test dont-clip-layer
depends on fix from https://codereview.chromium.org/2309623002/
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2296703003
Review-Url: https://codereview.chromium.org/2296703003
diff --git a/gm/aaclip.cpp b/gm/aaclip.cpp
index 1cb7157..9b341d3 100644
--- a/gm/aaclip.cpp
+++ b/gm/aaclip.cpp
@@ -9,6 +9,47 @@
#include "SkCanvas.h"
#include "SkPath.h"
+static void do_draw(SkCanvas* canvas, const SkRect& r) {
+ SkPaint paint;
+ paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+ paint.setColor(0x800000FF);
+ canvas->drawRect(r, paint);
+}
+
+/**
+ * Exercise kDontClipToLayer_Legacy_SaveLayerFlag flag, which does not limit the clip to the
+ * layer's bounds. Thus when a draw occurs, it can (depending on "where" it is) draw into the layer
+ * and/or draw onto the surrounding portions of the canvas, or both.
+ *
+ * This GM has a 100x100 rectangle (r), which its going to draw. However first it creates a layer
+ * with this flag covering 1/2 of the rectangle (upper half). Then it draws the rect in SRC mode.
+ *
+ * The portion of the draw that intersects the layer should see the SRC draw, apply it to the layer
+ * and then during restore, it will SRC_OVER that layer onto the canvas (SRC_OVER since the layer
+ * has no paint, so it gets the default xfermode during restore).
+ *
+ * The portion of the draw below the layer draws directly into the canvas. Since it is in SRC mode,
+ * it will wrote 0x80 to the canvas' alpha, making it appear darker when shown in the window.
+ * The portion in the layer, will end up SRC_OVERing the 0x80 layer pixels onto the canvas, so
+ * they will appear lighter (since the canvas was erased to white initially).
+ *
+ * Thus the expected result is the upper half to be light-blue w/ 0xFF for its alpha, and
+ * the lower half to be darker blue with 0x80 for its alpha.
+ */
+DEF_SIMPLE_GM(dont_clip_to_layer, canvas, 120, 120) {
+ SkRect r { 10, 10, 110, 110 };
+ SkRect r0 = SkRect::MakeXYWH(r.left(), r.top(), r.width(), r.height()/2);
+
+ SkCanvas::SaveLayerRec rec;
+ rec.fPaint = nullptr;
+ rec.fBounds = &r0;
+ rec.fBackdrop = nullptr;
+ rec.fSaveLayerFlags = 1 << 31;//SkCanvas::kDontClipToLayer_Legacy_SaveLayerFlag;
+ canvas->saveLayer(rec);
+ do_draw(canvas, r);
+ canvas->restore();
+}
+
/** Draw a 2px border around the target, then red behind the target;
set the clip to match the target, then draw >> the target in blue.
*/