# HG changeset patch # User Lee Salzman # Date 1504120456 14400 # Wed Aug 30 15:14:16 2017 -0400 # Node ID 708d52f954b6d7ca2497fcb5b5084c6483300e89 # Parent 33224536ce20d942576cd4b9ffb350d6dce397bc clip FreeType glyph bitmap to mask in Skia MozReview-Commit-ID: 9NqLj9SkHFo diff --git a/gfx/skia/skia/src/ports/SkFontHost_FreeType_common.cpp b/gfx/skia/skia/src/ports/SkFontHost_FreeType_common.cpp --- a/gfx/skia/skia/src/ports/SkFontHost_FreeType_common.cpp +++ b/gfx/skia/skia/src/ports/SkFontHost_FreeType_common.cpp @@ -390,65 +390,131 @@ void SkScalerContext_FreeType_Base::gene const SkMatrix& bitmapTransform) { const bool doBGR = SkToBool(fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag); const bool doVert = SkToBool(fRec.fFlags & SkScalerContext::kLCD_Vertical_Flag); switch ( face->glyph->format ) { case FT_GLYPH_FORMAT_OUTLINE: { FT_Outline* outline = &face->glyph->outline; - FT_BBox bbox; - FT_Bitmap target; int dx = 0, dy = 0; if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) { dx = SkFixedToFDot6(glyph.getSubXFixed()); dy = SkFixedToFDot6(glyph.getSubYFixed()); // negate dy since freetype-y-goes-up and skia-y-goes-down dy = -dy; } - FT_Outline_Get_CBox(outline, &bbox); - /* - what we really want to do for subpixel is - offset(dx, dy) - compute_bounds - offset(bbox & !63) - but that is two calls to offset, so we do the following, which - achieves the same thing with only one offset call. - */ - FT_Outline_Translate(outline, dx - ((bbox.xMin + dx) & ~63), - dy - ((bbox.yMin + dy) & ~63)); + + memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight); if (SkMask::kLCD16_Format == glyph.fMaskFormat) { + FT_Outline_Translate(outline, dx, dy); FT_Error err = FT_Render_Glyph(face->glyph, doVert ? FT_RENDER_MODE_LCD_V : FT_RENDER_MODE_LCD); if (err) { SK_TRACEFTR(err, "Could not render glyph."); - sk_bzero(glyph.fImage, glyph.computeImageSize()); return; } + SkMask mask; glyph.toMask(&mask); +#ifdef SK_SHOW_TEXT_BLIT_COVERAGE + memset(mask.fImage, 0x80, mask.fBounds.height() * mask.fRowBytes); +#endif + FT_GlyphSlotRec& ftGlyph = *face->glyph; + + if (!SkIRect::Intersects(mask.fBounds, + SkIRect::MakeXYWH( ftGlyph.bitmap_left, + -ftGlyph.bitmap_top, + ftGlyph.bitmap.width, + ftGlyph.bitmap.rows))) + { + return; + } + + // If the FT_Bitmap extent is larger, discard bits of the bitmap outside the mask. + // If the SkMask extent is larger, shrink mask to fit bitmap (clearing discarded). + unsigned char* origBuffer = ftGlyph.bitmap.buffer; + // First align the top left (origin). + if (-ftGlyph.bitmap_top < mask.fBounds.fTop) { + int32_t topDiff = mask.fBounds.fTop - (-ftGlyph.bitmap_top); + ftGlyph.bitmap.buffer += ftGlyph.bitmap.pitch * topDiff; + ftGlyph.bitmap.rows -= topDiff; + ftGlyph.bitmap_top = -mask.fBounds.fTop; + } + if (ftGlyph.bitmap_left < mask.fBounds.fLeft) { + int32_t leftDiff = mask.fBounds.fLeft - ftGlyph.bitmap_left; + ftGlyph.bitmap.buffer += leftDiff; + ftGlyph.bitmap.width -= leftDiff; + ftGlyph.bitmap_left = mask.fBounds.fLeft; + } + if (mask.fBounds.fTop < -ftGlyph.bitmap_top) { + mask.fImage += mask.fRowBytes * (-ftGlyph.bitmap_top - mask.fBounds.fTop); + mask.fBounds.fTop = -ftGlyph.bitmap_top; + } + if (mask.fBounds.fLeft < ftGlyph.bitmap_left) { + mask.fImage += sizeof(uint16_t) * (ftGlyph.bitmap_left - mask.fBounds.fLeft); + mask.fBounds.fLeft = ftGlyph.bitmap_left; + } + // Origins aligned, clean up the width and height. + int ftVertScale = (doVert ? 3 : 1); + int ftHoriScale = (doVert ? 1 : 3); + if (mask.fBounds.height() * ftVertScale < SkToInt(ftGlyph.bitmap.rows)) { + ftGlyph.bitmap.rows = mask.fBounds.height() * ftVertScale; + } + if (mask.fBounds.width() * ftHoriScale < SkToInt(ftGlyph.bitmap.width)) { + ftGlyph.bitmap.width = mask.fBounds.width() * ftHoriScale; + } + if (SkToInt(ftGlyph.bitmap.rows) < mask.fBounds.height() * ftVertScale) { + mask.fBounds.fBottom = mask.fBounds.fTop + ftGlyph.bitmap.rows / ftVertScale; + } + if (SkToInt(ftGlyph.bitmap.width) < mask.fBounds.width() * ftHoriScale) { + mask.fBounds.fRight = mask.fBounds.fLeft + ftGlyph.bitmap.width / ftHoriScale; + } if (fPreBlend.isApplicable()) { - copyFT2LCD16(face->glyph->bitmap, mask, doBGR, + copyFT2LCD16(ftGlyph.bitmap, mask, doBGR, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB); } else { - copyFT2LCD16(face->glyph->bitmap, mask, doBGR, + copyFT2LCD16(ftGlyph.bitmap, mask, doBGR, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB); } + // Restore the buffer pointer so FreeType can properly free it. + ftGlyph.bitmap.buffer = origBuffer; } else { + FT_BBox bbox; + FT_Bitmap target; + FT_Outline_Get_CBox(outline, &bbox); + /* + what we really want to do for subpixel is + offset(dx, dy) + compute_bounds + offset(bbox & !63) + but that is two calls to offset, so we do the following, which + achieves the same thing with only one offset call. + */ + FT_Outline_Translate(outline, dx - ((bbox.xMin + dx) & ~63), + dy - ((bbox.yMin + dy) & ~63)); + target.width = glyph.fWidth; target.rows = glyph.fHeight; target.pitch = glyph.rowBytes(); target.buffer = reinterpret_cast(glyph.fImage); target.pixel_mode = compute_pixel_mode( (SkMask::Format)fRec.fMaskFormat); target.num_grays = 256; - memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight); FT_Outline_Get_Bitmap(face->glyph->library, outline, &target); +#ifdef SK_SHOW_TEXT_BLIT_COVERAGE + for (int y = 0; y < glyph.fHeight; ++y) { + for (int x = 0; x < glyph.fWidth; ++x) { + uint8_t& a = ((uint8_t*)glyph.fImage)[(glyph.rowBytes() * y) + x]; + a = SkTMax(a, 0x20); + } + } +#endif } } break; case FT_GLYPH_FORMAT_BITMAP: { FT_Pixel_Mode pixel_mode = static_cast(face->glyph->bitmap.pixel_mode); SkMask::Format maskFormat = static_cast(glyph.fMaskFormat); // Assume that the other formats do not exist.