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);
+