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1 
2 /*
3  * Copyright 2006 The Android Open Source Project
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 
9 
10 #include "SkBitmap.h"
11 #include "SkMask.h"
12 
13 #ifndef ClearLow3Bits_DEFINED
14 #define ClearLow3Bits_DEFINED
15     #define ClearLow3Bits(x)    ((unsigned)(x) >> 3 << 3)
16 #endif
17 
18 /*
19     SK_BLITBWMASK_NAME          name of function(const SkBitmap& bitmap, const SkMask& mask, const SkIRect& clip, SK_BLITBWMASK_ARGS)
20     SK_BLITBWMASK_ARGS          list of additional arguments to SK_BLITBWMASK_NAME, beginning with a comma
21     SK_BLITBWMASK_BLIT8         name of function(U8CPU byteMask, SK_BLITBWMASK_DEVTYPE* dst, int x, int y)
22     SK_BLITBWMASK_GETADDR       either writable_addr[8,16,32]
23     SK_BLITBWMASK_DEVTYPE       either U32 or U16 or U8
24 */
25 
SK_BLITBWMASK_NAME(const SkPixmap & dst,const SkMask & srcMask,const SkIRect & clip SK_BLITBWMASK_ARGS)26 static void SK_BLITBWMASK_NAME(const SkPixmap& dst, const SkMask& srcMask,
27                                const SkIRect& clip SK_BLITBWMASK_ARGS) {
28     SkASSERT(clip.fRight <= srcMask.fBounds.fRight);
29 
30     int cx = clip.fLeft;
31     int cy = clip.fTop;
32     int maskLeft = srcMask.fBounds.fLeft;
33     unsigned mask_rowBytes = srcMask.fRowBytes;
34     size_t bitmap_rowBytes = dst.rowBytes();
35     unsigned height = clip.height();
36 
37     SkASSERT(mask_rowBytes != 0);
38     SkASSERT(bitmap_rowBytes != 0);
39     SkASSERT(height != 0);
40 
41     const uint8_t* bits = srcMask.getAddr1(cx, cy);
42     SK_BLITBWMASK_DEVTYPE* device = dst.SK_BLITBWMASK_GETADDR(cx, cy);
43 
44     if (cx == maskLeft && clip.fRight == srcMask.fBounds.fRight)
45     {
46         do {
47             SK_BLITBWMASK_DEVTYPE* dst = device;
48             unsigned rb = mask_rowBytes;
49             do {
50                 U8CPU mask = *bits++;
51                 SK_BLITBWMASK_BLIT8(mask, dst);
52                 dst += 8;
53             } while (--rb != 0);
54             device = (SK_BLITBWMASK_DEVTYPE*)((char*)device + bitmap_rowBytes);
55         } while (--height != 0);
56     }
57     else
58     {
59         int left_edge = cx - maskLeft;
60         SkASSERT(left_edge >= 0);
61         int rite_edge = clip.fRight - maskLeft;
62         SkASSERT(rite_edge > left_edge);
63 
64         int left_mask = 0xFF >> (left_edge & 7);
65         int rite_mask = 0xFF << (8 - (rite_edge & 7));
66         rite_mask &= 0xFF;  // only want low-8 bits of mask
67         int full_runs = (rite_edge >> 3) - ((left_edge + 7) >> 3);
68 
69         // check for empty right mask, so we don't read off the end (or go slower than we need to)
70         if (rite_mask == 0)
71         {
72             SkASSERT(full_runs >= 0);
73             full_runs -= 1;
74             rite_mask = 0xFF;
75         }
76         if (left_mask == 0xFF)
77             full_runs -= 1;
78 
79         // back up manually so we can keep in sync with our byte-aligned src
80         // and not trigger an assert from the getAddr## function
81         device -= left_edge & 7;
82 
83         if (full_runs < 0)
84         {
85             left_mask &= rite_mask;
86             SkASSERT(left_mask != 0);
87             do {
88                 U8CPU mask = *bits & left_mask;
89                 SK_BLITBWMASK_BLIT8(mask, device);
90                 bits += mask_rowBytes;
91                 device = (SK_BLITBWMASK_DEVTYPE*)((char*)device + bitmap_rowBytes);
92             } while (--height != 0);
93         }
94         else
95         {
96             do {
97                 int runs = full_runs;
98                 SK_BLITBWMASK_DEVTYPE* dst = device;
99                 const uint8_t* b = bits;
100                 U8CPU   mask;
101 
102                 mask = *b++ & left_mask;
103                 SK_BLITBWMASK_BLIT8(mask, dst);
104                 dst += 8;
105 
106                 while (--runs >= 0)
107                 {
108                     mask = *b++;
109                     SK_BLITBWMASK_BLIT8(mask, dst);
110                     dst += 8;
111                 }
112 
113                 mask = *b & rite_mask;
114                 SK_BLITBWMASK_BLIT8(mask, dst);
115 
116                 bits += mask_rowBytes;
117                 device = (SK_BLITBWMASK_DEVTYPE*)((char*)device + bitmap_rowBytes);
118             } while (--height != 0);
119         }
120     }
121 }
122 
123 #undef SK_BLITBWMASK_NAME
124 #undef SK_BLITBWMASK_ARGS
125 #undef SK_BLITBWMASK_BLIT8
126 #undef SK_BLITBWMASK_GETADDR
127 #undef SK_BLITBWMASK_DEVTYPE
128 #undef SK_BLITBWMASK_DOROWSETUP
129