1 /*
2  * Copyright 2015 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "GrCopySurfaceOp.h"
9 
10 // returns true if the read/written rect intersects the src/dst and false if not.
ClipSrcRectAndDstPoint(const GrSurface * dst,const GrSurface * src,const SkIRect & srcRect,const SkIPoint & dstPoint,SkIRect * clippedSrcRect,SkIPoint * clippedDstPoint)11 bool GrCopySurfaceOp::ClipSrcRectAndDstPoint(const GrSurface* dst,
12                                              const GrSurface* src,
13                                              const SkIRect& srcRect,
14                                              const SkIPoint& dstPoint,
15                                              SkIRect* clippedSrcRect,
16                                              SkIPoint* clippedDstPoint) {
17     *clippedSrcRect = srcRect;
18     *clippedDstPoint = dstPoint;
19 
20     // clip the left edge to src and dst bounds, adjusting dstPoint if necessary
21     if (clippedSrcRect->fLeft < 0) {
22         clippedDstPoint->fX -= clippedSrcRect->fLeft;
23         clippedSrcRect->fLeft = 0;
24     }
25     if (clippedDstPoint->fX < 0) {
26         clippedSrcRect->fLeft -= clippedDstPoint->fX;
27         clippedDstPoint->fX = 0;
28     }
29 
30     // clip the top edge to src and dst bounds, adjusting dstPoint if necessary
31     if (clippedSrcRect->fTop < 0) {
32         clippedDstPoint->fY -= clippedSrcRect->fTop;
33         clippedSrcRect->fTop = 0;
34     }
35     if (clippedDstPoint->fY < 0) {
36         clippedSrcRect->fTop -= clippedDstPoint->fY;
37         clippedDstPoint->fY = 0;
38     }
39 
40     // clip the right edge to the src and dst bounds.
41     if (clippedSrcRect->fRight > src->width()) {
42         clippedSrcRect->fRight = src->width();
43     }
44     if (clippedDstPoint->fX + clippedSrcRect->width() > dst->width()) {
45         clippedSrcRect->fRight = clippedSrcRect->fLeft + dst->width() - clippedDstPoint->fX;
46     }
47 
48     // clip the bottom edge to the src and dst bounds.
49     if (clippedSrcRect->fBottom > src->height()) {
50         clippedSrcRect->fBottom = src->height();
51     }
52     if (clippedDstPoint->fY + clippedSrcRect->height() > dst->height()) {
53         clippedSrcRect->fBottom = clippedSrcRect->fTop + dst->height() - clippedDstPoint->fY;
54     }
55 
56     // The above clipping steps may have inverted the rect if it didn't intersect either the src or
57     // dst bounds.
58     return !clippedSrcRect->isEmpty();
59 }
60 
Make(GrSurface * dst,GrSurface * src,const SkIRect & srcRect,const SkIPoint & dstPoint)61 std::unique_ptr<GrOp> GrCopySurfaceOp::Make(GrSurface* dst, GrSurface* src, const SkIRect& srcRect,
62                                             const SkIPoint& dstPoint) {
63     SkASSERT(dst);
64     SkASSERT(src);
65     if (GrPixelConfigIsSint(dst->config()) != GrPixelConfigIsSint(src->config())) {
66         return nullptr;
67     }
68     if (GrPixelConfigIsCompressed(dst->config())) {
69         return nullptr;
70     }
71     SkIRect clippedSrcRect;
72     SkIPoint clippedDstPoint;
73     // If the rect is outside the src or dst then we've already succeeded.
74     if (!ClipSrcRectAndDstPoint(dst, src, srcRect, dstPoint, &clippedSrcRect, &clippedDstPoint)) {
75         return nullptr;
76     }
77     return std::unique_ptr<GrOp>(new GrCopySurfaceOp(dst, src, clippedSrcRect, clippedDstPoint));
78 }
79