Add factory class for generating various flavors of GrTextContext.

src/gpu/SkGpuDevice.cpp

Index: src/gpu/SkGpuDevice.cpp
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 5ba174cafcc53e9f483b7844c1f1d98b173629ac..a5d5be1903fabb15eec2b3ddd99a5ea0e5e104cf 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -200,6 +200,12 @@ void SkGpuDevice::initFromRenderTarget(GrContext* context,
     fContext = context;
     fContext->ref();
 
+#if SK_DISTANCEFIELD_FONTS
+    fTextContextFactory = new GrTTextContextFactory<GrDistanceFieldTextContext>();
+#else
+    fTextContextFactory = new GrTTextContextFactory<GrBitmapTextContext>();
+#endif
+
     fRenderTarget = NULL;
     fNeedClear = false;
 
@@ -235,6 +241,12 @@ SkGpuDevice::SkGpuDevice(GrContext* context,
     fContext = context;
     fContext->ref();
 
+#if SK_DISTANCEFIELD_FONTS
+    fTextContextFactory = new GrTTextContextFactory<GrDistanceFieldTextContext>();
+#else
+    fTextContextFactory = new GrTTextContextFactory<GrBitmapTextContext>();
+#endif
+
     fRenderTarget = NULL;
     fNeedClear = false;
 
@@ -279,6 +291,10 @@ SkGpuDevice::~SkGpuDevice() {
     if (fDrawProcs) {
         delete fDrawProcs;
     }
+    
+    if (fTextContextFactory) {
+        delete fTextContextFactory;
+    }
 
     // The GrContext takes a ref on the target. We don't want to cause the render
     // target to be unnecessarily kept alive.
@@ -1820,13 +1836,15 @@ void SkGpuDevice::drawText(const SkDraw& draw, const void* text,
 
         SkDEBUGCODE(this->validate();)
 
-        GrDistanceFieldTextContext context(fContext, grPaint, paint);
+        GrDistanceFieldTextContext* context = 
+                (GrDistanceFieldTextContext*) fTextContextFactory->Create(fContext, grPaint, paint);
 
-        SkAutoGlyphCache    autoCache(context.getSkPaint(), &this->fLeakyProperties, NULL);
+        SkAutoGlyphCache    autoCache(context->getSkPaint(), &this->fLeakyProperties, NULL);
         SkGlyphCache*       cache = autoCache.getCache();
         GrFontScaler*       fontScaler = get_gr_font_scaler(cache);
 
-        context.drawText((const char *)text, byteLength, x, y, cache, fontScaler);
+        context->drawText((const char *)text, byteLength, x, y, cache, fontScaler);
+        fTextContextFactory->Destroy(context);
 #endif
     } else {
         SkDraw myDraw(draw);
@@ -1836,9 +1854,10 @@ void SkGpuDevice::drawText(const SkDraw& draw, const void* text,
             return;
         }
 
-        GrBitmapTextContext context(fContext, grPaint, paint.getColor());
-        myDraw.fProcs = this->initDrawForText(&context);
+        GrTextContext* context = fTextContextFactory->Create(fContext, grPaint, paint);
+        myDraw.fProcs = this->initDrawForText(context);
         this->INHERITED::drawText(myDraw, text, byteLength, x, y, paint);
+        fTextContextFactory->Destroy(context);
     }
 }
 
@@ -1861,14 +1880,16 @@ void SkGpuDevice::drawPosText(const SkDraw& draw, const void* text,
 
         SkDEBUGCODE(this->validate();)
 
-        GrDistanceFieldTextContext context(fContext, grPaint, paint);
+        GrDistanceFieldTextContext* context = 
+                (GrDistanceFieldTextContext*) fTextContextFactory->Create(fContext, grPaint, paint);

[bsalomon, 2014/01/21 20:46:17]

Does phase 2 remove the need for this downcast?

[jvanverth1, 2014/01/21 21:10:56]

Yes. The current shared interface is for working with SkDraw. The new one will
be closer to GrDistanceFieldContext, so this cast won't be necessary.

 
-        SkAutoGlyphCache    autoCache(context.getSkPaint(), &this->fLeakyProperties, NULL);
+        SkAutoGlyphCache    autoCache(context->getSkPaint(), &this->fLeakyProperties, NULL);
         SkGlyphCache*       cache = autoCache.getCache();
         GrFontScaler*       fontScaler = get_gr_font_scaler(cache);
 
-        context.drawPosText((const char *)text, byteLength, pos, constY, scalarsPerPos,
+        context->drawPosText((const char *)text, byteLength, pos, constY, scalarsPerPos,
                             cache, fontScaler);
+        fTextContextFactory->Destroy(context);
 #endif
     } else {
         SkDraw myDraw(draw);
@@ -1877,10 +1898,12 @@ void SkGpuDevice::drawPosText(const SkDraw& draw, const void* text,
         if (!skPaint2GrPaintShader(this, paint, true, &grPaint)) {
             return;
         }
-        GrBitmapTextContext context(fContext, grPaint, paint.getColor());
-        myDraw.fProcs = this->initDrawForText(&context);
+
+        GrTextContext* context = fTextContextFactory->Create(fContext, grPaint, paint);
+        myDraw.fProcs = this->initDrawForText(context);
         this->INHERITED::drawPosText(myDraw, text, byteLength, pos, constY,
                                         scalarsPerPos, paint);
+        fTextContextFactory->Destroy(context);
     }
 }