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 #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 */