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

include/core/SkBitmap.h

@@ -508,6 +508,9 @@ public:
     */
     void    setFlags(unsigned flags);
 
+    bool isOpaque() const { return (fFlags & kColorsAreOpaque_Flag) != 0; }
+    void setIsOpaque(bool isOpaque);
+
     /** Returns the number of colors in the table.
     */
     int count() const { return fCount; }

samplecode/SampleDitherBitmap.cpp

@@ -10,7 +10,7 @@ static SkBitmap make_bitmap() {
 
     SkPMColor* c = ctable->lockColors();
     for (int i = 0; i < 256; i++) {
-        c[i] = SkPackARGB32(0xFF, 0, 0, i);
+        c[i] = SkPackARGB32(0xFF, i, 0, 0);
     }
     ctable->unlockColors(true);
     bm.setConfig(SkBitmap::kIndex8_Config, 256, 32);
@@ -51,12 +51,31 @@ protected:
         canvas->drawColor(0xFFDDDDDD);
     }
     
+    static void setBitmapOpaque(SkBitmap* bm, bool isOpaque) {
+        SkAutoLockPixels alp(*bm);  // needed for ctable
+        bm->setIsOpaque(isOpaque);
+        SkColorTable* ctable = bm->getColorTable();
+        if (ctable) {
+            ctable->setIsOpaque(isOpaque);
+        }
+    }
+    
     static void draw2(SkCanvas* canvas, const SkBitmap& bm) {
         SkPaint paint;
-        
+        SkBitmap bitmap(bm);
-        canvas->drawBitmap(bm, 0, 0, &paint);
+
+        setBitmapOpaque(&bitmap, false);
+        paint.setDither(false);
+        canvas->drawBitmap(bitmap, 0, 0, &paint);
         paint.setDither(true);
-        canvas->drawBitmap(bm, 0, SkIntToScalar(bm.height() + 10), &paint);
+        canvas->drawBitmap(bitmap, 0, SkIntToScalar(bm.height() + 10), &paint);
+
+        setBitmapOpaque(&bitmap, true);
+        SkScalar x = SkIntToScalar(bm.width() + 10);
+        paint.setDither(false);
+        canvas->drawBitmap(bitmap, x, 0, &paint);
+        paint.setDither(true);
+        canvas->drawBitmap(bitmap, x, SkIntToScalar(bm.height() + 10), &paint);
     }
     
     virtual void onDraw(SkCanvas* canvas) {

src/core/SkBitmap.cpp

@@ -793,6 +793,8 @@ bool SkBitmap::copyTo(SkBitmap* dst, Config dstConfig, Allocator* alloc) const {
         canvas.drawBitmap(*this, 0, 0, &paint);
     }
 
+    tmp.setIsOpaque(this->isOpaque());
+
     dst->swap(tmp);
     return true;
 }

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;
 }
 

src/core/SkBlitter.cpp

@@ -896,16 +896,8 @@ SkBlitter* SkBlitter::Choose(const SkBitmap& device,
         ((SkPaint*)&paint)->setShader(shader)->unref();
     }
     
-    bool doDither = paint.isDither();
+    if (shader && !shader->setContext(device, paint, matrix)) {
-
+        return SkNEW(SkNullBlitter);
-    if (shader)
-    {
-        if (!shader->setContext(device, paint, matrix))
-            return SkNEW(SkNullBlitter);
-        
-        // disable dither if our shader is natively 16bit (no need to upsample)
-        if (shader->getFlags() & SkShader::kIntrinsicly16_Flag)
-            doDither = false;
     }
 
     switch (device.getConfig()) {
@@ -929,7 +921,7 @@ SkBlitter* SkBlitter::Choose(const SkBitmap& device,
         {
             if (mode)
                 SK_PLACEMENT_NEW_ARGS(blitter, SkRGB16_Shader_Xfermode_Blitter, storage, storageSize, (device, paint));
-            else if (SkShader::CanCallShadeSpan16(shader->getFlags()) && !doDither)
+            else if (shader->canCallShadeSpan16())
                 SK_PLACEMENT_NEW_ARGS(blitter, SkRGB16_Shader16_Blitter, storage, storageSize, (device, paint));
             else
                 SK_PLACEMENT_NEW_ARGS(blitter, SkRGB16_Shader_Blitter, storage, storageSize, (device, paint));

src/core/SkColorTable.cpp

@@ -132,6 +132,14 @@ const uint16_t* SkColorTable::lock16BitCache()
     return f16BitCache;
 }
 
+void SkColorTable::setIsOpaque(bool isOpaque) {
+    if (isOpaque) {
+        fFlags |= kColorsAreOpaque_Flag;
+    } else {
+        fFlags &= ~kColorsAreOpaque_Flag;
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 SkColorTable::SkColorTable(SkFlattenableReadBuffer& buffer) {

tests/BitmapCopyTest.cpp

@@ -11,6 +11,57 @@ static const char* gConfigName[] = {
     "None", "A1", "A8", "Index8", "565", "4444", "8888", "RLE_Index8"
 };
 
+static void report_opaqueness(skiatest::Reporter* reporter, const SkBitmap& src,
+                              const SkBitmap& dst) {
+    SkString str;
+    str.printf("src %s opaque:%d, dst %s opaque:%d",
+               gConfigName[src.config()], src.isOpaque(),
+               gConfigName[dst.config()], dst.isOpaque());
+    reporter->reportFailed(str);
+}
+
+static bool canHaveAlpha(SkBitmap::Config config) {
+    return config != SkBitmap::kRGB_565_Config;
+}
+
+// copyTo() should preserve isOpaque when it makes sense
+static void test_isOpaque(skiatest::Reporter* reporter, const SkBitmap& src,
+                          SkBitmap::Config dstConfig) {
+    SkBitmap bitmap(src);
+    SkBitmap dst;
+
+    // we need the lock so that we get a valid colorTable (when available)
+    SkAutoLockPixels alp(bitmap);
+    SkColorTable* ctable = bitmap.getColorTable();
+    unsigned ctableFlags = ctable ? ctable->getFlags() : 0;
+
+    if (canHaveAlpha(bitmap.config()) && canHaveAlpha(dstConfig)) {
+        bitmap.setIsOpaque(false);
+        if (ctable) {
+            ctable->setFlags(ctableFlags & ~SkColorTable::kColorsAreOpaque_Flag);
+        }
+        REPORTER_ASSERT(reporter, bitmap.copyTo(&dst, dstConfig));
+        REPORTER_ASSERT(reporter, dst.config() == dstConfig);
+        if (bitmap.isOpaque() != dst.isOpaque()) {
+            report_opaqueness(reporter, bitmap, dst);
+        }
+    }
+
+    bitmap.setIsOpaque(true);
+    if (ctable) {
+        ctable->setFlags(ctableFlags | SkColorTable::kColorsAreOpaque_Flag);
+    }
+    REPORTER_ASSERT(reporter, bitmap.copyTo(&dst, dstConfig));
+    REPORTER_ASSERT(reporter, dst.config() == dstConfig);
+    if (bitmap.isOpaque() != dst.isOpaque()) {
+        report_opaqueness(reporter, bitmap, dst);
+    }
+
+    if (ctable) {
+        ctable->setFlags(ctableFlags);
+    }
+}
+
 static void init_src(const SkBitmap& bitmap) {
     SkAutoLockPixels lock(bitmap);
     if (bitmap.getPixels()) {
@@ -83,6 +134,7 @@ static void TestBitmapCopy(skiatest::Reporter* reporter) {
                 REPORTER_ASSERT(reporter, src.width() == dst.width());
                 REPORTER_ASSERT(reporter, src.height() == dst.height());
                 REPORTER_ASSERT(reporter, dst.config() == gPairs[j].fConfig);
+                test_isOpaque(reporter, src, dst.config());
                 if (src.config() == dst.config()) {
                     SkAutoLockPixels srcLock(src);
                     SkAutoLockPixels dstLock(dst);

xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj

@@ -47,7 +47,6 @@
 		0057785F0FF17CCC00582CD9 /* SampleMipMap.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 2794C04E0FE72903009AD112 /* SampleMipMap.cpp */; };
 		005778B40FF5616F00582CD9 /* SampleShapes.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 003145310FB9B48F00B10956 /* SampleShapes.cpp */; };
 		005E92DC0FF08507008965B9 /* SampleFilter2.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0041CE290F00A12400695E8C /* SampleFilter2.cpp */; };
-		005E92DE0FF0850E008965B9 /* SampleFillType.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0041CE270F00A12400695E8C /* SampleFillType.cpp */; };
 		005E92E00FF08512008965B9 /* SampleFilter.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0041CE280F00A12400695E8C /* SampleFilter.cpp */; };
 		007A7CB30F01658C00A2D6EE /* SamplePicture.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 007A7CA40F01658C00A2D6EE /* SamplePicture.cpp */; };
 		007A7CB40F01658C00A2D6EE /* SamplePoints.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 007A7CA50F01658C00A2D6EE /* SamplePoints.cpp */; };
@@ -71,6 +70,8 @@
 		00A7295D0FD8397600D5051F /* SampleAll.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 2762F6740FCCCB01002BD8B4 /* SampleAll.cpp */; };
 		00AF77B00FE2EA2D007F9650 /* SampleTestGL.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00A729630FD93ED600D5051F /* SampleTestGL.cpp */; };
 		00AF787E0FE94433007F9650 /* SamplePath.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00003C640EFC22A8000FF73A /* SamplePath.cpp */; };
+		00AF9B18103CD5EB00CBBCB3 /* SampleDitherBitmap.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00AF9B17103CD5EB00CBBCB3 /* SampleDitherBitmap.cpp */; };
+		00C1B809103857A400FA5948 /* SampleFillType.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0041CE270F00A12400695E8C /* SampleFillType.cpp */; };
 		00F53F480FFCFC4D003FA70A /* SampleGradients.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00C55DA00F8552DC000CAC09 /* SampleGradients.cpp */; };
 		00FF39140FC6ED2C00915187 /* SampleEffects.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00FF39130FC6ED2C00915187 /* SampleEffects.cpp */; };
 		0156F80407C56A3000C6122B /* Foundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 0156F80307C56A3000C6122B /* Foundation.framework */; };
@@ -197,6 +198,7 @@
 		00A7282D0FD43D3700D5051F /* SkMovie.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SkMovie.cpp; path = ../../src/images/SkMovie.cpp; sourceTree = SOURCE_ROOT; };
 		00A7282E0FD43D3700D5051F /* SkMovie_gif.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SkMovie_gif.cpp; path = ../../src/images/SkMovie_gif.cpp; sourceTree = SOURCE_ROOT; };
 		00A729630FD93ED600D5051F /* SampleTestGL.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleTestGL.cpp; path = ../../samplecode/SampleTestGL.cpp; sourceTree = SOURCE_ROOT; };
+		00AF9B17103CD5EB00CBBCB3 /* SampleDitherBitmap.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleDitherBitmap.cpp; path = ../../samplecode/SampleDitherBitmap.cpp; sourceTree = SOURCE_ROOT; };
 		00C55DA00F8552DC000CAC09 /* SampleGradients.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleGradients.cpp; path = ../../samplecode/SampleGradients.cpp; sourceTree = SOURCE_ROOT; };
 		00D6B5CB0F72DC4300C466B9 /* SampleFuzz.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleFuzz.cpp; path = ../../samplecode/SampleFuzz.cpp; sourceTree = SOURCE_ROOT; };
 		00FF39130FC6ED2C00915187 /* SampleEffects.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleEffects.cpp; path = ../../samplecode/SampleEffects.cpp; sourceTree = SOURCE_ROOT; };
@@ -277,6 +279,7 @@
 				0041CE250F00A12400695E8C /* SampleEmboss.cpp */,
 				0041CE260F00A12400695E8C /* SampleEncode.cpp */,
 				0041CE270F00A12400695E8C /* SampleFillType.cpp */,
+				00AF9B17103CD5EB00CBBCB3 /* SampleDitherBitmap.cpp */,
 				0041CE280F00A12400695E8C /* SampleFilter.cpp */,
 				0041CE290F00A12400695E8C /* SampleFilter2.cpp */,
 				0041CE2A0F00A12400695E8C /* SampleFontCache.cpp */,
@@ -568,13 +571,14 @@
 				00AF787E0FE94433007F9650 /* SamplePath.cpp in Sources */,
 				0088C1160FEC311C00CE52F5 /* SampleXfermodes.cpp in Sources */,
 				005E92DC0FF08507008965B9 /* SampleFilter2.cpp in Sources */,
-				005E92DE0FF0850E008965B9 /* SampleFillType.cpp in Sources */,
 				005E92E00FF08512008965B9 /* SampleFilter.cpp in Sources */,
 				0057785F0FF17CCC00582CD9 /* SampleMipMap.cpp in Sources */,
 				005778B40FF5616F00582CD9 /* SampleShapes.cpp in Sources */,
 				00F53F480FFCFC4D003FA70A /* SampleGradients.cpp in Sources */,
 				27005D16100903C100E275B6 /* SampleLines.cpp in Sources */,
 				27005D5F10095B2B00E275B6 /* SampleCircle.cpp in Sources */,
+				00C1B809103857A400FA5948 /* SampleFillType.cpp in Sources */,
+				00AF9B18103CD5EB00CBBCB3 /* SampleDitherBitmap.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};