/*
=================
R_CreateShadowVolumeInFrustum
Adds new verts and indexes to the shadow volume.
If the frustum completely defines the projected light,
makeClippedPlanes should be true, which will cause sil quads to
be added along all clipped edges.
If the frustum is just part of a point light, clipped planes don't
need to be added.
=================
*/
static void R_CreateShadowVolumeInFrustum( const idRenderEntityLocal *ent,
const srfTriangles_t *tri,
const idRenderLightLocal *light,
const idVec3 lightOrigin,
const idPlane frustum[6],
const idPlane &farPlane,
bool makeClippedPlanes ) {
int i;
int numTris;
unsigned short *pointCull;
int numCapIndexes;
int firstShadowIndex;
int firstShadowVert;
int cullBits;
pointCull = (unsigned short *)_alloca16( tri->numVerts * sizeof( pointCull[0] ) );
// test the vertexes for inside the light frustum, which will allow
// us to completely cull away some triangles from consideration.
R_CalcPointCull( tri, frustum, pointCull );
// this may not be the first frustum added to the volume
firstShadowIndex = numShadowIndexes;
firstShadowVert = numShadowVerts;
// decide which triangles front shadow volumes, clipping as needed
numClipSilEdges = 0;
numTris = tri->numIndexes / 3;
for ( i = 0 ; i < numTris ; i++ ) {
int i1, i2, i3;
faceCastsShadow[i] = 0; // until shown otherwise
// if it isn't facing the right way, don't add it
// to the shadow volume
if ( globalFacing[i] ) {
continue;
}
i1 = tri->silIndexes[ i*3 + 0 ];
i2 = tri->silIndexes[ i*3 + 1 ];
i3 = tri->silIndexes[ i*3 + 2 ];
// if all the verts are off one side of the frustum,
// don't add any of them
if ( TRIANGLE_CULLED( i1, i2, i3 ) ) {
continue;
}
/*
=================
R_CreateShadowVolumeInFrustum
Adds new verts and indexes to the shadow volume.
If the frustum completely defines the projected light,
makeClippedPlanes should be true, which will cause sil quads to
be added along all clipped edges.
If the frustum is just part of a point light, clipped planes don't
need to be added.
=================
*/
static void R_CreateShadowVolumeInFrustum( const idRenderEntityLocal *ent,
const srfTriangles_t *tri,
const idRenderLightLocal *light,
const idVec3 lightOrigin,
const idPlane frustum[6],
const idPlane &farPlane,
bool makeClippedPlanes ) {
int i;
int numTris;
unsigned short *pointCull;
int numCapIndexes;
int firstShadowIndex;
int firstShadowVert;
int cullBits;
pointCull = (unsigned short *)_alloca16( tri->numVerts * sizeof( pointCull[0] ) );
// test the vertexes for inside the light frustum, which will allow
// us to completely cull away some triangles from consideration.
R_CalcPointCull( tri, frustum, pointCull );
// this may not be the first frustum added to the volume
firstShadowIndex = numShadowIndexes;
firstShadowVert = numShadowVerts;
// decide which triangles front shadow volumes, clipping as needed
int numFace = 0;
numClipSilEdges = 0;
numTris = tri->numIndexes / 3;
for ( i = 0 ; i < numTris ; i++ ) {
int i1, i2, i3;
faceCastsShadow[i] = 0; // until shown otherwise
// if it isn't facing the right way, don't add it
// to the shadow volume
if ( globalFacing[i] ) {
continue;
}
++numFace;
i1 = tri->silIndexes[ i*3 + 0 ];
i2 = tri->silIndexes[ i*3 + 1 ];
i3 = tri->silIndexes[ i*3 + 2 ];
// if all the verts are off one side of the frustum,
// don't add any of them
if ( TRIANGLE_CULLED( i1, i2, i3 ) ) {
continue;
}
// make sure the verts that are not on the negative sides
// of the frustum are copied over.
// we need to get the original verts even from clipped triangles
// so the edges reference correctly, because an edge may be unclipped
// even when a triangle is clipped.
if ( numShadowVerts + 6 > MAX_SHADOW_VERTS ) {
overflowed = true;
return;
}
if ( !POINT_CULLED(i1) && remap[i1] == -1 ) {
remap[i1] = numShadowVerts;
shadowVerts[ numShadowVerts ].ToVec3() = tri->verts[i1].xyz;
numShadowVerts+=2;
}
if ( !POINT_CULLED(i2) && remap[i2] == -1 ) {
remap[i2] = numShadowVerts;
shadowVerts[ numShadowVerts ].ToVec3() = tri->verts[i2].xyz;
numShadowVerts+=2;
}
if ( !POINT_CULLED(i3) && remap[i3] == -1 ) {
remap[i3] = numShadowVerts;
shadowVerts[ numShadowVerts ].ToVec3() = tri->verts[i3].xyz;
numShadowVerts+=2;
}
// clip the triangle if any points are on the negative sides
if ( TRIANGLE_CLIPPED( i1, i2, i3 ) ) {
cullBits = ( ( pointCull[ i1 ] ^ 0xfc0 ) | ( pointCull[ i2 ] ^ 0xfc0 ) | ( pointCull[ i3 ] ^ 0xfc0 ) ) >> 6;
// this will also define clip edges that will become
// silhouette planes
if ( R_ClipTriangleToLight( tri->verts[i1].xyz, tri->verts[i2].xyz,
tri->verts[i3].xyz, cullBits, frustum ) ) {
faceCastsShadow[i] = 1;
}
} else {
// instead of overflowing or drawing a streamer shadow, don't draw a shadow at all
if ( numShadowIndexes + 3 > MAX_SHADOW_INDEXES ) {
overflowed = true;
return;
}
if ( remap[i1] == -1 || remap[i2] == -1 || remap[i3] == -1 ) {
common->Error( "R_CreateShadowVolumeInFrustum: bad remap[]" );
}
shadowIndexes[numShadowIndexes++] = remap[i3];
shadowIndexes[numShadowIndexes++] = remap[i2];
shadowIndexes[numShadowIndexes++] = remap[i1];
faceCastsShadow[i] = 1;
}
}
