New GM: image_scale_aligned
To verify alignment for various image scaling modes.
BUG=skia:4649
R=reed@google.com
Review URL: https://codereview.chromium.org/1514923002
diff --git a/gm/imagescalealigned.cpp b/gm/imagescalealigned.cpp
new file mode 100644
index 0000000..fbcdafb
--- /dev/null
+++ b/gm/imagescalealigned.cpp
@@ -0,0 +1,153 @@
+/*
+ * 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 "SkImage.h"
+#include "SkSurface.h"
+#include "SkTArray.h"
+
+class ImageScaleAlignedGM : public skiagm::GM {
+protected:
+ void onOnceBeforeDraw() override {
+ const SkVector vectors[] = { { 1, 0 }, { 0, 1 } };
+
+ for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
+ auto& set = fSets.push_back();
+
+ set.fVector = vectors[i];
+ set.fImages.push_back().reset(MakeImage(vectors[i], SK_ColorGREEN));
+ set.fScales.push_back() = 1;
+ set.fImages.push_back().reset(MakeImage(vectors[i], SK_ColorRED));
+ set.fScales.push_back() = kStretchFactor;
+ set.fImages.push_back().reset(MakeImage(vectors[i], SK_ColorGREEN));
+ set.fScales.push_back() = 1;
+ }
+ }
+
+ SkString onShortName() override {
+ return SkString("image_scale_aligned");
+ }
+
+ SkISize onISize() override {
+ return SkISize::Make(550, 300);
+ }
+
+ void onDraw(SkCanvas* canvas) override {
+ struct {
+ SkPoint offset;
+ SkScalar scale;
+ } cfgs[] = {
+ { { 10, 10 }, 1 },
+ { { 140.5f, 10 }, 1 },
+ { { 10, 80.5f }, 1 },
+ { { 140.5f, 80.5f }, 1 },
+
+ { { 280.49f, 10.49f }, 1 },
+ { { 410.51f, 10.49f }, 1 },
+ { { 280.49f, 80.51f }, 1 },
+ { { 410.51f, 80.51f }, 1 },
+
+ { { 10, 170 }, 1.1f },
+ { { 140.5f, 170 }, 1.1f },
+ { { 10, 240.5f }, 1.1f },
+ { { 140.5f, 240.5f }, 1.1f },
+
+ { { 280.49f, 170.49f }, 1.1f },
+ { { 410.51f, 170.49f }, 1.1f },
+ { { 280.49f, 240.51f }, 1.1f },
+ { { 410.51f, 240.51f }, 1.1f },
+ };
+
+ for (size_t i = 0; i < SK_ARRAY_COUNT(cfgs); ++i) {
+ SkAutoCanvasRestore acr(canvas, true);
+ canvas->translate(cfgs[i].offset.x(), cfgs[i].offset.y());
+ canvas->scale(cfgs[i].scale, cfgs[i].scale);
+ drawSets(canvas);
+ }
+ }
+
+private:
+ struct ImageSet {
+ SkSTArray<3, SkAutoTUnref<SkImage>, true> fImages;
+ SkSTArray<3, SkScalar> fScales;
+ SkVector fVector;
+ };
+
+ static SkImage* MakeImage(const SkVector& vec, SkColor color) {
+ const SkPoint start = SkPoint::Make(vec.y() * kSegLen / 2, vec.x() * kSegLen / 2);
+ const SkPoint end = SkPoint::Make(start.x() + vec.x() * (kSegLen - 1),
+ start.y() + vec.y() * (kSegLen - 1));
+
+ SkAutoTUnref<SkSurface> surface(SkSurface::NewRasterN32Premul(kSegLen, kSegLen));
+ surface->getCanvas()->clear(SK_ColorTRANSPARENT);
+
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setColor(SK_ColorBLACK);
+ surface->getCanvas()->drawLine(start.x(), start.y(), end.x(), end.y(), paint);
+ surface->getCanvas()->drawPoint(start.x(), start.y(), color);
+ surface->getCanvas()->drawPoint(end.x(), end.y(), color);
+
+ return surface->newImageSnapshot();
+ }
+
+ void drawSets(SkCanvas* canvas) const {
+ SkAutoCanvasRestore acr(canvas, true);
+
+ const SkFilterQuality filters[] = {
+ kNone_SkFilterQuality,
+ kLow_SkFilterQuality,
+ kMedium_SkFilterQuality,
+ kHigh_SkFilterQuality
+ };
+ const bool AAs[] = { false, true };
+
+ SkPaint paint;
+ for (int i = 0; i < fSets.count(); ++i) {
+ auto& set = fSets[i];
+ SkPoint lastPt;
+ for (size_t j = 0; j < SK_ARRAY_COUNT(AAs); ++j) {
+ paint.setAntiAlias(AAs[j]);
+ for (size_t k = 0; k < SK_ARRAY_COUNT(filters); ++k) {
+ paint.setFilterQuality(filters[k]);
+ lastPt = drawSet(canvas, set, paint);
+ canvas->translate((kSegLen / 2) * set.fVector.y(),
+ (kSegLen / 2) * set.fVector.x());
+ }
+ }
+ canvas->translate(lastPt.x() + kSegLen,
+ - SkIntToScalar(kSegLen) / 2 * SK_ARRAY_COUNT(filters) * SK_ARRAY_COUNT(AAs));
+ }
+ }
+
+ SkPoint drawSet(SkCanvas* canvas, const ImageSet& set, const SkPaint& paint) const {
+ SkASSERT(set.fImages.count() == set.fScales.count());
+
+ SkPoint pt = SkPoint::Make(0, 0);
+ for (int i = 0; i < set.fImages.count(); ++i) {
+ auto& img = set.fImages[i];
+ const SkRect dst =
+ SkRect::MakeXYWH(pt.x(), pt.y(),
+ img->width() * (1 + (set.fScales[i] - 1) * set.fVector.x()),
+ img->height() * (1 + (set.fScales[i] - 1) * set.fVector.y()));
+
+ canvas->drawImageRect(img, dst, &paint);
+ pt.offset(dst.width() * set.fVector.x(), dst.height() * set.fVector.y());
+ }
+
+ return pt;
+ }
+
+ static const unsigned kSegLen = 9;
+ static const unsigned kStretchFactor = 2;
+ SkSTArray<2, ImageSet> fSets;
+
+ typedef GM INHERITED;
+};
+
+DEF_GM(return new ImageScaleAlignedGM();)