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# HG changeset patch
# User Lee Salzman <lsalzman@mozilla.com>
# 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<true>(face->glyph->bitmap, mask, doBGR,
+ copyFT2LCD16<true>(ftGlyph.bitmap, mask, doBGR,
fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
} else {
- copyFT2LCD16<false>(face->glyph->bitmap, mask, doBGR,
+ copyFT2LCD16<false>(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<uint8_t*>(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<uint8_t>(a, 0x20);
+ }
+ }
+#endif
}
} break;
case FT_GLYPH_FORMAT_BITMAP: {
FT_Pixel_Mode pixel_mode = static_cast<FT_Pixel_Mode>(face->glyph->bitmap.pixel_mode);
SkMask::Format maskFormat = static_cast<SkMask::Format>(glyph.fMaskFormat);
// Assume that the other formats do not exist.
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