The Tor Browser / file comparison
comparison: gfx/skia/trunk/src/core/SkBitmap_scroll.cpp
gfx/skia/trunk/src/core/SkBitmap_scroll.cpp
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
equal
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replaced
| -1:000000000000 | 0:2c95da583e10 |
|---|---|
| 1 | |
| 2 /* | |
| 3 * Copyright 2011 Google Inc. | |
| 4 * | |
| 5 * Use of this source code is governed by a BSD-style license that can be | |
| 6 * found in the LICENSE file. | |
| 7 */ | |
| 8 #include "SkBitmap.h" | |
| 9 #include "SkRegion.h" | |
| 10 | |
| 11 bool SkBitmap::scrollRect(const SkIRect* subset, int dx, int dy, | |
| 12 SkRegion* inval) const | |
| 13 { | |
| 14 if (this->isImmutable() || kUnknown_SkColorType == this->colorType()) { | |
| 15 return false; | |
| 16 } | |
| 17 | |
| 18 if (NULL != subset) { | |
| 19 SkBitmap tmp; | |
| 20 | |
| 21 return this->extractSubset(&tmp, *subset) && | |
| 22 // now call again with no rectangle | |
| 23 tmp.scrollRect(NULL, dx, dy, inval); | |
| 24 } | |
| 25 | |
| 26 int shift = this->bytesPerPixel() >> 1; | |
| 27 int width = this->width(); | |
| 28 int height = this->height(); | |
| 29 | |
| 30 // check if there's nothing to do | |
| 31 if ((dx | dy) == 0 || width <= 0 || height <= 0) { | |
| 32 if (NULL != inval) { | |
| 33 inval->setEmpty(); | |
| 34 } | |
| 35 return true; | |
| 36 } | |
| 37 | |
| 38 // compute the inval region now, before we see if there are any pixels | |
| 39 if (NULL != inval) { | |
| 40 SkIRect r; | |
| 41 | |
| 42 r.set(0, 0, width, height); | |
| 43 // initial the region with the entire bounds | |
| 44 inval->setRect(r); | |
| 45 // do the "scroll" | |
| 46 r.offset(dx, dy); | |
| 47 | |
| 48 // check if we scrolled completely away | |
| 49 if (!SkIRect::Intersects(r, inval->getBounds())) { | |
| 50 // inval has already been updated... | |
| 51 return true; | |
| 52 } | |
| 53 | |
| 54 // compute the dirty area | |
| 55 inval->op(r, SkRegion::kDifference_Op); | |
| 56 } | |
| 57 | |
| 58 SkAutoLockPixels alp(*this); | |
| 59 // if we have no pixels, just return (inval is already updated) | |
| 60 // don't call readyToDraw(), since we don't require a colortable per se | |
| 61 if (this->getPixels() == NULL) { | |
| 62 return true; | |
| 63 } | |
| 64 | |
| 65 char* dst = (char*)this->getPixels(); | |
| 66 const char* src = dst; | |
| 67 int rowBytes = (int)this->rowBytes(); // need rowBytes to be signed | |
| 68 | |
| 69 if (dy <= 0) { | |
| 70 src -= dy * rowBytes; | |
| 71 height += dy; | |
| 72 } else { | |
| 73 dst += dy * rowBytes; | |
| 74 height -= dy; | |
| 75 // now jump src/dst to the last scanline | |
| 76 src += (height - 1) * rowBytes; | |
| 77 dst += (height - 1) * rowBytes; | |
| 78 // now invert rowbytes so we copy backwards in the loop | |
| 79 rowBytes = -rowBytes; | |
| 80 } | |
| 81 | |
| 82 if (dx <= 0) { | |
| 83 src -= dx << shift; | |
| 84 width += dx; | |
| 85 } else { | |
| 86 dst += dx << shift; | |
| 87 width -= dx; | |
| 88 } | |
| 89 | |
| 90 // If the X-translation would push it completely beyond the region, | |
| 91 // then there's nothing to draw. | |
| 92 if (width <= 0) { | |
| 93 return true; | |
| 94 } | |
| 95 | |
| 96 width <<= shift; // now width is the number of bytes to move per line | |
| 97 while (--height >= 0) { | |
| 98 memmove(dst, src, width); | |
| 99 dst += rowBytes; | |
| 100 src += rowBytes; | |
| 101 } | |
| 102 | |
| 103 this->notifyPixelsChanged(); | |
| 104 return true; | |
| 105 } |
