add sample for gradients



git-svn-id: http://skia.googlecode.com/svn/trunk@144 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleGradients.cpp b/samplecode/SampleGradients.cpp
new file mode 100644
index 0000000..c80d653
--- /dev/null
+++ b/samplecode/SampleGradients.cpp
@@ -0,0 +1,114 @@
+#include "SampleCode.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkGradientShader.h"
+
+struct GradData {
+    int             fCount;
+    const SkColor*  fColors;
+    const SkScalar* fPos;
+};
+
+static const SkColor gColors[] = {
+    SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorWHITE, SK_ColorBLACK
+};
+static const SkScalar gPos0[] = { 0, SK_Scalar1 };
+static const SkScalar gPos1[] = { SK_Scalar1/4, SK_Scalar1*3/4 };
+static const SkScalar gPos2[] = {
+    0, SK_Scalar1/8, SK_Scalar1/2, SK_Scalar1*7/8, SK_Scalar1
+};
+
+static const GradData gGradData[] = {
+    { 2, gColors, NULL },
+    { 2, gColors, gPos0 },
+    { 2, gColors, gPos1 },
+    { 5, gColors, NULL },
+    { 5, gColors, gPos2 }
+};
+
+static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data,
+                            SkShader::TileMode tm, SkUnitMapper* mapper) {
+    return SkGradientShader::CreateLinear(pts, data.fColors, data.fPos,
+                                          data.fCount, tm, mapper);
+}
+                                          
+static SkShader* MakeRadial(const SkPoint pts[2], const GradData& data,
+                            SkShader::TileMode tm, SkUnitMapper* mapper) {
+    SkPoint center;
+    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
+               SkScalarAve(pts[0].fY, pts[1].fY));
+    return SkGradientShader::CreateRadial(center, center.fX, data.fColors,
+                                          data.fPos, data.fCount, tm, mapper);
+}
+
+static SkShader* MakeSweep(const SkPoint pts[2], const GradData& data,
+                           SkShader::TileMode tm, SkUnitMapper* mapper) {
+    SkPoint center;
+    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
+               SkScalarAve(pts[0].fY, pts[1].fY));
+    return SkGradientShader::CreateSweep(center.fX, center.fY, data.fColors,
+                                         data.fPos, data.fCount, mapper);
+}
+
+typedef SkShader* (*GradMaker)(const SkPoint pts[2], const GradData& data,
+                     SkShader::TileMode tm, SkUnitMapper* mapper);
+static const GradMaker gGradMakers[] = {
+    MakeLinear, MakeRadial, MakeSweep
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+class GradientsView : public SkView {
+public:
+	GradientsView() {}
+    
+protected:
+    // overrides from SkEventSink
+    virtual bool onQuery(SkEvent* evt) {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "Gradients");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+
+    void drawBG(SkCanvas* canvas) {
+        canvas->drawColor(0xFFDDDDDD);
+    }
+    
+    virtual void onDraw(SkCanvas* canvas) {
+        this->drawBG(canvas);
+        
+        SkPoint pts[2] = {
+            { 0, 0 },
+            { SkIntToScalar(100), SkIntToScalar(100) }
+        };
+        SkShader::TileMode tm = SkShader::kClamp_TileMode;
+        SkRect r = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        
+        canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
+        for (size_t i = 0; i < SK_ARRAY_COUNT(gGradData); i++) {
+            canvas->save();
+            for (size_t j = 0; j < SK_ARRAY_COUNT(gGradMakers); j++) {
+                SkShader* shader = gGradMakers[j](pts, gGradData[i], tm, NULL);
+                paint.setShader(shader);
+                canvas->drawRect(r, paint);
+                shader->unref();
+                canvas->translate(0, SkIntToScalar(120));
+            }
+            canvas->restore();
+            canvas->translate(SkIntToScalar(120), 0);
+        }
+    }
+    
+private:
+    typedef SkView INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new GradientsView; }
+static SkViewRegister reg(MyFactory);
+
diff --git a/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj b/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj
index 24777c7..7eea0ed 100644
--- a/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj
+++ b/xcode/sampleapp/SampleApp.xcodeproj/project.pbxproj
@@ -68,6 +68,7 @@
 		008C4D980F77DAEE0056981C /* SampleHairline.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 008C4D970F77DAEE0056981C /* SampleHairline.cpp */; };
 		009CC9190F65918A002185BE /* SampleFontScalerTest.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 009CC9180F65918A002185BE /* SampleFontScalerTest.cpp */; };
 		00A41E4B0EFC312F00C9CBEB /* SampleArc.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00A41E4A0EFC312F00C9CBEB /* SampleArc.cpp */; };
+		00C55DA10F8552DC000CAC09 /* SampleGradients.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 00C55DA00F8552DC000CAC09 /* SampleGradients.cpp */; };
 		0156F80407C56A3000C6122B /* Foundation.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 0156F80307C56A3000C6122B /* Foundation.framework */; };
 		01FC44D507BD3BB800D228F4 /* Quartz.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 01FC44D407BD3BB800D228F4 /* Quartz.framework */; };
 		8D0C4E8D0486CD37000505A6 /* InfoPlist.strings in Resources */ = {isa = PBXBuildFile; fileRef = 0867D6AAFE840B52C02AAC07 /* InfoPlist.strings */; };
@@ -183,6 +184,7 @@
 		008C4D970F77DAEE0056981C /* SampleHairline.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleHairline.cpp; path = ../../samplecode/SampleHairline.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; };
 		00A41E4A0EFC312F00C9CBEB /* SampleArc.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SampleArc.cpp; path = ../../samplecode/SampleArc.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; };
 		0156F80307C56A3000C6122B /* Foundation.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Foundation.framework; path = /System/Library/Frameworks/Foundation.framework; sourceTree = "<absolute>"; };
 		01FC44D407BD3BB800D228F4 /* Quartz.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Quartz.framework; path = /System/Library/Frameworks/Quartz.framework; sourceTree = "<absolute>"; };
@@ -218,6 +220,7 @@
 			children = (
 				007A7CA40F01658C00A2D6EE /* SamplePicture.cpp */,
 				00D6B5CB0F72DC4300C466B9 /* SampleFuzz.cpp */,
+				00C55DA00F8552DC000CAC09 /* SampleGradients.cpp */,
 				009CC9180F65918A002185BE /* SampleFontScalerTest.cpp */,
 				007A7CA50F01658C00A2D6EE /* SamplePoints.cpp */,
 				007A7CA70F01658C00A2D6EE /* SampleRegion.cpp */,
@@ -519,6 +522,7 @@
 				007A7CB30F01658C00A2D6EE /* SamplePicture.cpp in Sources */,
 				0041CE440F00A12400695E8C /* SampleLines.cpp in Sources */,
 				008C4D980F77DAEE0056981C /* SampleHairline.cpp in Sources */,
+				00C55DA10F8552DC000CAC09 /* SampleGradients.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};