidth( 1 );
	#endif
}

#endif



/*
** RB_CalcFireRiseEnvTexCoords
*/
void RB_CalcFireRiseEnvTexCoords( float *st ) {
	int i;
	float       *v, *normal;
	vec3_t viewer, reflected;
	float d;

	v = tess.xyz[0].v;
	normal = tess.normal[0].v;
	VectorNegate( backEnd.currentEntity->e.fireRiseDir, viewer );

	for ( i = 0 ; i < tess.numVertexes ; i++, v += 4, normal += 4, st += 2 )
	{
		VectorNormalizeFast( viewer );

		d = DotProduct( normal, viewer );

		reflected[0] = normal[0] * 2 * d - viewer[0];
		reflected[1] = normal[1] * 2 * d - viewer[1];
		reflected[2] = normal[2] * 2 * d - viewer[2];

		st[0] = 0.5 + reflected[1] * 0.5;
		st[1] = 0.5 - reflected[2] * 0.5;
	}
}


/*
** RB_CalcSwapTexCoords
*/
void RB_CalcSwapTexCoords( float *st ) {
	int i;

	for ( i = 0; i < tess.numVertexes; i++, st += 2 )
	{
		float s = st[0];
		float t = st[1];

		st[0] = t;
		st[1] = 1.0 - s;    // err, flaming effect needs this
	}
}

/*
** RB_CalcTurbulentTexCoords
*/
void RB_CalcTurbulentTexCoords( const waveForm_t *wf, float *st ) {
	int i;
	float now;

	now = ( wf->phase + tess.shaderTime * wf->frequency );

	for ( i = 0; i < tess.numVertexes; i++, st += 2 )
	{
		float s = st[0];
		float t = st[1];

		st[0] = s + tr.sinTable[ ( ( int ) ( ( ( tess.xyz[i].v[0] + tess.xyz[i].v[2] ) * 1.0 / 128 * 0.125 + now ) * FUNCTABLE_SIZE ) ) & ( FUNCTABLE_MASK ) ] * wf->amplitude;
		st[1] = t + tr.sinTable[ ( ( int ) ( ( tess.xyz[i].v[1] * 1.0 / 128 * 0.125 + now ) * FUNCTABLE_SIZE ) ) & ( FUNCTABLE_MASK ) ] * wf->amplitude;
	}
}

/*
** RB_CalcScaleTexCoords
*/
void RB_CalcScaleTexCoords( const float scale[2], float *st ) {
	int i;

	for ( i = 0; i < tess.numVertexes; i++, st += 2 )
	{
		st[0] *= scale[0];
		st[1] *= scale[1];
	}
}

/*
** RB_CalcScrollTexCoords
*/
void RB_CalcScrollTexCoords( const float scrollSpeed[2], float *st ) {
	int i;
	float timeScale = tess.shaderTime;
	float adjustedScrollS, adjustedScrollT;

	adjustedScrollS = scrollSpeed[0] * timeScale;
	adjustedScrollT = scrollSpeed[1] * timeScale;

	// clamp so coordinates don't continuously get larger, causing problems
	// with hardware limits
	adjustedScrollS = adjustedScrollS - floor( adjustedScrollS );
	adjustedScrollT = adjustedScrollT - floor( adjustedScrollT );

	for ( i = 0; i < tess.numVertexes; i++, st += 2 )
	{
		st[0] += adjustedScrollS;
		st[1] += adjustedScrollT;
	}
}

/*
** RB_CalcTransformTexCoords
*/
void RB_CalcTransformTexCoords( const texModInfo_t *tmi, float *st  ) {
	int i;

	for ( i = 0; i < tess.numVertexes; i++, st += 2 )
	{
		float s = st[0];
		float t = st[1];

		st[0] = s * tmi->matrix[0][0] + t * tmi->matrix[1][0] + tmi->translate[0];
		st[1] = s * tmi->matrix[0][1] + t * tmi->matrix[1][1] + tmi->translate[1];
	}
}

/*
** RB_CalcRotateTexCoords
*/
void RB_CalcRotateTexCoords( float degsPerSecond, float *st ) {
	float timeScale = tess.shaderTime;
	float degs;
	int index;
	float sinValue, cosValue;
	texModInfo_t tmi;

	degs = -degsPerSecond * timeScale;
	index = degs * ( FUNCTABLE_SIZE / 360.0f );

	sinValue = tr.sinTable[ index & FUNCTABLE_MASK ];
	cosValue = tr.sinTable[ ( index + FUNCTABLE_SIZE / 4 ) & FUNCTABLE_MASK ];

	tmi.matrix[0][0] = cosValue;
	tmi.matrix[1][0] = -sinValue;
	tmi.translate[0] = 0.5 - 0.5 * cosValue + 0.5 * sinValue;

	tmi.matrix[0][1] = sinValue;
	tmi.matrix[1][1] = cosValue;
	tmi.translate[1] = 0.5 - 0.5 * sinValue - 0.5 * cosValue;

	RB_CalcTransformTexCoords( &tmi, st );
}

/*
** RB_CalcSpecularAlpha
**
** Calculates specular coefficient and places it in the alpha channel
*/
vec3_t lightOrigin = { -960, 1980, 96 };        // FIXME: track dynamically

void RB_CalcSpecularAlpha( unsigned char *alphas ) {
	int i;
	float       *v, *normal;
	vec3_t viewer,  reflected;
	float l, d;
	int b;
	vec3_t lightDir;
	int numVertexes;

	v = tess.xyz[0].v;
	normal = tess.normal[0].v;

	alphas += 3;

	numVertexes = tess.numVertexes;
	for ( i = 0 ; i < numVertexes ; i++, v += 4, normal += 4, alphas += 4 ) {
		float ilength;

		VectorSubtract( lightOrigin, v, lightDir );
//		ilength = Q_rsqrt( DotProduct( lightDir, lightDir ) );
		VectorNormalizeFast( lightDir );

		// calculate the specular color
		d = DotProduct( normal, lightDir );
//		d *= ilength;

		// we don't optimize for the d < 0 case since this tends to
		// cause visual artifacts such as faceted "snapping"
		reflected[0] = normal[0] * 2 * d - lightDir[0];
		reflected[1] = normal[1] * 2 * d - lightDir[1];
		reflected[2] = normal[2] * 2 * d - lightDir[2];

		VectorSubtract( backEnd.orientation.viewOrigin, v, viewer );
		ilength = Q_rsqrt( DotProduct( viewer, viewer ) );
		l = DotProduct( reflected, viewer );
		l *= ilength;

		if ( l < 0 ) {
			b = 0;
		} else {
			l = l * l;
			l = l * l;
			b = l * 255;
			if ( b > 255 ) {
				b = 255;
			}
		}

		*alphas = b;
	}
}

/*
** RB_CalcDiffuseColor
**
** The basic vertex lighting calc
*/

#if 1

// ydnar: faster, table-based version of this function
// saves about 1-2ms per frame on my machine with 64 x 1000 triangle models in scene
void RB_CalcDiffuseColor( unsigned char *colors ) {
	int i, dp, *colorsInt;
	float           *normal;
	trRefEntity_t   *ent;
	vec3_t lightDir;
	int numVertexes;


	ent = backEnd.currentEntity;
	VectorCopy( ent->lightDir, lightDir );

	normal = tess.normal[ 0 ].v;
	colorsInt = (int*) colors;

	numVertexes = tess.numVertexes;
	for ( i = 0; i < numVertexes; i++, normal += 4, colorsInt++ )
	{
		dp = myftol( ENTITY_LIGHT_STEPS * DotProduct( normal, lightDir ) );

		// ydnar: enable this for twosided lighting
		//%	if( tess.shader->cullType == CT_TWO_SIDED )
		//%		dp = fabs( dp );

		if ( dp <= 0 ) {
			*colorsInt = ent->entityLightInt[ 0 ];
		} else if ( dp >= ENTITY_LIGHT_STEPS ) {
			*colorsInt = ent->entityLightInt[ ENTITY_LIGHT_STEPS - 1 ];
		} else {
			*colorsInt = ent->entityLightInt[ dp ];
		}
	}
}

#else

void RB_CalcDiffuseColor( unsigned char *colors ) {
	int i, j;
	float           *v, *normal;
	float incoming;
	trRefEntity_t   *ent;
	int ambientLightInt;
	vec3_t ambientLight;
	vec3_t lightDir;
	vec3_t directedLight;
	int numVertexes;

	if ( r_dynamiclight->integer ) {
		RB_CalcDiffuseColorFast( colors );
		return;
	}

	ent = backEnd.currentEntity;
	ambientLightInt = ent->ambientLightInt;
	VectorCopy( ent->ambientLight, ambientLight );
	VectorCopy( ent->directedLight, directedLight );
	VectorCopy( ent->lightDir, lightDir );

	v = tess.xyz[0].v;
	normal = tess.normal[0].v;

	numVertexes = tess.numVertexes;
	for ( i = 0 ; i < numVertexes ; i++, v += 4, normal += 4 ) {
		incoming = DotProduct( normal, lightDir );
		if ( incoming <= 0 ) {
			*(int *)&colors[i * 4] = ambientLightInt;
			continue;
		}
		j = myftol( ambientLight[0] + incoming * directedLight[0] );
		if ( j > 255 ) {
			j = 255;
		}
		colors[i * 4 + 0] = j;

		j = myftol( ambientLight[1] + incoming * directedLight[1] );
		if ( j > 255 ) {
			j = 255;
		}
		colors[i * 4 + 1] = j;

		j = myftol( ambientLight[2] + incoming * directedLight[2] );
		if ( j > 255 ) {
			j = 255;
		}
		colors[i * 4 + 2] = j;

		colors[i * 4 + 3] = 255;
	}
}

#endif

