DBL image_pattern(const Vector3d& EPoint, const BasicPattern* pPattern)
{
DBL xcoor = 0.0, ycoor = 0.0;
int index = -1;
RGBFTColour colour;
const ImageData *image = dynamic_cast<const ImagePatternImpl*>(pPattern)->pImage;
DBL Value;
colour.Clear();
// going to have to change this
// need to know if bump point is off of image for all 3 points
if(map_pos(EPoint, pPattern, &xcoor, &ycoor))
return 0.0;
else
image_colour_at(image, xcoor, ycoor, colour, &index); // TODO ALPHA - we should decide whether we prefer premultiplied or non-premultiplied alpha
if((index == -1) || image->Use)
{
if(image->Use == USE_ALPHA)
{
// use alpha channel or red channel
if(image->data->HasTransparency() == true)
Value = colour.transm();
else
Value = colour.red(); // otherwise, just use the red channel
}
else
// use grey-scaled version of the color
Value = colour.Greyscale();
}
else
Value = index / 255.0;
if(Value < 0)
Value = 0;
else if(Value > 1.0)
Value = 1.0;
return Value;
}
