Update PDF backend to support fallback fonts on Android.
R=edisonn@google.com, reed@google.com, vandebo@chromium.org
Review URL: https://codereview.chromium.org/24364008
git-svn-id: http://skia.googlecode.com/svn/trunk@11586 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/pdf/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index d13d30c..e4b07f0 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -33,6 +33,22 @@
#include "SkTypefacePriv.h"
#include "SkTSet.h"
+#ifdef SK_BUILD_FOR_ANDROID
+#include "SkTypeface_android.h"
+
+struct TypefaceFallbackData {
+ SkTypeface* typeface;
+ int lowerBounds;
+ int upperBounds;
+
+ bool operator==(const TypefaceFallbackData& b) const {
+ return typeface == b.typeface &&
+ lowerBounds == b.lowerBounds &&
+ upperBounds == b.upperBounds;
+ }
+};
+#endif
+
// Utility functions
static void emit_pdf_color(SkColor color, SkWStream* result) {
@@ -1115,6 +1131,112 @@
return;
}
+#ifdef SK_BUILD_FOR_ANDROID
+ /*
+ * In the case that we have enabled fallback fonts on Android we need to
+ * take the following steps to ensure that the PDF draws all characters,
+ * regardless of their underlying font file, correctly.
+ *
+ * 1. Convert input into GlyphID encoding if it currently is not
+ * 2. Iterate over the glyphIDs and identify the actual typeface that each
+ * glyph resolves to
+ * 3. Iterate over those typefaces and recursively call this function with
+ * only the glyphs (and their positions) that the typeface is capable of
+ * resolving.
+ */
+ if (paint.getPaintOptionsAndroid().isUsingFontFallbacks()) {
+ uint16_t* glyphIDs = NULL;
+ SkGlyphStorage tmpStorage(0);
+ size_t numGlyphs = 0;
+
+ // convert to glyphIDs
+ if (paint.getTextEncoding() == SkPaint::kGlyphID_TextEncoding) {
+ numGlyphs = len / 2;
+ glyphIDs = reinterpret_cast<uint16_t*>(const_cast<void*>(text));
+ } else {
+ numGlyphs = paint.textToGlyphs(text, len, NULL);
+ tmpStorage.reset(numGlyphs);
+ paint.textToGlyphs(text, len, tmpStorage.get());
+ glyphIDs = tmpStorage.get();
+ }
+
+ // if no typeface is provided in the paint get the default
+ SkAutoTUnref<SkTypeface> origFace(SkSafeRef(paint.getTypeface()));
+ if (NULL == origFace.get()) {
+ origFace.reset(SkTypeface::RefDefault());
+ }
+ const uint16_t origGlyphCount = origFace->countGlyphs();
+
+ // keep a list of the already visited typefaces and some data about them
+ SkTDArray<TypefaceFallbackData> visitedTypefaces;
+
+ // find all the typefaces needed to resolve this run of text
+ bool usesOriginalTypeface = false;
+ for (uint16_t x = 0; x < numGlyphs; ++x) {
+ // optimization that checks to see if original typeface can resolve the glyph
+ if (glyphIDs[x] < origGlyphCount) {
+ usesOriginalTypeface = true;
+ continue;
+ }
+
+ // find the fallback typeface that supports this glyph
+ TypefaceFallbackData data;
+ data.typeface = SkGetTypefaceForGlyphID(glyphIDs[x], origFace.get(),
+ paint.getPaintOptionsAndroid(),
+ &data.lowerBounds, &data.upperBounds);
+ // add the typeface and its data if we don't have it
+ if (data.typeface && !visitedTypefaces.contains(data)) {
+ visitedTypefaces.push(data);
+ }
+ }
+
+ // if the original font was used then add it to the list as well
+ if (usesOriginalTypeface) {
+ TypefaceFallbackData* data = visitedTypefaces.push();
+ data->typeface = origFace.get();
+ data->lowerBounds = 0;
+ data->upperBounds = origGlyphCount;
+ }
+
+ // keep a scratch glyph and pos storage
+ SkAutoTMalloc<SkScalar> posStorage(len * scalarsPerPos);
+ SkScalar* tmpPos = posStorage.get();
+ SkGlyphStorage glyphStorage(numGlyphs);
+ uint16_t* tmpGlyphIDs = glyphStorage.get();
+
+ // loop through all the valid typefaces, trim the glyphs to only those
+ // resolved by the typeface, and then draw that run of glyphs
+ for (int x = 0; x < visitedTypefaces.count(); ++x) {
+ const TypefaceFallbackData& data = visitedTypefaces[x];
+
+ int tmpGlyphCount = 0;
+ for (uint16_t y = 0; y < numGlyphs; ++y) {
+ if (glyphIDs[y] >= data.lowerBounds && glyphIDs[y] < data.upperBounds) {
+ tmpGlyphIDs[tmpGlyphCount] = glyphIDs[y] - data.lowerBounds;
+ memcpy(&(tmpPos[tmpGlyphCount * scalarsPerPos]),
+ &(pos[y * scalarsPerPos]),
+ scalarsPerPos * sizeof(SkScalar));
+ tmpGlyphCount++;
+ }
+ }
+
+ // recursively call this function with the right typeface
+ SkPaint tmpPaint = paint;
+ tmpPaint.setTypeface(data.typeface);
+ tmpPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+
+ // turn off fallback chaining
+ SkPaintOptionsAndroid paintOpts = tmpPaint.getPaintOptionsAndroid();
+ paintOpts.setUseFontFallbacks(false);
+ tmpPaint.setPaintOptionsAndroid(paintOpts);
+
+ this->drawPosText(d, tmpGlyphIDs, tmpGlyphCount * 2, tmpPos, constY,
+ scalarsPerPos, tmpPaint);
+ }
+ return;
+ }
+#endif
+
SkGlyphStorage storage(0);
uint16_t* glyphIDs = NULL;
size_t numGlyphs = force_glyph_encoding(paint, text, len, &storage,
diff --git a/src/ports/SkFontConfigInterface_android.cpp b/src/ports/SkFontConfigInterface_android.cpp
index 7382d00..9c188d9 100644
--- a/src/ports/SkFontConfigInterface_android.cpp
+++ b/src/ports/SkFontConfigInterface_android.cpp
@@ -104,6 +104,9 @@
SkPaintOptionsAndroid::FontVariant fontVariant);
SkTypeface* nextLogicalTypeface(SkFontID currFontID, SkFontID origFontID,
const SkPaintOptionsAndroid& options);
+ SkTypeface* getTypefaceForGlyphID(uint16_t glyphID, const SkTypeface* origTypeface,
+ const SkPaintOptionsAndroid& options,
+ int* lowerBounds, int* upperBounds);
private:
void addFallbackFamily(FamilyRecID fontRecID);
@@ -672,6 +675,61 @@
return SkSafeRef(nextLogicalTypeface);
}
+SkTypeface* SkFontConfigInterfaceAndroid::getTypefaceForGlyphID(uint16_t glyphID,
+ const SkTypeface* origTypeface,
+ const SkPaintOptionsAndroid& opts,
+ int* lBounds, int* uBounds) {
+ // If we aren't using fallbacks then we shouldn't be calling this
+ SkASSERT(opts.isUsingFontFallbacks());
+ SkASSERT(origTypeface);
+
+ SkTypeface* currentTypeface = NULL;
+ int lowerBounds = 0; //inclusive
+ int upperBounds = origTypeface->countGlyphs(); //exclusive
+
+ // check to see if the glyph is in the bounds of the origTypeface
+ if (glyphID < upperBounds) {
+ currentTypeface = const_cast<SkTypeface*>(origTypeface);
+ } else {
+ FallbackFontList* currentFallbackList = findFallbackFontList(opts.getLanguage());
+ SkASSERT(currentFallbackList);
+
+ // If an object is set to prefer "kDefault_Variant" it means they have no preference
+ // In this case, we set the value to "kCompact_Variant"
+ SkPaintOptionsAndroid::FontVariant variant = opts.getFontVariant();
+ if (variant == SkPaintOptionsAndroid::kDefault_Variant) {
+ variant = SkPaintOptionsAndroid::kCompact_Variant;
+ }
+
+ int32_t acceptedVariants = SkPaintOptionsAndroid::kDefault_Variant | variant;
+ SkTypeface::Style origStyle = origTypeface->style();
+
+ for (int x = 0; x < currentFallbackList->count(); ++x) {
+ const FamilyRecID familyRecID = currentFallbackList->getAt(x);
+ const SkPaintOptionsAndroid& familyOptions = fFontFamilies[familyRecID].fPaintOptions;
+ if ((familyOptions.getFontVariant() & acceptedVariants) != 0) {
+ FontRecID matchedFont = find_best_style(fFontFamilies[familyRecID], origStyle);
+ currentTypeface = this->getTypefaceForFontRec(matchedFont);
+ lowerBounds = upperBounds;
+ upperBounds += currentTypeface->countGlyphs();
+ if (glyphID < upperBounds) {
+ break;
+ }
+ }
+ }
+ }
+
+ if (NULL != currentTypeface) {
+ if (lBounds) {
+ *lBounds = lowerBounds;
+ }
+ if (uBounds) {
+ *uBounds = upperBounds;
+ }
+ }
+ return currentTypeface;
+}
+
///////////////////////////////////////////////////////////////////////////////
bool SkGetFallbackFamilyNameForChar(SkUnichar uni, SkString* name) {
@@ -704,6 +762,14 @@
}
+SkTypeface* SkGetTypefaceForGlyphID(uint16_t glyphID, const SkTypeface* origTypeface,
+ const SkPaintOptionsAndroid& options,
+ int* lowerBounds, int* upperBounds) {
+ SkFontConfigInterfaceAndroid* fontConfig = getSingletonInterface();
+ return fontConfig->getTypefaceForGlyphID(glyphID, origTypeface, options,
+ lowerBounds, upperBounds);
+}
+
///////////////////////////////////////////////////////////////////////////////
#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK