/* * Copyright 2011 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "SkBitmapCache.h" #include "SkBitmapController.h" #include "SkBitmapProcState.h" #include "SkColorPriv.h" #include "SkFilterProc.h" #include "SkPaint.h" #include "SkShader.h" // for tilemodes #include "SkUtilsArm.h" #include "SkBitmapScaler.h" #include "SkMipMap.h" #include "SkPixelRef.h" #include "SkImageEncoder.h" #include "SkResourceCache.h" #if !SK_ARM_NEON_IS_NONE // These are defined in src/opts/SkBitmapProcState_arm_neon.cpp extern const SkBitmapProcState::SampleProc32 gSkBitmapProcStateSample32_neon[]; extern void S16_D16_filter_DX_neon(const SkBitmapProcState&, const uint32_t*, int, uint16_t*); extern void Clamp_S16_D16_filter_DX_shaderproc_neon(const void *, int, int, uint16_t*, int); extern void Repeat_S16_D16_filter_DX_shaderproc_neon(const void *, int, int, uint16_t*, int); extern void SI8_opaque_D32_filter_DX_neon(const SkBitmapProcState&, const uint32_t*, int, SkPMColor*); extern void SI8_opaque_D32_filter_DX_shaderproc_neon(const void *, int, int, uint32_t*, int); extern void Clamp_SI8_opaque_D32_filter_DX_shaderproc_neon(const void*, int, int, uint32_t*, int); #endif extern void Clamp_S32_opaque_D32_nofilter_DX_shaderproc(const void*, int, int, uint32_t*, int); #define NAME_WRAP(x) x #include "SkBitmapProcState_filter.h" #include "SkBitmapProcState_procs.h" SkBitmapProcState::SkBitmapProcState(const SkBitmapProvider& provider, SkShader::TileMode tmx, SkShader::TileMode tmy) : fProvider(provider) , fBMState(nullptr) { fTileModeX = tmx; fTileModeY = tmy; } SkBitmapProcState::SkBitmapProcState(const SkBitmap& bm, SkShader::TileMode tmx, SkShader::TileMode tmy) : fProvider(SkBitmapProvider(bm)) , fBMState(nullptr) { fTileModeX = tmx; fTileModeY = tmy; } SkBitmapProcState::~SkBitmapProcState() { SkInPlaceDeleteCheck(fBMState, fBMStateStorage.get()); } /////////////////////////////////////////////////////////////////////////////// // true iff the matrix contains, at most, scale and translate elements static bool matrix_only_scale_translate(const SkMatrix& m) { return m.getType() <= (SkMatrix::kScale_Mask | SkMatrix::kTranslate_Mask); } /** * For the purposes of drawing bitmaps, if a matrix is "almost" translate * go ahead and treat it as if it were, so that subsequent code can go fast. */ static bool just_trans_clamp(const SkMatrix& matrix, const SkPixmap& pixmap) { SkASSERT(matrix_only_scale_translate(matrix)); if (matrix.getType() & SkMatrix::kScale_Mask) { SkRect dst; SkRect src = SkRect::Make(pixmap.bounds()); // Can't call mapRect(), since that will fix up inverted rectangles, // e.g. when scale is negative, and we don't want to return true for // those. matrix.mapPoints(SkTCast<SkPoint*>(&dst), SkTCast<const SkPoint*>(&src), 2); // Now round all 4 edges to device space, and then compare the device // width/height to the original. Note: we must map all 4 and subtract // rather than map the "width" and compare, since we care about the // phase (in pixel space) that any translate in the matrix might impart. SkIRect idst; dst.round(&idst); return idst.width() == pixmap.width() && idst.height() == pixmap.height(); } // if we got here, we're either kTranslate_Mask or identity return true; } static bool just_trans_general(const SkMatrix& matrix) { SkASSERT(matrix_only_scale_translate(matrix)); if (matrix.getType() & SkMatrix::kScale_Mask) { const SkScalar tol = SK_Scalar1 / 32768; if (!SkScalarNearlyZero(matrix[SkMatrix::kMScaleX] - SK_Scalar1, tol)) { return false; } if (!SkScalarNearlyZero(matrix[SkMatrix::kMScaleY] - SK_Scalar1, tol)) { return false; } } // if we got here, treat us as either kTranslate_Mask or identity return true; } static bool valid_for_filtering(unsigned dimension) { // for filtering, width and height must fit in 14bits, since we use steal // 2 bits from each to store our 4bit subpixel data return (dimension & ~0x3FFF) == 0; } /* * Analyze filter-quality and matrix, and decide how to implement that. * * In general, we cascade down the request level [ High ... None ] * - for a given level, if we can fulfill it, fine, else * - else we downgrade to the next lower level and try again. * We can always fulfill requests for Low and None * - sometimes we will "ignore" Low and give None, but this is likely a legacy perf hack * and may be removed. */ bool SkBitmapProcState::chooseProcs(const SkMatrix& inv, const SkPaint& paint) { fPixmap.reset(); fInvMatrix = inv; fFilterLevel = paint.getFilterQuality(); const int origW = fProvider.info().width(); const int origH = fProvider.info().height(); bool allow_ignore_fractional_translate = true; // historical default if (kMedium_SkFilterQuality == fFilterLevel) { allow_ignore_fractional_translate = false; } SkDefaultBitmapController controller; fBMState = controller.requestBitmap(fProvider, inv, paint.getFilterQuality(), fBMStateStorage.get(), fBMStateStorage.size()); // Note : we allow the controller to return an empty (zero-dimension) result. Should we? if (nullptr == fBMState || fBMState->pixmap().info().isEmpty()) { return false; } fPixmap = fBMState->pixmap(); fInvMatrix = fBMState->invMatrix(); fFilterLevel = fBMState->quality(); SkASSERT(fPixmap.addr()); bool trivialMatrix = (fInvMatrix.getType() & ~SkMatrix::kTranslate_Mask) == 0; bool clampClamp = SkShader::kClamp_TileMode == fTileModeX && SkShader::kClamp_TileMode == fTileModeY; // Most of the scanline procs deal with "unit" texture coordinates, as this // makes it easy to perform tiling modes (repeat = (x & 0xFFFF)). To generate // those, we divide the matrix by its dimensions here. // // We don't do this if we're either trivial (can ignore the matrix) or clamping // in both X and Y since clamping to width,height is just as easy as to 0xFFFF. if (!(clampClamp || trivialMatrix)) { fInvMatrix.postIDiv(fPixmap.width(), fPixmap.height()); } // Now that all possible changes to the matrix have taken place, check // to see if we're really close to a no-scale matrix. If so, explicitly // set it to be so. Subsequent code may inspect this matrix to choose // a faster path in this case. // This code will only execute if the matrix has some scale component; // if it's already pure translate then we won't do this inversion. if (matrix_only_scale_translate(fInvMatrix)) { SkMatrix forward; if (fInvMatrix.invert(&forward)) { if ((clampClamp && allow_ignore_fractional_translate) ? just_trans_clamp(forward, fPixmap) : just_trans_general(forward)) { fInvMatrix.setTranslate(-forward.getTranslateX(), -forward.getTranslateY()); } } } fInvProc = fInvMatrix.getMapXYProc(); fInvType = fInvMatrix.getType(); fInvSx = SkScalarToFixed(fInvMatrix.getScaleX()); fInvSxFractionalInt = SkScalarToFractionalInt(fInvMatrix.getScaleX()); fInvKy = SkScalarToFixed(fInvMatrix.getSkewY()); fInvKyFractionalInt = SkScalarToFractionalInt(fInvMatrix.getSkewY()); fAlphaScale = SkAlpha255To256(paint.getAlpha()); fShaderProc32 = nullptr; fShaderProc16 = nullptr; fSampleProc32 = nullptr; // recompute the triviality of the matrix here because we may have // changed it! trivialMatrix = (fInvMatrix.getType() & ~SkMatrix::kTranslate_Mask) == 0; // If our target pixmap is the same as the original, then we revert back to legacy behavior // and allow the code to ignore fractional translate. // // The width/height check allows allow_ignore_fractional_translate to stay false if we // previously set it that way (e.g. we started in kMedium). // if (fPixmap.width() == origW && fPixmap.height() == origH) { allow_ignore_fractional_translate = true; } if (kLow_SkFilterQuality == fFilterLevel && allow_ignore_fractional_translate) { // Only try bilerp if the matrix is "interesting" and // the image has a suitable size. if (fInvType <= SkMatrix::kTranslate_Mask || !valid_for_filtering(fPixmap.width() | fPixmap.height())) { fFilterLevel = kNone_SkFilterQuality; } } return this->chooseScanlineProcs(trivialMatrix, clampClamp, paint); } bool SkBitmapProcState::chooseScanlineProcs(bool trivialMatrix, bool clampClamp, const SkPaint& paint) { fMatrixProc = this->chooseMatrixProc(trivialMatrix); // TODO(dominikg): SkASSERT(fMatrixProc) instead? chooseMatrixProc never returns nullptr. if (nullptr == fMatrixProc) { return false; } /////////////////////////////////////////////////////////////////////// const SkAlphaType at = fPixmap.alphaType(); // No need to do this if we're doing HQ sampling; if filter quality is // still set to HQ by the time we get here, then we must have installed // the shader procs above and can skip all this. if (fFilterLevel < kHigh_SkFilterQuality) { int index = 0; if (fAlphaScale < 256) { // note: this distinction is not used for D16 index |= 1; } if (fInvType <= (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask)) { index |= 2; } if (fFilterLevel > kNone_SkFilterQuality) { index |= 4; } // bits 3,4,5 encoding the source bitmap format switch (fPixmap.colorType()) { case kN32_SkColorType: if (kPremul_SkAlphaType != at && kOpaque_SkAlphaType != at) { return false; } index |= 0; break; case kRGB_565_SkColorType: index |= 8; break; case kIndex_8_SkColorType: if (kPremul_SkAlphaType != at && kOpaque_SkAlphaType != at) { return false; } index |= 16; break; case kARGB_4444_SkColorType: if (kPremul_SkAlphaType != at && kOpaque_SkAlphaType != at) { return false; } index |= 24; break; case kAlpha_8_SkColorType: index |= 32; fPaintPMColor = SkPreMultiplyColor(paint.getColor()); break; case kGray_8_SkColorType: index |= 40; fPaintPMColor = SkPreMultiplyColor(paint.getColor()); break; default: // TODO(dominikg): Should we ever get here? SkASSERT(false) instead? return false; } #if !SK_ARM_NEON_IS_ALWAYS static const SampleProc32 gSkBitmapProcStateSample32[] = { S32_opaque_D32_nofilter_DXDY, S32_alpha_D32_nofilter_DXDY, S32_opaque_D32_nofilter_DX, S32_alpha_D32_nofilter_DX, S32_opaque_D32_filter_DXDY, S32_alpha_D32_filter_DXDY, S32_opaque_D32_filter_DX, S32_alpha_D32_filter_DX, S16_opaque_D32_nofilter_DXDY, S16_alpha_D32_nofilter_DXDY, S16_opaque_D32_nofilter_DX, S16_alpha_D32_nofilter_DX, S16_opaque_D32_filter_DXDY, S16_alpha_D32_filter_DXDY, S16_opaque_D32_filter_DX, S16_alpha_D32_filter_DX, SI8_opaque_D32_nofilter_DXDY, SI8_alpha_D32_nofilter_DXDY, SI8_opaque_D32_nofilter_DX, SI8_alpha_D32_nofilter_DX, SI8_opaque_D32_filter_DXDY, SI8_alpha_D32_filter_DXDY, SI8_opaque_D32_filter_DX, SI8_alpha_D32_filter_DX, S4444_opaque_D32_nofilter_DXDY, S4444_alpha_D32_nofilter_DXDY, S4444_opaque_D32_nofilter_DX, S4444_alpha_D32_nofilter_DX, S4444_opaque_D32_filter_DXDY, S4444_alpha_D32_filter_DXDY, S4444_opaque_D32_filter_DX, S4444_alpha_D32_filter_DX, // A8 treats alpha/opaque the same (equally efficient) SA8_alpha_D32_nofilter_DXDY, SA8_alpha_D32_nofilter_DXDY, SA8_alpha_D32_nofilter_DX, SA8_alpha_D32_nofilter_DX, SA8_alpha_D32_filter_DXDY, SA8_alpha_D32_filter_DXDY, SA8_alpha_D32_filter_DX, SA8_alpha_D32_filter_DX, // todo: possibly specialize on opaqueness SG8_alpha_D32_nofilter_DXDY, SG8_alpha_D32_nofilter_DXDY, SG8_alpha_D32_nofilter_DX, SG8_alpha_D32_nofilter_DX, SG8_alpha_D32_filter_DXDY, SG8_alpha_D32_filter_DXDY, SG8_alpha_D32_filter_DX, SG8_alpha_D32_filter_DX }; #endif fSampleProc32 = SK_ARM_NEON_WRAP(gSkBitmapProcStateSample32)[index]; index >>= 1; // shift away any opaque/alpha distinction // our special-case shaderprocs if (SK_ARM_NEON_WRAP(SI8_opaque_D32_filter_DX) == fSampleProc32 && clampClamp) { fShaderProc32 = SK_ARM_NEON_WRAP(Clamp_SI8_opaque_D32_filter_DX_shaderproc); } else if (S32_opaque_D32_nofilter_DX == fSampleProc32 && clampClamp) { fShaderProc32 = Clamp_S32_opaque_D32_nofilter_DX_shaderproc; } if (nullptr == fShaderProc32) { fShaderProc32 = this->chooseShaderProc32(); } } // see if our platform has any accelerated overrides this->platformProcs(); return true; } static void Clamp_S32_D32_nofilter_trans_shaderproc(const void* sIn, int x, int y, SkPMColor* SK_RESTRICT colors, int count) { const SkBitmapProcState& s = *static_cast<const SkBitmapProcState*>(sIn); SkASSERT(((s.fInvType & ~SkMatrix::kTranslate_Mask)) == 0); SkASSERT(s.fInvKy == 0); SkASSERT(count > 0 && colors != nullptr); SkASSERT(kNone_SkFilterQuality == s.fFilterLevel); const int maxX = s.fPixmap.width() - 1; const int maxY = s.fPixmap.height() - 1; int ix = s.fFilterOneX + x; int iy = SkClampMax(s.fFilterOneY + y, maxY); const SkPMColor* row = s.fPixmap.addr32(0, iy); // clamp to the left if (ix < 0) { int n = SkMin32(-ix, count); sk_memset32(colors, row[0], n); count -= n; if (0 == count) { return; } colors += n; SkASSERT(-ix == n); ix = 0; } // copy the middle if (ix <= maxX) { int n = SkMin32(maxX - ix + 1, count); memcpy(colors, row + ix, n * sizeof(SkPMColor)); count -= n; if (0 == count) { return; } colors += n; } SkASSERT(count > 0); // clamp to the right sk_memset32(colors, row[maxX], count); } 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 int sk_int_mirror(int x, int n) { x = sk_int_mod(x, 2 * n); if (x >= n) { x = n + ~(x - n); } return x; } static void Repeat_S32_D32_nofilter_trans_shaderproc(const void* sIn, int x, int y, SkPMColor* SK_RESTRICT colors, int count) { const SkBitmapProcState& s = *static_cast<const SkBitmapProcState*>(sIn); SkASSERT(((s.fInvType & ~SkMatrix::kTranslate_Mask)) == 0); SkASSERT(s.fInvKy == 0); SkASSERT(count > 0 && colors != nullptr); SkASSERT(kNone_SkFilterQuality == s.fFilterLevel); const int stopX = s.fPixmap.width(); const int stopY = s.fPixmap.height(); int ix = s.fFilterOneX + x; int iy = sk_int_mod(s.fFilterOneY + y, stopY); const SkPMColor* row = s.fPixmap.addr32(0, iy); ix = sk_int_mod(ix, stopX); for (;;) { int n = SkMin32(stopX - ix, count); memcpy(colors, row + ix, n * sizeof(SkPMColor)); count -= n; if (0 == count) { return; } colors += n; ix = 0; } } static void S32_D32_constX_shaderproc(const void* sIn, int x, int y, SkPMColor* SK_RESTRICT colors, int count) { const SkBitmapProcState& s = *static_cast<const SkBitmapProcState*>(sIn); SkASSERT((s.fInvType & ~(SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask)) == 0); SkASSERT(s.fInvKy == 0); SkASSERT(count > 0 && colors != nullptr); SkASSERT(1 == s.fPixmap.width()); int iY0; int iY1 SK_INIT_TO_AVOID_WARNING; int iSubY SK_INIT_TO_AVOID_WARNING; if (kNone_SkFilterQuality != s.fFilterLevel) { SkBitmapProcState::MatrixProc mproc = s.getMatrixProc(); uint32_t xy[2]; mproc(s, xy, 1, x, y); iY0 = xy[0] >> 18; iY1 = xy[0] & 0x3FFF; iSubY = (xy[0] >> 14) & 0xF; } else { int yTemp; if (s.fInvType > SkMatrix::kTranslate_Mask) { const SkBitmapProcStateAutoMapper mapper(s, x, y); // When the matrix has a scale component the setup code in // chooseProcs multiples the inverse matrix by the inverse of the // bitmap's width and height. Since this method is going to do // its own tiling and sampling we need to undo that here. if (SkShader::kClamp_TileMode != s.fTileModeX || SkShader::kClamp_TileMode != s.fTileModeY) { yTemp = SkFractionalIntToInt(mapper.fractionalIntY() * s.fPixmap.height()); } else { yTemp = mapper.intY(); } } else { yTemp = s.fFilterOneY + y; } const int stopY = s.fPixmap.height(); switch (s.fTileModeY) { case SkShader::kClamp_TileMode: iY0 = SkClampMax(yTemp, stopY-1); break; case SkShader::kRepeat_TileMode: iY0 = sk_int_mod(yTemp, stopY); break; case SkShader::kMirror_TileMode: default: iY0 = sk_int_mirror(yTemp, stopY); break; } #ifdef SK_DEBUG { const SkBitmapProcStateAutoMapper mapper(s, x, y); int iY2; if (s.fInvType > SkMatrix::kTranslate_Mask && (SkShader::kClamp_TileMode != s.fTileModeX || SkShader::kClamp_TileMode != s.fTileModeY)) { iY2 = SkFractionalIntToInt(mapper.fractionalIntY() * s.fPixmap.height()); } else { iY2 = mapper.intY(); } switch (s.fTileModeY) { case SkShader::kClamp_TileMode: iY2 = SkClampMax(iY2, stopY-1); break; case SkShader::kRepeat_TileMode: iY2 = sk_int_mod(iY2, stopY); break; case SkShader::kMirror_TileMode: default: iY2 = sk_int_mirror(iY2, stopY); break; } SkASSERT(iY0 == iY2); } #endif } const SkPMColor* row0 = s.fPixmap.addr32(0, iY0); SkPMColor color; if (kNone_SkFilterQuality != s.fFilterLevel) { const SkPMColor* row1 = s.fPixmap.addr32(0, iY1); if (s.fAlphaScale < 256) { Filter_32_alpha(iSubY, *row0, *row1, &color, s.fAlphaScale); } else { Filter_32_opaque(iSubY, *row0, *row1, &color); } } else { if (s.fAlphaScale < 256) { color = SkAlphaMulQ(*row0, s.fAlphaScale); } else { color = *row0; } } sk_memset32(colors, color, count); } static void DoNothing_shaderproc(const void*, int x, int y, SkPMColor* SK_RESTRICT colors, int count) { // if we get called, the matrix is too tricky, so we just draw nothing sk_memset32(colors, 0, count); } bool SkBitmapProcState::setupForTranslate() { SkPoint pt; const SkBitmapProcStateAutoMapper mapper(*this, 0, 0, &pt); /* * if the translate is larger than our ints, we can get random results, or * worse, we might get 0x80000000, which wreaks havoc on us, since we can't * negate it. */ const SkScalar too_big = SkIntToScalar(1 << 30); if (SkScalarAbs(pt.fX) > too_big || SkScalarAbs(pt.fY) > too_big) { return false; } // Since we know we're not filtered, we re-purpose these fields allow // us to go from device -> src coordinates w/ just an integer add, // rather than running through the inverse-matrix fFilterOneX = mapper.intX(); fFilterOneY = mapper.intY(); return true; } SkBitmapProcState::ShaderProc32 SkBitmapProcState::chooseShaderProc32() { if (kN32_SkColorType != fPixmap.colorType()) { return nullptr; } static const unsigned kMask = SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask; if (1 == fPixmap.width() && 0 == (fInvType & ~kMask)) { if (kNone_SkFilterQuality == fFilterLevel && fInvType <= SkMatrix::kTranslate_Mask && !this->setupForTranslate()) { return DoNothing_shaderproc; } return S32_D32_constX_shaderproc; } if (fAlphaScale < 256) { return nullptr; } if (fInvType > SkMatrix::kTranslate_Mask) { return nullptr; } if (kNone_SkFilterQuality != fFilterLevel) { return nullptr; } SkShader::TileMode tx = (SkShader::TileMode)fTileModeX; SkShader::TileMode ty = (SkShader::TileMode)fTileModeY; if (SkShader::kClamp_TileMode == tx && SkShader::kClamp_TileMode == ty) { if (this->setupForTranslate()) { return Clamp_S32_D32_nofilter_trans_shaderproc; } return DoNothing_shaderproc; } if (SkShader::kRepeat_TileMode == tx && SkShader::kRepeat_TileMode == ty) { if (this->setupForTranslate()) { return Repeat_S32_D32_nofilter_trans_shaderproc; } return DoNothing_shaderproc; } return nullptr; } /////////////////////////////////////////////////////////////////////////////// #ifdef SK_DEBUG static void check_scale_nofilter(uint32_t bitmapXY[], int count, unsigned mx, unsigned my) { unsigned y = *bitmapXY++; SkASSERT(y < my); const uint16_t* xptr = reinterpret_cast<const uint16_t*>(bitmapXY); for (int i = 0; i < count; ++i) { SkASSERT(xptr[i] < mx); } } static void check_scale_filter(uint32_t bitmapXY[], int count, unsigned mx, unsigned my) { uint32_t YY = *bitmapXY++; unsigned y0 = YY >> 18; unsigned y1 = YY & 0x3FFF; SkASSERT(y0 < my); SkASSERT(y1 < my); for (int i = 0; i < count; ++i) { uint32_t XX = bitmapXY[i]; unsigned x0 = XX >> 18; unsigned x1 = XX & 0x3FFF; SkASSERT(x0 < mx); SkASSERT(x1 < mx); } } static void check_affine_nofilter(uint32_t bitmapXY[], int count, unsigned mx, unsigned my) { for (int i = 0; i < count; ++i) { uint32_t XY = bitmapXY[i]; unsigned x = XY & 0xFFFF; unsigned y = XY >> 16; SkASSERT(x < mx); SkASSERT(y < my); } } static void check_affine_filter(uint32_t bitmapXY[], int count, unsigned mx, unsigned my) { for (int i = 0; i < count; ++i) { uint32_t YY = *bitmapXY++; unsigned y0 = YY >> 18; unsigned y1 = YY & 0x3FFF; SkASSERT(y0 < my); SkASSERT(y1 < my); uint32_t XX = *bitmapXY++; unsigned x0 = XX >> 18; unsigned x1 = XX & 0x3FFF; SkASSERT(x0 < mx); SkASSERT(x1 < mx); } } void SkBitmapProcState::DebugMatrixProc(const SkBitmapProcState& state, uint32_t bitmapXY[], int count, int x, int y) { SkASSERT(bitmapXY); SkASSERT(count > 0); state.fMatrixProc(state, bitmapXY, count, x, y); void (*proc)(uint32_t bitmapXY[], int count, unsigned mx, unsigned my); // There are four formats possible: // scale -vs- affine // filter -vs- nofilter if (state.fInvType <= (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask)) { proc = state.fFilterLevel != kNone_SkFilterQuality ? check_scale_filter : check_scale_nofilter; } else { proc = state.fFilterLevel != kNone_SkFilterQuality ? check_affine_filter : check_affine_nofilter; } proc(bitmapXY, count, state.fPixmap.width(), state.fPixmap.height()); } SkBitmapProcState::MatrixProc SkBitmapProcState::getMatrixProc() const { return DebugMatrixProc; } #endif /////////////////////////////////////////////////////////////////////////////// /* The storage requirements for the different matrix procs are as follows, where each X or Y is 2 bytes, and N is the number of pixels/elements: scale/translate nofilter Y(4bytes) + N * X affine/perspective nofilter N * (X Y) scale/translate filter Y Y + N * (X X) affine/perspective filter N * (Y Y X X) */ int SkBitmapProcState::maxCountForBufferSize(size_t bufferSize) const { int32_t size = static_cast<int32_t>(bufferSize); size &= ~3; // only care about 4-byte aligned chunks if (fInvType <= (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask)) { size -= 4; // the shared Y (or YY) coordinate if (size < 0) { size = 0; } size >>= 1; } else { size >>= 2; } if (fFilterLevel != kNone_SkFilterQuality) { size >>= 1; } return size; } /////////////////////// void Clamp_S32_opaque_D32_nofilter_DX_shaderproc(const void* sIn, int x, int y, SkPMColor* SK_RESTRICT dst, int count) { const SkBitmapProcState& s = *static_cast<const SkBitmapProcState*>(sIn); SkASSERT((s.fInvType & ~(SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask)) == 0); const unsigned maxX = s.fPixmap.width() - 1; SkFractionalInt fx; int dstY; { const SkBitmapProcStateAutoMapper mapper(s, x, y); const unsigned maxY = s.fPixmap.height() - 1; dstY = SkClampMax(mapper.intY(), maxY); fx = mapper.fractionalIntX(); } const SkPMColor* SK_RESTRICT src = s.fPixmap.addr32(0, dstY); const SkFractionalInt dx = s.fInvSxFractionalInt; // Check if we're safely inside [0...maxX] so no need to clamp each computed index. // if ((uint64_t)SkFractionalIntToInt(fx) <= maxX && (uint64_t)SkFractionalIntToInt(fx + dx * (count - 1)) <= maxX) { int count4 = count >> 2; for (int i = 0; i < count4; ++i) { SkPMColor src0 = src[SkFractionalIntToInt(fx)]; fx += dx; SkPMColor src1 = src[SkFractionalIntToInt(fx)]; fx += dx; SkPMColor src2 = src[SkFractionalIntToInt(fx)]; fx += dx; SkPMColor src3 = src[SkFractionalIntToInt(fx)]; fx += dx; dst[0] = src0; dst[1] = src1; dst[2] = src2; dst[3] = src3; dst += 4; } for (int i = (count4 << 2); i < count; ++i) { unsigned index = SkFractionalIntToInt(fx); SkASSERT(index <= maxX); *dst++ = src[index]; fx += dx; } } else { for (int i = 0; i < count; ++i) { dst[i] = src[SkClampMax(SkFractionalIntToInt(fx), maxX)]; fx += dx; } } }