Stop supporting HW dither

src/gpu/SkGr.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGr.h"
 
 #include "GrCaps.h"
@@ skipping 690 matching lines @@
         *ctOut = ct;
     }
     if (ptOut) {
         *ptOut = pt;
     }
     return true;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-bool SkPaint2GrPaintNoShader(GrContext* context, GrRenderTarget* rt, const SkPaint& skPaint,
-                             GrColor paintColor, bool constantColor, GrPaint* grPaint) {
+bool SkPaint2GrPaintNoShader(GrContext* context, const SkPaint& skPaint, GrColor paintColor,
+                             bool constantColor, GrPaint* grPaint) {
 
-    grPaint->setDither(skPaint.isDither());
     grPaint->setAntiAlias(skPaint.isAntiAlias());
 
     SkXfermode* mode = skPaint.getXfermode();
     GrXPFactory* xpFactory = nullptr;
     if (!SkXfermode::AsXPFactory(mode, &xpFactory)) {
         // Fall back to src-over
         // return false here?
         xpFactory = GrPorterDuffXPFactory::Create(SkXfermode::kSrcOver_Mode);
     }
     SkASSERT(xpFactory);
@@ skipping 16 matching lines @@
                                                   &array)) {
                 for (int i = 0; i < array.count(); ++i) {
                     grPaint->addColorFragmentProcessor(array[i]);
                     array[i]->unref();
                 }
             }
         }
     }
 
 #ifndef SK_IGNORE_GPU_DITHER
-    // If the dither flag is set, then we need to see if the underlying context
-    // supports it. If not, then install a dither effect.
     if (skPaint.isDither() && grPaint->numColorFragmentProcessors() > 0) {
-        // What are we rendering into?
-        SkASSERT(rt);
-
-        // Suspect the dithering flag has no effect on these configs, otherwise
-        // fall back on setting the appropriate state.
-        if (GrPixelConfigIs8888(rt->config()) ||
-            GrPixelConfigIs8888(rt->config())) {
-            // The dither flag is set and the target is likely
-            // not going to be dithered by the GPU.
-            SkAutoTUnref<GrFragmentProcessor> fp(GrDitherEffect::Create());
-            if (fp.get()) {
-                grPaint->addColorFragmentProcessor(fp);
-                grPaint->setDither(false);
-            }
-        }
+        grPaint->addColorFragmentProcessor(GrDitherEffect::Create())->unref();
     }
 #endif
     return true;
 }
 
-bool SkPaint2GrPaint(GrContext* context, GrRenderTarget* rt, const SkPaint& skPaint,
-                     const SkMatrix& viewM, bool constantColor, GrPaint* grPaint) {
+bool SkPaint2GrPaint(GrContext* context,const SkPaint& skPaint, const SkMatrix& viewM,
+                     bool constantColor, GrPaint* grPaint) {
     SkShader* shader = skPaint.getShader();
     if (nullptr == shader) {
-        return SkPaint2GrPaintNoShader(context, rt, skPaint, SkColor2GrColor(skPaint.getColor()),
+        return SkPaint2GrPaintNoShader(context, skPaint, SkColor2GrColor(skPaint.getColor()),
                                        constantColor, grPaint);
     }
 
     GrColor paintColor = SkColor2GrColor(skPaint.getColor());
 
     const GrFragmentProcessor* fp = shader->asFragmentProcessor(context, viewM, NULL,
         skPaint.getFilterQuality(), grPaint->getProcessorDataManager());
     if (!fp) {
         return false;
     }
     grPaint->addColorFragmentProcessor(fp)->unref();
     constantColor = false;
 
     // The grcolor is automatically set when calling asFragmentProcessor.
     // If the shader can be seen as an effect it returns true and adds its effect to the grpaint.
-    return SkPaint2GrPaintNoShader(context, rt, skPaint, paintColor, constantColor, grPaint);
+    return SkPaint2GrPaintNoShader(context, skPaint, paintColor, constantColor, grPaint);
 }
 
 SkImageInfo GrMakeInfoFromTexture(GrTexture* tex, int w, int h, bool isOpaque) {
 #ifdef SK_DEBUG
     const GrSurfaceDesc& desc = tex->desc();
     SkASSERT(w <= desc.fWidth);
     SkASSERT(h <= desc.fHeight);
 #endif
     const GrPixelConfig config = tex->config();
     SkColorType ct;
@@ skipping 45 matching lines @@
             SkErrorInternals::SetError( kInvalidPaint_SkError,
                                         "Sorry, I don't understand the filtering "
                                         "mode you asked for.  Falling back to "
                                         "MIPMaps.");
             textureFilterMode = GrTextureParams::kMipMap_FilterMode;
             break;
 
     }
     return textureFilterMode;
 }