Add convex polygon rendering effect and GM to test it.
BUG=skia:2051
R=robertphillips@google.com, jvanverth@google.com
Author: bsalomon@google.com
Review URL: https://codereview.chromium.org/149683004
git-svn-id: http://skia.googlecode.com/svn/trunk@13242 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/convexpolyeffect.cpp b/gm/convexpolyeffect.cpp
new file mode 100644
index 0000000..f438a08
--- /dev/null
+++ b/gm/convexpolyeffect.cpp
@@ -0,0 +1,172 @@
+
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+// This test only works with the GPU backend.
+
+#include "gm.h"
+
+#if SK_SUPPORT_GPU
+
+#include "GrContext.h"
+#include "GrPathUtils.h"
+#include "GrTest.h"
+#include "SkColorPriv.h"
+#include "SkDevice.h"
+#include "SkGeometry.h"
+#include "SkTLList.h"
+
+#include "effects/GrConvexPolyEffect.h"
+
+namespace {
+extern const GrVertexAttrib kAttribs[] = {
+ {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
+};
+}
+
+namespace skiagm {
+/**
+ * This GM directly exercises a GrEffect that draws convex polygons.
+ */
+class ConvexPolyEffect : public GM {
+public:
+ ConvexPolyEffect() {
+ this->setBGColor(0xFFFFFFFF);
+ }
+
+protected:
+ virtual SkString onShortName() SK_OVERRIDE {
+ return SkString("convex_poly_effect");
+ }
+
+ virtual SkISize onISize() SK_OVERRIDE {
+ return make_isize(475, 530);
+ }
+
+ virtual uint32_t onGetFlags() const SK_OVERRIDE {
+ // This is a GPU-specific GM.
+ return kGPUOnly_Flag;
+ }
+
+ virtual void onOnceBeforeDraw() SK_OVERRIDE {
+ SkPath tri;
+ tri.moveTo(5.f, 5.f);
+ tri.lineTo(100.f, 20.f);
+ tri.lineTo(15.f, 100.f);
+
+ fPaths.addToTail(tri);
+ fPaths.addToTail(SkPath())->reverseAddPath(tri);
+
+ tri.close();
+ fPaths.addToTail(tri);
+
+ SkPath ngon;
+ static const SkScalar kRadius = 50.f;
+ const SkPoint center = { kRadius, kRadius };
+ for (int i = 0; i < GrConvexPolyEffect::kMaxEdges; ++i) {
+ SkScalar angle = 2 * SK_ScalarPI * i / GrConvexPolyEffect::kMaxEdges;
+ SkPoint point;
+ point.fY = SkScalarSinCos(angle, &point.fX);
+ point.scale(kRadius);
+ point = center + point;
+ if (0 == i) {
+ ngon.moveTo(point);
+ } else {
+ ngon.lineTo(point);
+ }
+ }
+
+ fPaths.addToTail(ngon);
+ SkMatrix scaleM;
+ scaleM.setScale(1.1f, 0.4f);
+ ngon.transform(scaleM);
+ fPaths.addToTail(ngon);
+ }
+
+ virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+ SkBaseDevice* device = canvas->getTopDevice();
+ GrRenderTarget* rt = device->accessRenderTarget();
+ if (NULL == rt) {
+ return;
+ }
+ GrContext* context = rt->getContext();
+ if (NULL == context) {
+ return;
+ }
+
+ const SkPath* path;
+ SkScalar y = 0;
+ for (SkTLList<SkPath>::Iter iter(fPaths, SkTLList<SkPath>::Iter::kHead_IterStart);
+ NULL != (path = iter.get());
+ iter.next()) {
+ SkScalar x = 0;
+
+ for (int et = 0; et < GrConvexPolyEffect::kEdgeTypeCnt; ++et) {
+ GrTestTarget tt;
+ context->getTestTarget(&tt);
+ if (NULL == tt.target()) {
+ SkDEBUGFAIL("Couldn't get Gr test target.");
+ return;
+ }
+ GrDrawState* drawState = tt.target()->drawState();
+ drawState->setVertexAttribs<kAttribs>(SK_ARRAY_COUNT(kAttribs));
+
+ SkMatrix m;
+ SkPath p;
+ m.setTranslate(x, y);
+ path->transform(m, &p);
+
+ GrConvexPolyEffect::EdgeType edgeType = (GrConvexPolyEffect::EdgeType) et;
+ SkAutoTUnref<GrEffectRef> effect(GrConvexPolyEffect::Create(edgeType, p));
+ if (!effect) {
+ SkDEBUGFAIL("Couldn't create convex poly effect.");
+ return;
+ }
+ drawState->addCoverageEffect(effect, 1);
+ drawState->setIdentityViewMatrix();
+ drawState->setRenderTarget(rt);
+ drawState->setColor(0xff000000);
+
+ SkPoint verts[4];
+ SkRect bounds = p.getBounds();
+ // Make sure any artifacts around the exterior of path are visible by using overly
+ // conservative bounding geometry.
+ bounds.outset(5.f, 5.f);
+ bounds.toQuad(verts);
+
+ tt.target()->setVertexSourceToArray(verts, 4);
+ tt.target()->setIndexSourceToBuffer(context->getQuadIndexBuffer());
+ tt.target()->drawIndexed(kTriangleFan_GrPrimitiveType, 0, 0, 4, 6);
+
+ x += path->getBounds().width() + 10.f;
+ }
+
+ // Draw AA and non AA paths using normal API for reference.
+ canvas->save();
+ canvas->translate(x, y);
+ SkPaint paint;
+ canvas->drawPath(*path, paint);
+ canvas->translate(path->getBounds().width() + 10.f, 0);
+ paint.setAntiAlias(true);
+ canvas->drawPath(*path, paint);
+ canvas->restore();
+
+ y += path->getBounds().height() + 20.f;
+ }
+ }
+
+private:
+ SkTLList<SkPath> fPaths;
+
+ typedef GM INHERITED;
+};
+
+DEF_GM( return SkNEW(ConvexPolyEffect); )
+
+}
+
+#endif