From 98d653e97b85dbdf934dac5cab71f2f3dc94aa48 Mon Sep 17 00:00:00 2001
From: Bas Schouten <bschouten@mozilla.com>
Date: Tue, 15 May 2012 16:57:51 +0200
Subject: [PATCH] Bug 717393 - Part 1: Add helper for creating DWriteGlyphRuns.
 r=jrmuizel

---
 gfx/2d/DrawTargetD2D.cpp  | 29 ++-------------
 gfx/2d/HelpersD2D.h       | 75 +++++++++++++++++++++++++++++++++++++++
 gfx/2d/ScaledFontDWrite.h |  3 --
 3 files changed, 78 insertions(+), 29 deletions(-)

diff --git a/gfx/2d/DrawTargetD2D.cpp b/gfx/2d/DrawTargetD2D.cpp
index 6564b36752a..a8ffb7744da 100644
--- a/gfx/2d/DrawTargetD2D.cpp
+++ b/gfx/2d/DrawTargetD2D.cpp
@@ -910,34 +910,11 @@ DrawTargetD2D::FillGlyphs(ScaledFont *aFont,
 
   RefPtr<ID2D1Brush> brush = CreateBrushForPattern(aPattern, aOptions.mAlpha);
 
-  DWRITE_GLYPH_RUN glyphRun;
-
-  glyphRun.bidiLevel = 0;
-  glyphRun.fontEmSize = font->mSize;
-  glyphRun.isSideways = FALSE;
-  glyphRun.fontFace = font->mFontFace;
-  glyphRun.glyphCount = aBuffer.mNumGlyphs;
-  
-  std::vector<UINT16> indices;
-  std::vector<FLOAT> advances;
-  std::vector<DWRITE_GLYPH_OFFSET> offsets;
-  indices.resize(aBuffer.mNumGlyphs);
-  advances.resize(aBuffer.mNumGlyphs);
-  offsets.resize(aBuffer.mNumGlyphs);
-
-  memset(&advances.front(), 0, sizeof(FLOAT) * aBuffer.mNumGlyphs);
-  for (unsigned int i = 0; i < aBuffer.mNumGlyphs; i++) {
-    indices[i] = aBuffer.mGlyphs[i].mIndex;
-    offsets[i].advanceOffset = aBuffer.mGlyphs[i].mPosition.x;
-    offsets[i].ascenderOffset = -aBuffer.mGlyphs[i].mPosition.y;
-  }
-
-  glyphRun.glyphAdvances = &advances.front();
-  glyphRun.glyphIndices = &indices.front();
-  glyphRun.glyphOffsets = &offsets.front();
+  AutoDWriteGlyphRun autoRun;
+  DWriteGlyphRunFromGlyphs(aBuffer, font, &autoRun);
 
   if (brush) {
-    rt->DrawGlyphRun(D2D1::Point2F(), &glyphRun, brush);
+    rt->DrawGlyphRun(D2D1::Point2F(), &autoRun, brush);
   }
 
   FinalizeRTForOperation(aOptions.mCompositionOp, aPattern, Rect(0, 0, (Float)mSize.width, (Float)mSize.height));
diff --git a/gfx/2d/HelpersD2D.h b/gfx/2d/HelpersD2D.h
index d631d96017a..7c0e2ea947d 100644
--- a/gfx/2d/HelpersD2D.h
+++ b/gfx/2d/HelpersD2D.h
@@ -39,8 +39,11 @@
 #define MOZILLA_GFX_HELPERSD2D_H_
 
 #include <d2d1.h>
+#include <dwrite.h>
 #include "2D.h"
 
+#include "ScaledFontDWrite.h"
+
 namespace mozilla {
 namespace gfx {
 
@@ -212,6 +215,78 @@ struct ShaderConstantRectD3D10
   operator float* () { return &mX; }
 };
 
+static DWRITE_MATRIX
+DWriteMatrixFromMatrix(Matrix &aMatrix)
+{
+  DWRITE_MATRIX mat;
+  mat.m11 = aMatrix._11;
+  mat.m12 = aMatrix._12;
+  mat.m21 = aMatrix._21;
+  mat.m22 = aMatrix._22;
+  mat.dx = aMatrix._31;
+  mat.dy = aMatrix._32;
+  return mat;
+}
+
+class AutoDWriteGlyphRun : public DWRITE_GLYPH_RUN
+{
+    static const int kNumAutoGlyphs = 256;
+
+public:
+    AutoDWriteGlyphRun() {
+        glyphCount = 0;
+    }
+
+    ~AutoDWriteGlyphRun() {
+        if (glyphCount > kNumAutoGlyphs) {
+            delete[] glyphIndices;
+            delete[] glyphAdvances;
+            delete[] glyphOffsets;
+        }
+    }
+
+    void allocate(int aNumGlyphs) {
+        glyphCount = aNumGlyphs;
+        if (aNumGlyphs <= kNumAutoGlyphs) {
+            glyphIndices = &mAutoIndices[0];
+            glyphAdvances = &mAutoAdvances[0];
+            glyphOffsets = &mAutoOffsets[0];
+        } else {
+            glyphIndices = new UINT16[aNumGlyphs];
+            glyphAdvances = new FLOAT[aNumGlyphs];
+            glyphOffsets = new DWRITE_GLYPH_OFFSET[aNumGlyphs];
+        }
+    }
+
+private:
+    DWRITE_GLYPH_OFFSET mAutoOffsets[kNumAutoGlyphs];
+    FLOAT               mAutoAdvances[kNumAutoGlyphs];
+    UINT16              mAutoIndices[kNumAutoGlyphs];
+};
+
+static void
+DWriteGlyphRunFromGlyphs(const GlyphBuffer &aGlyphs, ScaledFontDWrite *aFont, AutoDWriteGlyphRun *run)
+{
+  run->allocate(aGlyphs.mNumGlyphs);
+
+  FLOAT *advances = const_cast<FLOAT*>(run->glyphAdvances);
+  UINT16 *indices = const_cast<UINT16*>(run->glyphIndices);
+  DWRITE_GLYPH_OFFSET *offsets = const_cast<DWRITE_GLYPH_OFFSET*>(run->glyphOffsets);
+
+  memset(advances, 0, sizeof(FLOAT) * aGlyphs.mNumGlyphs);
+  for (unsigned int i = 0; i < aGlyphs.mNumGlyphs; i++) {
+    indices[i] = aGlyphs.mGlyphs[i].mIndex;
+    offsets[i].advanceOffset = aGlyphs.mGlyphs[i].mPosition.x;
+    offsets[i].ascenderOffset = -aGlyphs.mGlyphs[i].mPosition.y;
+  }
+    
+  run->bidiLevel = 0;
+  run->fontFace = aFont->mFontFace;
+  run->fontEmSize = aFont->mSize;
+  run->glyphCount = aGlyphs.mNumGlyphs;
+  run->isSideways = FALSE;
+}
+
 }
 }
 
diff --git a/gfx/2d/ScaledFontDWrite.h b/gfx/2d/ScaledFontDWrite.h
index 05d76b4aeae..c22c58c2730 100644
--- a/gfx/2d/ScaledFontDWrite.h
+++ b/gfx/2d/ScaledFontDWrite.h
@@ -59,9 +59,6 @@ public:
   virtual TemporaryRef<Path> GetPathForGlyphs(const GlyphBuffer &aBuffer, const DrawTarget *aTarget);
   virtual void CopyGlyphsToBuilder(const GlyphBuffer &aBuffer, PathBuilder *aBuilder);
 
-private:
-  friend class DrawTargetD2D;
-
   void CopyGlyphsToSink(const GlyphBuffer &aBuffer, ID2D1GeometrySink *aSink);
 
   RefPtr<IDWriteFontFace> mFontFace;