1 files changed, 343 insertions, 0 deletions
diff --git a/src/rend2/tr_shadows.c b/src/rend2/tr_shadows.c
new file mode 100644
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--- /dev/null
+++ b/src/rend2/tr_shadows.c
@@ -0,0 +1,343 @@
+/*
+===========================================================================
+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
+===========================================================================
+*/
+#include "tr_local.h"
+
+
+/*
+
+  for a projection shadow:
+
+  point[x] += light vector * ( z - shadow plane )
+  point[y] +=
+  point[z] = shadow plane
+
+  1 0 light[x] / light[z]
+
+*/
+
+typedef struct {
+	int		i2;
+	int		facing;
+} edgeDef_t;
+
+#define	MAX_EDGE_DEFS	32
+
+static	edgeDef_t	edgeDefs[SHADER_MAX_VERTEXES][MAX_EDGE_DEFS];
+static	int			numEdgeDefs[SHADER_MAX_VERTEXES];
+static	int			facing[SHADER_MAX_INDEXES/3];
+
+void R_AddEdgeDef( int i1, int i2, int facing ) {
+	int		c;
+
+	c = numEdgeDefs[ i1 ];
+	if ( c == MAX_EDGE_DEFS ) {
+		return;		// overflow
+	}
+	edgeDefs[ i1 ][ c ].i2 = i2;
+	edgeDefs[ i1 ][ c ].facing = facing;
+
+	numEdgeDefs[ i1 ]++;
+}
+
+void R_RenderShadowEdges( void ) {
+	int		i;
+
+#if 0
+	int		numTris;
+
+	// dumb way -- render every triangle's edges
+	numTris = tess.numIndexes / 3;
+
+	for ( i = 0 ; i < numTris ; i++ ) {
+		int		i1, i2, i3;
+
+		if ( !facing[i] ) {
+			continue;
+		}
+
+		i1 = tess.indexes[ i*3 + 0 ];
+		i2 = tess.indexes[ i*3 + 1 ];
+		i3 = tess.indexes[ i*3 + 2 ];
+
+		qglBegin( GL_TRIANGLE_STRIP );
+		qglVertex3fv( tess.xyz[ i1 ] );
+		qglVertex3fv( tess.xyz[ i1 + tess.numVertexes ] );
+		qglVertex3fv( tess.xyz[ i2 ] );
+		qglVertex3fv( tess.xyz[ i2 + tess.numVertexes ] );
+		qglVertex3fv( tess.xyz[ i3 ] );
+		qglVertex3fv( tess.xyz[ i3 + tess.numVertexes ] );
+		qglVertex3fv( tess.xyz[ i1 ] );
+		qglVertex3fv( tess.xyz[ i1 + tess.numVertexes ] );
+		qglEnd();
+	}
+#else
+	int		c, c2;
+	int		j, k;
+	int		i2;
+	int		c_edges, c_rejected;
+	int		hit[2];
+
+	// an edge is NOT a silhouette edge if its face doesn't face the light,
+	// or if it has a reverse paired edge that also faces the light.
+	// A well behaved polyhedron would have exactly two faces for each edge,
+	// but lots of models have dangling edges or overfanned edges
+	c_edges = 0;
+	c_rejected = 0;
+
+	for ( i = 0 ; i < tess.numVertexes ; i++ ) {
+		c = numEdgeDefs[ i ];
+		for ( j = 0 ; j < c ; j++ ) {
+			if ( !edgeDefs[ i ][ j ].facing ) {
+				continue;
+			}
+
+			hit[0] = 0;
+			hit[1] = 0;
+
+			i2 = edgeDefs[ i ][ j ].i2;
+			c2 = numEdgeDefs[ i2 ];
+			for ( k = 0 ; k < c2 ; k++ ) {
+				if ( edgeDefs[ i2 ][ k ].i2 == i ) {
+					hit[ edgeDefs[ i2 ][ k ].facing ]++;
+				}
+			}
+
+			// if it doesn't share the edge with another front facing
+			// triangle, it is a sil edge
+			if ( hit[ 1 ] == 0 ) {
+				qglBegin( GL_TRIANGLE_STRIP );
+				qglVertex3fv( tess.xyz[ i ] );
+				qglVertex3fv( tess.xyz[ i + tess.numVertexes ] );
+				qglVertex3fv( tess.xyz[ i2 ] );
+				qglVertex3fv( tess.xyz[ i2 + tess.numVertexes ] );
+				qglEnd();
+				c_edges++;
+			} else {
+				c_rejected++;
+			}
+		}
+	}
+#endif
+}
+
+/*
+=================
+RB_ShadowTessEnd
+
+triangleFromEdge[ v1 ][ v2 ]
+
+
+  set triangle from edge( v1, v2, tri )
+  if ( facing[ triangleFromEdge[ v1 ][ v2 ] ] && !facing[ triangleFromEdge[ v2 ][ v1 ] ) {
+  }
+=================
+*/
+void RB_ShadowTessEnd( void ) {
+	int		i;
+	int		numTris;
+	vec3_t	lightDir;
+	GLboolean rgba[4];
+
+	// we can only do this if we have enough space in the vertex buffers
+	if ( tess.numVertexes >= SHADER_MAX_VERTEXES / 2 ) {
+		return;
+	}
+
+	if ( glConfig.stencilBits < 4 ) {
+		return;
+	}
+
+	VectorCopy( backEnd.currentEntity->lightDir, lightDir );
+
+	// project vertexes away from light direction
+	for ( i = 0 ; i < tess.numVertexes ; i++ ) {
+		VectorMA( tess.xyz[i], -512, lightDir, tess.xyz[i+tess.numVertexes] );
+	}
+
+	// decide which triangles face the light
+	Com_Memset( numEdgeDefs, 0, 4 * tess.numVertexes );
+
+	numTris = tess.numIndexes / 3;
+	for ( i = 0 ; i < numTris ; i++ ) {
+		int		i1, i2, i3;
+		vec3_t	d1, d2, normal;
+		float	*v1, *v2, *v3;
+		float	d;
+
+		i1 = tess.indexes[ i*3 + 0 ];
+		i2 = tess.indexes[ i*3 + 1 ];
+		i3 = tess.indexes[ i*3 + 2 ];
+
+		v1 = tess.xyz[ i1 ];
+		v2 = tess.xyz[ i2 ];
+		v3 = tess.xyz[ i3 ];
+
+		VectorSubtract( v2, v1, d1 );
+		VectorSubtract( v3, v1, d2 );
+		CrossProduct( d1, d2, normal );
+
+		d = DotProduct( normal, lightDir );
+		if ( d > 0 ) {
+			facing[ i ] = 1;
+		} else {
+			facing[ i ] = 0;
+		}
+
+		// create the edges
+		R_AddEdgeDef( i1, i2, facing[ i ] );
+		R_AddEdgeDef( i2, i3, facing[ i ] );
+		R_AddEdgeDef( i3, i1, facing[ i ] );
+	}
+
+	// draw the silhouette edges
+
+	GL_Bind( tr.whiteImage );
+	qglEnable( GL_CULL_FACE );
+	GL_State( GLS_SRCBLEND_ONE | GLS_DSTBLEND_ZERO );
+	qglColor3f( 0.2f, 0.2f, 0.2f );
+
+	// don't write to the color buffer
+	qglGetBooleanv(GL_COLOR_WRITEMASK, rgba);
+	qglColorMask( GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE );
+
+	qglEnable( GL_STENCIL_TEST );
+	qglStencilFunc( GL_ALWAYS, 1, 255 );
+
+	// mirrors have the culling order reversed
+	if ( backEnd.viewParms.isMirror ) {
+		qglCullFace( GL_FRONT );
+		qglStencilOp( GL_KEEP, GL_KEEP, GL_INCR );
+
+		R_RenderShadowEdges();
+
+		qglCullFace( GL_BACK );
+		qglStencilOp( GL_KEEP, GL_KEEP, GL_DECR );
+
+		R_RenderShadowEdges();
+	} else {
+		qglCullFace( GL_BACK );
+		qglStencilOp( GL_KEEP, GL_KEEP, GL_INCR );
+
+		R_RenderShadowEdges();
+
+		qglCullFace( GL_FRONT );
+		qglStencilOp( GL_KEEP, GL_KEEP, GL_DECR );
+
+		R_RenderShadowEdges();
+	}
+
+
+	// reenable writing to the color buffer
+	qglColorMask(rgba[0], rgba[1], rgba[2], rgba[3]);
+}
+
+
+/*
+=================
+RB_ShadowFinish
+
+Darken everything that is is a shadow volume.
+We have to delay this until everything has been shadowed,
+because otherwise shadows from different body parts would
+overlap and double darken.
+=================
+*/
+void RB_ShadowFinish( void ) {
+	if ( r_shadows->integer != 2 ) {
+		return;
+	}
+	if ( glConfig.stencilBits < 4 ) {
+		return;
+	}
+	qglEnable( GL_STENCIL_TEST );
+	qglStencilFunc( GL_NOTEQUAL, 0, 255 );
+
+	qglDisable (GL_CLIP_PLANE0);
+	qglDisable (GL_CULL_FACE);
+
+	GL_Bind( tr.whiteImage );
+
+    qglLoadIdentity ();
+
+	qglColor3f( 0.6f, 0.6f, 0.6f );
+	GL_State( GLS_DEPTHMASK_TRUE | GLS_SRCBLEND_DST_COLOR | GLS_DSTBLEND_ZERO );
+
+//	qglColor3f( 1, 0, 0 );
+//	GL_State( GLS_DEPTHMASK_TRUE | GLS_SRCBLEND_ONE | GLS_DSTBLEND_ZERO );
+
+	qglBegin( GL_QUADS );
+	qglVertex3f( -100, 100, -10 );
+	qglVertex3f( 100, 100, -10 );
+	qglVertex3f( 100, -100, -10 );
+	qglVertex3f( -100, -100, -10 );
+	qglEnd ();
+
+	qglColor4f(1,1,1,1);
+	qglDisable( GL_STENCIL_TEST );
+}
+
+
+/*
+=================
+RB_ProjectionShadowDeform
+
+=================
+*/
+void RB_ProjectionShadowDeform( void ) {
+	float	*xyz;
+	int		i;
+	float	h;
+	vec3_t	ground;
+	vec3_t	light;
+	float	groundDist;
+	float	d;
+	vec3_t	lightDir;
+
+	xyz = ( float * ) tess.xyz;
+
+	ground[0] = backEnd.or.axis[0][2];
+	ground[1] = backEnd.or.axis[1][2];
+	ground[2] = backEnd.or.axis[2][2];
+
+	groundDist = backEnd.or.origin[2] - backEnd.currentEntity->e.shadowPlane;
+
+	VectorCopy( backEnd.currentEntity->lightDir, lightDir );
+	d = DotProduct( lightDir, ground );
+	// don't let the shadows get too long or go negative
+	if ( d < 0.5 ) {
+		VectorMA( lightDir, (0.5 - d), ground, lightDir );
+		d = DotProduct( lightDir, ground );
+	}
+	d = 1.0 / d;
+
+	light[0] = lightDir[0] * d;
+	light[1] = lightDir[1] * d;
+	light[2] = lightDir[2] * d;
+
+	for ( i = 0; i < tess.numVertexes; i++, xyz += 4 ) {
+		h = DotProduct( xyz, ground ) + groundDist;
+
+		xyz[0] -= light[0] * h;
+		xyz[1] -= light[1] * h;
+		xyz[2] -= light[2] * h;
+	}
+}