implement fontmetrics
git-svn-id: http://skia.googlecode.com/svn/trunk@116 2bbb7eff-a529-9590-31e7-b0007b416f81
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reed@android.com
parent
ea446b9bc5
commit
0bf64d48cc
@ -17,6 +17,7 @@
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#include <carbon/carbon.h>
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#include "SkFontHost.h"
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#include "SkDescriptor.h"
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#include "SkEndian.h"
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#include "SkPoint.h"
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// Give 1MB font cache budget
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@ -90,14 +91,13 @@ protected:
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virtual void generateMetrics(SkGlyph* glyph);
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virtual void generateImage(const SkGlyph& glyph);
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virtual void generatePath(const SkGlyph& glyph, SkPath* path);
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virtual void generateLineHeight(SkPoint* ascent, SkPoint* descent);
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virtual void generateFontMetrics(SkPaint::FontMetrics* mX, SkPaint::FontMetrics* mY);
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// virtual SkDeviceContext getDC() { return NULL; } // not implemented on Mac
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private:
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ATSUTextLayout fLayout;
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ATSUStyle fStyle;
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CGColorSpaceRef fGrayColorSpace;
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CGAffineTransform fTransform;
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static OSStatus MoveTo(const Float32Point *pt, void *cb);
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static OSStatus Line(const Float32Point *pt, void *cb);
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@ -106,18 +106,31 @@ private:
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};
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SkScalerContext_Mac::SkScalerContext_Mac(const SkDescriptor* desc)
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: SkScalerContext(desc), fLayout(0), fStyle(0) {
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: SkScalerContext(desc), fLayout(0), fStyle(0)
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{
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SkAutoMutexAcquire ac(gFTMutex);
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OSStatus err;
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err = ::ATSUCreateStyle(&fStyle);
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SkASSERT(0 == err);
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Fixed fixedSize = SkScalarToFixed(fRec.fTextSize);
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static const ATSUAttributeTag sizeTag = kATSUSizeTag;
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static const ByteCount sizeTagSize = sizeof(Fixed);
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const ATSUAttributeValuePtr values[] = { &fixedSize };
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err = ::ATSUSetAttributes(fStyle,1,&sizeTag,&sizeTagSize,values);
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SkMatrix m;
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fRec.getSingleMatrix(&m);
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fTransform = CGAffineTransformMake(SkScalarToFloat(m[SkMatrix::kMScaleX]),
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SkScalarToFloat(m[SkMatrix::kMSkewX]),
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SkScalarToFloat(m[SkMatrix::kMSkewY]),
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SkScalarToFloat(m[SkMatrix::kMScaleY]),
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SkScalarToFloat(m[SkMatrix::kMTransX]),
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SkScalarToFloat(m[SkMatrix::kMTransY]));
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Fixed fixedSize = SK_Fixed1; //SkScalarToFixed(fRec.fTextSize);
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static const ATSUAttributeTag tags[] = { kATSUSizeTag, kATSUFontMatrixTag };
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static const ByteCount sizes[] = { sizeof(Fixed), sizeof(fTransform) };
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const ATSUAttributeValuePtr values[] = { &fixedSize, &fTransform };
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err = ::ATSUSetAttributes(fStyle, SK_ARRAY_COUNT(tags),
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tags, sizes, values);
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SkASSERT(0 == err);
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err = ::ATSUCreateTextLayout(&fLayout);
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@ -188,21 +201,118 @@ void SkScalerContext_Mac::generateMetrics(SkGlyph* glyph) {
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}
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}
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static void convert_metrics(SkPaint::FontMetrics* dst,
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const ATSFontMetrics& src) {
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dst->fTop = -SkFloatToScalar(src.ascent);
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dst->fAscent = -SkFloatToScalar(src.ascent);
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dst->fDescent = SkFloatToScalar(src.descent);
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dst->fBottom = SkFloatToScalar(src.descent);
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dst->fLeading = SkFloatToScalar(src.leading);
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}
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static void* get_font_table(ATSFontRef fontID, uint32_t tag) {
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ByteCount size;
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OSStatus err = ATSFontGetTable(fontID, tag, 0, 0, NULL, &size);
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if (err) {
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return NULL;
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}
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void* data = sk_malloc_throw(size);
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err = ATSFontGetTable(fontID, tag, 0, size, data, &size);
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if (err) {
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sk_free(data);
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data = NULL;
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}
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return data;
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}
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static int get_be16(const void* data, size_t offset) {
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const char* ptr = reinterpret_cast<const char*>(data);
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uint16_t value = *reinterpret_cast<const uint16_t*>(ptr + offset);
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int n = SkEndian_SwapBE16(value);
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// now force it to be signed
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return n << 16 >> 16;
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}
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#define SFNT_HEAD_UPEM_OFFSET 18
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#define SFNT_HEAD_YMIN_OFFSET 38
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#define SFNT_HEAD_YMAX_OFFSET 42
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#define SFNT_HEAD_STYLE_OFFSET 44
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#define SFNT_HHEA_ASCENT_OFFSET 4
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#define SFNT_HHEA_DESCENT_OFFSET 6
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#define SFNT_HHEA_LEADING_OFFSET 8
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static bool init_vertical_metrics(ATSFontRef font, SkPoint pts[5]) {
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void* head = get_font_table(font, 'head');
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if (NULL == head) {
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return false;
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}
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void* hhea = get_font_table(font, 'hhea');
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if (NULL == hhea) {
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sk_free(head);
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return false;
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}
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int upem = get_be16(head, SFNT_HEAD_UPEM_OFFSET);
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int ys[5];
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ys[0] = -get_be16(head, SFNT_HEAD_YMAX_OFFSET);
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ys[1] = -get_be16(hhea, SFNT_HHEA_ASCENT_OFFSET);
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ys[2] = -get_be16(hhea, SFNT_HHEA_DESCENT_OFFSET);
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ys[3] = -get_be16(head, SFNT_HEAD_YMIN_OFFSET);
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ys[4] = get_be16(hhea, SFNT_HHEA_LEADING_OFFSET);
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// now do some cleanup, to ensure y[max,min] are really that
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if (ys[0] > ys[1]) {
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ys[0] = ys[1];
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}
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if (ys[3] < ys[2]) {
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ys[3] = ys[2];
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}
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for (int i = 0; i < 5; i++) {
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pts[i].set(0, SkIntToScalar(ys[i]) / upem);
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}
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sk_free(hhea);
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sk_free(head);
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return true;
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}
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void SkScalerContext_Mac::generateFontMetrics(SkPaint::FontMetrics* mx,
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SkPaint::FontMetrics* my) {
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#if 0
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OSStatus ATSFontGetVerticalMetrics (
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ATSFontRef iFont,
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ATSOptionFlags iOptions,
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ATSFontMetrics *oMetrics
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);
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#endif
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//SkASSERT(false);
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if (mx)
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memset(mx, 0, sizeof(SkPaint::FontMetrics));
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if (my)
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memset(my, 0, sizeof(SkPaint::FontMetrics));
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return;
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SkPoint pts[5];
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if (!init_vertical_metrics(fRec.fFontID, pts)) {
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// these are not as accurate as init_vertical_metrics :(
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ATSFontMetrics metrics;
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ATSFontGetVerticalMetrics(fRec.fFontID, kATSOptionFlagsDefault,
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&metrics);
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pts[0].set(0, -SkFloatToScalar(metrics.ascent));
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pts[1].set(0, -SkFloatToScalar(metrics.ascent));
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pts[2].set(0, -SkFloatToScalar(metrics.descent));
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pts[3].set(0, -SkFloatToScalar(metrics.descent));
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pts[4].set(0, SkFloatToScalar(metrics.leading)); //+ or -?
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}
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SkMatrix m;
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fRec.getSingleMatrix(&m);
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m.mapPoints(pts, 5);
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if (mx) {
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mx->fTop = pts[0].fX;
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mx->fAscent = pts[1].fX;
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mx->fDescent = pts[2].fX;
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mx->fBottom = pts[3].fX;
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mx->fLeading = pts[4].fX;
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}
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if (my) {
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my->fTop = pts[0].fY;
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my->fAscent = pts[1].fY;
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my->fDescent = pts[2].fY;
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my->fBottom = pts[3].fY;
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my->fLeading = pts[4].fY;
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}
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}
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void SkScalerContext_Mac::generateImage(const SkGlyph& glyph)
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@ -226,7 +336,8 @@ void SkScalerContext_Mac::generateImage(const SkGlyph& glyph)
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CGGlyph glyphID = glyph.getGlyphID();
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CGFontRef fontRef = CGFontCreateWithPlatformFont(&fRec.fFontID);
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CGContextSetFont(contextRef, fontRef);
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CGContextSetFontSize(contextRef, SkScalarToFloat(fRec.fTextSize));
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CGContextSetFontSize(contextRef, 1); //SkScalarToFloat(fRec.fTextSize));
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CGContextSetTextMatrix(contextRef, fTransform);
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CGContextShowGlyphsAtPoint(contextRef, -glyph.fLeft,
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glyph.fTop + glyph.fHeight, &glyphID, 1);
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@ -248,16 +359,6 @@ void SkScalerContext_Mac::generatePath(const SkGlyph& glyph, SkPath* path)
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SkASSERT(err == noErr);
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}
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void SkScalerContext_Mac::generateLineHeight(SkPoint* ascent, SkPoint* descent)
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{
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ATSUTextMeasurement textAscent, textDescent;
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ByteCount actual = 0;
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OSStatus err = ::ATSUGetAttribute(fStyle,kATSULineAscentTag,sizeof(ATSUTextMeasurement),&textAscent,&actual);
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ascent->set(0,textAscent);
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err = ::ATSUGetAttribute(fStyle,kATSULineDescentTag,sizeof(ATSUTextMeasurement),&textDescent,&actual);
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descent->set(0,textDescent);
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}
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OSStatus SkScalerContext_Mac::MoveTo(const Float32Point *pt, void *cb)
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{
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reinterpret_cast<SkPath*>(cb)->moveTo(F32PtToSkPoint(*pt));
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