Refactor helper function for SkBitmapShader to GrFragmentProcessor

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"
 #include "GrDrawContext.h"
 #include "GrXferProcessor.h"
 #include "SkColorFilter.h"
 #include "SkConfig8888.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkErrorInternals.h"
 #include "SkGrPixelRef.h"
 #include "SkMessageBus.h"
 #include "SkPixelRef.h"
 #include "SkResourceCache.h"
 #include "SkTextureCompressor.h"
 #include "SkYUVPlanesCache.h"
+#include "effects/GrBicubicEffect.h"
 #include "effects/GrDitherEffect.h"
 #include "effects/GrPorterDuffXferProcessor.h"
 #include "effects/GrYUVtoRGBEffect.h"
 
 #ifndef SK_IGNORE_ETC1_SUPPORT
 #  include "ktx.h"
 #  include "etc1.h"
 #endif
 
 /*  Fill out buffer with the compressed format Ganesh expects from a colortable
@@ skipping 794 matching lines @@
     }
     return SkImageInfo::Make(w, h, ct, at);
 }
 
 
 void GrWrapTextureInBitmap(GrTexture* src, int w, int h, bool isOpaque, SkBitmap* dst) {
     const SkImageInfo info = GrMakeInfoFromTexture(src, w, h, isOpaque);
     dst->setInfo(info);
     dst->setPixelRef(SkNEW_ARGS(SkGrPixelRef, (info, src)))->unref();
 }
+
+GrTextureParams::FilterMode GrSkFilterQualityToGrFilterMode(SkFilterQuality paintFilterQuality,
+                                                            const SkMatrix& viewM,
+                                                            const SkMatrix& localM,
+                                                            bool* doBicubic) {
+    *doBicubic = false;
+    GrTextureParams::FilterMode textureFilterMode;
+    switch (paintFilterQuality) {
+        case kNone_SkFilterQuality:
+            textureFilterMode = GrTextureParams::kNone_FilterMode;
+            break;
+        case kLow_SkFilterQuality:
+            textureFilterMode = GrTextureParams::kBilerp_FilterMode;
+            break;
+        case kMedium_SkFilterQuality: {
+            SkMatrix matrix;
+            matrix.setConcat(viewM, localM);
+            if (matrix.getMinScale() < SK_Scalar1) {
+                textureFilterMode = GrTextureParams::kMipMap_FilterMode;
+            } else {
+                // Don't trigger MIP level generation unnecessarily.
+                textureFilterMode = GrTextureParams::kBilerp_FilterMode;
+            }
+            break;
+        }
+        case kHigh_SkFilterQuality: {
+            SkMatrix matrix;
+            matrix.setConcat(viewM, localM);
+            *doBicubic = GrBicubicEffect::ShouldUseBicubic(matrix, &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;
+
+    }
+    return textureFilterMode;
+}