void IAGSEngine::GetRawColorComponents(int32 coldepth, int32 color, int32 *red, int32 *green, int32 *blue, int32 *alpha) {
if (red)
*red = getr_depth(coldepth, color);
if (green)
*green = getg_depth(coldepth, color);
if (blue)
*blue = getb_depth(coldepth, color);
if (alpha)
*alpha = geta_depth(coldepth, color);
}
/* geta:
* Extracts the alpha component (ranging 0-255) from a pixel in the format
* being used by the current video mode.
*/
int geta(int c)
{
return geta_depth(_color_depth, c);
}
virtual Image* load(const std::string& filename,
bool convertToDisplayFormat = true)
{
BITMAP *bmp = load_bitmap(filename.c_str(), NULL);
if (bmp == NULL)
{
throw GCN_EXCEPTION(
std::string("Unable to load image file: ") + filename);
}
int bitmapBpp = bitmap_color_depth(bmp);
// As a BITMAP without an alpha channel in Allegro has
// all it's alpha values set to zero we have to check
// if the BITMAP has an alpha channel. If no alpha channel
// exists then we need to change the alpha values to 255
// before creating the OpenGL image.
bool hasAlphaChannel = false;
int x, y;
for (y = 0; y < bmp->h; y++)
{
for (x = 0; x < bmp->w; x++)
{
int pixel = getpixel(bmp, x, y);
if (geta_depth(bitmapBpp, pixel) != 0)
{
hasAlphaChannel = true;
}
}
}
unsigned int *pixels = new unsigned int[bmp->w * bmp->h];
for (y = 0; y < bmp->h; y++)
{
for (x = 0; x < bmp->w; x++)
{
int pixel = getpixel(bmp,x, y);
if (!hasAlphaChannel)
{
pixels[x + y * bmp->w] = pixel | 0xff000000;
}
else
{
pixels[x + y * bmp->w] = pixel;
}
}
}
OpenGLImage *image = new OpenGLImage(pixels,
bmp->w,
bmp->h,
convertToDisplayFormat);
delete[] pixels;
destroy_bitmap(bmp);
return image;
}
