/*
* Copyright 2010 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrTemplates.h"
#include "GrFontScaler.h"
#include "SkDescriptor.h"
#include "SkDistanceFieldGen.h"
#include "SkGlyphCache.h"
///////////////////////////////////////////////////////////////////////////////
GrFontDescKey::GrFontDescKey(const SkDescriptor& desc) : fHash(desc.getChecksum()) {
size_t size = desc.getLength();
if (size <= sizeof(fStorage)) {
fDesc = GrTCast<SkDescriptor*>(fStorage);
} else {
fDesc = SkDescriptor::Alloc(size);
}
memcpy(fDesc, &desc, size);
}
GrFontDescKey::~GrFontDescKey() {
if (fDesc != GrTCast<SkDescriptor*>(fStorage)) {
SkDescriptor::Free(fDesc);
}
}
bool GrFontDescKey::lt(const GrFontDescKey& rh) const {
const SkDescriptor* srcDesc = (&rh)->fDesc;
size_t lenLH = fDesc->getLength();
size_t lenRH = srcDesc->getLength();
int cmp = memcmp(fDesc, srcDesc, SkTMin<size_t>(lenLH, lenRH));
if (0 == cmp) {
return lenLH < lenRH;
} else {
return cmp < 0;
}
}
bool GrFontDescKey::eq(const GrFontDescKey& rh) const {
const SkDescriptor* srcDesc = (&rh)->fDesc;
return fDesc->equals(*srcDesc);
}
///////////////////////////////////////////////////////////////////////////////
GrFontScaler::GrFontScaler(SkGlyphCache* strike) {
fStrike = strike;
fKey = NULL;
}
GrFontScaler::~GrFontScaler() {
SkSafeUnref(fKey);
}
GrMaskFormat GrFontScaler::getMaskFormat() const {
SkMask::Format format = fStrike->getMaskFormat();
switch (format) {
case SkMask::kBW_Format:
// fall through to kA8 -- we store BW glyphs in our 8-bit cache
case SkMask::kA8_Format:
return kA8_GrMaskFormat;
case SkMask::kLCD16_Format:
return kA565_GrMaskFormat;
case SkMask::kARGB32_Format:
return kARGB_GrMaskFormat;
default:
SkDEBUGFAIL("unsupported SkMask::Format");
return kA8_GrMaskFormat;
}
}
const GrFontDescKey* GrFontScaler::getKey() {
if (NULL == fKey) {
fKey = SkNEW_ARGS(GrFontDescKey, (fStrike->getDescriptor()));
}
return fKey;
}
GrMaskFormat GrFontScaler::getPackedGlyphMaskFormat(GrGlyph::PackedID packed) const {
const SkGlyph& glyph = fStrike->getGlyphIDMetrics(GrGlyph::UnpackID(packed),
GrGlyph::UnpackFixedX(packed),
GrGlyph::UnpackFixedY(packed));
SkMask::Format format = static_cast<SkMask::Format>(glyph.fMaskFormat);
switch (format) {
case SkMask::kBW_Format:
// fall through to kA8 -- we store BW glyphs in our 8-bit cache
case SkMask::kA8_Format:
return kA8_GrMaskFormat;
case SkMask::kLCD16_Format:
return kA565_GrMaskFormat;
case SkMask::kARGB32_Format:
return kARGB_GrMaskFormat;
default:
SkDEBUGFAIL("unsupported SkMask::Format");
return kA8_GrMaskFormat;
}
}
bool GrFontScaler::getPackedGlyphBounds(GrGlyph::PackedID packed, SkIRect* bounds) {
const SkGlyph& glyph = fStrike->getGlyphIDMetrics(GrGlyph::UnpackID(packed),
GrGlyph::UnpackFixedX(packed),
GrGlyph::UnpackFixedY(packed));
bounds->setXYWH(glyph.fLeft, glyph.fTop, glyph.fWidth, glyph.fHeight);
return true;
}
bool GrFontScaler::getPackedGlyphDFBounds(GrGlyph::PackedID packed, SkIRect* bounds) {
const SkGlyph& glyph = fStrike->getGlyphIDMetrics(GrGlyph::UnpackID(packed),
GrGlyph::UnpackFixedX(packed),
GrGlyph::UnpackFixedY(packed));
bounds->setXYWH(glyph.fLeft, glyph.fTop, glyph.fWidth, glyph.fHeight);
bounds->outset(SK_DistanceFieldPad, SK_DistanceFieldPad);
return true;
}
namespace {
// expands each bit in a bitmask to 0 or ~0 of type INT_TYPE. Used to expand a BW glyph mask to
// A8, RGB565, or RGBA8888.
template <typename INT_TYPE>
void expand_bits(INT_TYPE* dst,
const uint8_t* src,
int width,
int height,
int dstRowBytes,
int srcRowBytes) {
for (int i = 0; i < height; ++i) {
int rowWritesLeft = width;
const uint8_t* s = src;
INT_TYPE* d = dst;
while (rowWritesLeft > 0) {
unsigned mask = *s++;
for (int i = 7; i >= 0 && rowWritesLeft; --i, --rowWritesLeft) {
*d++ = (mask & (1 << i)) ? (INT_TYPE)(~0UL) : 0;
}
}
dst = reinterpret_cast<INT_TYPE*>(reinterpret_cast<intptr_t>(dst) + dstRowBytes);
src += srcRowBytes;
}
}
}
bool GrFontScaler::getPackedGlyphImage(GrGlyph::PackedID packed,
int width, int height,
int dstRB, void* dst) {
const SkGlyph& glyph = fStrike->getGlyphIDMetrics(GrGlyph::UnpackID(packed),
GrGlyph::UnpackFixedX(packed),
GrGlyph::UnpackFixedY(packed));
SkASSERT(glyph.fWidth == width);
SkASSERT(glyph.fHeight == height);
const void* src = fStrike->findImage(glyph);
if (NULL == src) {
return false;
}
int srcRB = glyph.rowBytes();
// The windows font host sometimes has BW glyphs in a non-BW strike. So it is important here to
// check the glyph's format, not the strike's format, and to be able to convert to any of the
// GrMaskFormats.
if (SkMask::kBW_Format == glyph.fMaskFormat) {
// expand bits to our mask type
const uint8_t* bits = reinterpret_cast<const uint8_t*>(src);
switch (this->getMaskFormat()) {
case kA8_GrMaskFormat:{
uint8_t* bytes = reinterpret_cast<uint8_t*>(dst);
expand_bits(bytes, bits, width, height, dstRB, srcRB);
break;
}
case kA565_GrMaskFormat: {
uint16_t* rgb565 = reinterpret_cast<uint16_t*>(dst);
expand_bits(rgb565, bits, width, height, dstRB, srcRB);
break;
}
default:
SkFAIL("Invalid GrMaskFormat");
}
} else if (srcRB == dstRB) {
memcpy(dst, src, dstRB * height);
} else {
const int bbp = GrMaskFormatBytesPerPixel(this->getMaskFormat());
for (int y = 0; y < height; y++) {
memcpy(dst, src, width * bbp);
src = (const char*)src + srcRB;
dst = (char*)dst + dstRB;
}
}
return true;
}
bool GrFontScaler::getPackedGlyphDFImage(GrGlyph::PackedID packed,
int width, int height,
void* dst) {
const SkGlyph& glyph = fStrike->getGlyphIDMetrics(GrGlyph::UnpackID(packed),
GrGlyph::UnpackFixedX(packed),
GrGlyph::UnpackFixedY(packed));
SkASSERT(glyph.fWidth + 2*SK_DistanceFieldPad == width);
SkASSERT(glyph.fHeight + 2*SK_DistanceFieldPad == height);
const void* image = fStrike->findImage(glyph);
if (NULL == image) {
return false;
}
// now generate the distance field
SkASSERT(dst);
SkMask::Format maskFormat = static_cast<SkMask::Format>(glyph.fMaskFormat);
if (SkMask::kA8_Format == maskFormat) {
// make the distance field from the image
SkGenerateDistanceFieldFromA8Image((unsigned char*)dst,
(unsigned char*)image,
glyph.fWidth, glyph.fHeight,
glyph.rowBytes());
} else if (SkMask::kBW_Format == maskFormat) {
// make the distance field from the image
SkGenerateDistanceFieldFromBWImage((unsigned char*)dst,
(unsigned char*)image,
glyph.fWidth, glyph.fHeight,
glyph.rowBytes());
} else {
return false;
}
return true;
}
// we should just return const SkPath* (NULL means false)
bool GrFontScaler::getGlyphPath(uint16_t glyphID, SkPath* path) {
const SkGlyph& glyph = fStrike->getGlyphIDMetrics(glyphID);
const SkPath* skPath = fStrike->findPath(glyph);
if (skPath) {
*path = *skPath;
return true;
}
return false;
}