diff options
Diffstat (limited to 'src/ports/SkFontHost_FreeType.cpp')
| -rw-r--r-- | src/ports/SkFontHost_FreeType.cpp | 206 |
1 files changed, 41 insertions, 165 deletions
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp index 0d72fa1dc5..497a259a5b 100644 --- a/src/ports/SkFontHost_FreeType.cpp +++ b/src/ports/SkFontHost_FreeType.cpp @@ -16,6 +16,7 @@ #include "SkFontHost.h" #include "SkGlyph.h" #include "SkMask.h" +#include "SkMaskGamma.h" #include "SkAdvancedTypefaceMetrics.h" #include "SkScalerContext.h" #include "SkStream.h" @@ -57,14 +58,6 @@ //#define DUMP_STRIKE_CREATION //#define SK_GAMMA_APPLY_TO_A8 -//#define SK_GAMMA_SRGB - -#ifndef SK_GAMMA_CONTRAST - #define SK_GAMMA_CONTRAST 0x66 -#endif -#ifndef SK_GAMMA_EXPONENT - #define SK_GAMMA_EXPONENT 2.2 -#endif #ifdef SK_DEBUG #define SkASSERT_CONTINUE(pred) \ @@ -100,8 +93,6 @@ static bool gLCDSupportValid; // true iff |gLCDSupport| has been set. static bool gLCDSupport; // true iff LCD is supported by the runtime. static int gLCDExtra; // number of extra pixels for filtering. -static const uint8_t* gGammaTables[2]; - ///////////////////////////////////////////////////////////////////////// // See http://freetype.sourceforge.net/freetype2/docs/reference/ft2-bitmap_handling.html#FT_Bitmap_Embolden @@ -153,7 +144,7 @@ protected: virtual uint16_t generateCharToGlyph(SkUnichar uni); virtual void generateAdvance(SkGlyph* glyph); virtual void generateMetrics(SkGlyph* glyph); - virtual void generateImage(const SkGlyph& glyph); + virtual void generateImage(const SkGlyph& glyph, SkMaskGamma::PreBlend* maskPreBlend); virtual void generatePath(const SkGlyph& glyph, SkPath* path); virtual void generateFontMetrics(SkPaint::FontMetrics* mx, SkPaint::FontMetrics* my); @@ -670,25 +661,9 @@ void SkFontHost::FilterRec(SkScalerContext::Rec* rec) { #endif rec->setHinting(h); -#ifndef SK_USE_COLOR_LUMINANCE - // for compatibility at the moment, discretize luminance to 3 settings - // black, white, gray. This helps with fontcache utilization, since we - // won't create multiple entries that in the end map to the same results. - { - unsigned lum = rec->getLuminanceByte(); - if (gGammaTables[0] || gGammaTables[1]) { - if (lum <= BLACK_LUMINANCE_LIMIT) { - lum = 0; - } else if (lum >= WHITE_LUMINANCE_LIMIT) { - lum = SkScalerContext::kLuminance_Max; - } else { - lum = SkScalerContext::kLuminance_Max >> 1; - } - } else { - lum = 0; // no gamma correct, so use 0 since SkPaint uses that - // when measuring text w/o regard for luminance - } - rec->setLuminanceBits(lum); +#ifndef SK_GAMMA_APPLY_TO_A8 + if (!isLCD(*rec)) { + rec->ignorePreBlend(); } #endif } @@ -716,7 +691,6 @@ SkScalerContext_FreeType::SkScalerContext_FreeType(const SkDescriptor* desc) if (!InitFreetype()) { sk_throw(); } - SkFontHost::GetGammaTables(gGammaTables); } ++gFTCount; @@ -1169,103 +1143,6 @@ void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) { /////////////////////////////////////////////////////////////////////////////// -#ifdef SK_USE_COLOR_LUMINANCE - -static float apply_contrast(float srca, float contrast) { - return srca + ((1.0f - srca) * contrast * srca); -} - -#ifdef SK_GAMMA_SRGB -static float lin(float per) { - if (per <= 0.04045f) { - return per / 12.92f; - } - return powf((per + 0.055f) / 1.055, 2.4f); -} -static float per(float lin) { - if (lin <= 0.0031308f) { - return lin * 12.92f; - } - return 1.055f * powf(lin, 1.0f / 2.4f) - 0.055f; -} -#else //SK_GAMMA_SRGB -static float lin(float per) { - const float g = SK_GAMMA_EXPONENT; - return powf(per, g); -} -static float per(float lin) { - const float g = SK_GAMMA_EXPONENT; - return powf(lin, 1.0f / g); -} -#endif //SK_GAMMA_SRGB - -static void build_gamma_table(uint8_t table[256], int srcI) { - const float src = (float)srcI / 255.0f; - const float linSrc = lin(src); - const float linDst = 1.0f - linSrc; - const float dst = per(linDst); - - // have our contrast value taper off to 0 as the src luminance becomes white - const float contrast = SK_GAMMA_CONTRAST / 255.0f * linDst; - const float step = 1.0f / 256.0f; - - //Remove discontinuity and instability when src is close to dst. - if (fabs(src - dst) < 0.01f) { - float rawSrca = 0.0f; - for (int i = 0; i < 256; ++i, rawSrca += step) { - float srca = apply_contrast(rawSrca, contrast); - table[i] = sk_float_round2int(255.0f * srca); - } - } else { - float rawSrca = 0.0f; - for (int i = 0; i < 256; ++i, rawSrca += step) { - float srca = apply_contrast(rawSrca, contrast); - SkASSERT(srca <= 1.0f); - float dsta = 1 - srca; - - //Calculate the output we want. - float linOut = (linSrc * srca + dsta * linDst); - SkASSERT(linOut <= 1.0f); - float out = per(linOut); - - //Undo what the blit blend will do. - float result = (out - dst) / (src - dst); - SkASSERT(sk_float_round2int(255.0f * result) <= 255); - - table[i] = sk_float_round2int(255.0f * result); - } - } -} - -static const uint8_t* getGammaTable(U8CPU luminance) { - static uint8_t gGammaTables[4][256]; - static bool gInited; - if (!gInited) { - build_gamma_table(gGammaTables[0], 0x00); - build_gamma_table(gGammaTables[1], 0x55); - build_gamma_table(gGammaTables[2], 0xAA); - build_gamma_table(gGammaTables[3], 0xFF); - - gInited = true; - } - SkASSERT(0 == (luminance >> 8)); - return gGammaTables[luminance >> 6]; -} - -#else //SK_USE_COLOR_LUMINANCE -static const uint8_t* getIdentityTable() { - static bool gOnce; - static uint8_t gIdentityTable[256]; - if (!gOnce) { - for (int i = 0; i < 256; ++i) { - gIdentityTable[i] = i; - } - gOnce = true; - } - return gIdentityTable; -} -#endif //SK_USE_COLOR_LUMINANCE - static uint16_t packTriple(unsigned r, unsigned g, unsigned b) { return SkPackRGB16(r >> 3, g >> 2, b >> 3); } @@ -1281,6 +1158,7 @@ static int bittst(const uint8_t data[], int bitOffset) { return lowBit & 1; } +template<bool APPLY_PREBLEND> static void copyFT2LCD16(const SkGlyph& glyph, const FT_Bitmap& bitmap, int lcdIsBGR, bool lcdIsVert, const uint8_t* tableR, const uint8_t* tableG, const uint8_t* tableB) { @@ -1325,25 +1203,25 @@ static void copyFT2LCD16(const SkGlyph& glyph, const FT_Bitmap& bitmap, SkTSwap(srcR, srcB); } for (int x = 0; x < width; x++) { - dst[x] = packTriple(tableR[*srcR++], - tableG[*srcG++], - tableB[*srcB++]); + dst[x] = packTriple(sk_apply_lut_if<APPLY_PREBLEND>(*srcR++, tableR), + sk_apply_lut_if<APPLY_PREBLEND>(*srcG++, tableG), + sk_apply_lut_if<APPLY_PREBLEND>(*srcB++, tableB)); } src += 3 * bitmap.pitch; } else { // horizontal stripes const uint8_t* triple = src; if (lcdIsBGR) { for (int x = 0; x < width; x++) { - dst[x] = packTriple(tableR[triple[2]], - tableG[triple[1]], - tableB[triple[0]]); + dst[x] = packTriple(sk_apply_lut_if<APPLY_PREBLEND>(triple[2], tableR), + sk_apply_lut_if<APPLY_PREBLEND>(triple[1], tableG), + sk_apply_lut_if<APPLY_PREBLEND>(triple[0], tableB)); triple += 3; } } else { for (int x = 0; x < width; x++) { - dst[x] = packTriple(tableR[triple[0]], - tableG[triple[1]], - tableB[triple[2]]); + dst[x] = packTriple(sk_apply_lut_if<APPLY_PREBLEND>(triple[0], tableR), + sk_apply_lut_if<APPLY_PREBLEND>(triple[1], tableG), + sk_apply_lut_if<APPLY_PREBLEND>(triple[2], tableB)); triple += 3; } } @@ -1355,7 +1233,7 @@ static void copyFT2LCD16(const SkGlyph& glyph, const FT_Bitmap& bitmap, } } -void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { +void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph, SkMaskGamma::PreBlend* maskPreBlend) { SkAutoMutexAcquire ac(gFTMutex); FT_Error err; @@ -1373,25 +1251,15 @@ void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { return; } -#ifdef SK_USE_COLOR_LUMINANCE - SkColor lumColor = fRec.getLuminanceColor(); - const uint8_t* tableR = getGammaTable(SkColorGetR(lumColor)); - const uint8_t* tableG = getGammaTable(SkColorGetG(lumColor)); - const uint8_t* tableB = getGammaTable(SkColorGetB(lumColor)); -#else - unsigned lum = fRec.getLuminanceByte(); - const uint8_t* tableR; - const uint8_t* tableG; - const uint8_t* tableB; - - bool isWhite = lum >= WHITE_LUMINANCE_LIMIT; - bool isBlack = lum <= BLACK_LUMINANCE_LIMIT; - if ((gGammaTables[0] || gGammaTables[1]) && (isBlack || isWhite)) { - tableR = tableG = tableB = gGammaTables[isBlack ? 0 : 1]; - } else { - tableR = tableG = tableB = getIdentityTable(); + //Must be careful not to use these if maskPreBlend == NULL + const uint8_t* tableR = NULL; + const uint8_t* tableG = NULL; + const uint8_t* tableB = NULL; + if (maskPreBlend) { + tableR = maskPreBlend->fR; + tableG = maskPreBlend->fG; + tableB = maskPreBlend->fB; } -#endif const bool doBGR = SkToBool(fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag); const bool doVert = fLCDIsVert; @@ -1427,8 +1295,13 @@ void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { if (SkMask::kLCD16_Format == glyph.fMaskFormat) { FT_Render_Glyph(fFace->glyph, doVert ? FT_RENDER_MODE_LCD_V : FT_RENDER_MODE_LCD); - copyFT2LCD16(glyph, fFace->glyph->bitmap, doBGR, doVert, - tableR, tableG, tableB); + if (maskPreBlend) { + copyFT2LCD16<true>(glyph, fFace->glyph->bitmap, doBGR, doVert, + tableR, tableG, tableB); + } else { + copyFT2LCD16<false>(glyph, fFace->glyph->bitmap, doBGR, doVert, + tableR, tableG, tableB); + } } else { target.width = glyph.fWidth; target.rows = glyph.fHeight; @@ -1493,8 +1366,13 @@ void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { dst += glyph.rowBytes(); } } else if (SkMask::kLCD16_Format == glyph.fMaskFormat) { - copyFT2LCD16(glyph, fFace->glyph->bitmap, doBGR, doVert, - tableR, tableG, tableB); + if (maskPreBlend) { + copyFT2LCD16<true>(glyph, fFace->glyph->bitmap, doBGR, doVert, + tableR, tableG, tableB); + } else { + copyFT2LCD16<false>(glyph, fFace->glyph->bitmap, doBGR, doVert, + tableR, tableG, tableB); + } } else { SkDEBUGFAIL("unknown glyph bitmap transform needed"); } @@ -1507,16 +1385,14 @@ void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { // We used to always do this pre-USE_COLOR_LUMINANCE, but with colorlum, // it is optional -#if defined(SK_GAMMA_APPLY_TO_A8) || !defined(SK_USE_COLOR_LUMINANCE) - if (SkMask::kA8_Format == glyph.fMaskFormat) { - SkASSERT(tableR == tableG && tableR == tableB); - const uint8_t* table = tableR; +#if defined(SK_GAMMA_APPLY_TO_A8) + if (SkMask::kA8_Format == glyph.fMaskFormat && maskPreBlend) { uint8_t* SK_RESTRICT dst = (uint8_t*)glyph.fImage; unsigned rowBytes = glyph.rowBytes(); for (int y = glyph.fHeight - 1; y >= 0; --y) { for (int x = glyph.fWidth - 1; x >= 0; --x) { - dst[x] = table[dst[x]]; + dst[x] = tableG[dst[x]]; } dst += rowBytes; } |