void PtexReader::getPixel(int faceid, int u, int v,
float* result, int firstchan, int nchannels,
Ptex::Res res)
{
memset(result, 0, nchannels);
// clip nchannels against actual number available
nchannels = PtexUtils::min(nchannels,
_header.nchannels-firstchan);
if (nchannels <= 0) return;
// get raw pixel data
PtexPtr<PtexFaceData> data ( getData(faceid, res) );
if (!data) return;
void* pixel = alloca(_pixelsize);
data->getPixel(u, v, pixel);
// adjust for firstchan offset
int datasize = DataSize(_header.datatype);
if (firstchan)
pixel = (char*) pixel + datasize * firstchan;
// convert/copy to result as needed
if (_header.datatype == dt_float)
memcpy(result, pixel, datasize * nchannels);
else
ConvertToFloat(result, pixel, _header.datatype, nchannels);
}
void PtexReader::TiledFaceBase::getPixel(int ui, int vi, void* result)
{
int tileu = ui >> _tileres.ulog2;
int tilev = vi >> _tileres.vlog2;
PtexPtr<PtexFaceData> tile ( getTile(tilev * _ntilesu + tileu) );
tile->getPixel(ui - (tileu<<_tileres.ulog2),
vi - (tilev<<_tileres.vlog2), result);
}