Add new GM to directly exercise perspective bitmap drawing
BUG=skia:3326
Review URL: https://codereview.chromium.org/1309543012
diff --git a/gm/perspshaders.cpp b/gm/perspshaders.cpp
new file mode 100644
index 0000000..07a41e9
--- /dev/null
+++ b/gm/perspshaders.cpp
@@ -0,0 +1,184 @@
+/*
+ * Copyright 2015 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 "SkGradientShader.h"
+#include "SkImage.h"
+#include "SkPath.h"
+#include "SkSurface.h"
+
+static SkImage* make_image(SkCanvas* origCanvas, int w, int h) {
+ SkImageInfo info = SkImageInfo::MakeN32Premul(w, h);
+ SkAutoTUnref<SkSurface> surface(origCanvas->newSurface(info));
+ if (nullptr == surface) {
+ surface.reset(SkSurface::NewRaster(info));
+ }
+ SkCanvas* canvas = surface->getCanvas();
+
+ sk_tool_utils::draw_checkerboard(canvas, SK_ColorRED, SK_ColorGREEN, w/10);
+ return surface->newImageSnapshot();
+}
+
+static SkBitmap make_bitmap(int w, int h) {
+ SkBitmap bitmap;
+ bitmap.allocN32Pixels(w, h);
+ SkCanvas canvas(bitmap);
+
+ sk_tool_utils::draw_checkerboard(&canvas, SK_ColorBLUE, SK_ColorYELLOW, w/10);
+ return bitmap;
+}
+
+namespace skiagm {
+
+class PerspShadersGM : public GM {
+public:
+ PerspShadersGM(bool doAA) : fDoAA(doAA) { }
+
+protected:
+ SkString onShortName() override {
+ SkString name;
+ name.printf("persp_shaders_%s",
+ fDoAA ? "aa" : "bw");
+ return name;
+ }
+
+ SkISize onISize() override {
+ return SkISize::Make(kCellSize*kNumCols, kCellSize*kNumRows);
+ }
+
+ void onOnceBeforeDraw() override {
+ fBitmap = make_bitmap(kCellSize, kCellSize);
+
+ fBitmapShader.reset(SkShader::CreateBitmapShader(fBitmap,
+ SkShader::kClamp_TileMode,
+ SkShader::kClamp_TileMode));
+ SkPoint pts1[] = {
+ { 0, 0 },
+ { SkIntToScalar(kCellSize), SkIntToScalar(kCellSize) }
+ };
+ SkPoint pts2[] = {
+ { 0, 0 },
+ { 0, SkIntToScalar(kCellSize) }
+ };
+ static const SkColor colors[] = {
+ SK_ColorRED, SK_ColorGREEN, SK_ColorRED, SK_ColorGREEN, SK_ColorRED
+ };
+ static const SkScalar pos[] = { 0, 0.25f, 0.5f, 0.75f, SK_Scalar1 };
+
+ fLinearGrad1.reset(SkGradientShader::CreateLinear(pts1, colors, pos,
+ SK_ARRAY_COUNT(colors),
+ SkShader::kClamp_TileMode));
+ fLinearGrad2.reset(SkGradientShader::CreateLinear(pts2, colors, pos,
+ SK_ARRAY_COUNT(colors),
+ SkShader::kClamp_TileMode));
+
+ fPerspMatrix.reset();
+ fPerspMatrix.setPerspY(SK_Scalar1 / 50);
+
+ fPath.moveTo(0, 0);
+ fPath.lineTo(0, SkIntToScalar(kCellSize));
+ fPath.lineTo(kCellSize/2.0f, kCellSize/2.0f);
+ fPath.lineTo(SkIntToScalar(kCellSize), SkIntToScalar(kCellSize));
+ fPath.lineTo(SkIntToScalar(kCellSize), 0);
+ fPath.close();
+ }
+
+ void drawRow(SkCanvas* canvas, SkFilterQuality filterQ) {
+ SkPaint filterPaint;
+ filterPaint.setFilterQuality(filterQ);
+ filterPaint.setAntiAlias(fDoAA);
+
+ SkPaint pathPaint;
+ pathPaint.setShader(fBitmapShader);
+ pathPaint.setFilterQuality(filterQ);
+ pathPaint.setAntiAlias(fDoAA);
+
+ SkPaint gradPaint1;
+ gradPaint1.setShader(fLinearGrad1);
+ gradPaint1.setAntiAlias(fDoAA);
+ SkPaint gradPaint2;
+ gradPaint2.setShader(fLinearGrad2);
+ gradPaint2.setAntiAlias(fDoAA);
+
+ SkRect r = SkRect::MakeWH(SkIntToScalar(kCellSize), SkIntToScalar(kCellSize));
+
+ canvas->save();
+
+ canvas->save();
+ canvas->concat(fPerspMatrix);
+ canvas->drawBitmapRect(fBitmap, r, &filterPaint);
+ canvas->restore();
+
+ canvas->translate(SkIntToScalar(kCellSize), 0);
+ canvas->save();
+ canvas->concat(fPerspMatrix);
+ canvas->drawImage(fImage, 0, 0, &filterPaint);
+ canvas->restore();
+
+ canvas->translate(SkIntToScalar(kCellSize), 0);
+ canvas->save();
+ canvas->concat(fPerspMatrix);
+ canvas->drawRect(r, pathPaint);
+ canvas->restore();
+
+ canvas->translate(SkIntToScalar(kCellSize), 0);
+ canvas->save();
+ canvas->concat(fPerspMatrix);
+ canvas->drawPath(fPath, pathPaint);
+ canvas->restore();
+
+ canvas->translate(SkIntToScalar(kCellSize), 0);
+ canvas->save();
+ canvas->concat(fPerspMatrix);
+ canvas->drawRect(r, gradPaint1);
+ canvas->restore();
+
+ canvas->translate(SkIntToScalar(kCellSize), 0);
+ canvas->save();
+ canvas->concat(fPerspMatrix);
+ canvas->drawPath(fPath, gradPaint2);
+ canvas->restore();
+
+ canvas->restore();
+ }
+
+ void onDraw(SkCanvas* canvas) override {
+ if (!fImage) {
+ fImage.reset(make_image(canvas, kCellSize, kCellSize));
+ }
+
+ this->drawRow(canvas, kNone_SkFilterQuality);
+ canvas->translate(0, SkIntToScalar(kCellSize));
+ this->drawRow(canvas, kLow_SkFilterQuality);
+ canvas->translate(0, SkIntToScalar(kCellSize));
+ this->drawRow(canvas, kMedium_SkFilterQuality);
+ canvas->translate(0, SkIntToScalar(kCellSize));
+ this->drawRow(canvas, kHigh_SkFilterQuality);
+ canvas->translate(0, SkIntToScalar(kCellSize));
+ }
+private:
+ static const int kCellSize = 50;
+ static const int kNumRows = 4;
+ static const int kNumCols = 6;
+
+ bool fDoAA;
+ SkPath fPath;
+ SkAutoTUnref<SkShader> fBitmapShader;
+ SkAutoTUnref<SkShader> fLinearGrad1;
+ SkAutoTUnref<SkShader> fLinearGrad2;
+ SkMatrix fPerspMatrix;
+ SkAutoTUnref<SkImage> fImage;
+ SkBitmap fBitmap;
+
+ typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new PerspShadersGM(true);)
+DEF_GM(return new PerspShadersGM(false);)
+}