SkPaintFilterCanvas should inherit the target canvas state
Currently, SkPaintFilterCanvas does not provide any help in cloning
target canvas state. While that could be handled in subclasses, it is
easy to miss (see linked bug).
This CL adds a new constructor variant which ensures that the initial
matrix and clip bounds are inherited from the target canvas.
BUG=516790
R=reed@google.com,robertphillips@google.com
Review URL: https://codereview.chromium.org/1294013002
diff --git a/tests/CanvasTest.cpp b/tests/CanvasTest.cpp
index 0d5c862..5aa3d46 100644
--- a/tests/CanvasTest.cpp
+++ b/tests/CanvasTest.cpp
@@ -52,6 +52,7 @@
#include "SkMatrix.h"
#include "SkNWayCanvas.h"
#include "SkPaint.h"
+#include "SkPaintFilterCanvas.h"
#include "SkPath.h"
#include "SkPicture.h"
#include "SkPictureRecord.h"
@@ -782,3 +783,38 @@
canvas.clipPath(path); // should not assert here
canvas.restore();
}
+
+namespace {
+
+class MockFilterCanvas : public SkPaintFilterCanvas {
+public:
+ MockFilterCanvas(SkCanvas* canvas) : INHERITED(canvas) { }
+
+protected:
+ void onFilterPaint(SkPaint *paint, Type type) const override { }
+
+private:
+ typedef SkPaintFilterCanvas INHERITED;
+};
+
+} // anonymous namespace
+
+// SkPaintFilterCanvas should inherit the initial target canvas state.
+DEF_TEST(PaintFilterCanvas_ConsistentState, reporter) {
+ SkCanvas canvas(100, 100);
+ canvas.clipRect(SkRect::MakeXYWH(12.7f, 12.7f, 75, 75));
+ canvas.scale(0.5f, 0.75f);
+
+ SkRect clip1, clip2;
+
+ MockFilterCanvas filterCanvas(&canvas);
+ REPORTER_ASSERT(reporter, canvas.getTotalMatrix() == filterCanvas.getTotalMatrix());
+ REPORTER_ASSERT(reporter, canvas.getClipBounds(&clip1) == filterCanvas.getClipBounds(&clip2));
+ REPORTER_ASSERT(reporter, clip1 == clip2);
+
+ filterCanvas.clipRect(SkRect::MakeXYWH(30.5f, 30.7f, 100, 100));
+ filterCanvas.scale(0.75f, 0.5f);
+ REPORTER_ASSERT(reporter, canvas.getTotalMatrix() == filterCanvas.getTotalMatrix());
+ REPORTER_ASSERT(reporter, canvas.getClipBounds(&clip1) == filterCanvas.getClipBounds(&clip2));
+ REPORTER_ASSERT(reporter, clip1 == clip2);
+}