| /* |
| * Copyright 2008 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "include/core/SkShader.h" |
| #include "include/private/SkTo.h" |
| #include "src/core/SkBitmapProcState.h" |
| #include "src/core/SkUtils.h" |
| |
| /* |
| * 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(SkFixed fx, |
| SkFixed dx, |
| int count, unsigned max) { |
| SkASSERT(count > 0); |
| |
| // 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; |
| } |
| |
| // Note: it seems the test should be (fx <= max && lastFx <= max); but |
| // historically it's been a strict inequality check, and changing produces |
| // unexpected diffs. Further investigation is needed. |
| |
| // 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! |
| if ((unsigned)SkFixedFloorToInt(fx) >= max) { |
| return false; |
| } |
| |
| // Promote to 64bit (48.16) to avoid overflow. |
| const uint64_t lastFx = fx + sk_64_mul(dx, count - 1); |
| |
| return SkTFitsIn<int32_t>(lastFx) && (unsigned)SkFixedFloorToInt(SkTo<int32_t>(lastFx)) < max; |
| } |
| |
| // When not filtering, we store 32-bit y, 16-bit x, 16-bit x, 16-bit x, ... |
| // When filtering we write out 32-bit encodings, pairing 14.4 x0 with 14-bit x1. |
| |
| // The clamp routines may try to fall into one of these unclamped decal fast-paths. |
| // (Only clamp works in the right coordinate space to check for decal.) |
| static void decal_nofilter_scale(uint32_t dst[], SkFixed fx, SkFixed dx, int count) { |
| // can_truncate_to_fixed_for_decal() checked only that stepping fx+=dx count-1 |
| // times doesn't overflow fx, so we take unusual care not to step count times. |
| for (; count > 2; count -= 2) { |
| *dst++ = pack_two_shorts( (fx + 0) >> 16, |
| (fx + dx) >> 16); |
| fx += dx+dx; |
| } |
| |
| SkASSERT(count <= 2); |
| switch (count) { |
| case 2: ((uint16_t*)dst)[1] = SkToU16((fx + dx) >> 16); |
| case 1: ((uint16_t*)dst)[0] = SkToU16((fx + 0) >> 16); |
| } |
| } |
| |
| // A generic implementation for unfiltered scale+translate, templated on tiling method. |
| template <unsigned (*tile)(SkFixed, int), bool tryDecal> |
| static void nofilter_scale(const SkBitmapProcState& s, |
| uint32_t xy[], int count, int x, int y) { |
| SkASSERT(s.fInvMatrix.isScaleTranslate()); |
| |
| // Write out our 32-bit y, and get our intial fx. |
| SkFractionalInt fx; |
| { |
| const SkBitmapProcStateAutoMapper mapper(s, x, y); |
| *xy++ = tile(mapper.fixedY(), s.fPixmap.height() - 1); |
| fx = mapper.fractionalIntX(); |
| } |
| |
| const unsigned maxX = s.fPixmap.width() - 1; |
| if (0 == maxX) { |
| // If width == 1, all the x-values must refer to that pixel, and must be zero. |
| memset(xy, 0, count * sizeof(uint16_t)); |
| return; |
| } |
| |
| const SkFractionalInt dx = s.fInvSxFractionalInt; |
| |
| if (tryDecal) { |
| const SkFixed fixedFx = SkFractionalIntToFixed(fx); |
| const SkFixed fixedDx = SkFractionalIntToFixed(dx); |
| |
| if (can_truncate_to_fixed_for_decal(fixedFx, fixedDx, count, maxX)) { |
| decal_nofilter_scale(xy, fixedFx, fixedDx, count); |
| return; |
| } |
| } |
| |
| // Remember, each x-coordinate is 16-bit. |
| for (; count >= 2; count -= 2) { |
| *xy++ = pack_two_shorts(tile(SkFractionalIntToFixed(fx ), maxX), |
| tile(SkFractionalIntToFixed(fx + dx), maxX)); |
| fx += dx+dx; |
| } |
| |
| auto xx = (uint16_t*)xy; |
| while (count --> 0) { |
| *xx++ = tile(SkFractionalIntToFixed(fx), maxX); |
| fx += dx; |
| } |
| } |
| |
| template <unsigned (*tile)(SkFixed, int)> |
| static void nofilter_affine(const SkBitmapProcState& s, |
| uint32_t xy[], int count, int x, int y) { |
| SkASSERT(!s.fInvMatrix.hasPerspective()); |
| |
| const SkBitmapProcStateAutoMapper mapper(s, x, y); |
| |
| SkFractionalInt fx = mapper.fractionalIntX(), |
| fy = mapper.fractionalIntY(), |
| dx = s.fInvSxFractionalInt, |
| dy = s.fInvKyFractionalInt; |
| int maxX = s.fPixmap.width () - 1, |
| maxY = s.fPixmap.height() - 1; |
| |
| while (count --> 0) { |
| *xy++ = (tile(SkFractionalIntToFixed(fy), maxY) << 16) |
| | (tile(SkFractionalIntToFixed(fx), maxX) ); |
| fx += dx; |
| fy += dy; |
| } |
| } |
| |
| // Extract the high four fractional bits from fx, the lerp parameter when filtering. |
| static unsigned extract_low_bits_clamp(SkFixed fx, int /*max*/) { |
| // If we're already scaled up to by max like clamp/decal, |
| // just grab the high four fractional bits. |
| return (fx >> 12) & 0xf; |
| } |
| static unsigned extract_low_bits_repeat_mirror(SkFixed fx, int max) { |
| // In repeat or mirror fx is in [0,1], so scale up by max first. |
| // TODO: remove the +1 here and the -1 at the call sites... |
| return extract_low_bits_clamp((fx & 0xffff) * (max+1), max); |
| } |
| |
| template <unsigned (*tile)(SkFixed, int), unsigned (*extract_low_bits)(SkFixed, int)> |
| static uint32_t pack(SkFixed f, unsigned max, SkFixed one) { |
| uint32_t packed = tile(f, max); // low coordinate in high bits |
| packed = (packed << 4) | extract_low_bits(f, max); // (lerp weight _is_ coord fractional part) |
| packed = (packed << 14) | tile((f + one), max); // high coordinate in low bits |
| return packed; |
| } |
| |
| template <unsigned (*tile)(SkFixed, int), unsigned (*extract_low_bits)(SkFixed, int), bool tryDecal> |
| static void filter_scale(const SkBitmapProcState& s, |
| uint32_t xy[], int count, int x, int y) { |
| SkASSERT(s.fInvMatrix.isScaleTranslate()); |
| |
| const unsigned maxX = s.fPixmap.width() - 1; |
| const SkFractionalInt dx = s.fInvSxFractionalInt; |
| SkFractionalInt fx; |
| { |
| const SkBitmapProcStateAutoMapper mapper(s, x, y); |
| const unsigned maxY = s.fPixmap.height() - 1; |
| // compute our two Y values up front |
| *xy++ = pack<tile, extract_low_bits>(mapper.fixedY(), maxY, s.fFilterOneY); |
| // now initialize fx |
| fx = mapper.fractionalIntX(); |
| } |
| |
| // For historical reasons we check both ends are < maxX rather than <= maxX. |
| // TODO: try changing this? See also can_truncate_to_fixed_for_decal(). |
| if (tryDecal && |
| (unsigned)SkFractionalIntToInt(fx ) < maxX && |
| (unsigned)SkFractionalIntToInt(fx + dx*(count-1)) < maxX) { |
| while (count --> 0) { |
| SkFixed fixedFx = SkFractionalIntToFixed(fx); |
| SkASSERT((fixedFx >> (16 + 14)) == 0); |
| *xy++ = (fixedFx >> 12 << 14) | ((fixedFx >> 16) + 1); |
| fx += dx; |
| } |
| return; |
| } |
| |
| while (count --> 0) { |
| *xy++ = pack<tile, extract_low_bits>(SkFractionalIntToFixed(fx), maxX, s.fFilterOneX); |
| fx += dx; |
| } |
| } |
| |
| template <unsigned (*tile)(SkFixed, int), unsigned (*extract_low_bits)(SkFixed, int)> |
| static void filter_affine(const SkBitmapProcState& s, |
| uint32_t xy[], int count, int x, int y) { |
| SkASSERT(!s.fInvMatrix.hasPerspective()); |
| |
| const SkBitmapProcStateAutoMapper mapper(s, x, y); |
| |
| SkFixed oneX = s.fFilterOneX, |
| oneY = s.fFilterOneY; |
| |
| SkFractionalInt fx = mapper.fractionalIntX(), |
| fy = mapper.fractionalIntY(), |
| dx = s.fInvSxFractionalInt, |
| dy = s.fInvKyFractionalInt; |
| unsigned maxX = s.fPixmap.width () - 1, |
| maxY = s.fPixmap.height() - 1; |
| while (count --> 0) { |
| *xy++ = pack<tile, extract_low_bits>(SkFractionalIntToFixed(fy), maxY, oneY); |
| *xy++ = pack<tile, extract_low_bits>(SkFractionalIntToFixed(fx), maxX, oneX); |
| |
| fy += dy; |
| fx += dx; |
| } |
| } |
| |
| // 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 inline unsigned SK_USHIFT16(unsigned x) { |
| return x >> 16; |
| } |
| |
| static unsigned clamp(SkFixed fx, int max) { |
| return SkClampMax(fx >> 16, max); |
| } |
| static unsigned repeat(SkFixed fx, int max) { |
| SkASSERT(max < 65535); |
| return SK_USHIFT16((unsigned)(fx & 0xFFFF) * (max + 1)); |
| } |
| static unsigned mirror(SkFixed fx, int max) { |
| SkASSERT(max < 65535); |
| // s is 0xFFFFFFFF if we're on an odd interval, or 0 if an even interval |
| SkFixed s = SkLeftShift(fx, 15) >> 31; |
| |
| // This should be exactly the same as repeat(fx ^ s, max) from here on. |
| return SK_USHIFT16( ((fx ^ s) & 0xFFFF) * (max + 1) ); |
| } |
| |
| static const SkBitmapProcState::MatrixProc ClampX_ClampY_Procs[] = { |
| nofilter_scale <clamp, true>, filter_scale <clamp, extract_low_bits_clamp, true>, |
| nofilter_affine<clamp>, filter_affine<clamp, extract_low_bits_clamp>, |
| }; |
| static const SkBitmapProcState::MatrixProc RepeatX_RepeatY_Procs[] = { |
| nofilter_scale <repeat, false>, filter_scale <repeat, extract_low_bits_repeat_mirror,false>, |
| nofilter_affine<repeat>, filter_affine<repeat, extract_low_bits_repeat_mirror>, |
| }; |
| static const SkBitmapProcState::MatrixProc MirrorX_MirrorY_Procs[] = { |
| nofilter_scale <mirror, false>, filter_scale <mirror, extract_low_bits_repeat_mirror, false>, |
| nofilter_affine<mirror>, filter_affine<mirror, extract_low_bits_repeat_mirror>, |
| }; |
| |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // This next chunk has some specializations for unfiltered translate-only matrices. |
| |
| static inline U16CPU int_clamp(int x, int n) { |
| if (x < 0) { x = 0; } |
| if (x >= n) { x = n - 1; } |
| return x; |
| } |
| |
| /* returns 0...(n-1) given any x (positive or negative). |
| |
| As an example, if n (which is always positive) is 5... |
| |
| x: -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 |
| returns: 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 |
| */ |
| static inline int sk_int_mod(int x, int n) { |
| SkASSERT(n > 0); |
| if ((unsigned)x >= (unsigned)n) { |
| if (x < 0) { |
| x = n + ~(~x % n); |
| } else { |
| x = x % n; |
| } |
| } |
| return x; |
| } |
| |
| static inline U16CPU int_repeat(int x, int n) { |
| return sk_int_mod(x, n); |
| } |
| |
| static inline U16CPU int_mirror(int x, int n) { |
| x = sk_int_mod(x, 2 * n); |
| if (x >= n) { |
| x = n + ~(x - n); |
| } |
| return x; |
| } |
| |
| static void fill_sequential(uint16_t xptr[], int pos, int count) { |
| while (count --> 0) { |
| *xptr++ = pos++; |
| } |
| } |
| |
| static void fill_backwards(uint16_t xptr[], int pos, int count) { |
| while (count --> 0) { |
| SkASSERT(pos >= 0); |
| *xptr++ = pos--; |
| } |
| } |
| |
| static void clampx_nofilter_trans(const SkBitmapProcState& s, |
| uint32_t xy[], int count, int x, int y) { |
| SkASSERT(s.fInvMatrix.isTranslate()); |
| |
| const SkBitmapProcStateAutoMapper mapper(s, x, y); |
| *xy++ = int_clamp(mapper.intY(), s.fPixmap.height()); |
| int xpos = mapper.intX(); |
| |
| const int width = s.fPixmap.width(); |
| if (1 == width) { |
| // all of the following X values must be 0 |
| memset(xy, 0, count * sizeof(uint16_t)); |
| return; |
| } |
| |
| uint16_t* xptr = reinterpret_cast<uint16_t*>(xy); |
| int n; |
| |
| // fill before 0 as needed |
| if (xpos < 0) { |
| n = -xpos; |
| if (n > count) { |
| n = count; |
| } |
| memset(xptr, 0, n * sizeof(uint16_t)); |
| count -= n; |
| if (0 == count) { |
| return; |
| } |
| xptr += n; |
| xpos = 0; |
| } |
| |
| // fill in 0..width-1 if needed |
| if (xpos < width) { |
| n = width - xpos; |
| if (n > count) { |
| n = count; |
| } |
| fill_sequential(xptr, xpos, n); |
| count -= n; |
| if (0 == count) { |
| return; |
| } |
| xptr += n; |
| } |
| |
| // fill the remaining with the max value |
| sk_memset16(xptr, width - 1, count); |
| } |
| |
| static void repeatx_nofilter_trans(const SkBitmapProcState& s, |
| uint32_t xy[], int count, int x, int y) { |
| SkASSERT(s.fInvMatrix.isTranslate()); |
| |
| const SkBitmapProcStateAutoMapper mapper(s, x, y); |
| *xy++ = int_repeat(mapper.intY(), s.fPixmap.height()); |
| int xpos = mapper.intX(); |
| |
| const int width = s.fPixmap.width(); |
| if (1 == width) { |
| // all of the following X values must be 0 |
| memset(xy, 0, count * sizeof(uint16_t)); |
| return; |
| } |
| |
| uint16_t* xptr = reinterpret_cast<uint16_t*>(xy); |
| int start = sk_int_mod(xpos, width); |
| int n = width - start; |
| if (n > count) { |
| n = count; |
| } |
| fill_sequential(xptr, start, n); |
| xptr += n; |
| count -= n; |
| |
| while (count >= width) { |
| fill_sequential(xptr, 0, width); |
| xptr += width; |
| count -= width; |
| } |
| |
| if (count > 0) { |
| fill_sequential(xptr, 0, count); |
| } |
| } |
| |
| static void mirrorx_nofilter_trans(const SkBitmapProcState& s, |
| uint32_t xy[], int count, int x, int y) { |
| SkASSERT(s.fInvMatrix.isTranslate()); |
| |
| const SkBitmapProcStateAutoMapper mapper(s, x, y); |
| *xy++ = int_mirror(mapper.intY(), s.fPixmap.height()); |
| int xpos = mapper.intX(); |
| |
| const int width = s.fPixmap.width(); |
| if (1 == width) { |
| // all of the following X values must be 0 |
| memset(xy, 0, count * sizeof(uint16_t)); |
| return; |
| } |
| |
| uint16_t* xptr = reinterpret_cast<uint16_t*>(xy); |
| // need to know our start, and our initial phase (forward or backward) |
| bool forward; |
| int n; |
| int start = sk_int_mod(xpos, 2 * width); |
| if (start >= width) { |
| start = width + ~(start - width); |
| forward = false; |
| n = start + 1; // [start .. 0] |
| } else { |
| forward = true; |
| n = width - start; // [start .. width) |
| } |
| if (n > count) { |
| n = count; |
| } |
| if (forward) { |
| fill_sequential(xptr, start, n); |
| } else { |
| fill_backwards(xptr, start, n); |
| } |
| forward = !forward; |
| xptr += n; |
| count -= n; |
| |
| while (count >= width) { |
| if (forward) { |
| fill_sequential(xptr, 0, width); |
| } else { |
| fill_backwards(xptr, width - 1, width); |
| } |
| forward = !forward; |
| xptr += width; |
| count -= width; |
| } |
| |
| if (count > 0) { |
| if (forward) { |
| fill_sequential(xptr, 0, count); |
| } else { |
| fill_backwards(xptr, width - 1, count); |
| } |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // The main entry point to the file, choosing between everything above. |
| |
| SkBitmapProcState::MatrixProc SkBitmapProcState::chooseMatrixProc(bool translate_only_matrix) { |
| SkASSERT(!fInvMatrix.hasPerspective()); |
| SkASSERT(fTileModeX == fTileModeY); |
| SkASSERT(fTileModeX != SkTileMode::kDecal); |
| |
| // Check for our special case translate methods when there is no scale/affine/perspective. |
| if (translate_only_matrix && kNone_SkFilterQuality == fFilterQuality) { |
| switch (fTileModeX) { |
| default: SkASSERT(false); |
| case SkTileMode::kClamp: return clampx_nofilter_trans; |
| case SkTileMode::kRepeat: return repeatx_nofilter_trans; |
| case SkTileMode::kMirror: return mirrorx_nofilter_trans; |
| } |
| } |
| |
| // The arrays are all [ nofilter, filter ]. |
| int index = fFilterQuality > kNone_SkFilterQuality ? 1 : 0; |
| if (!fInvMatrix.isScaleTranslate()) { |
| index |= 2; |
| } |
| |
| if (fTileModeX == SkTileMode::kClamp) { |
| // clamp gets special version of filterOne, working in non-normalized space (allowing decal) |
| fFilterOneX = SK_Fixed1; |
| fFilterOneY = SK_Fixed1; |
| return ClampX_ClampY_Procs[index]; |
| } |
| |
| // all remaining procs use this form for filterOne, putting them into normalized space. |
| fFilterOneX = SK_Fixed1 / fPixmap.width(); |
| fFilterOneY = SK_Fixed1 / fPixmap.height(); |
| |
| if (fTileModeX == SkTileMode::kRepeat) { |
| return RepeatX_RepeatY_Procs[index]; |
| } |
| |
| return MirrorX_MirrorY_Procs[index]; |
| } |
