use platform-independent font for gm

src/fonts/SkTestScalerContext.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBitmap.h"
+#include "SkCanvas.h"
+#include "SkDescriptor.h"
+#include "SkGlyph.h"
+#include "SkMask.h"
+// #include "SkOTUtils.h"
+#include "SkScalerContext.h"
+#include "SkTestScalerContext.h"
+#include "SkTypefaceCache.h"
+
+class SkTestTypeface : public SkTypeface {
+public:
+    SkTestTypeface(SkPaint::FontMetrics (*funct)(SkTDArray<SkPath*>& , SkTDArray<SkFixed>& ),
+                   SkTypeface::Style style) 
+        : SkTypeface(style, SkTypefaceCache::NewFontID(), false) {
+        fMetrics = (*funct)(fPaths, fWidths);
+    }
+
+    virtual ~SkTestTypeface() {
+        fPaths.deleteAll();
+    }
+
+    void getAdvance(SkGlyph* glyph) {
+        glyph->fAdvanceX = fWidths[SkGlyph::ID2Code(glyph->fID)];
+        glyph->fAdvanceY = 0;
+    }
+
+    void getFontMetrics(SkPaint::FontMetrics* metrics) {
+        *metrics = fMetrics;
+    }
+
+    void getMetrics(SkGlyph* glyph) {
+        glyph->fAdvanceX = fWidths[SkGlyph::ID2Code(glyph->fID)];
+        glyph->fAdvanceY = 0;
+    }
+
+    void getPath(const SkGlyph& glyph, SkPath* path) {
+        *path = *fPaths[SkGlyph::ID2Code(glyph.fID)];
+    }
+
+protected:
+    virtual SkScalerContext* onCreateScalerContext(const SkDescriptor* desc) const SK_OVERRIDE;
+
+    virtual void onFilterRec(SkScalerContextRec* rec) const SK_OVERRIDE {
+        rec->setHinting(SkPaint::kNo_Hinting);
+        rec->fMaskFormat = SkMask::kA8_Format;
+    }
+
+    virtual SkAdvancedTypefaceMetrics* onGetAdvancedTypefaceMetrics(
+                                    SkAdvancedTypefaceMetrics::PerGlyphInfo ,
+                                    const uint32_t* glyphIDs,
+                                    uint32_t glyphIDsCount) const SK_OVERRIDE {
+    // pdf only
+        SkAdvancedTypefaceMetrics* info = new SkAdvancedTypefaceMetrics;
+        info->fEmSize = 0;
+        info->fLastGlyphID = SkToU16(onCountGlyphs() - 1);
+        info->fStyle = 0;
+        info->fFontName.set("SkiaTest");
+        info->fType = SkAdvancedTypefaceMetrics::kOther_Font;
+        info->fItalicAngle = 0;
+        info->fAscent = 0;
+        info->fDescent = 0;
+        info->fStemV = 0;
+        info->fCapHeight = 0;
+        info->fBBox = SkIRect::MakeEmpty();
+        return info;
+    }
+
+    virtual SkStream* onOpenStream(int* ttcIndex) const SK_OVERRIDE {
+        SkASSERT(0);  // don't expect to get here
+        return NULL;
+    }
+
+    virtual void onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocal) const SK_OVERRIDE {
+        SkASSERT(0);  // don't expect to get here
+    }
+
+    virtual int onCharsToGlyphs(const void* chars, Encoding encoding,
+                                uint16_t glyphs[], int glyphCount) const SK_OVERRIDE {
+        SkASSERT(encoding == kUTF8_Encoding);
+        for (int index = 0; index < glyphCount; ++index) {
+            int ch = ((unsigned char*) chars)[index];
+            SkASSERT(ch < 0x7F);
+            if (ch < 0x20) {
+                glyphs[index] = 0;
+            } else {
+                glyphs[index] = ch - 0x20;
+            }
+        }
+        return glyphCount;
+    }
+
+    virtual int onCountGlyphs() const SK_OVERRIDE {
+        return fPaths.count();
+    }
+
+    virtual int onGetUPEM() const SK_OVERRIDE {
+        SkASSERT(0);  // don't expect to get here
+        return 1;
+    }
+
+    virtual SkTypeface::LocalizedStrings* onCreateFamilyNameIterator() const SK_OVERRIDE {
+        SkString familyName("SkiaTest");
+        SkString language("und"); //undetermined
+    SkASSERT(0);  // incomplete
+        return NULL;
+   //     return new SkOTUtils::LocalizedStrings_SingleName(familyName, language);
+    }
+
+    virtual int onGetTableTags(SkFontTableTag tags[]) const SK_OVERRIDE {
+        return 0;
+    }
+
+    virtual size_t onGetTableData(SkFontTableTag tag, size_t offset,
+                                  size_t length, void* data) const SK_OVERRIDE {
+        return 0;
+    }
+
+private:
+    SkTDArray<SkPath* > fPaths;
+    SkTDArray<SkFixed> fWidths;
+    SkPaint::FontMetrics fMetrics;
+    friend class SkTestScalerContext;
+};
+
+SkTypeface* CreateTestTypeface(SkPaint::FontMetrics (*funct)(SkTDArray<SkPath*>& pathArray,
+                               SkTDArray<SkFixed>& widthArray),
+                               SkTypeface::Style style) {
+    SkTypeface* test = SkNEW_ARGS(SkTestTypeface, (funct, style));
+    return test;
+}
+
+class SkTestScalerContext : public SkScalerContext {
+public:
+    SkTestScalerContext(SkTestTypeface* face, const SkDescriptor* desc)
+        : SkScalerContext(face, desc)
+        , fFace(face)
+    {
+        fRec.getSingleMatrix(&fMatrix);
+        this->forceGenerateImageFromPath();
+    }
+
+    virtual ~SkTestScalerContext() {
+    }
+
+protected:
+    virtual unsigned generateGlyphCount() SK_OVERRIDE {
+        return fFace->onCountGlyphs();
+    }
+
+    virtual uint16_t generateCharToGlyph(SkUnichar uni) SK_OVERRIDE {
+        uint8_t ch = (uint8_t) uni;
+        SkASSERT(ch < 0x7f);
+        uint16_t glyph;
+        (void) fFace->onCharsToGlyphs((const void *) &ch, SkTypeface::kUTF8_Encoding, &glyph, 1);
+        return glyph;
+    }
+
+    virtual void generateAdvance(SkGlyph* glyph) SK_OVERRIDE {
+        fFace->getAdvance(glyph);
+
+        SkVector advance;
+        fMatrix.mapXY(SkFixedToScalar(glyph->fAdvanceX),
+                      SkFixedToScalar(glyph->fAdvanceY), &advance);
+        glyph->fAdvanceX = SkScalarToFixed(advance.fX);
+        glyph->fAdvanceY = SkScalarToFixed(advance.fY);
+    }
+
+    virtual void generateMetrics(SkGlyph* glyph) SK_OVERRIDE {
+        fFace->getMetrics(glyph);
+
+        SkVector advance;
+        fMatrix.mapXY(SkFixedToScalar(glyph->fAdvanceX),
+                      SkFixedToScalar(glyph->fAdvanceY), &advance);
+        glyph->fAdvanceX = SkScalarToFixed(advance.fX);
+        glyph->fAdvanceY = SkScalarToFixed(advance.fY);
+
+        SkPath path;
+        fFace->getPath(*glyph, &path);
+        path.transform(fMatrix);
+
+        SkRect storage;
+        const SkPaint paint;
+        const SkRect& newBounds = paint.doComputeFastBounds(path.getBounds(),
+                                                            &storage,
+                                                            SkPaint::kFill_Style);
+        SkIRect ibounds;
+        newBounds.roundOut(&ibounds);
+        glyph->fLeft = ibounds.fLeft;
+        glyph->fTop = ibounds.fTop;
+        glyph->fWidth = ibounds.width();
+        glyph->fHeight = ibounds.height();
+        glyph->fMaskFormat = SkMask::kARGB32_Format;
+    }
+
+    virtual void generateImage(const SkGlyph& glyph) SK_OVERRIDE {
+        SkPath path;
+        fFace->getPath(glyph, &path);
+
+        SkBitmap bm;
+        bm.installPixels(SkImageInfo::MakeN32Premul(glyph.fWidth, glyph.fHeight),
+                            glyph.fImage, glyph.rowBytes());
+        bm.eraseColor(0);
+
+        SkCanvas canvas(bm);
+        canvas.translate(-SkIntToScalar(glyph.fLeft),
+                            -SkIntToScalar(glyph.fTop));
+        canvas.concat(fMatrix);
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        canvas.drawPath(path, paint);
+    }
+
+    virtual void generatePath(const SkGlyph& glyph, SkPath* path) SK_OVERRIDE {
+        fFace->getPath(glyph, path);
+        path->transform(fMatrix);
+    }
+
+    virtual void generateFontMetrics(SkPaint::FontMetrics* ,
+                                     SkPaint::FontMetrics* metrics) SK_OVERRIDE {
+        fFace->getFontMetrics(metrics);
+        if (metrics) {
+            SkScalar scale = fMatrix.getScaleY();
+            metrics->fTop = SkScalarMul(metrics->fTop, scale);
+            metrics->fAscent = SkScalarMul(metrics->fAscent, scale);
+            metrics->fDescent = SkScalarMul(metrics->fDescent, scale);
+            metrics->fBottom = SkScalarMul(metrics->fBottom, scale);
+            metrics->fLeading = SkScalarMul(metrics->fLeading, scale);
+            metrics->fAvgCharWidth = SkScalarMul(metrics->fAvgCharWidth, scale);
+            metrics->fXMin = SkScalarMul(metrics->fXMin, scale);
+            metrics->fXMax = SkScalarMul(metrics->fXMax, scale);
+            metrics->fXHeight = SkScalarMul(metrics->fXHeight, scale);
+        }
+    }
+
+private:
+    SkTestTypeface*  fFace;
+    SkMatrix         fMatrix;
+};
+
+SkScalerContext* SkTestTypeface::onCreateScalerContext(const SkDescriptor* desc) const {
+    return SkNEW_ARGS(SkTestScalerContext, (const_cast<SkTestTypeface*>(this), desc));
+}