Shrink saveLayer device bounds when it supplies an explicit bounds and has a complex paint

tests/RecordDrawTest.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 #include "RecordTestUtils.h"
 
@@ skipping 119 matching lines @@
 DEF_TEST(RecordDraw_BBH, r) {
     SkRecord record;
     SkRecorder recorder(&record, W, H);
     recorder.save();
         recorder.clipRect(SkRect::MakeWH(400, 500));
         recorder.scale(2, 2);
         recorder.drawRect(SkRect::MakeWH(320, 240), SkPaint());
     recorder.restore();
 
     TestBBH bbh;
-    SkRecordFillBounds(record, &bbh);
+    SkRecordFillBounds(SkRect::MakeWH(SkIntToScalar(W), SkIntToScalar(H)), record, &bbh);
 
     REPORTER_ASSERT(r, bbh.fEntries.count() == 5);
     for (int i = 0; i < bbh.fEntries.count(); i++) {
         REPORTER_ASSERT(r, bbh.fEntries[i].opIndex == (unsigned)i);
 
         REPORTER_ASSERT(r, sloppy_rect_eq(SkRect::MakeWH(400, 480), bbh.fEntries[i].bounds));
     }
 }
 
 // A regression test for crbug.com/409110.
 DEF_TEST(RecordDraw_TextBounds, r) {
     SkRecord record;
     SkRecorder recorder(&record, W, H);
 
     // Two Chinese characters in UTF-8.
     const char text[] = { '\xe6', '\xbc', '\xa2', '\xe5', '\xad', '\x97' };
     const size_t bytes = SK_ARRAY_COUNT(text);
 
     const SkScalar xpos[] = { 10, 20 };
     recorder.drawPosTextH(text, bytes, xpos, 30, SkPaint());
 
     const SkPoint pos[] = { {40, 50}, {60, 70} };
     recorder.drawPosText(text, bytes, pos, SkPaint());
 
     TestBBH bbh;
-    SkRecordFillBounds(record, &bbh);
+    SkRecordFillBounds(SkRect::MakeWH(SkIntToScalar(W), SkIntToScalar(H)), record, &bbh);
     REPORTER_ASSERT(r, bbh.fEntries.count() == 2);
 
     // We can make these next assertions confidently because SkRecordFillBounds
     // builds its bounds by overestimating font metrics in a platform-independent way.
     // If that changes, these tests will need to be more flexible.
-    REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[0].bounds, SkRect::MakeLTRB(-110,  0, 140, 60)));
-    REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[1].bounds, SkRect::MakeLTRB(-80, 20, 180, 100)));
+    REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[0].bounds, SkRect::MakeLTRB(0,  0, 140, 60)));
+    REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[1].bounds, SkRect::MakeLTRB(0, 20, 180, 100)));
 }
 
 // Base test to ensure start/stop range is respected
 DEF_TEST(RecordDraw_PartialStartStop, r) {
     static const int kWidth = 10, kHeight = 10;
 
     SkRect r1 = { 0, 0, kWidth,   kHeight };
     SkRect r2 = { 0, 0, kWidth,   kHeight/2 };
     SkRect r3 = { 0, 0, kWidth/2, kHeight };
     SkPaint p;
@@ skipping 60 matching lines @@
         recorder.clipRect(SkRect::MakeWH(20, 40));
         recorder.drawRect(SkRect::MakeWH(20, 40), SkPaint());
     recorder.restore();
 
     // Under the original bug, the right edge value of the drawRect would be 20 less than asserted
     // here because we intersected it with a clip that had not been adjusted for the drop shadow.
     //
     // The second bug showed up as adjusting the picture bounds (0,0,50,50) by the drop shadow too.
     // The saveLayer, clipRect, and restore bounds were incorrectly (0,0,70,50).
     TestBBH bbh;
-    SkRecordFillBounds(record, &bbh);
+    SkRecordFillBounds(SkRect::MakeWH(50, 50), record, &bbh);
     REPORTER_ASSERT(r, bbh.fEntries.count() == 4);
     REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[0].bounds, SkRect::MakeLTRB(0, 0, 50, 50)));
     REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[1].bounds, SkRect::MakeLTRB(0, 0, 50, 50)));
     REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[2].bounds, SkRect::MakeLTRB(0, 0, 40, 40)));
     REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[3].bounds, SkRect::MakeLTRB(0, 0, 50, 50)));
 }
 
+// When a saveLayer provides an explicit bound and has a complex paint (e.g., one that
+// affects transparent black), that bound should serve to shrink the area of the required
+// backing store.
+DEF_TEST(RecordDraw_SaveLayerBoundsAffectsClipBounds, r) {
+    SkRecord record;
+    SkRecorder recorder(&record, 50, 50);
+
+    SkPaint p;
+    p.setXfermodeMode(SkXfermode::kSrc_Mode);
+
+    SkRect bounds = SkRect::MakeLTRB(10, 10, 40, 40);
+    recorder.saveLayer(&bounds, &p);
+    recorder.drawRect(SkRect::MakeLTRB(20, 20, 30, 30), SkPaint());
+    recorder.restore();
+
+    TestBBH bbh;
+    SkRecordFillBounds(SkRect::MakeWH(50, 50), record, &bbh);
+    REPORTER_ASSERT(r, bbh.fEntries.count() == 3);
+    REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[0].bounds, SkRect::MakeLTRB(10, 10, 40, 40)));
+    REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[1].bounds, SkRect::MakeLTRB(20, 20, 30, 30)));
+    REPORTER_ASSERT(r, sloppy_rect_eq(bbh.fEntries[2].bounds, SkRect::MakeLTRB(10, 10, 40, 40)));
+}
+
 DEF_TEST(RecordDraw_drawImage, r){
     class SkCanvasMock : public SkCanvas {
     public:
         SkCanvasMock(int width, int height) : INHERITED(width, height) {
             this->resetTestValues();
         }
         virtual ~SkCanvasMock() {}
         virtual void drawImage(const SkImage* image, SkScalar left, SkScalar top,
                                const SkPaint* paint = NULL) SK_OVERRIDE {
 
@@ skipping 33 matching lines @@
 
     {
         SkRecord record;
         SkRecorder recorder(&record, 10, 10);
         recorder.drawImageRect(image, 0, SkRect::MakeWH(10, 10));
         SkRecordDraw(record, &canvas, 0, 0);
     }
     REPORTER_ASSERT(r, canvas.fDrawImageRectCalled);
 
 }