Refactor helper function for SkBitmapShader to GrFragmentProcessor

src/gpu/SkGpuDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGpuDevice.h"
 
 #include "GrBlurUtils.h"
@@ skipping 1016 matching lines @@
 
     // If there is no mask filter than it is OK to handle the src rect -> dst rect scaling using
     // the view matrix rather than a local matrix.
     SkMatrix m;
     m.setScale(dstSize.fWidth / srcRect.width(),
                dstSize.fHeight / srcRect.height());
     SkMatrix viewM = *draw.fMatrix;
     viewM.preConcat(m);
 
     GrTextureParams params;
-    SkFilterQuality paintFilterQuality = paint.getFilterQuality();
-    GrTextureParams::FilterMode textureFilterMode;
-
-    bool doBicubic = false;
-
-    switch(paintFilterQuality) {
-        case kNone_SkFilterQuality:
-            textureFilterMode = GrTextureParams::kNone_FilterMode;
-            break;
-        case kLow_SkFilterQuality:
-            textureFilterMode = GrTextureParams::kBilerp_FilterMode;
-            break;
-        case kMedium_SkFilterQuality:
-            if (viewM.getMinScale() < SK_Scalar1) {
-                textureFilterMode = GrTextureParams::kMipMap_FilterMode;
-            } else {
-                // Don't trigger MIP level generation unnecessarily.
-                textureFilterMode = GrTextureParams::kBilerp_FilterMode;
-            }
-            break;
-        case kHigh_SkFilterQuality:
-            // Minification can look bad with the bicubic effect.
-            doBicubic =
-                GrBicubicEffect::ShouldUseBicubic(viewM, &textureFilterMode);
-            break;
-        default:
-            SkErrorInternals::SetError( kInvalidPaint_SkError,
-                                        "Sorry, I don't understand the filtering "
-                                        "mode you asked for.  Falling back to "
-                                        "MIPMaps.");
-            textureFilterMode = GrTextureParams::kMipMap_FilterMode;
-            break;
-    }
+    bool doBicubic;
+    GrTextureParams::FilterMode textureFilterMode =
+            GrSkFilterQualityToGrFilterMode(paint.getFilterQuality(), viewM, SkMatrix::I(),
+                                            &doBicubic);
 
     int tileFilterPad;
     if (doBicubic) {
         tileFilterPad = GrBicubicEffect::kFilterTexelPad;
     } else if (GrTextureParams::kNone_FilterMode == textureFilterMode) {
         tileFilterPad = 0;
     } else {
         tileFilterPad = 1;
     }
     params.setFilterMode(textureFilterMode);
@@ skipping 786 matching lines @@
 #endif
 }
 
 SkImageFilter::Cache* SkGpuDevice::getImageFilterCache() {
     // We always return a transient cache, so it is freed after each
     // filter traversal.
     return SkImageFilter::Cache::Create(kDefaultImageFilterCacheSize);
 }
 
 #endif