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 
9 #include "GrCopySurfaceBatch.h"
10 
11 // 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)12 bool GrCopySurfaceBatch::ClipSrcRectAndDstPoint(const GrSurface* dst,
13                                                 const GrSurface* src,
14                                                 const SkIRect& srcRect,
15                                                 const SkIPoint& dstPoint,
16                                                 SkIRect* clippedSrcRect,
17                                                 SkIPoint* clippedDstPoint) {
18     *clippedSrcRect = srcRect;
19     *clippedDstPoint = dstPoint;
20 
21     // clip the left edge to src and dst bounds, adjusting dstPoint if necessary
22     if (clippedSrcRect->fLeft < 0) {
23         clippedDstPoint->fX -= clippedSrcRect->fLeft;
24         clippedSrcRect->fLeft = 0;
25     }
26     if (clippedDstPoint->fX < 0) {
27         clippedSrcRect->fLeft -= clippedDstPoint->fX;
28         clippedDstPoint->fX = 0;
29     }
30 
31     // clip the top edge to src and dst bounds, adjusting dstPoint if necessary
32     if (clippedSrcRect->fTop < 0) {
33         clippedDstPoint->fY -= clippedSrcRect->fTop;
34         clippedSrcRect->fTop = 0;
35     }
36     if (clippedDstPoint->fY < 0) {
37         clippedSrcRect->fTop -= clippedDstPoint->fY;
38         clippedDstPoint->fY = 0;
39     }
40 
41     // clip the right edge to the src and dst bounds.
42     if (clippedSrcRect->fRight > src->width()) {
43         clippedSrcRect->fRight = src->width();
44     }
45     if (clippedDstPoint->fX + clippedSrcRect->width() > dst->width()) {
46         clippedSrcRect->fRight = clippedSrcRect->fLeft + dst->width() - clippedDstPoint->fX;
47     }
48 
49     // clip the bottom edge to the src and dst bounds.
50     if (clippedSrcRect->fBottom > src->height()) {
51         clippedSrcRect->fBottom = src->height();
52     }
53     if (clippedDstPoint->fY + clippedSrcRect->height() > dst->height()) {
54         clippedSrcRect->fBottom = clippedSrcRect->fTop + dst->height() - clippedDstPoint->fY;
55     }
56 
57     // The above clipping steps may have inverted the rect if it didn't intersect either the src or
58     // dst bounds.
59     return !clippedSrcRect->isEmpty();
60 }
61 
Create(GrSurface * dst,GrSurface * src,const SkIRect & srcRect,const SkIPoint & dstPoint)62 GrBatch* GrCopySurfaceBatch::Create(GrSurface* dst, GrSurface* src, const SkIRect& srcRect,
63                                     const SkIPoint& dstPoint) {
64     SkASSERT(dst);
65     SkASSERT(src);
66 
67     SkIRect clippedSrcRect;
68     SkIPoint clippedDstPoint;
69     // If the rect is outside the src or dst then we've already succeeded.
70     if (!ClipSrcRectAndDstPoint(dst, src, srcRect, dstPoint, &clippedSrcRect, &clippedDstPoint)) {
71         return nullptr;
72     }
73     return new GrCopySurfaceBatch(dst, src, clippedSrcRect, clippedDstPoint);
74 }
75