flag to make kClipToLayer_SaveFlag the default behavior

#define SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG to get the old behavior

The goal is to remove the feature of saveLayer that allows the canvas to draw outside of the top-most layer.

R=robertphillips@google.com, scroggo@google.com

Review URL: https://codereview.chromium.org/190723004

git-svn-id: http://skia.googlecode.com/svn/trunk@13730 2bbb7eff-a529-9590-31e7-b0007b416f81

expectations/gm/ignored-tests.txt

@@ -46,3 +46,9 @@ rrect_effect
 bezier_quad_effects
 bezier_conic_effects
 bezier_cubic_effects
+
+# reed: https://codereview.chromium.org/190723004/
+# This change removes an API that this GM was testing. If/when it lands and sticks,
+# I will likely just delete the GM.
+canvas-layer-state
+

gm/canvasstate.cpp

@@ -132,6 +132,7 @@ protected:
         // clear the canvas to red
         canvas->drawColor(SK_ColorRED);
 
+#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
         // both rects should appear
         drawTestPattern(canvas, 255, SkCanvas::kARGB_NoClipLayer_SaveFlag);
 
@@ -144,6 +145,7 @@ protected:
 
         // only the bottom rect should appear
         drawTestPattern(canvas, 0, SkCanvas::kARGB_NoClipLayer_SaveFlag);
+#endif
     }
 
     virtual uint32_t onGetFlags() const SK_OVERRIDE { return kSkipGPU_Flag; }

include/core/SkCanvas.h

@@ -18,6 +18,10 @@
 #include "SkRegion.h"
 #include "SkXfermode.h"
 
+// if not defined, we always assume ClipToLayer for saveLayer()
+//#define SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
+
+
 //#define SK_SUPPORT_LEGACY_WRITEPIXELSCONFIG
 //#define SK_SUPPORT_LEGACY_GETCLIPTYPE
 //#define SK_SUPPORT_LEGACY_GETTOTALCLIP
@@ -325,12 +329,18 @@ public:
         kHasAlphaLayer_SaveFlag     = 0x04,
         /** the layer needs to support 8-bits per color component */
         kFullColorLayer_SaveFlag    = 0x08,
-        /** the layer should clip against the bounds argument */
+        /**
+         *  the layer should clip against the bounds argument
+         *
+         *  if SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG is undefined, this is treated as always on.
+         */
         kClipToLayer_SaveFlag       = 0x10,
 
         // helper masks for common choices
         kMatrixClip_SaveFlag        = 0x03,
+#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
         kARGB_NoClipLayer_SaveFlag  = 0x0F,
+#endif
         kARGB_ClipLayer_SaveFlag    = 0x1F
     };
 

src/core/SkCanvas.cpp

@@ -812,7 +812,11 @@ int SkCanvas::save(SaveFlags flags) {
 }
 
 static bool bounds_affects_clip(SkCanvas::SaveFlags flags) {
+#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     return (flags & SkCanvas::kClipToLayer_SaveFlag) != 0;
+#else
+    return true;
+#endif
 }
 
 bool SkCanvas::clipRectBounds(const SkRect* bounds, SaveFlags flags,
@@ -872,6 +876,10 @@ static SkBaseDevice* createCompatibleDevice(SkCanvas* canvas,
 
 int SkCanvas::internalSaveLayer(const SkRect* bounds, const SkPaint* paint,
                                 SaveFlags flags, bool justForImageFilter) {
+#ifndef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
+    flags = (SaveFlags)(flags | kClipToLayer_SaveFlag);
+#endif
+
     // do this before we create the layer. We don't call the public save() since
     // that would invoke a possibly overridden virtual
     int count = this->internalSave(flags);

tests/CanvasStateTest.cpp

@@ -16,6 +16,7 @@
 #include "Test.h"
 
 static void test_complex_layers(skiatest::Reporter* reporter) {
+#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     const int WIDTH = 400;
     const int HEIGHT = 400;
     const int SPACER = 10;
@@ -87,12 +88,13 @@ static void test_complex_layers(skiatest::Reporter* reporter) {
                                           bitmaps[1].getPixels(),
                                           bitmaps[0].getSize()));
     }
+#endif
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 static void test_complex_clips(skiatest::Reporter* reporter) {
-
+#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     const int WIDTH = 400;
     const int HEIGHT = 400;
     const int SPACER = 10;
@@ -175,6 +177,7 @@ static void test_complex_clips(skiatest::Reporter* reporter) {
     REPORTER_ASSERT(reporter, !memcmp(bitmaps[0].getPixels(),
                                       bitmaps[1].getPixels(),
                                       bitmaps[0].getSize()));
+#endif
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -229,6 +232,7 @@ static void test_soft_clips(skiatest::Reporter* reporter) {
 }
 
 static void test_saveLayer_clip(skiatest::Reporter* reporter) {
+#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     const int WIDTH = 100;
     const int HEIGHT = 100;
     const int LAYER_WIDTH = 50;
@@ -259,6 +263,7 @@ static void test_saveLayer_clip(skiatest::Reporter* reporter) {
     REPORTER_ASSERT(reporter, clipStackBounds.height() == LAYER_HEIGHT);
 
     canvas.restore();
+#endif
 }
 
 DEF_TEST(CanvasState, reporter) {