Add path effect GM

Review URL: http://codereview.appspot.com/5649069/



git-svn-id: http://skia.googlecode.com/svn/trunk@3172 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 160 insertions, 0 deletions

diff --git a/gm/patheffects.cpp b/gm/patheffects.cpp
new file mode 100644
index 0000000000..c60611651f
--- /dev/null
+++ b/gm/patheffects.cpp
@@ -0,0 +1,160 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "gm.h"
+#include "SkCanvas.h"
+#include "SkPaint.h"
+#include "Sk1DPathEffect.h"
+#include "Sk2DPathEffect.h"
+#include "SkCornerPathEffect.h"
+#include "SkDashPathEffect.h"
+#include "SkDiscretePathEffect.h"
+
+namespace skiagm {
+
+static void compose_pe(SkPaint* paint) {
+    SkPathEffect* pe = paint->getPathEffect();
+    SkPathEffect* corner = new SkCornerPathEffect(25);
+    SkPathEffect* compose;
+    if (pe) {
+        compose = new SkComposePathEffect(pe, corner);
+        corner->unref();
+    } else {
+        compose = corner;
+    }
+    paint->setPathEffect(compose)->unref();
+}
+
+static void hair_pe(SkPaint* paint) {
+    paint->setStrokeWidth(0);
+}
+
+static void hair2_pe(SkPaint* paint) {
+    paint->setStrokeWidth(0);
+    compose_pe(paint);
+}
+
+static void stroke_pe(SkPaint* paint) {
+    paint->setStrokeWidth(12);
+    compose_pe(paint);
+}
+
+static void dash_pe(SkPaint* paint) {
+    SkScalar inter[] = { 20, 10, 10, 10 };
+    paint->setStrokeWidth(12);
+    paint->setPathEffect(new SkDashPathEffect(inter, SK_ARRAY_COUNT(inter),
+                                              0))->unref();
+    compose_pe(paint);
+}
+
+static const int gXY[] = {
+4, 0, 0, -4, 8, -4, 12, 0, 8, 4, 0, 4
+};
+
+static void scale(SkPath* path, SkScalar scale) {
+    SkMatrix m;
+    m.setScale(scale, scale);
+    path->transform(m);
+}
+
+static void one_d_pe(SkPaint* paint) {
+    SkPath  path;
+    path.moveTo(SkIntToScalar(gXY[0]), SkIntToScalar(gXY[1]));
+    for (unsigned i = 2; i < SK_ARRAY_COUNT(gXY); i += 2)
+        path.lineTo(SkIntToScalar(gXY[i]), SkIntToScalar(gXY[i+1]));
+    path.close();
+    path.offset(SkIntToScalar(-6), 0);
+    scale(&path, 1.5);
+    
+    paint->setPathEffect(new SkPath1DPathEffect(path, SkIntToScalar(21), 0,
+                                SkPath1DPathEffect::kRotate_Style))->unref();
+    compose_pe(paint);
+}
+
+typedef void (*PE_Proc)(SkPaint*);
+static const PE_Proc gPE[] = { hair_pe, hair2_pe, stroke_pe, dash_pe, one_d_pe };
+
+static void fill_pe(SkPaint* paint) {
+    paint->setStyle(SkPaint::kFill_Style);
+    paint->setPathEffect(NULL);
+}
+
+static void discrete_pe(SkPaint* paint) {
+    paint->setPathEffect(new SkDiscretePathEffect(10, 4))->unref();
+}
+
+static SkPathEffect* MakeTileEffect() {
+    SkMatrix m;
+    m.setScale(SkIntToScalar(12), SkIntToScalar(12));
+
+    SkPath path;
+    path.addCircle(0, 0, SkIntToScalar(5));
+    
+    return new SkPath2DPathEffect(m, path);
+}
+
+static void tile_pe(SkPaint* paint) {
+    paint->setPathEffect(MakeTileEffect())->unref();
+}
+
+static const PE_Proc gPE2[] = { fill_pe, discrete_pe, tile_pe };
+
+class PathEffectGM : public GM {
+public:
+    PathEffectGM() {}
+
+protected:
+    SkString onShortName() {
+        return SkString("patheffect");
+    }
+
+    SkISize onISize() { return make_isize(800, 600); }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        paint.setStyle(SkPaint::kStroke_Style);
+
+        SkPath path;
+        path.moveTo(20, 20);
+        path.lineTo(70, 120);
+        path.lineTo(120, 30);
+        path.lineTo(170, 80);
+        path.lineTo(240, 50);
+
+        size_t i;
+        canvas->save();
+        for (i = 0; i < SK_ARRAY_COUNT(gPE); i++) {
+            gPE[i](&paint);
+            canvas->drawPath(path, paint);
+            canvas->translate(0, 75);
+        }
+        canvas->restore();
+
+        path.reset();
+        SkRect r = { 0, 0, 250, 120 };
+        path.addOval(r, SkPath::kCW_Direction);
+        r.inset(50, 50);
+        path.addRect(r, SkPath::kCCW_Direction);
+
+        canvas->translate(320, 20);
+        for (i = 0; i < SK_ARRAY_COUNT(gPE2); i++) {
+            gPE2[i](&paint);
+            canvas->drawPath(path, paint);
+            canvas->translate(0, 160);
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* PathEffectFactory(void*) { return new PathEffectGM; }
+static GMRegistry regPathEffect(PathEffectFactory);
+
+}