| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkScalerContext.h" |
| |
| #include "SkAutoMalloc.h" |
| #include "SkAutoPixmapStorage.h" |
| #include "SkColorPriv.h" |
| #include "SkDescriptor.h" |
| #include "SkDraw.h" |
| #include "SkGlyph.h" |
| #include "SkMakeUnique.h" |
| #include "SkMaskFilter.h" |
| #include "SkMaskGamma.h" |
| #include "SkMatrix22.h" |
| #include "SkPaintPriv.h" |
| #include "SkPathEffect.h" |
| #include "SkRasterClip.h" |
| #include "SkRasterizer.h" |
| #include "SkReadBuffer.h" |
| #include "SkStroke.h" |
| #include "SkStrokeRec.h" |
| #include "SkWriteBuffer.h" |
| |
| #define ComputeBWRowBytes(width) (((unsigned)(width) + 7) >> 3) |
| |
| void SkGlyph::toMask(SkMask* mask) const { |
| SkASSERT(mask); |
| |
| mask->fImage = (uint8_t*)fImage; |
| mask->fBounds.set(fLeft, fTop, fLeft + fWidth, fTop + fHeight); |
| mask->fRowBytes = this->rowBytes(); |
| mask->fFormat = static_cast<SkMask::Format>(fMaskFormat); |
| } |
| |
| size_t SkGlyph::computeImageSize() const { |
| const size_t size = this->rowBytes() * fHeight; |
| |
| switch (fMaskFormat) { |
| case SkMask::k3D_Format: |
| return 3 * size; |
| default: |
| return size; |
| } |
| } |
| |
| void SkGlyph::zeroMetrics() { |
| fAdvanceX = 0; |
| fAdvanceY = 0; |
| fWidth = 0; |
| fHeight = 0; |
| fTop = 0; |
| fLeft = 0; |
| fRsbDelta = 0; |
| fLsbDelta = 0; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #ifdef SK_DEBUG |
| #define DUMP_RECx |
| #endif |
| |
| SkScalerContext::SkScalerContext(sk_sp<SkTypeface> typeface, const SkScalerContextEffects& effects, |
| const SkDescriptor* desc) |
| : fRec(*static_cast<const Rec*>(desc->findEntry(kRec_SkDescriptorTag, nullptr))) |
| |
| , fTypeface(std::move(typeface)) |
| , fPathEffect(sk_ref_sp(effects.fPathEffect)) |
| , fMaskFilter(sk_ref_sp(effects.fMaskFilter)) |
| , fRasterizer(sk_ref_sp(effects.fRasterizer)) |
| // Initialize based on our settings. Subclasses can also force this. |
| , fGenerateImageFromPath(fRec.fFrameWidth > 0 || fPathEffect != nullptr || fRasterizer != nullptr) |
| |
| , fPreBlend(fMaskFilter ? SkMaskGamma::PreBlend() : SkScalerContext::GetMaskPreBlend(fRec)) |
| , fPreBlendForFilter(fMaskFilter ? SkScalerContext::GetMaskPreBlend(fRec) |
| : SkMaskGamma::PreBlend()) |
| { |
| #ifdef DUMP_REC |
| desc->assertChecksum(); |
| SkDebugf("SkScalerContext checksum %x count %d length %d\n", |
| desc->getChecksum(), desc->getCount(), desc->getLength()); |
| SkDebugf(" textsize %g prescale %g preskew %g post [%g %g %g %g]\n", |
| rec->fTextSize, rec->fPreScaleX, rec->fPreSkewX, rec->fPost2x2[0][0], |
| rec->fPost2x2[0][1], rec->fPost2x2[1][0], rec->fPost2x2[1][1]); |
| SkDebugf(" frame %g miter %g hints %d framefill %d format %d join %d cap %d\n", |
| rec->fFrameWidth, rec->fMiterLimit, rec->fHints, rec->fFrameAndFill, |
| rec->fMaskFormat, rec->fStrokeJoin, rec->fStrokeCap); |
| SkDebugf(" pathEffect %x maskFilter %x\n", |
| desc->findEntry(kPathEffect_SkDescriptorTag, nullptr), |
| desc->findEntry(kMaskFilter_SkDescriptorTag, nullptr)); |
| #endif |
| } |
| |
| SkScalerContext::~SkScalerContext() {} |
| |
| void SkScalerContext::getAdvance(SkGlyph* glyph) { |
| // mark us as just having a valid advance |
| glyph->fMaskFormat = MASK_FORMAT_JUST_ADVANCE; |
| // we mark the format before making the call, in case the impl |
| // internally ends up calling its generateMetrics, which is OK |
| // albeit slower than strictly necessary |
| generateAdvance(glyph); |
| } |
| |
| void SkScalerContext::getMetrics(SkGlyph* glyph) { |
| generateMetrics(glyph); |
| |
| // for now we have separate cache entries for devkerning on and off |
| // in the future we might share caches, but make our measure/draw |
| // code make the distinction. Thus we zap the values if the caller |
| // has not asked for them. |
| if ((fRec.fFlags & SkScalerContext::kDevKernText_Flag) == 0) { |
| // no devkern, so zap the fields |
| glyph->fLsbDelta = glyph->fRsbDelta = 0; |
| } |
| |
| // if either dimension is empty, zap the image bounds of the glyph |
| if (0 == glyph->fWidth || 0 == glyph->fHeight) { |
| glyph->fWidth = 0; |
| glyph->fHeight = 0; |
| glyph->fTop = 0; |
| glyph->fLeft = 0; |
| glyph->fMaskFormat = 0; |
| return; |
| } |
| |
| if (fGenerateImageFromPath) { |
| SkPath devPath, fillPath; |
| SkMatrix fillToDevMatrix; |
| |
| this->internalGetPath(glyph->getPackedID(), &fillPath, &devPath, &fillToDevMatrix); |
| |
| if (fRasterizer) { |
| SkMask mask; |
| |
| if (fRasterizer->rasterize(fillPath, fillToDevMatrix, nullptr, |
| fMaskFilter.get(), &mask, |
| SkMask::kJustComputeBounds_CreateMode)) { |
| glyph->fLeft = mask.fBounds.fLeft; |
| glyph->fTop = mask.fBounds.fTop; |
| glyph->fWidth = SkToU16(mask.fBounds.width()); |
| glyph->fHeight = SkToU16(mask.fBounds.height()); |
| } else { |
| goto SK_ERROR; |
| } |
| } else { |
| // just use devPath |
| const SkIRect ir = devPath.getBounds().roundOut(); |
| |
| if (ir.isEmpty() || !ir.is16Bit()) { |
| goto SK_ERROR; |
| } |
| glyph->fLeft = ir.fLeft; |
| glyph->fTop = ir.fTop; |
| glyph->fWidth = SkToU16(ir.width()); |
| glyph->fHeight = SkToU16(ir.height()); |
| |
| if (glyph->fWidth > 0) { |
| switch (fRec.fMaskFormat) { |
| case SkMask::kLCD16_Format: |
| glyph->fWidth += 2; |
| glyph->fLeft -= 1; |
| break; |
| default: |
| break; |
| } |
| } |
| } |
| } |
| |
| if (SkMask::kARGB32_Format != glyph->fMaskFormat) { |
| glyph->fMaskFormat = fRec.fMaskFormat; |
| } |
| |
| // If we are going to create the mask, then we cannot keep the color |
| if ((fGenerateImageFromPath || fMaskFilter) && |
| SkMask::kARGB32_Format == glyph->fMaskFormat) { |
| glyph->fMaskFormat = SkMask::kA8_Format; |
| } |
| |
| if (fMaskFilter) { |
| SkMask src, dst; |
| SkMatrix matrix; |
| |
| glyph->toMask(&src); |
| fRec.getMatrixFrom2x2(&matrix); |
| |
| src.fImage = nullptr; // only want the bounds from the filter |
| if (fMaskFilter->filterMask(&dst, src, matrix, nullptr)) { |
| if (dst.fBounds.isEmpty() || !dst.fBounds.is16Bit()) { |
| goto SK_ERROR; |
| } |
| SkASSERT(dst.fImage == nullptr); |
| glyph->fLeft = dst.fBounds.fLeft; |
| glyph->fTop = dst.fBounds.fTop; |
| glyph->fWidth = SkToU16(dst.fBounds.width()); |
| glyph->fHeight = SkToU16(dst.fBounds.height()); |
| glyph->fMaskFormat = dst.fFormat; |
| } |
| } |
| return; |
| |
| SK_ERROR: |
| // draw nothing 'cause we failed |
| glyph->fLeft = 0; |
| glyph->fTop = 0; |
| glyph->fWidth = 0; |
| glyph->fHeight = 0; |
| // put a valid value here, in case it was earlier set to |
| // MASK_FORMAT_JUST_ADVANCE |
| glyph->fMaskFormat = fRec.fMaskFormat; |
| } |
| |
| #define SK_SHOW_TEXT_BLIT_COVERAGE 0 |
| |
| static void applyLUTToA8Mask(const SkMask& mask, const uint8_t* lut) { |
| uint8_t* SK_RESTRICT dst = (uint8_t*)mask.fImage; |
| unsigned rowBytes = mask.fRowBytes; |
| |
| for (int y = mask.fBounds.height() - 1; y >= 0; --y) { |
| for (int x = mask.fBounds.width() - 1; x >= 0; --x) { |
| dst[x] = lut[dst[x]]; |
| } |
| dst += rowBytes; |
| } |
| } |
| |
| template<bool APPLY_PREBLEND> |
| static void pack4xHToLCD16(const SkPixmap& src, const SkMask& dst, |
| const SkMaskGamma::PreBlend& maskPreBlend) { |
| #define SAMPLES_PER_PIXEL 4 |
| #define LCD_PER_PIXEL 3 |
| SkASSERT(kAlpha_8_SkColorType == src.colorType()); |
| SkASSERT(SkMask::kLCD16_Format == dst.fFormat); |
| |
| const int sample_width = src.width(); |
| const int height = src.height(); |
| |
| uint16_t* dstP = (uint16_t*)dst.fImage; |
| size_t dstRB = dst.fRowBytes; |
| // An N tap FIR is defined by |
| // out[n] = coeff[0]*x[n] + coeff[1]*x[n-1] + ... + coeff[N]*x[n-N] |
| // or |
| // out[n] = sum(i, 0, N, coeff[i]*x[n-i]) |
| |
| // The strategy is to use one FIR (different coefficients) for each of r, g, and b. |
| // This means using every 4th FIR output value of each FIR and discarding the rest. |
| // The FIRs are aligned, and the coefficients reach 5 samples to each side of their 'center'. |
| // (For r and b this is technically incorrect, but the coeffs outside round to zero anyway.) |
| |
| // These are in some fixed point repesentation. |
| // Adding up to more than one simulates ink spread. |
| // For implementation reasons, these should never add up to more than two. |
| |
| // Coefficients determined by a gausian where 5 samples = 3 std deviations (0x110 'contrast'). |
| // Calculated using tools/generate_fir_coeff.py |
| // With this one almost no fringing is ever seen, but it is imperceptibly blurry. |
| // The lcd smoothed text is almost imperceptibly different from gray, |
| // but is still sharper on small stems and small rounded corners than gray. |
| // This also seems to be about as wide as one can get and only have a three pixel kernel. |
| // TODO: caculate these at runtime so parameters can be adjusted (esp contrast). |
| static const unsigned int coefficients[LCD_PER_PIXEL][SAMPLES_PER_PIXEL*3] = { |
| //The red subpixel is centered inside the first sample (at 1/6 pixel), and is shifted. |
| { 0x03, 0x0b, 0x1c, 0x33, 0x40, 0x39, 0x24, 0x10, 0x05, 0x01, 0x00, 0x00, }, |
| //The green subpixel is centered between two samples (at 1/2 pixel), so is symetric |
| { 0x00, 0x02, 0x08, 0x16, 0x2b, 0x3d, 0x3d, 0x2b, 0x16, 0x08, 0x02, 0x00, }, |
| //The blue subpixel is centered inside the last sample (at 5/6 pixel), and is shifted. |
| { 0x00, 0x00, 0x01, 0x05, 0x10, 0x24, 0x39, 0x40, 0x33, 0x1c, 0x0b, 0x03, }, |
| }; |
| |
| for (int y = 0; y < height; ++y) { |
| const uint8_t* srcP = src.addr8(0, y); |
| |
| // TODO: this fir filter implementation is straight forward, but slow. |
| // It should be possible to make it much faster. |
| for (int sample_x = -4, pixel_x = 0; sample_x < sample_width + 4; sample_x += 4, ++pixel_x) { |
| int fir[LCD_PER_PIXEL] = { 0 }; |
| for (int sample_index = SkMax32(0, sample_x - 4), coeff_index = sample_index - (sample_x - 4) |
| ; sample_index < SkMin32(sample_x + 8, sample_width) |
| ; ++sample_index, ++coeff_index) |
| { |
| int sample_value = srcP[sample_index]; |
| for (int subpxl_index = 0; subpxl_index < LCD_PER_PIXEL; ++subpxl_index) { |
| fir[subpxl_index] += coefficients[subpxl_index][coeff_index] * sample_value; |
| } |
| } |
| for (int subpxl_index = 0; subpxl_index < LCD_PER_PIXEL; ++subpxl_index) { |
| fir[subpxl_index] /= 0x100; |
| fir[subpxl_index] = SkMin32(fir[subpxl_index], 255); |
| } |
| |
| U8CPU r = sk_apply_lut_if<APPLY_PREBLEND>(fir[0], maskPreBlend.fR); |
| U8CPU g = sk_apply_lut_if<APPLY_PREBLEND>(fir[1], maskPreBlend.fG); |
| U8CPU b = sk_apply_lut_if<APPLY_PREBLEND>(fir[2], maskPreBlend.fB); |
| #if SK_SHOW_TEXT_BLIT_COVERAGE |
| r = SkMax32(r, 10); g = SkMax32(g, 10); b = SkMax32(b, 10); |
| #endif |
| dstP[pixel_x] = SkPack888ToRGB16(r, g, b); |
| } |
| dstP = (uint16_t*)((char*)dstP + dstRB); |
| } |
| } |
| |
| static inline int convert_8_to_1(unsigned byte) { |
| SkASSERT(byte <= 0xFF); |
| return byte >> 7; |
| } |
| |
| static uint8_t pack_8_to_1(const uint8_t alpha[8]) { |
| unsigned bits = 0; |
| for (int i = 0; i < 8; ++i) { |
| bits <<= 1; |
| bits |= convert_8_to_1(alpha[i]); |
| } |
| return SkToU8(bits); |
| } |
| |
| static void packA8ToA1(const SkMask& mask, const uint8_t* src, size_t srcRB) { |
| const int height = mask.fBounds.height(); |
| const int width = mask.fBounds.width(); |
| const int octs = width >> 3; |
| const int leftOverBits = width & 7; |
| |
| uint8_t* dst = mask.fImage; |
| const int dstPad = mask.fRowBytes - SkAlign8(width)/8; |
| SkASSERT(dstPad >= 0); |
| |
| SkASSERT(width >= 0); |
| SkASSERT(srcRB >= (size_t)width); |
| const size_t srcPad = srcRB - width; |
| |
| for (int y = 0; y < height; ++y) { |
| for (int i = 0; i < octs; ++i) { |
| *dst++ = pack_8_to_1(src); |
| src += 8; |
| } |
| if (leftOverBits > 0) { |
| unsigned bits = 0; |
| int shift = 7; |
| for (int i = 0; i < leftOverBits; ++i, --shift) { |
| bits |= convert_8_to_1(*src++) << shift; |
| } |
| *dst++ = bits; |
| } |
| src += srcPad; |
| dst += dstPad; |
| } |
| } |
| |
| static void generateMask(const SkMask& mask, const SkPath& path, |
| const SkMaskGamma::PreBlend& maskPreBlend) { |
| SkPaint paint; |
| |
| int srcW = mask.fBounds.width(); |
| int srcH = mask.fBounds.height(); |
| int dstW = srcW; |
| int dstH = srcH; |
| int dstRB = mask.fRowBytes; |
| |
| SkMatrix matrix; |
| matrix.setTranslate(-SkIntToScalar(mask.fBounds.fLeft), |
| -SkIntToScalar(mask.fBounds.fTop)); |
| |
| paint.setAntiAlias(SkMask::kBW_Format != mask.fFormat); |
| switch (mask.fFormat) { |
| case SkMask::kBW_Format: |
| dstRB = 0; // signals we need a copy |
| break; |
| case SkMask::kA8_Format: |
| break; |
| case SkMask::kLCD16_Format: |
| // TODO: trigger off LCD orientation |
| dstW = 4*dstW - 8; |
| matrix.setTranslate(-SkIntToScalar(mask.fBounds.fLeft + 1), |
| -SkIntToScalar(mask.fBounds.fTop)); |
| matrix.postScale(SkIntToScalar(4), SK_Scalar1); |
| dstRB = 0; // signals we need a copy |
| break; |
| default: |
| SkDEBUGFAIL("unexpected mask format"); |
| } |
| |
| SkRasterClip clip; |
| clip.setRect(SkIRect::MakeWH(dstW, dstH)); |
| |
| const SkImageInfo info = SkImageInfo::MakeA8(dstW, dstH); |
| SkAutoPixmapStorage dst; |
| |
| if (0 == dstRB) { |
| if (!dst.tryAlloc(info)) { |
| // can't allocate offscreen, so empty the mask and return |
| sk_bzero(mask.fImage, mask.computeImageSize()); |
| return; |
| } |
| } else { |
| dst.reset(info, mask.fImage, dstRB); |
| } |
| sk_bzero(dst.writable_addr(), dst.getSafeSize()); |
| |
| SkDraw draw; |
| draw.fDst = dst; |
| draw.fRC = &clip; |
| draw.fMatrix = &matrix; |
| draw.drawPath(path, paint); |
| |
| switch (mask.fFormat) { |
| case SkMask::kBW_Format: |
| packA8ToA1(mask, dst.addr8(0, 0), dst.rowBytes()); |
| break; |
| case SkMask::kA8_Format: |
| if (maskPreBlend.isApplicable()) { |
| applyLUTToA8Mask(mask, maskPreBlend.fG); |
| } |
| break; |
| case SkMask::kLCD16_Format: |
| if (maskPreBlend.isApplicable()) { |
| pack4xHToLCD16<true>(dst, mask, maskPreBlend); |
| } else { |
| pack4xHToLCD16<false>(dst, mask, maskPreBlend); |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| |
| static void extract_alpha(const SkMask& dst, |
| const SkPMColor* srcRow, size_t srcRB) { |
| int width = dst.fBounds.width(); |
| int height = dst.fBounds.height(); |
| int dstRB = dst.fRowBytes; |
| uint8_t* dstRow = dst.fImage; |
| |
| for (int y = 0; y < height; ++y) { |
| for (int x = 0; x < width; ++x) { |
| dstRow[x] = SkGetPackedA32(srcRow[x]); |
| } |
| // zero any padding on each row |
| for (int x = width; x < dstRB; ++x) { |
| dstRow[x] = 0; |
| } |
| dstRow += dstRB; |
| srcRow = (const SkPMColor*)((const char*)srcRow + srcRB); |
| } |
| } |
| |
| void SkScalerContext::getImage(const SkGlyph& origGlyph) { |
| const SkGlyph* glyph = &origGlyph; |
| SkGlyph tmpGlyph; |
| |
| // in case we need to call generateImage on a mask-format that is different |
| // (i.e. larger) than what our caller allocated by looking at origGlyph. |
| SkAutoMalloc tmpGlyphImageStorage; |
| |
| // If we are going to draw-from-path, then we cannot generate color, since |
| // the path only makes a mask. This case should have been caught up in |
| // generateMetrics(). |
| SkASSERT(!fGenerateImageFromPath || |
| SkMask::kARGB32_Format != origGlyph.fMaskFormat); |
| |
| if (fMaskFilter) { // restore the prefilter bounds |
| tmpGlyph.initWithGlyphID(origGlyph.getPackedID()); |
| |
| // need the original bounds, sans our maskfilter |
| SkMaskFilter* mf = fMaskFilter.release(); // temp disable |
| this->getMetrics(&tmpGlyph); |
| fMaskFilter = sk_sp<SkMaskFilter>(mf); // restore |
| |
| // we need the prefilter bounds to be <= filter bounds |
| SkASSERT(tmpGlyph.fWidth <= origGlyph.fWidth); |
| SkASSERT(tmpGlyph.fHeight <= origGlyph.fHeight); |
| |
| if (tmpGlyph.fMaskFormat == origGlyph.fMaskFormat) { |
| tmpGlyph.fImage = origGlyph.fImage; |
| } else { |
| tmpGlyphImageStorage.reset(tmpGlyph.computeImageSize()); |
| tmpGlyph.fImage = tmpGlyphImageStorage.get(); |
| } |
| glyph = &tmpGlyph; |
| } |
| |
| if (fGenerateImageFromPath) { |
| SkPath devPath, fillPath; |
| SkMatrix fillToDevMatrix; |
| SkMask mask; |
| |
| this->internalGetPath(glyph->getPackedID(), &fillPath, &devPath, &fillToDevMatrix); |
| glyph->toMask(&mask); |
| |
| if (fRasterizer) { |
| mask.fFormat = SkMask::kA8_Format; |
| sk_bzero(glyph->fImage, mask.computeImageSize()); |
| |
| if (!fRasterizer->rasterize(fillPath, fillToDevMatrix, nullptr, |
| fMaskFilter.get(), &mask, |
| SkMask::kJustRenderImage_CreateMode)) { |
| return; |
| } |
| if (fPreBlend.isApplicable()) { |
| applyLUTToA8Mask(mask, fPreBlend.fG); |
| } |
| } else { |
| SkASSERT(SkMask::kARGB32_Format != mask.fFormat); |
| generateMask(mask, devPath, fPreBlend); |
| } |
| } else { |
| generateImage(*glyph); |
| } |
| |
| if (fMaskFilter) { |
| SkMask srcM, dstM; |
| SkMatrix matrix; |
| |
| // the src glyph image shouldn't be 3D |
| SkASSERT(SkMask::k3D_Format != glyph->fMaskFormat); |
| |
| SkAutoSMalloc<32*32> a8storage; |
| glyph->toMask(&srcM); |
| if (SkMask::kARGB32_Format == srcM.fFormat) { |
| // now we need to extract the alpha-channel from the glyph's image |
| // and copy it into a temp buffer, and then point srcM at that temp. |
| srcM.fFormat = SkMask::kA8_Format; |
| srcM.fRowBytes = SkAlign4(srcM.fBounds.width()); |
| size_t size = srcM.computeImageSize(); |
| a8storage.reset(size); |
| srcM.fImage = (uint8_t*)a8storage.get(); |
| extract_alpha(srcM, |
| (const SkPMColor*)glyph->fImage, glyph->rowBytes()); |
| } |
| |
| fRec.getMatrixFrom2x2(&matrix); |
| |
| if (fMaskFilter->filterMask(&dstM, srcM, matrix, nullptr)) { |
| int width = SkFastMin32(origGlyph.fWidth, dstM.fBounds.width()); |
| int height = SkFastMin32(origGlyph.fHeight, dstM.fBounds.height()); |
| int dstRB = origGlyph.rowBytes(); |
| int srcRB = dstM.fRowBytes; |
| |
| const uint8_t* src = (const uint8_t*)dstM.fImage; |
| uint8_t* dst = (uint8_t*)origGlyph.fImage; |
| |
| if (SkMask::k3D_Format == dstM.fFormat) { |
| // we have to copy 3 times as much |
| height *= 3; |
| } |
| |
| // clean out our glyph, since it may be larger than dstM |
| //sk_bzero(dst, height * dstRB); |
| |
| while (--height >= 0) { |
| memcpy(dst, src, width); |
| src += srcRB; |
| dst += dstRB; |
| } |
| SkMask::FreeImage(dstM.fImage); |
| |
| if (fPreBlendForFilter.isApplicable()) { |
| applyLUTToA8Mask(srcM, fPreBlendForFilter.fG); |
| } |
| } |
| } |
| } |
| |
| void SkScalerContext::getPath(SkPackedGlyphID glyphID, SkPath* path) { |
| this->internalGetPath(glyphID, nullptr, path, nullptr); |
| } |
| |
| void SkScalerContext::getFontMetrics(SkPaint::FontMetrics* fm) { |
| SkASSERT(fm); |
| this->generateFontMetrics(fm); |
| } |
| |
| SkUnichar SkScalerContext::generateGlyphToChar(uint16_t glyph) { |
| return 0; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| void SkScalerContext::internalGetPath(SkPackedGlyphID glyphID, SkPath* fillPath, |
| SkPath* devPath, SkMatrix* fillToDevMatrix) { |
| SkPath path; |
| generatePath(glyphID.code(), &path); |
| |
| if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) { |
| SkFixed dx = glyphID.getSubXFixed(); |
| SkFixed dy = glyphID.getSubYFixed(); |
| if (dx | dy) { |
| path.offset(SkFixedToScalar(dx), SkFixedToScalar(dy)); |
| } |
| } |
| |
| if (fRec.fFrameWidth > 0 || fPathEffect != nullptr) { |
| // need the path in user-space, with only the point-size applied |
| // so that our stroking and effects will operate the same way they |
| // would if the user had extracted the path themself, and then |
| // called drawPath |
| SkPath localPath; |
| SkMatrix matrix, inverse; |
| |
| fRec.getMatrixFrom2x2(&matrix); |
| if (!matrix.invert(&inverse)) { |
| // assume fillPath and devPath are already empty. |
| return; |
| } |
| path.transform(inverse, &localPath); |
| // now localPath is only affected by the paint settings, and not the canvas matrix |
| |
| SkStrokeRec rec(SkStrokeRec::kFill_InitStyle); |
| |
| if (fRec.fFrameWidth > 0) { |
| rec.setStrokeStyle(fRec.fFrameWidth, |
| SkToBool(fRec.fFlags & kFrameAndFill_Flag)); |
| // glyphs are always closed contours, so cap type is ignored, |
| // so we just pass something. |
| rec.setStrokeParams((SkPaint::Cap)fRec.fStrokeCap, |
| (SkPaint::Join)fRec.fStrokeJoin, |
| fRec.fMiterLimit); |
| } |
| |
| if (fPathEffect) { |
| SkPath effectPath; |
| if (fPathEffect->filterPath(&effectPath, localPath, &rec, nullptr)) { |
| localPath.swap(effectPath); |
| } |
| } |
| |
| if (rec.needToApply()) { |
| SkPath strokePath; |
| if (rec.applyToPath(&strokePath, localPath)) { |
| localPath.swap(strokePath); |
| } |
| } |
| |
| // now return stuff to the caller |
| if (fillToDevMatrix) { |
| *fillToDevMatrix = matrix; |
| } |
| if (devPath) { |
| localPath.transform(matrix, devPath); |
| } |
| if (fillPath) { |
| fillPath->swap(localPath); |
| } |
| } else { // nothing tricky to do |
| if (fillToDevMatrix) { |
| fillToDevMatrix->reset(); |
| } |
| if (devPath) { |
| if (fillPath == nullptr) { |
| devPath->swap(path); |
| } else { |
| *devPath = path; |
| } |
| } |
| |
| if (fillPath) { |
| fillPath->swap(path); |
| } |
| } |
| |
| if (devPath) { |
| devPath->updateBoundsCache(); |
| } |
| if (fillPath) { |
| fillPath->updateBoundsCache(); |
| } |
| } |
| |
| |
| void SkScalerContextRec::getMatrixFrom2x2(SkMatrix* dst) const { |
| dst->setAll(fPost2x2[0][0], fPost2x2[0][1], 0, |
| fPost2x2[1][0], fPost2x2[1][1], 0, |
| 0, 0, 1); |
| } |
| |
| void SkScalerContextRec::getLocalMatrix(SkMatrix* m) const { |
| SkPaintPriv::MakeTextMatrix(m, fTextSize, fPreScaleX, fPreSkewX); |
| } |
| |
| void SkScalerContextRec::getSingleMatrix(SkMatrix* m) const { |
| this->getLocalMatrix(m); |
| |
| // now concat the device matrix |
| SkMatrix deviceMatrix; |
| this->getMatrixFrom2x2(&deviceMatrix); |
| m->postConcat(deviceMatrix); |
| } |
| |
| bool SkScalerContextRec::computeMatrices(PreMatrixScale preMatrixScale, SkVector* s, SkMatrix* sA, |
| SkMatrix* GsA, SkMatrix* G_inv, SkMatrix* A_out) |
| { |
| // A is the 'total' matrix. |
| SkMatrix A; |
| this->getSingleMatrix(&A); |
| |
| // The caller may find the 'total' matrix useful when dealing directly with EM sizes. |
| if (A_out) { |
| *A_out = A; |
| } |
| |
| // GA is the matrix A with rotation removed. |
| SkMatrix GA; |
| bool skewedOrFlipped = A.getSkewX() || A.getSkewY() || A.getScaleX() < 0 || A.getScaleY() < 0; |
| if (skewedOrFlipped) { |
| // QR by Givens rotations. G is Q^T and GA is R. G is rotational (no reflections). |
| // h is where A maps the horizontal baseline. |
| SkPoint h = SkPoint::Make(SK_Scalar1, 0); |
| A.mapPoints(&h, 1); |
| |
| // G is the Givens Matrix for A (rotational matrix where GA[0][1] == 0). |
| SkMatrix G; |
| SkComputeGivensRotation(h, &G); |
| |
| GA = G; |
| GA.preConcat(A); |
| |
| // The 'remainingRotation' is G inverse, which is fairly simple since G is 2x2 rotational. |
| if (G_inv) { |
| G_inv->setAll( |
| G.get(SkMatrix::kMScaleX), -G.get(SkMatrix::kMSkewX), G.get(SkMatrix::kMTransX), |
| -G.get(SkMatrix::kMSkewY), G.get(SkMatrix::kMScaleY), G.get(SkMatrix::kMTransY), |
| G.get(SkMatrix::kMPersp0), G.get(SkMatrix::kMPersp1), G.get(SkMatrix::kMPersp2)); |
| } |
| } else { |
| GA = A; |
| if (G_inv) { |
| G_inv->reset(); |
| } |
| } |
| |
| // If the 'total' matrix is singular, set the 'scale' to something finite and zero the matrices. |
| // All underlying ports have issues with zero text size, so use the matricies to zero. |
| // If one of the scale factors is less than 1/256 then an EM filling square will |
| // never affect any pixels. |
| if (SkScalarAbs(GA.get(SkMatrix::kMScaleX)) <= SK_ScalarNearlyZero || |
| SkScalarAbs(GA.get(SkMatrix::kMScaleY)) <= SK_ScalarNearlyZero) |
| { |
| s->fX = SK_Scalar1; |
| s->fY = SK_Scalar1; |
| sA->setScale(0, 0); |
| if (GsA) { |
| GsA->setScale(0, 0); |
| } |
| if (G_inv) { |
| G_inv->reset(); |
| } |
| return false; |
| } |
| |
| // At this point, given GA, create s. |
| switch (preMatrixScale) { |
| case kFull_PreMatrixScale: |
| s->fX = SkScalarAbs(GA.get(SkMatrix::kMScaleX)); |
| s->fY = SkScalarAbs(GA.get(SkMatrix::kMScaleY)); |
| break; |
| case kVertical_PreMatrixScale: { |
| SkScalar yScale = SkScalarAbs(GA.get(SkMatrix::kMScaleY)); |
| s->fX = yScale; |
| s->fY = yScale; |
| break; |
| } |
| case kVerticalInteger_PreMatrixScale: { |
| SkScalar realYScale = SkScalarAbs(GA.get(SkMatrix::kMScaleY)); |
| SkScalar intYScale = SkScalarRoundToScalar(realYScale); |
| if (intYScale == 0) { |
| intYScale = SK_Scalar1; |
| } |
| s->fX = intYScale; |
| s->fY = intYScale; |
| break; |
| } |
| } |
| |
| // The 'remaining' matrix sA is the total matrix A without the scale. |
| if (!skewedOrFlipped && ( |
| (kFull_PreMatrixScale == preMatrixScale) || |
| (kVertical_PreMatrixScale == preMatrixScale && A.getScaleX() == A.getScaleY()))) |
| { |
| // If GA == A and kFull_PreMatrixScale, sA is identity. |
| // If GA == A and kVertical_PreMatrixScale and A.scaleX == A.scaleY, sA is identity. |
| sA->reset(); |
| } else if (!skewedOrFlipped && kVertical_PreMatrixScale == preMatrixScale) { |
| // If GA == A and kVertical_PreMatrixScale, sA.scaleY is SK_Scalar1. |
| sA->reset(); |
| sA->setScaleX(A.getScaleX() / s->fY); |
| } else { |
| // TODO: like kVertical_PreMatrixScale, kVerticalInteger_PreMatrixScale with int scales. |
| *sA = A; |
| sA->preScale(SkScalarInvert(s->fX), SkScalarInvert(s->fY)); |
| } |
| |
| // The 'remainingWithoutRotation' matrix GsA is the non-rotational part of A without the scale. |
| if (GsA) { |
| *GsA = GA; |
| // G is rotational so reorders with the scale. |
| GsA->preScale(SkScalarInvert(s->fX), SkScalarInvert(s->fY)); |
| } |
| |
| return true; |
| } |
| |
| SkAxisAlignment SkScalerContext::computeAxisAlignmentForHText() { |
| // Why fPost2x2 can be used here. |
| // getSingleMatrix multiplies in getLocalMatrix, which consists of |
| // * fTextSize (a scale, which has no effect) |
| // * fPreScaleX (a scale in x, which has no effect) |
| // * fPreSkewX (has no effect, but would on vertical text alignment). |
| // In other words, making the text bigger, stretching it along the |
| // horizontal axis, or fake italicizing it does not move the baseline. |
| |
| if (0 == fRec.fPost2x2[1][0]) { |
| // The x axis is mapped onto the x axis. |
| return kX_SkAxisAlignment; |
| } |
| if (0 == fRec.fPost2x2[0][0]) { |
| // The x axis is mapped onto the y axis. |
| return kY_SkAxisAlignment; |
| } |
| return kNone_SkAxisAlignment; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| class SkScalerContext_Empty : public SkScalerContext { |
| public: |
| SkScalerContext_Empty(sk_sp<SkTypeface> typeface, const SkScalerContextEffects& effects, |
| const SkDescriptor* desc) |
| : SkScalerContext(std::move(typeface), effects, desc) {} |
| |
| protected: |
| unsigned generateGlyphCount() override { |
| return 0; |
| } |
| uint16_t generateCharToGlyph(SkUnichar uni) override { |
| return 0; |
| } |
| void generateAdvance(SkGlyph* glyph) override { |
| glyph->zeroMetrics(); |
| } |
| void generateMetrics(SkGlyph* glyph) override { |
| glyph->zeroMetrics(); |
| } |
| void generateImage(const SkGlyph& glyph) override {} |
| void generatePath(SkGlyphID glyph, SkPath* path) override {} |
| void generateFontMetrics(SkPaint::FontMetrics* metrics) override { |
| if (metrics) { |
| sk_bzero(metrics, sizeof(*metrics)); |
| } |
| } |
| }; |
| |
| extern SkScalerContext* SkCreateColorScalerContext(const SkDescriptor* desc); |
| |
| std::unique_ptr<SkScalerContext> SkTypeface::createScalerContext( |
| const SkScalerContextEffects& effects, const SkDescriptor* desc, bool allowFailure) const |
| { |
| std::unique_ptr<SkScalerContext> c(this->onCreateScalerContext(effects, desc)); |
| if (!c && !allowFailure) { |
| c = skstd::make_unique<SkScalerContext_Empty>(sk_ref_sp(const_cast<SkTypeface*>(this)), |
| effects, desc); |
| } |
| return c; |
| } |
