/*
==================
R_AddClipSilEdges
Add sil edges for each triangle clipped to the side of
the frustum.
Only done for simple projected lights, not point lights.
==================
*/
static void R_AddClipSilEdges( void ) {
int v1, v2;
int v1_back, v2_back;
int i;
// don't allow it to overflow
if ( numShadowIndexes + numClipSilEdges * 6 > MAX_SHADOW_INDEXES ) {
overflowed = true;
return;
}
for ( i = 0 ; i < numClipSilEdges ; i++ ) {
v1 = clipSilEdges[i][0];
v2 = clipSilEdges[i][1];
v1_back = v1 + 1;
v2_back = v2 + 1;
if ( PointsOrdered( shadowVerts[ v1 ].ToVec3(), shadowVerts[ v2 ].ToVec3() ) ) {
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v1_back;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v2_back;
shadowIndexes[numShadowIndexes++] = v1_back;
} else {
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v2_back;
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v2_back;
shadowIndexes[numShadowIndexes++] = v1_back;
}
}
}
/*
==================
R_AddClipSilEdges
Add sil edges for each triangle clipped to the side of
the frustum.
Only done for simple projected lights, not point lights.
==================
*/
static void R_AddClipSilEdges(stencilRef_t *st) {
int v1, v2;
int v1_back, v2_back;
int i;
// don't allow it to overflow
if (st->numShadowIndexes + st->numClipSilEdges * 6 > MAX_SHADOW_INDEXES) {
st->overflowed = true;
return;
}
for (i = 0; i < st->numClipSilEdges; i++) {
v1 = st->clipSilEdges[i][0];
v2 = st->clipSilEdges[i][1];
v1_back = v1 + 1;
v2_back = v2 + 1;
if (PointsOrdered(st->shadowVerts[v1].ToVec3(), st->shadowVerts[v2].ToVec3())) {
st->shadowIndexes[st->numShadowIndexes++] = v1;
st->shadowIndexes[st->numShadowIndexes++] = v2;
st->shadowIndexes[st->numShadowIndexes++] = v1_back;
st->shadowIndexes[st->numShadowIndexes++] = v2;
st->shadowIndexes[st->numShadowIndexes++] = v2_back;
st->shadowIndexes[st->numShadowIndexes++] = v1_back;
}
else {
st->shadowIndexes[st->numShadowIndexes++] = v1;
st->shadowIndexes[st->numShadowIndexes++] = v2;
st->shadowIndexes[st->numShadowIndexes++] = v2_back;
st->shadowIndexes[st->numShadowIndexes++] = v1;
st->shadowIndexes[st->numShadowIndexes++] = v2_back;
st->shadowIndexes[st->numShadowIndexes++] = v1_back;
}
}
}
/*
=================
R_AddSilEdges
Add quads from the front points to the projected points
for each silhouette edge in the light
=================
*/
static void R_AddSilEdges( const srfTriangles_t *tri, unsigned short *pointCull, const idPlane frustum[6] ) {
int v1, v2;
int i;
silEdge_t *sil;
int numPlanes;
numPlanes = tri->numIndexes / 3;
// add sil edges for any true silhouette boundaries on the surface
for ( i = 0 ; i < tri->numSilEdges ; i++ ) {
sil = tri->silEdges + i;
if ( sil->p1 < 0 || sil->p1 > numPlanes || sil->p2 < 0 || sil->p2 > numPlanes ) {
common->Error( "Bad sil planes" );
}
// an edge will be a silhouette edge if the face on one side
// casts a shadow, but the face on the other side doesn't.
// "casts a shadow" means that it has some surface in the projection,
// not just that it has the correct facing direction
// This will cause edges that are exactly on the frustum plane
// to be considered sil edges if the face inside casts a shadow.
if ( !( faceCastsShadow[ sil->p1 ] ^ faceCastsShadow[ sil->p2 ] ) ) {
continue;
}
// if the edge is completely off the negative side of
// a frustum plane, don't add it at all. This can still
// happen even if the face is visible and casting a shadow
// if it is partially clipped
if ( EDGE_CULLED( sil->v1, sil->v2 ) ) {
continue;
}
// see if the edge needs to be clipped
if ( EDGE_CLIPPED( sil->v1, sil->v2 ) ) {
if ( numShadowVerts + 4 > MAX_SHADOW_VERTS ) {
overflowed = true;
return;
}
v1 = numShadowVerts;
v2 = v1 + 2;
if ( !R_ClipLineToLight( tri->verts[ sil->v1 ].xyz, tri->verts[ sil->v2 ].xyz,
frustum, shadowVerts[v1].ToVec3(), shadowVerts[v2].ToVec3() ) ) {
continue; // clipped away
}
numShadowVerts += 4;
} else {
// use the entire edge
v1 = remap[ sil->v1 ];
v2 = remap[ sil->v2 ];
if ( v1 < 0 || v2 < 0 ) {
common->Error( "R_AddSilEdges: bad remap[]" );
}
}
// don't overflow
if ( numShadowIndexes + 6 > MAX_SHADOW_INDEXES ) {
overflowed = true;
return;
}
// we need to choose the correct way of triangulating the silhouette quad
// consistantly between any two points, no matter which order they are specified.
// If this wasn't done, slight rasterization cracks would show in the shadow
// volume when two sil edges were exactly coincident
if ( faceCastsShadow[ sil->p2 ] ) {
if ( PointsOrdered( shadowVerts[ v1 ].ToVec3(), shadowVerts[ v2 ].ToVec3() ) ) {
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v1+1;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v1+1;
shadowIndexes[numShadowIndexes++] = v2+1;
}
else {
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v2 + 1;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v1 + 1;
shadowIndexes[numShadowIndexes++] = v2 + 1;
}
} else {
if ( PointsOrdered( shadowVerts[ v1 ].ToVec3(), shadowVerts[ v2 ].ToVec3() ) ) {
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v1+1;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v2+1;
shadowIndexes[numShadowIndexes++] = v1+1;
} else {
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v2;
shadowIndexes[numShadowIndexes++] = v2+1;
shadowIndexes[numShadowIndexes++] = v1;
shadowIndexes[numShadowIndexes++] = v2+1;
shadowIndexes[numShadowIndexes++] = v1+1;
}
}
}
}
