add tests for extractAlpha

git-svn-id: http://skia.googlecode.com/svn/trunk@346 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 97 insertions, 0 deletions

diff --git a/samplecode/SampleExtractAlpha.cpp b/samplecode/SampleExtractAlpha.cpp
new file mode 100644
index 0000000000..37c49a0968
--- /dev/null
+++ b/samplecode/SampleExtractAlpha.cpp
@@ -0,0 +1,93 @@
+#include "SampleCode.h"
+#include "SkColorPriv.h"
+#include "SkGradientShader.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkUtils.h"
+
+static SkBitmap make_bitmap() {
+    SkBitmap bm;
+    SkColorTable* ctable = new SkColorTable(256);
+
+    SkPMColor* c = ctable->lockColors();
+    for (int i = 0; i < 256; i++) {
+        c[i] = SkPackARGB32(255 - i, 0, 0, 0);
+    }
+    ctable->unlockColors(true);
+    bm.setConfig(SkBitmap::kIndex8_Config, 256, 256);
+    bm.allocPixels(ctable);
+    ctable->unref();
+
+    bm.lockPixels();
+    const float cx = bm.width() * 0.5f;
+    const float cy = bm.height() * 0.5f;
+    for (int y = 0; y < bm.height(); y++) {
+        float dy = y - cy;
+        dy *= dy;
+        uint8_t* p = bm.getAddr8(0, y);
+        for (int x = 0; x < 256; x++) {
+            float dx = x - cx;
+            dx *= dx;
+            float d = (dx + dy) / (cx/2);
+            int id = (int)d;
+            if (id > 255) {
+                id = 255;
+            }
+            p[x] = id;
+        }
+    }
+    bm.unlockPixels();
+    return bm;
+}
+
+class ExtractAlphaView : public SkView {
+    SkBitmap    fBM8;
+    SkBitmap    fBM32;
+    SkBitmap    fBM4;
+public:
+	ExtractAlphaView() {
+        fBM8 = make_bitmap();
+        fBM8.copyTo(&fBM32, SkBitmap::kARGB_8888_Config);
+        fBM8.copyTo(&fBM4, SkBitmap::kARGB_4444_Config);
+    }
+    
+protected:
+    // overrides from SkEventSink
+    virtual bool onQuery(SkEvent* evt) {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "DitherBitmap");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+    
+    void drawBG(SkCanvas* canvas) {
+        canvas->drawColor(0xFFDDDDDD);
+    }
+    
+    virtual void onDraw(SkCanvas* canvas) {
+        drawBG(canvas);
+        
+        const SkBitmap* srcBM[] = { &fBM8, &fBM32, &fBM4 };
+        
+        SkPaint paint;
+        paint.setColor(SK_ColorRED);
+        for (int i = 0; i < 3; i++) {
+            canvas->drawBitmap(*srcBM[i], 0, 0, &paint);
+            SkBitmap tmp;
+            srcBM[i]->extractAlpha(&tmp);
+            canvas->drawBitmap(tmp, 0, SkIntToScalar(tmp.height() + 10), &paint);
+            
+            canvas->translate(SkIntToScalar(tmp.width() + 10), 0);
+        }
+    }
+    
+private:
+    typedef SkView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new ExtractAlphaView; }
+static SkViewRegister reg(MyFactory);
+
diff --git a/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj b/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj
index ad9053dedd..50aee209ca 100644
--- a/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj
+++ b/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj
@@ -62,6 +62,7 @@
 		007A7CBF0F01658C00A2D6EE /* SampleTypeface.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 007A7CB00F01658C00A2D6EE /* SampleTypeface.cpp */; };
 		007A7CC00F01658C00A2D6EE /* SampleVertices.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 007A7CB10F01658C00A2D6EE /* SampleVertices.cpp */; };
 		007C785E0F3B4C230004B142 /* SamplePathClip.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 007C785D0F3B4C230004B142 /* SamplePathClip.cpp */; };
+		00840B75104C69F5005B3EDC /* SampleExtractAlpha.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00840B74104C69F5005B3EDC /* SampleExtractAlpha.cpp */; };
 		0088C1160FEC311C00CE52F5 /* SampleXfermodes.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 007A7CB20F01658C00A2D6EE /* SampleXfermodes.cpp */; };
 		008C4D980F77DAEE0056981C /* SampleHairline.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 008C4D970F77DAEE0056981C /* SampleHairline.cpp */; };
 		009490320FB0A5B90063C792 /* SampleLayerMask.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 009490310FB0A5B90063C792 /* SampleLayerMask.cpp */; };
@@ -195,6 +196,7 @@
 		007A7CB10F01658C00A2D6EE /* SampleVertices.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleVertices.cpp; path = ../../samplecode/SampleVertices.cpp; sourceTree = SOURCE_ROOT; };
 		007A7CB20F01658C00A2D6EE /* SampleXfermodes.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleXfermodes.cpp; path = ../../samplecode/SampleXfermodes.cpp; sourceTree = SOURCE_ROOT; };
 		007C785D0F3B4C230004B142 /* SamplePathClip.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SamplePathClip.cpp; path = ../../samplecode/SamplePathClip.cpp; sourceTree = SOURCE_ROOT; };
+		00840B74104C69F5005B3EDC /* SampleExtractAlpha.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleExtractAlpha.cpp; path = ../../samplecode/SampleExtractAlpha.cpp; sourceTree = SOURCE_ROOT; };
 		008C4D970F77DAEE0056981C /* SampleHairline.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleHairline.cpp; path = ../../samplecode/SampleHairline.cpp; sourceTree = SOURCE_ROOT; };
 		009490310FB0A5B90063C792 /* SampleLayerMask.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleLayerMask.cpp; path = ../../samplecode/SampleLayerMask.cpp; sourceTree = SOURCE_ROOT; };
 		009CC9180F65918A002185BE /* SampleFontScalerTest.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleFontScalerTest.cpp; path = ../../samplecode/SampleFontScalerTest.cpp; sourceTree = SOURCE_ROOT; };
@@ -286,6 +288,7 @@
 				0041CE260F00A12400695E8C /* SampleEncode.cpp */,
 				0041CE270F00A12400695E8C /* SampleFillType.cpp */,
 				00AF9B17103CD5EB00CBBCB3 /* SampleDitherBitmap.cpp */,
+				00840B74104C69F5005B3EDC /* SampleExtractAlpha.cpp */,
 				0041CE280F00A12400695E8C /* SampleFilter.cpp */,
 				0041CE290F00A12400695E8C /* SampleFilter2.cpp */,
 				0041CE2A0F00A12400695E8C /* SampleFontCache.cpp */,
@@ -591,6 +594,7 @@
 				001B871E1042184D00C84ED4 /* Forth.cpp in Sources */,
 				00BB289B104781D00057BF7E /* SampleForth.cpp in Sources */,
 				00ED55F3104A10EB00F51FF8 /* StdWords.cpp in Sources */,
+				00840B75104C69F5005B3EDC /* SampleExtractAlpha.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};