@ kPremul_SkAlphaType
pixel components are premultiplied by alpha
constexpr SkColor SK_ColorWHITE
void SK_SPI SkDebugf(const char format[],...) SK_PRINTF_LIKE(1
static void draw(SkCanvas *canvas, SkRect &target, int x, int y)
void clear(SkColor color)
#define REG_FIDDLE(NAME, W, H, TEXT, I)
static SkImageInfo MakeN32(int width, int height, SkAlphaType at)