| #ifndef SkBitmapProcState_utils_DEFINED | |
| #define SkBitmapProcState_utils_DEFINED | |
| // Helper to ensure that when we shift down, we do it w/o sign-extension | |
| // so the caller doesn't have to manually mask off the top 16 bits | |
| // | |
| static unsigned SK_USHIFT16(unsigned x) { | |
| return x >> 16; | |
| } | |
| /* | |
| * The decal_ functions require that | |
| * 1. dx > 0 | |
| * 2. [fx, fx+dx, fx+2dx, fx+3dx, ... fx+(count-1)dx] are all <= maxX | |
| * | |
| * In addition, we use SkFractionalInt to keep more fractional precision than | |
| * just SkFixed, so we will abort the decal_ call if dx is very small, since | |
| * the decal_ function just operates on SkFixed. If that were changed, we could | |
| * skip the very_small test here. | |
| */ | |
| static inline bool can_truncate_to_fixed_for_decal(SkFractionalInt frX, | |
| SkFractionalInt frDx, | |
| int count, unsigned max) { | |
| SkFixed dx = SkFractionalIntToFixed(frDx); | |
| // if decal_ kept SkFractionalInt precision, this would just be dx <= 0 | |
| // I just made up the 1/256. Just don't want to perceive accumulated error | |
| // if we truncate frDx and lose its low bits. | |
| if (dx <= SK_Fixed1 / 256) { | |
| return false; | |
| } | |
| // We cast to unsigned so we don't have to check for negative values, which | |
| // will now appear as very large positive values, and thus fail our test! | |
| SkFixed fx = SkFractionalIntToFixed(frX); | |
| return (unsigned)SkFixedFloorToInt(fx) <= max && | |
| (unsigned)SkFixedFloorToInt(fx + dx * (count - 1)) < max; | |
| } | |
| #endif /* #ifndef SkBitmapProcState_utils_DEFINED */ |