Upstream version 10.38.208.0

[platform/framework/web/crosswalk.git] / src / third_party / skia / src / ports / SkScalerContext_win_dw.cpp

diff --git a/src/third_party/skia/src/ports/SkScalerContext_win_dw.cpp b/src/third_party/skia/src/ports/SkScalerContext_win_dw.cpp
index f27497b..33ef0d5 100644 (file)
--- a/src/third_party/skia/src/ports/SkScalerContext_win_dw.cpp
+++ b/src/third_party/skia/src/ports/SkScalerContext_win_dw.cpp
@@ -398,11 +398,11 @@ void SkScalerContext_DW::generateAdvance(SkGlyph* glyph) {
     glyph->fAdvanceY = SkScalarToFixed(vecs[0].fY);
 }
 
-void SkScalerContext_DW::generateMetrics(SkGlyph* glyph) {
-    glyph->fWidth = 0;
-
-    this->generateAdvance(glyph);
-
+HRESULT SkScalerContext_DW::getBoundingBox(SkGlyph* glyph,
+                                           DWRITE_RENDERING_MODE renderingMode,
+                                           DWRITE_TEXTURE_TYPE textureType,
+                                           RECT* bbox)
+{
     //Measure raster size.
     fXform.dx = SkFixedToFloat(glyph->getSubXFixed());
     fXform.dy = SkFixedToFloat(glyph->getSubYFixed());
@@ -426,25 +426,70 @@ void SkScalerContext_DW::generateMetrics(SkGlyph* glyph) {
     run.glyphOffsets = &offset;
 
     SkTScopedComPtr<IDWriteGlyphRunAnalysis> glyphRunAnalysis;
-    HRVM(fTypeface->fFactory->CreateGlyphRunAnalysis(
-             &run,
-             1.0f, // pixelsPerDip,
-             &fXform,
-             fRenderingMode,
-             fMeasuringMode,
-             0.0f, // baselineOriginX,
-             0.0f, // baselineOriginY,
-             &glyphRunAnalysis),
-         "Could not create glyph run analysis.");
-
-    RECT bbox;
-    HRVM(glyphRunAnalysis->GetAlphaTextureBounds(fTextureType, &bbox),
-         "Could not get texture bounds.");
+    HRM(fTypeface->fFactory->CreateGlyphRunAnalysis(
+            &run,
+            1.0f, // pixelsPerDip,
+            &fXform,
+            renderingMode,
+            fMeasuringMode,
+            0.0f, // baselineOriginX,
+            0.0f, // baselineOriginY,
+            &glyphRunAnalysis),
+        "Could not create glyph run analysis.");
+
+    HRM(glyphRunAnalysis->GetAlphaTextureBounds(textureType, bbox),
+        "Could not get texture bounds.");
+
+    return S_OK;
+}
 
+/** GetAlphaTextureBounds succeeds but sometimes returns empty bounds like
+ *  { 0x80000000, 0x80000000, 0x80000000, 0x80000000 }
+ *  for small, but not quite zero, sized glyphs.
+ *  Only set as non-empty if the returned bounds are non-empty.
+ */
+static bool glyph_check_and_set_bounds(SkGlyph* glyph, const RECT& bbox) {
+    if (bbox.left >= bbox.right || bbox.top >= bbox.bottom) {
+        return false;
+    }
     glyph->fWidth = SkToU16(bbox.right - bbox.left);
     glyph->fHeight = SkToU16(bbox.bottom - bbox.top);
     glyph->fLeft = SkToS16(bbox.left);
     glyph->fTop = SkToS16(bbox.top);
+    return true;
+}
+
+void SkScalerContext_DW::generateMetrics(SkGlyph* glyph) {
+    glyph->fWidth = 0;
+    glyph->fHeight = 0;
+    glyph->fLeft = 0;
+    glyph->fTop = 0;
+
+    this->generateAdvance(glyph);
+
+    RECT bbox;
+    HRVM(this->getBoundingBox(glyph, fRenderingMode, fTextureType, &bbox),
+         "Requested bounding box could not be determined.");
+
+    if (glyph_check_and_set_bounds(glyph, bbox)) {
+        return;
+    }
+
+    // GetAlphaTextureBounds succeeds but returns an empty RECT if there are no
+    // glyphs of the specified texture type. When this happens, try with the
+    // alternate texture type.
+    if (DWRITE_TEXTURE_CLEARTYPE_3x1 == fTextureType) {
+        HRVM(this->getBoundingBox(glyph,
+                                  DWRITE_RENDERING_MODE_ALIASED,
+                                  DWRITE_TEXTURE_ALIASED_1x1,
+                                  &bbox),
+             "Fallback bounding box could not be determined.");
+        if (glyph_check_and_set_bounds(glyph, bbox)) {
+            glyph->fForceBW = 1;
+        }
+    }
+    // TODO: handle the case where a request for DWRITE_TEXTURE_ALIASED_1x1
+    // fails, and try DWRITE_TEXTURE_CLEARTYPE_3x1.
 }
 
 void SkScalerContext_DW::generateFontMetrics(SkPaint::FontMetrics* metrics) {
@@ -602,9 +647,12 @@ static void rgb_to_lcd32(const uint8_t* SK_RESTRICT src, const SkGlyph& glyph,
     }
 }
 
-const void* SkScalerContext_DW::drawDWMask(const SkGlyph& glyph) {
+const void* SkScalerContext_DW::drawDWMask(const SkGlyph& glyph,
+                                           DWRITE_RENDERING_MODE renderingMode,
+                                           DWRITE_TEXTURE_TYPE textureType)
+{
     int sizeNeeded = glyph.fWidth * glyph.fHeight;
-    if (DWRITE_RENDERING_MODE_ALIASED != fRenderingMode) {
+    if (DWRITE_RENDERING_MODE_ALIASED != renderingMode) {
         sizeNeeded *= 3;
     }
     if (sizeNeeded > fBits.count()) {
@@ -639,7 +687,7 @@ const void* SkScalerContext_DW::drawDWMask(const SkGlyph& glyph) {
     HRNM(fTypeface->fFactory->CreateGlyphRunAnalysis(&run,
                                           1.0f, // pixelsPerDip,
                                           &fXform,
-                                          fRenderingMode,
+                                          renderingMode,
                                           fMeasuringMode,
                                           0.0f, // baselineOriginX,
                                           0.0f, // baselineOriginY,
@@ -653,7 +701,7 @@ const void* SkScalerContext_DW::drawDWMask(const SkGlyph& glyph) {
     bbox.top = glyph.fTop;
     bbox.right = glyph.fLeft + glyph.fWidth;
     bbox.bottom = glyph.fTop + glyph.fHeight;
-    HRNM(glyphRunAnalysis->CreateAlphaTexture(fTextureType,
+    HRNM(glyphRunAnalysis->CreateAlphaTexture(textureType,
                                               &bbox,
                                               fBits.begin(),
                                               sizeNeeded),
@@ -663,7 +711,13 @@ const void* SkScalerContext_DW::drawDWMask(const SkGlyph& glyph) {
 
 void SkScalerContext_DW::generateImage(const SkGlyph& glyph) {
     //Create the mask.
-    const void* bits = this->drawDWMask(glyph);
+    DWRITE_RENDERING_MODE renderingMode = fRenderingMode;
+    DWRITE_TEXTURE_TYPE textureType = fTextureType;
+    if (glyph.fForceBW) {
+        renderingMode = DWRITE_RENDERING_MODE_ALIASED;
+        textureType = DWRITE_TEXTURE_ALIASED_1x1;
+    }
+    const void* bits = this->drawDWMask(glyph, renderingMode, textureType);
     if (!bits) {
         sk_bzero(glyph.fImage, glyph.computeImageSize());
         return;
@@ -671,7 +725,7 @@ void SkScalerContext_DW::generateImage(const SkGlyph& glyph) {
 
     //Copy the mask into the glyph.
     const uint8_t* src = (const uint8_t*)bits;
-    if (DWRITE_RENDERING_MODE_ALIASED == fRenderingMode) {
+    if (DWRITE_RENDERING_MODE_ALIASED == renderingMode) {
         bilevel_to_bw(src, glyph);
         const_cast<SkGlyph&>(glyph).fMaskFormat = SkMask::kBW_Format;
     } else if (!isLCD(fRec)) {