fixes around isOpaque and dithering

- copyTo() now preserves isOpaqueness, and BitmapCopyTest tests it
- bitmap shader doesn't claim to have shadespan16 if dithering is on, since its
  sampler doesn't auto-dither (note that gradients do auto-dither in their
  16bit sampler)
- blitter setup just relies on the shader to report if its 16bit sampler can be
  called (allowing gradients to say yes regardless of dither, but bitmaps to say
  no if dithering is on)



git-svn-id: http://skia.googlecode.com/svn/trunk@331 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 13 insertions, 5 deletions

diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index 7eb8ea148b..353388b74c 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -102,19 +102,19 @@ bool SkBitmapProcShader::setContext(const SkBitmap& device,
     }
 
     // update fFlags
-    fFlags = 0;
+    uint32_t flags = 0;
     if (bitmapIsOpaque && (255 == this->getPaintAlpha())) {
-        fFlags |= kOpaqueAlpha_Flag;
+        flags |= kOpaqueAlpha_Flag;
     }
 
     switch (fState.fBitmap->config()) {
         case SkBitmap::kRGB_565_Config:
-            fFlags |= (kHasSpan16_Flag | kIntrinsicly16_Flag);
+            flags |= (kHasSpan16_Flag | kIntrinsicly16_Flag);
             break;
         case SkBitmap::kIndex8_Config:
         case SkBitmap::kARGB_8888_Config:
             if (bitmapIsOpaque) {
-                fFlags |= kHasSpan16_Flag;
+                flags |= kHasSpan16_Flag;
             }
             break;
         case SkBitmap::kA8_Config:
@@ -123,11 +123,19 @@ bool SkBitmapProcShader::setContext(const SkBitmap& device,
             break;
     }
 
+    if (paint.isDither()) {
+        // gradients can auto-dither in their 16bit sampler, but we don't so
+        // we clear the flag here
+        flags &= ~kHasSpan16_Flag;
+    }
+
     // if we're only 1-pixel heigh, and we don't rotate, then we can claim this
     if (1 == fState.fBitmap->height() &&
             only_scale_and_translate(this->getTotalInverse())) {
-        fFlags |= kConstInY_Flag;
+        flags |= kConstInY_Flag;
     }
+
+    fFlags = flags;
     return true;
 }