ref_ptr<PrimitiveSet> VTXReader::processStrip(unsigned short * indexArray,
std::istream * str,
int offset)
{
VTXStrip strip;
DrawElementsUShort * drawElements;
ref_ptr<PrimitiveSet> primSet;
unsigned short * start;
unsigned short * end;
// Seek to the strip
str->seekg(offset);
// Read it. We have to do this in a kind of screwy way because of the
// weird byte packing. Valve uses pragma pack, but we can't do that
// because it's non-portable. Of course, I'm assuming a 4-byte alignment
// here, which might also be non-portable...
str->read((char *) &strip, VTX_STRIP_SIZE - 8);
str->read((char *) &strip.num_bone_state_changes, 8);
// Get the range of indices in question from the strip
start = &indexArray[strip.index_offset];
end = &indexArray[strip.index_offset + strip.num_indices];
// Create the primitive set (based on the flag)
if (strip.strip_flags & STRIP_IS_TRI_LIST)
drawElements =
new DrawElementsUShort(PrimitiveSet::TRIANGLES, start, end);
else
drawElements =
new DrawElementsUShort(PrimitiveSet::TRIANGLE_STRIP, start, end);
// Flip the indices to get the front faces correct
std::reverse(drawElements->begin(), drawElements->end());
// Return the primitive set
primSet = drawElements;
return primSet;
}
