@ kSaturation
saturation of source with hue and luminosity of destination
static void draw(SkCanvas *canvas, SkRect &target, int x, int y)
void drawColor(SkColor color, SkBlendMode mode=SkBlendMode::kSrcOver)
void drawImage(const SkImage *image, SkScalar left, SkScalar top)
#define REG_FIDDLE(NAME, W, H, TEXT, I)