void
GL::EnableClipPlanes(const ConvexPolygon& aPolygon, UniqueId aPolygonId)
{
MOZ_ASSERT(IsCurrent());
MOZ_ASSERT(aPolygon.NumSides() <= mMaxClipPlanes);
if (mClipPolygonId == aPolygonId) {
return;
}
if (aPolygon.IsEmpty()) {
if (!mNumClipPlanes) {
Enable(GL_CLIP_PLANE0);
} else {
for (size_t i = 1; i < mNumClipPlanes; i++) {
Disable(GL_CLIP_PLANE0 + i);
}
}
mNumClipPlanes = 1;
// We specify a single clip plane equation that fails for all vertices.
const double planeEquation[] = {0, 0, 0, -1};
ClipPlane(GL_CLIP_PLANE0, planeEquation);
mClipPolygonId = aPolygonId;
return;
}
for (size_t i = mNumClipPlanes; i < aPolygon.NumSides(); i++) {
Enable(GL_CLIP_PLANE0 + i);
}
for (size_t i = aPolygon.NumSides(); i < mNumClipPlanes; i++) {
Disable(GL_CLIP_PLANE0 + i);
}
mNumClipPlanes = aPolygon.NumSides();
for (size_t i = 0; i < aPolygon.NumSides(); i++) {
const Line& line = aPolygon.Sides()[i];
const double planeEquation[] = {line.A, line.B, 0, -line.C};
ClipPlane(GL_CLIP_PLANE0 + i, planeEquation);
}
mClipPolygonId = aPolygonId;
}
ClipPlane *ClipPlane::getOrCreate(int plane)
{
return getOrCreateImpl(ClipPlane(plane));
}