first cut at HQ GPU scaling; refactored existing bicubic scaler

src/core/SkBitmapProcShader.cpp

Index: src/core/SkBitmapProcShader.cpp
diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index 0e7ac6a27758b348ce549daa482055750bc4c392..24d3909542f0fa5d43da16d0ea7691c8d9b2457e 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -11,6 +11,10 @@
 #include "SkPixelRef.h"
 #include "SkErrorInternals.h"
 
+#include "../effects/SkBicubicImageFilter.h"

[reed1, 2013/09/03 20:57:37]

do we need the path to scope where these headers are?

[humper, 2013/09/03 21:45:53]

Probably not -- this one picks out a file from src/effects; just putting
effects/ in there will pick out include/effects.  I'll move the header.

[bsalomon, 2013/09/04 13:06:15]

I think we actually shouldn't have core depend on anything in effects. We pretty
loosey goosey about cross dependencies but effects is still optional from a skia
library build.


Is it just the coeffs that're being shared? Maybe just dupe 'em.

+#include "effects/GrSimpleTextureEffect.h"
+#include "effects/GrBicubicEffect.h"
+
 bool SkBitmapProcShader::CanDo(const SkBitmap& bm, TileMode tx, TileMode ty) {
     switch (bm.config()) {
         case SkBitmap::kA8_Config:
@@ -367,11 +371,9 @@ GrEffectRef* SkBitmapProcShader::asNewEffect(GrContext* context, const SkPaint&
             textureFilterMode = GrTextureParams::kMipMap_FilterMode;
             break;
         case SkPaint::kHigh_FilterLevel:
-            SkErrorInternals::SetError( kInvalidPaint_SkError,
-                                        "Sorry, I don't yet support high quality "
-                                        "filtering on the GPU; falling back to "
-                                        "MIPMaps.");
-            textureFilterMode = GrTextureParams::kMipMap_FilterMode;
+            // fall back to no filtering here; we will install another
+            // shader that will do the HQ filtering.
+            textureFilterMode = GrTextureParams::kNone_FilterMode;
             break;
         default:
             SkErrorInternals::SetError( kInvalidPaint_SkError,
@@ -386,11 +388,17 @@ GrEffectRef* SkBitmapProcShader::asNewEffect(GrContext* context, const SkPaint&
     GrTexture* texture = GrLockAndRefCachedBitmapTexture(context, fRawBitmap, &params);
 
     if (NULL == texture) {
-        SkDebugf("Couldn't convert bitmap to texture.\n");
+        SkErrorInternals::SetError( kInternalError_SkError,
+                                    "Couldn't convert bitmap to texture.");
         return NULL;
     }
 
-    GrEffectRef* effect = GrSimpleTextureEffect::Create(texture, matrix, params);
+    GrEffectRef* effect = NULL;
+    if (paintFilterLevel == SkPaint::kHigh_FilterLevel) {
+        effect = GrBicubicEffect::Create(texture, SkBicubicImageFilter::fMitchellCoefficients, matrix, params);
+    } else {
+        effect = GrSimpleTextureEffect::Create(texture, matrix, params);
+    }
     GrUnlockAndUnrefCachedBitmapTexture(texture);
     return effect;
 }