blob: 5855eec1b188427c7ab647b793163c90ec679c92 [file] [log] [blame]
/* libs/graphics/ports/SkFontHost_FreeType.cpp
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include "SkScalerContext.h"
#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkDescriptor.h"
#include "SkFDot6.h"
#include "SkFontHost.h"
#include "SkMask.h"
#include "SkStream.h"
#include "SkString.h"
#include "SkThread.h"
#include "SkTemplates.h"
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_OUTLINE_H
#include FT_SIZES_H
#ifdef FT_ADVANCES_H
#include FT_ADVANCES_H
#endif
//#define ENABLE_GLYPH_SPEW // for tracing calls
//#define DUMP_STRIKE_CREATION
#ifdef SK_DEBUG
#define SkASSERT_CONTINUE(pred) \
do { \
if (!(pred)) \
SkDebugf("file %s:%d: assert failed '" #pred "'\n", __FILE__, __LINE__); \
} while (false)
#else
#define SkASSERT_CONTINUE(pred)
#endif
//////////////////////////////////////////////////////////////////////////
struct SkFaceRec;
static SkMutex gFTMutex;
static int gFTCount;
static FT_Library gFTLibrary;
static SkFaceRec* gFaceRecHead;
/////////////////////////////////////////////////////////////////////////
class SkScalerContext_FreeType : public SkScalerContext {
public:
SkScalerContext_FreeType(const SkDescriptor* desc);
virtual ~SkScalerContext_FreeType();
protected:
virtual unsigned generateGlyphCount() const;
virtual uint16_t generateCharToGlyph(SkUnichar uni);
virtual void generateAdvance(SkGlyph* glyph);
virtual void generateMetrics(SkGlyph* glyph);
virtual void generateImage(const SkGlyph& glyph);
virtual void generatePath(const SkGlyph& glyph, SkPath* path);
virtual void generateFontMetrics(SkPaint::FontMetrics* mx,
SkPaint::FontMetrics* my);
private:
SkFaceRec* fFaceRec;
FT_Face fFace; // reference to shared face in gFaceRecHead
FT_Size fFTSize; // our own copy
SkFixed fScaleX, fScaleY;
FT_Matrix fMatrix22;
uint32_t fLoadGlyphFlags;
FT_Error setupSize();
};
///////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////
#include "SkStream.h"
struct SkFaceRec {
SkFaceRec* fNext;
FT_Face fFace;
FT_StreamRec fFTStream;
SkStream* fSkStream;
uint32_t fRefCnt;
uint32_t fFontID;
SkFaceRec(SkStream* strm, uint32_t fontID);
~SkFaceRec() {
SkFontHost::CloseStream(fFontID, fSkStream);
}
};
extern "C" {
static unsigned long sk_stream_read(FT_Stream stream,
unsigned long offset,
unsigned char* buffer,
unsigned long count ) {
SkStream* str = (SkStream*)stream->descriptor.pointer;
if (count) {
if (!str->rewind()) {
return 0;
} else {
unsigned long ret;
if (offset) {
ret = str->read(NULL, offset);
if (ret != offset) {
return 0;
}
}
ret = str->read(buffer, count);
if (ret != count) {
return 0;
}
count = ret;
}
}
return count;
}
static void sk_stream_close( FT_Stream stream) {}
}
SkFaceRec::SkFaceRec(SkStream* strm, uint32_t fontID)
: fSkStream(strm), fFontID(fontID) {
// SkDEBUGF(("SkFaceRec: opening %s (%p)\n", key.c_str(), strm));
bzero(&fFTStream, sizeof(fFTStream));
fFTStream.size = fSkStream->getLength();
fFTStream.descriptor.pointer = fSkStream;
fFTStream.read = sk_stream_read;
fFTStream.close = sk_stream_close;
}
static SkFaceRec* ref_ft_face(uint32_t fontID) {
SkFaceRec* rec = gFaceRecHead;
while (rec) {
if (rec->fFontID == fontID) {
SkASSERT(rec->fFace);
rec->fRefCnt += 1;
return rec;
}
rec = rec->fNext;
}
SkStream* strm = SkFontHost::OpenStream(fontID);
if (NULL == strm) {
SkDEBUGF(("SkFontHost::OpenStream failed opening %x\n", fontID));
sk_throw();
return 0;
}
// this passes ownership of strm to the rec
rec = SkNEW_ARGS(SkFaceRec, (strm, fontID));
FT_Open_Args args;
memset(&args, 0, sizeof(args));
const void* memoryBase = strm->getMemoryBase();
if (NULL != memoryBase) {
//printf("mmap(%s)\n", keyString.c_str());
args.flags = FT_OPEN_MEMORY;
args.memory_base = (const FT_Byte*)memoryBase;
args.memory_size = strm->getLength();
} else {
//printf("fopen(%s)\n", keyString.c_str());
args.flags = FT_OPEN_STREAM;
args.stream = &rec->fFTStream;
}
FT_Error err = FT_Open_Face(gFTLibrary, &args, 0, &rec->fFace);
if (err) { // bad filename, try the default font
fprintf(stderr, "ERROR: unable to open font '%x'\n", fontID);
SkDELETE(rec);
sk_throw();
return 0;
} else {
SkASSERT(rec->fFace);
//fprintf(stderr, "Opened font '%s'\n", filename.c_str());
rec->fNext = gFaceRecHead;
gFaceRecHead = rec;
rec->fRefCnt = 1;
return rec;
}
}
static void unref_ft_face(FT_Face face) {
SkFaceRec* rec = gFaceRecHead;
SkFaceRec* prev = NULL;
while (rec) {
SkFaceRec* next = rec->fNext;
if (rec->fFace == face) {
if (--rec->fRefCnt == 0) {
if (prev) {
prev->fNext = next;
} else {
gFaceRecHead = next;
}
FT_Done_Face(face);
SkDELETE(rec);
}
return;
}
prev = rec;
rec = next;
}
SkASSERT("shouldn't get here, face not in list");
}
///////////////////////////////////////////////////////////////////////////
SkScalerContext_FreeType::SkScalerContext_FreeType(const SkDescriptor* desc)
: SkScalerContext(desc), fFTSize(NULL) {
SkAutoMutexAcquire ac(gFTMutex);
FT_Error err;
if (gFTCount == 0) {
err = FT_Init_FreeType(&gFTLibrary);
// SkDEBUGF(("FT_Init_FreeType returned %d\n", err));
SkASSERT(err == 0);
}
++gFTCount;
// load the font file
fFaceRec = ref_ft_face(fRec.fFontID);
fFace = fFaceRec ? fFaceRec->fFace : NULL;
// compute our factors from the record
SkMatrix m;
fRec.getSingleMatrix(&m);
#ifdef DUMP_STRIKE_CREATION
SkString keyString;
SkFontHost::GetDescriptorKeyString(desc, &keyString);
printf("========== strike [%g %g %g] [%g %g %g %g] hints %d format %d %s\n", SkScalarToFloat(fRec.fTextSize),
SkScalarToFloat(fRec.fPreScaleX), SkScalarToFloat(fRec.fPreSkewX),
SkScalarToFloat(fRec.fPost2x2[0][0]), SkScalarToFloat(fRec.fPost2x2[0][1]),
SkScalarToFloat(fRec.fPost2x2[1][0]), SkScalarToFloat(fRec.fPost2x2[1][1]),
fRec.fHints, fRec.fMaskFormat, keyString.c_str());
#endif
// now compute our scale factors
SkScalar sx = m.getScaleX();
SkScalar sy = m.getScaleY();
if (m.getSkewX() || m.getSkewY() || sx < 0 || sy < 0) {
// sort of give up on hinting
sx = SkMaxScalar(SkScalarAbs(sx), SkScalarAbs(m.getSkewX()));
sy = SkMaxScalar(SkScalarAbs(m.getSkewY()), SkScalarAbs(sy));
sx = sy = SkScalarAve(sx, sy);
SkScalar inv = SkScalarInvert(sx);
// flip the skew elements to go from our Y-down system to FreeType's
fMatrix22.xx = SkScalarToFixed(SkScalarMul(m.getScaleX(), inv));
fMatrix22.xy = -SkScalarToFixed(SkScalarMul(m.getSkewX(), inv));
fMatrix22.yx = -SkScalarToFixed(SkScalarMul(m.getSkewY(), inv));
fMatrix22.yy = SkScalarToFixed(SkScalarMul(m.getScaleY(), inv));
} else {
fMatrix22.xx = fMatrix22.yy = SK_Fixed1;
fMatrix22.xy = fMatrix22.yx = 0;
}
fScaleX = SkScalarToFixed(sx);
fScaleY = SkScalarToFixed(sy);
// compute the flags we send to Load_Glyph
{
uint32_t flags = FT_LOAD_DEFAULT;
uint32_t render_flags = FT_LOAD_TARGET_NORMAL;
// we force autohinting at the moment
switch (fRec.fHints) {
case kNo_Hints:
flags |= FT_LOAD_NO_HINTING;
break;
case kSubpixel_Hints:
flags |= FT_LOAD_FORCE_AUTOHINT;
render_flags = FT_LOAD_TARGET_LIGHT;
break;
case kNormal_Hints:
flags |= FT_LOAD_FORCE_AUTOHINT;
#ifdef ANDROID
/* Switch to light hinting (vertical only) to address some chars
that behaved poorly with NORMAL. In the future we could consider
making this choice exposed at runtime to the caller.
*/
render_flags = FT_LOAD_TARGET_LIGHT;
#endif
break;
}
if (SkMask::kBW_Format == fRec.fMaskFormat)
render_flags = FT_LOAD_TARGET_MONO;
else if (SkMask::kLCD_Format == fRec.fMaskFormat)
render_flags = FT_LOAD_TARGET_LCD;
fLoadGlyphFlags = flags | render_flags;
}
// now create the FT_Size
{
FT_Error err;
err = FT_New_Size(fFace, &fFTSize);
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::FT_New_Size(%x): FT_Set_Char_Size(0x%x, 0x%x) returned 0x%x\n",
fFaceRec->fFontID, fScaleX, fScaleY, err));
fFace = NULL;
return;
}
err = FT_Activate_Size(fFTSize);
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%x, 0x%x, 0x%x) returned 0x%x\n",
fFaceRec->fFontID, fScaleX, fScaleY, err));
fFTSize = NULL;
}
err = FT_Set_Char_Size( fFace,
SkFixedToFDot6(fScaleX), SkFixedToFDot6(fScaleY),
72, 72);
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::FT_Set_Char_Size(%x, 0x%x, 0x%x) returned 0x%x\n",
fFaceRec->fFontID, fScaleX, fScaleY, err));
fFace = NULL;
return;
}
FT_Set_Transform( fFace, &fMatrix22, NULL);
}
}
SkScalerContext_FreeType::~SkScalerContext_FreeType() {
if (fFTSize != NULL) {
FT_Done_Size(fFTSize);
}
SkAutoMutexAcquire ac(gFTMutex);
if (fFace != NULL) {
unref_ft_face(fFace);
}
if (--gFTCount == 0) {
// SkDEBUGF(("FT_Done_FreeType\n"));
FT_Done_FreeType(gFTLibrary);
SkDEBUGCODE(gFTLibrary = NULL;)
}
}
/* We call this before each use of the fFace, since we may be sharing
this face with other context (at different sizes).
*/
FT_Error SkScalerContext_FreeType::setupSize() {
/* In the off-chance that a font has been removed, we want to error out
right away, so call resolve just to be sure.
TODO: perhaps we can skip this, by walking the global font cache and
killing all of the contexts when we know that a given fontID is going
away...
*/
if (SkFontHost::ResolveTypeface(fRec.fFontID) == NULL) {
return (FT_Error)-1;
}
FT_Error err = FT_Activate_Size(fFTSize);
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%x, 0x%x, 0x%x) returned 0x%x\n",
fFaceRec->fFontID, fScaleX, fScaleY, err));
fFTSize = NULL;
} else {
// seems we need to reset this every time (not sure why, but without it
// I get random italics from some other fFTSize)
FT_Set_Transform( fFace, &fMatrix22, NULL);
}
return err;
}
unsigned SkScalerContext_FreeType::generateGlyphCount() const {
return fFace->num_glyphs;
}
uint16_t SkScalerContext_FreeType::generateCharToGlyph(SkUnichar uni) {
return SkToU16(FT_Get_Char_Index( fFace, uni ));
}
static FT_Pixel_Mode compute_pixel_mode(SkMask::Format format) {
switch (format) {
case SkMask::kBW_Format:
return FT_PIXEL_MODE_MONO;
case SkMask::kLCD_Format:
return FT_PIXEL_MODE_LCD;
case SkMask::kA8_Format:
default:
return FT_PIXEL_MODE_GRAY;
}
}
static void set_glyph_metrics_on_error(SkGlyph* glyph) {
glyph->fRsbDelta = 0;
glyph->fLsbDelta = 0;
glyph->fWidth = 0;
glyph->fHeight = 0;
glyph->fTop = 0;
glyph->fLeft = 0;
glyph->fAdvanceX = 0;
glyph->fAdvanceY = 0;
}
void SkScalerContext_FreeType::generateAdvance(SkGlyph* glyph) {
#ifdef FT_ADVANCES_H
/* unhinted and light hinted text have linearly scaled advances
* which are very cheap to compute with some font formats...
*/
{
SkAutoMutexAcquire ac(gFTMutex);
if (this->setupSize()) {
set_glyph_metrics_on_error(glyph);
return;
}
FT_Error error;
FT_Fixed advance;
error = FT_Get_Advance( fFace, glyph->getGlyphID(fBaseGlyphCount),
fLoadGlyphFlags | FT_ADVANCE_FLAG_FAST_ONLY,
&advance );
if (0 == error) {
glyph->fRsbDelta = 0;
glyph->fLsbDelta = 0;
glyph->fAdvanceX = advance; // advance *2/3; //DEBUG
glyph->fAdvanceY = 0;
return;
}
}
#endif /* FT_ADVANCES_H */
/* otherwise, we need to load/hint the glyph, which is slower */
this->generateMetrics(glyph);
return;
}
void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) {
SkAutoMutexAcquire ac(gFTMutex);
glyph->fRsbDelta = 0;
glyph->fLsbDelta = 0;
FT_Error err;
if (this->setupSize()) {
goto ERROR;
}
err = FT_Load_Glyph( fFace, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags );
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::generateMetrics(%x): FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n",
fFaceRec->fFontID, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, err));
ERROR:
set_glyph_metrics_on_error(glyph);
return;
}
switch ( fFace->glyph->format ) {
case FT_GLYPH_FORMAT_OUTLINE:
FT_BBox bbox;
FT_Outline_Get_CBox(&fFace->glyph->outline, &bbox);
if (kSubpixel_Hints == fRec.fHints) {
int dx = glyph->getSubXFixed() >> 10;
int dy = glyph->getSubYFixed() >> 10;
// negate dy since freetype-y-goes-up and skia-y-goes-down
bbox.xMin += dx;
bbox.yMin -= dy;
bbox.xMax += dx;
bbox.yMax -= dy;
}
bbox.xMin &= ~63;
bbox.yMin &= ~63;
bbox.xMax = (bbox.xMax + 63) & ~63;
bbox.yMax = (bbox.yMax + 63) & ~63;
glyph->fWidth = SkToU16((bbox.xMax - bbox.xMin) >> 6);
glyph->fHeight = SkToU16((bbox.yMax - bbox.yMin) >> 6);
glyph->fTop = -SkToS16(bbox.yMax >> 6);
glyph->fLeft = SkToS16(bbox.xMin >> 6);
break;
case FT_GLYPH_FORMAT_BITMAP:
glyph->fWidth = SkToU16(fFace->glyph->bitmap.width);
glyph->fHeight = SkToU16(fFace->glyph->bitmap.rows);
glyph->fTop = -SkToS16(fFace->glyph->bitmap_top);
glyph->fLeft = SkToS16(fFace->glyph->bitmap_left);
break;
default:
SkASSERT(!"unknown glyph format");
goto ERROR;
}
if (kNormal_Hints == fRec.fHints) {
glyph->fAdvanceX = SkFDot6ToFixed(fFace->glyph->advance.x);
glyph->fAdvanceY = -SkFDot6ToFixed(fFace->glyph->advance.y);
if (fRec.fFlags & kDevKernText_Flag) {
glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta);
glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta);
}
} else {
glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance);
glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance);
}
#ifdef ENABLE_GLYPH_SPEW
SkDEBUGF(("FT_Set_Char_Size(this:%p sx:%x sy:%x ", this, fScaleX, fScaleY));
SkDEBUGF(("Metrics(glyph:%d flags:0x%x) w:%d\n", glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, glyph->fWidth));
#endif
}
void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) {
SkAutoMutexAcquire ac(gFTMutex);
FT_Error err;
if (this->setupSize()) {
goto ERROR;
}
err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), fLoadGlyphFlags);
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::generateImage: FT_Load_Glyph(glyph:%d width:%d height:%d rb:%d flags:%d) returned 0x%x\n",
glyph.getGlyphID(fBaseGlyphCount), glyph.fWidth, glyph.fHeight, glyph.rowBytes(), fLoadGlyphFlags, err));
ERROR:
memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight);
return;
}
switch ( fFace->glyph->format ) {
case FT_GLYPH_FORMAT_OUTLINE: {
FT_Outline* outline = &fFace->glyph->outline;
FT_BBox bbox;
FT_Bitmap target;
int dx = 0, dy = 0;
if (kSubpixel_Hints == fRec.fHints) {
dx = glyph.getSubXFixed() >> 10;
dy = glyph.getSubYFixed() >> 10;
// 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));
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(gFTLibrary, outline, &target);
} break;
case FT_GLYPH_FORMAT_BITMAP: {
SkASSERT_CONTINUE(glyph.fWidth == fFace->glyph->bitmap.width);
SkASSERT_CONTINUE(glyph.fHeight == fFace->glyph->bitmap.rows);
SkASSERT_CONTINUE(glyph.fTop == -fFace->glyph->bitmap_top);
SkASSERT_CONTINUE(glyph.fLeft == fFace->glyph->bitmap_left);
const uint8_t* src = (const uint8_t*)fFace->glyph->bitmap.buffer;
uint8_t* dst = (uint8_t*)glyph.fImage;
unsigned srcRowBytes = fFace->glyph->bitmap.pitch;
unsigned dstRowBytes = glyph.rowBytes();
unsigned minRowBytes = SkMin32(srcRowBytes, dstRowBytes);
unsigned extraRowBytes = dstRowBytes - minRowBytes;
for (int y = fFace->glyph->bitmap.rows - 1; y >= 0; --y) {
memcpy(dst, src, minRowBytes);
memset(dst + minRowBytes, 0, extraRowBytes);
src += srcRowBytes;
dst += dstRowBytes;
}
} break;
default:
SkASSERT(!"unknown glyph format");
goto ERROR;
}
}
///////////////////////////////////////////////////////////////////////////////
#define ft2sk(x) SkFixedToScalar((x) << 10)
#if FREETYPE_MAJOR >= 2 && FREETYPE_MINOR >= 3
#define CONST_PARAM const
#else // older freetype doesn't use const here
#define CONST_PARAM
#endif
static int move_proc(CONST_PARAM FT_Vector* pt, void* ctx) {
SkPath* path = (SkPath*)ctx;
path->close(); // to close the previous contour (if any)
path->moveTo(ft2sk(pt->x), -ft2sk(pt->y));
return 0;
}
static int line_proc(CONST_PARAM FT_Vector* pt, void* ctx) {
SkPath* path = (SkPath*)ctx;
path->lineTo(ft2sk(pt->x), -ft2sk(pt->y));
return 0;
}
static int quad_proc(CONST_PARAM FT_Vector* pt0, CONST_PARAM FT_Vector* pt1,
void* ctx) {
SkPath* path = (SkPath*)ctx;
path->quadTo(ft2sk(pt0->x), -ft2sk(pt0->y), ft2sk(pt1->x), -ft2sk(pt1->y));
return 0;
}
static int cubic_proc(CONST_PARAM FT_Vector* pt0, CONST_PARAM FT_Vector* pt1,
CONST_PARAM FT_Vector* pt2, void* ctx) {
SkPath* path = (SkPath*)ctx;
path->cubicTo(ft2sk(pt0->x), -ft2sk(pt0->y), ft2sk(pt1->x),
-ft2sk(pt1->y), ft2sk(pt2->x), -ft2sk(pt2->y));
return 0;
}
void SkScalerContext_FreeType::generatePath(const SkGlyph& glyph,
SkPath* path) {
SkAutoMutexAcquire ac(gFTMutex);
SkASSERT(&glyph && path);
if (this->setupSize()) {
path->reset();
return;
}
uint32_t flags = fLoadGlyphFlags;
flags |= FT_LOAD_NO_BITMAP; // ignore embedded bitmaps so we're sure to get the outline
flags &= ~FT_LOAD_RENDER; // don't scan convert (we just want the outline)
FT_Error err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), flags);
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n",
glyph.getGlyphID(fBaseGlyphCount), flags, err));
path->reset();
return;
}
FT_Outline_Funcs funcs;
funcs.move_to = move_proc;
funcs.line_to = line_proc;
funcs.conic_to = quad_proc;
funcs.cubic_to = cubic_proc;
funcs.shift = 0;
funcs.delta = 0;
err = FT_Outline_Decompose(&fFace->glyph->outline, &funcs, path);
if (err != 0) {
SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n",
glyph.getGlyphID(fBaseGlyphCount), flags, err));
path->reset();
return;
}
path->close();
}
void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* mx,
SkPaint::FontMetrics* my) {
if (NULL == mx && NULL == my) {
return;
}
SkAutoMutexAcquire ac(gFTMutex);
if (this->setupSize()) {
if (mx) {
bzero(mx, sizeof(SkPaint::FontMetrics));
}
if (my) {
bzero(my, sizeof(SkPaint::FontMetrics));
}
return;
}
SkPoint pts[5];
SkFixed ys[5];
FT_Face face = fFace;
int upem = face->units_per_EM;
SkFixed scaleY = fScaleY;
SkFixed mxy = fMatrix22.xy;
SkFixed myy = fMatrix22.yy;
int leading = face->height - face->ascender + face->descender;
if (leading < 0) {
leading = 0;
}
ys[0] = -face->bbox.yMax;
ys[1] = -face->ascender;
ys[2] = -face->descender;
ys[3] = -face->bbox.yMin;
ys[4] = leading;
// convert upem-y values into scalar points
for (int i = 0; i < 5; i++) {
SkFixed y = SkMulDiv(scaleY, ys[i], upem);
SkFixed x = SkFixedMul(mxy, y);
y = SkFixedMul(myy, y);
pts[i].set(SkFixedToScalar(x), SkFixedToScalar(y));
}
if (mx) {
mx->fTop = pts[0].fX;
mx->fAscent = pts[1].fX;
mx->fDescent = pts[2].fX;
mx->fBottom = pts[3].fX;
mx->fLeading = pts[4].fX;
}
if (my) {
my->fTop = pts[0].fY;
my->fAscent = pts[1].fY;
my->fDescent = pts[2].fY;
my->fBottom = pts[3].fY;
my->fLeading = pts[4].fY;
}
}
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
SkScalerContext* SkFontHost::CreateScalerContext(const SkDescriptor* desc) {
return SkNEW_ARGS(SkScalerContext_FreeType, (desc));
}
///////////////////////////////////////////////////////////////////////////////
/* Export this so that other parts of our FonttHost port can make use of our
ability to extract the name+style from a stream, using FreeType's api.
*/
SkTypeface::Style find_name_and_style(SkStream* stream, SkString* name) {
FT_Library library;
if (FT_Init_FreeType(&library)) {
name->set(NULL);
return SkTypeface::kNormal;
}
FT_Open_Args args;
memset(&args, 0, sizeof(args));
const void* memoryBase = stream->getMemoryBase();
FT_StreamRec streamRec;
if (NULL != memoryBase) {
args.flags = FT_OPEN_MEMORY;
args.memory_base = (const FT_Byte*)memoryBase;
args.memory_size = stream->getLength();
} else {
memset(&streamRec, 0, sizeof(streamRec));
streamRec.size = stream->read(NULL, 0);
streamRec.descriptor.pointer = stream;
streamRec.read = sk_stream_read;
streamRec.close = sk_stream_close;
args.flags = FT_OPEN_STREAM;
args.stream = &streamRec;
}
FT_Face face;
if (FT_Open_Face(library, &args, 0, &face)) {
FT_Done_FreeType(library);
name->set(NULL);
return SkTypeface::kNormal;
}
name->set(face->family_name);
int style = SkTypeface::kNormal;
if (face->style_flags & FT_STYLE_FLAG_BOLD) {
style |= SkTypeface::kBold;
}
if (face->style_flags & FT_STYLE_FLAG_ITALIC) {
style |= SkTypeface::kItalic;
}
FT_Done_Face(face);
FT_Done_FreeType(library);
return (SkTypeface::Style)style;
}