+PixelFormat get_sized_pixelformat(PixelFormat pf, unsigned size)
+{
+ if(!size || size>4)
+ throw invalid_argument("get_sized_pixelformat");
+
+ switch(pf)
+ {
+ case SRGB:
+ case SRGB_ALPHA: break;
+ case SRGB8: pf = SRGB; break;
+ case SRGB8_ALPHA8: pf = SRGB_ALPHA; break;
+ default: pf = get_base_pixelformat(pf);
+ }
+
+ switch(size)
+ {
+ case 1:
+ switch(pf)
+ {
+ case RED: return R8;
+ case RG: return RG8;
+ case RGB: return RGB8;
+ case RGBA: return RGBA8;
+ case SRGB: return SRGB8;
+ case SRGB_ALPHA: return SRGB8_ALPHA8;
+ case LUMINANCE: return LUMINANCE8;
+ case SLUMINANCE: return SLUMINANCE8;
+ case LUMINANCE_ALPHA: return LUMINANCE8_ALPHA8;
+ case SLUMINANCE_ALPHA: return SLUMINANCE8_ALPHA8;
+ default: throw invalid_argument("get_sized_pixelformat");
+ }
+ case 2:
+ switch(pf)
+ {
+ case RED: return R16F;
+ case RG: return RG16F;
+ case RGB: return RGB16F;
+ case RGBA: return RGBA16F;
+ case DEPTH_COMPONENT: return DEPTH_COMPONENT16;
+ default: throw invalid_argument("get_sized_pixelformat");
+ }
+ case 3:
+ if(pf==DEPTH_COMPONENT)
+ return DEPTH_COMPONENT24;
+ else
+ throw invalid_argument("get_sized_pixelformat");
+ case 4:
+ switch(pf)
+ {
+ case RED: return R32F;
+ case RG: return RG32F;
+ case RGB: return RGB32F;
+ case RGBA: return RGBA32F;
+ case DEPTH_COMPONENT: return DEPTH_COMPONENT32;
+ default: throw invalid_argument("get_sized_pixelformat");
+ }
+ default:
+ throw invalid_argument("get_sized_pixelformat");
+ }
+}
+