void SkScalerContext_FreeType_Base::generateGlyphImage(
FT_Face face,
const SkGlyph& glyph,
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;
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;
}
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.");
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>(ftGlyph.bitmap, mask, doBGR,
fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
} else {
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;
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.
SkASSERT(FT_PIXEL_MODE_MONO == pixel_mode ||
FT_PIXEL_MODE_GRAY == pixel_mode ||
FT_PIXEL_MODE_BGRA == pixel_mode);
// These are the only formats this ScalerContext should request.
SkASSERT(SkMask::kBW_Format == maskFormat ||
SkMask::kA8_Format == maskFormat ||
SkMask::kARGB32_Format == maskFormat ||
SkMask::kLCD16_Format == maskFormat);
// If no scaling needed, directly copy glyph bitmap.
if (bitmapTransform.isIdentity()) {
SkMask dstMask;
glyph.toMask(&dstMask);
copyFTBitmap(face->glyph->bitmap, dstMask);
break;
}
// Otherwise, scale the bitmap.
// Copy the FT_Bitmap into an SkBitmap (either A8 or ARGB)
SkBitmap unscaledBitmap;
// TODO: mark this as sRGB when the blits will be sRGB.
unscaledBitmap.allocPixels(SkImageInfo::Make(face->glyph->bitmap.width,
face->glyph->bitmap.rows,
SkColorType_for_FTPixelMode(pixel_mode),
kPremul_SkAlphaType));
SkMask unscaledBitmapAlias;
unscaledBitmapAlias.fImage = reinterpret_cast<uint8_t*>(unscaledBitmap.getPixels());
unscaledBitmapAlias.fBounds.set(0, 0, unscaledBitmap.width(), unscaledBitmap.height());
unscaledBitmapAlias.fRowBytes = unscaledBitmap.rowBytes();
unscaledBitmapAlias.fFormat = SkMaskFormat_for_SkColorType(unscaledBitmap.colorType());
copyFTBitmap(face->glyph->bitmap, unscaledBitmapAlias);
// Wrap the glyph's mask in a bitmap, unless the glyph's mask is BW or LCD.
// BW requires an A8 target for resizing, which can then be down sampled.
// LCD should use a 4x A8 target, which will then be down sampled.
// For simplicity, LCD uses A8 and is replicated.
int bitmapRowBytes = 0;
if (SkMask::kBW_Format != maskFormat && SkMask::kLCD16_Format != maskFormat) {
bitmapRowBytes = glyph.rowBytes();
}
SkBitmap dstBitmap;
// TODO: mark this as sRGB when the blits will be sRGB.
dstBitmap.setInfo(SkImageInfo::Make(glyph.fWidth, glyph.fHeight,
SkColorType_for_SkMaskFormat(maskFormat),
kPremul_SkAlphaType),
bitmapRowBytes);
if (SkMask::kBW_Format == maskFormat || SkMask::kLCD16_Format == maskFormat) {
dstBitmap.allocPixels();
} else {
dstBitmap.setPixels(glyph.fImage);
}
// Scale unscaledBitmap into dstBitmap.
SkCanvas canvas(dstBitmap);
#ifdef SK_SHOW_TEXT_BLIT_COVERAGE
canvas.clear(0x33FF0000);
#else
canvas.clear(SK_ColorTRANSPARENT);
#endif
canvas.translate(-glyph.fLeft, -glyph.fTop);
canvas.concat(bitmapTransform);
canvas.translate(face->glyph->bitmap_left, -face->glyph->bitmap_top);
SkPaint paint;
paint.setFilterQuality(kMedium_SkFilterQuality);
canvas.drawBitmap(unscaledBitmap, 0, 0, &paint);
// If the destination is BW or LCD, convert from A8.
if (SkMask::kBW_Format == maskFormat) {
// Copy the A8 dstBitmap into the A1 glyph.fImage.
SkMask dstMask;
glyph.toMask(&dstMask);
packA8ToA1(dstMask, dstBitmap.getAddr8(0, 0), dstBitmap.rowBytes());
} else if (SkMask::kLCD16_Format == maskFormat) {
// Copy the A8 dstBitmap into the LCD16 glyph.fImage.
uint8_t* src = dstBitmap.getAddr8(0, 0);
uint16_t* dst = reinterpret_cast<uint16_t*>(glyph.fImage);
for (int y = dstBitmap.height(); y --> 0;) {
for (int x = 0; x < dstBitmap.width(); ++x) {
dst[x] = grayToRGB16(src[x]);
}
dst = (uint16_t*)((char*)dst + glyph.rowBytes());
src += dstBitmap.rowBytes();
}
}
} break;
default:
SkDEBUGFAIL("unknown glyph format");
memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight);
return;
}
// We used to always do this pre-USE_COLOR_LUMINANCE, but with colorlum,
// it is optional
#if defined(SK_GAMMA_APPLY_TO_A8)
if (SkMask::kA8_Format == glyph.fMaskFormat && fPreBlend.isApplicable()) {
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] = fPreBlend.fG[dst[x]];
}
dst += rowBytes;
}
}
#endif
}
void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGlyph& glyph) {
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;
if (fRec.fFlags & SkScalerContext::kEmbolden_Flag &&
!(face->style_flags & FT_STYLE_FLAG_BOLD)) {
emboldenOutline(face, outline);
}
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));
if (SkMask::kLCD16_Format == glyph.fMaskFormat) {
FT_Render_Glyph(face->glyph, doVert ? FT_RENDER_MODE_LCD_V : FT_RENDER_MODE_LCD);
SkMask mask;
glyph.toMask(&mask);
if (fPreBlend.isApplicable()) {
copyFT2LCD16<true>(face->glyph->bitmap, mask, doBGR,
fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
} else {
copyFT2LCD16<false>(face->glyph->bitmap, mask, doBGR,
fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
}
} else {
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);
}
} 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.
SkASSERT(FT_PIXEL_MODE_MONO == pixel_mode ||
FT_PIXEL_MODE_GRAY == pixel_mode ||
FT_PIXEL_MODE_BGRA == pixel_mode);
// These are the only formats this ScalerContext should request.
SkASSERT(SkMask::kBW_Format == maskFormat ||
SkMask::kA8_Format == maskFormat ||
SkMask::kARGB32_Format == maskFormat ||
SkMask::kLCD16_Format == maskFormat);
if (fRec.fFlags & SkScalerContext::kEmbolden_Flag &&
!(face->style_flags & FT_STYLE_FLAG_BOLD))
{
FT_GlyphSlot_Own_Bitmap(face->glyph);
FT_Bitmap_Embolden(face->glyph->library, &face->glyph->bitmap,
kBitmapEmboldenStrength, 0);
}
// If no scaling needed, directly copy glyph bitmap.
if (glyph.fWidth == face->glyph->bitmap.width &&
glyph.fHeight == face->glyph->bitmap.rows &&
glyph.fTop == -face->glyph->bitmap_top &&
glyph.fLeft == face->glyph->bitmap_left)
{
SkMask dstMask;
glyph.toMask(&dstMask);
copyFTBitmap(face->glyph->bitmap, dstMask);
break;
}
// Otherwise, scale the bitmap.
// Copy the FT_Bitmap into an SkBitmap (either A8 or ARGB)
SkBitmap unscaledBitmap;
unscaledBitmap.setConfig(SkBitmapConfig_for_FTPixelMode(pixel_mode),
face->glyph->bitmap.width, face->glyph->bitmap.rows);
unscaledBitmap.allocPixels();
SkMask unscaledBitmapAlias;
unscaledBitmapAlias.fImage = reinterpret_cast<uint8_t*>(unscaledBitmap.getPixels());
unscaledBitmapAlias.fBounds.set(0, 0, unscaledBitmap.width(), unscaledBitmap.height());
unscaledBitmapAlias.fRowBytes = unscaledBitmap.rowBytes();
unscaledBitmapAlias.fFormat = SkMaskFormat_for_SkBitmapConfig(unscaledBitmap.config());
copyFTBitmap(face->glyph->bitmap, unscaledBitmapAlias);
// Wrap the glyph's mask in a bitmap, unless the glyph's mask is BW or LCD.
// BW requires an A8 target for resizing, which can then be down sampled.
// LCD should use a 4x A8 target, which will then be down sampled.
// For simplicity, LCD uses A8 and is replicated.
int bitmapRowBytes = 0;
if (SkMask::kBW_Format != maskFormat && SkMask::kLCD16_Format != maskFormat) {
bitmapRowBytes = glyph.rowBytes();
}
SkBitmap dstBitmap;
dstBitmap.setConfig(SkBitmapConfig_for_SkMaskFormat(maskFormat),
glyph.fWidth, glyph.fHeight, bitmapRowBytes);
if (SkMask::kBW_Format == maskFormat || SkMask::kLCD16_Format == maskFormat) {
dstBitmap.allocPixels();
} else {
dstBitmap.setPixels(glyph.fImage);
}
// Scale unscaledBitmap into dstBitmap.
SkCanvas canvas(dstBitmap);
canvas.clear(SK_ColorTRANSPARENT);
canvas.scale(SkIntToScalar(glyph.fWidth) / SkIntToScalar(face->glyph->bitmap.width),
SkIntToScalar(glyph.fHeight) / SkIntToScalar(face->glyph->bitmap.rows));
SkPaint paint;
paint.setFilterLevel(SkPaint::kLow_FilterLevel);
canvas.drawBitmap(unscaledBitmap, 0, 0, &paint);
// If the destination is BW or LCD, convert from A8.
if (SkMask::kBW_Format == maskFormat) {
// Copy the A8 dstBitmap into the A1 glyph.fImage.
SkMask dstMask;
glyph.toMask(&dstMask);
packA8ToA1(dstMask, dstBitmap.getAddr8(0, 0), dstBitmap.rowBytes());
} else if (SkMask::kLCD16_Format == maskFormat) {
// Copy the A8 dstBitmap into the LCD16 glyph.fImage.
uint8_t* src = dstBitmap.getAddr8(0, 0);
uint16_t* dst = reinterpret_cast<uint16_t*>(glyph.fImage);
for (int y = dstBitmap.height(); y --> 0;) {
for (int x = 0; x < dstBitmap.width(); ++x) {
dst[x] = grayToRGB16(src[x]);
}
dst = (uint16_t*)((char*)dst + glyph.rowBytes());
src += dstBitmap.rowBytes();
}
}
} break;
default:
SkDEBUGFAIL("unknown glyph format");
memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight);
return;
}
// We used to always do this pre-USE_COLOR_LUMINANCE, but with colorlum,
// it is optional
#if defined(SK_GAMMA_APPLY_TO_A8)
if (SkMask::kA8_Format == glyph.fMaskFormat && fPreBlend.isApplicable()) {
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] = fPreBlend.fG[dst[x]];
}
dst += rowBytes;
}
}
#endif
}