VirtualBox

source: vbox/trunk/src/VBox/Main/src-all/DisplayResampleImage.cpp@ 67954

Last change on this file since 67954 was 63486, checked in by vboxsync, 8 years ago

removed dead code

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 5.0 KB
Line 
1/* $Id: DisplayResampleImage.cpp 63486 2016-08-15 14:57:55Z vboxsync $ */
2/** @file
3 * Image resampling code, used for snapshot thumbnails.
4 */
5
6/*
7 * Copyright (C) 2009-2016 Oracle Corporation
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 */
17
18#include <iprt/types.h>
19
20DECLINLINE(void) imageSetPixel (uint8_t *im, int x, int y, int color, int w)
21{
22 *(int32_t *)(im + y * w * 4 + x * 4) = color;
23}
24
25#define trueColorGetAlpha(c) (((c) & 0x7F000000) >> 24)
26#define trueColorGetRed(c) (((c) & 0xFF0000) >> 16)
27#define trueColorGetGreen(c) (((c) & 0x00FF00) >> 8)
28#define trueColorGetBlue(c) ((c) & 0x0000FF)
29
30/* Fast integer implementation for 32 bpp bitmap scaling.
31 * Using fixed point values * 16.
32 */
33typedef int32_t FIXEDPOINT;
34#define INT_TO_FIXEDPOINT(i) (FIXEDPOINT)((i) << 4)
35#define FIXEDPOINT_TO_INT(v) (int)((v) >> 4)
36#define FIXEDPOINT_FLOOR(v) ((v) & ~0xF)
37#define FIXEDPOINT_FRACTION(v) ((v) & 0xF)
38
39/* For 32 bit source only. */
40void BitmapScale32 (uint8_t *dst,
41 int dstW, int dstH,
42 const uint8_t *src,
43 int iDeltaLine,
44 int srcW, int srcH)
45{
46 int x, y;
47
48 for (y = 0; y < dstH; y++)
49 {
50 FIXEDPOINT sy1 = INT_TO_FIXEDPOINT(y * srcH) / dstH;
51 FIXEDPOINT sy2 = INT_TO_FIXEDPOINT((y + 1) * srcH) / dstH;
52
53 for (x = 0; x < dstW; x++)
54 {
55 FIXEDPOINT red = 0, green = 0, blue = 0;
56
57 FIXEDPOINT sx1 = INT_TO_FIXEDPOINT(x * srcW) / dstW;
58 FIXEDPOINT sx2 = INT_TO_FIXEDPOINT((x + 1) * srcW) / dstW;
59
60 FIXEDPOINT spixels = (sx2 - sx1) * (sy2 - sy1);
61
62 FIXEDPOINT sy = sy1;
63
64 do
65 {
66 FIXEDPOINT yportion;
67 if (FIXEDPOINT_FLOOR (sy) == FIXEDPOINT_FLOOR (sy1))
68 {
69 yportion = INT_TO_FIXEDPOINT(1) - FIXEDPOINT_FRACTION(sy);
70 if (yportion > sy2 - sy1)
71 {
72 yportion = sy2 - sy1;
73 }
74 sy = FIXEDPOINT_FLOOR (sy);
75 }
76 else if (sy == FIXEDPOINT_FLOOR (sy2))
77 {
78 yportion = FIXEDPOINT_FRACTION(sy2);
79 }
80 else
81 {
82 yportion = INT_TO_FIXEDPOINT(1);
83 }
84
85 const uint8_t *pu8SrcLine = src + iDeltaLine * FIXEDPOINT_TO_INT(sy);
86 FIXEDPOINT sx = sx1;
87 do
88 {
89 FIXEDPOINT xportion;
90 FIXEDPOINT pcontribution;
91 int p;
92 if (FIXEDPOINT_FLOOR (sx) == FIXEDPOINT_FLOOR (sx1))
93 {
94 xportion = INT_TO_FIXEDPOINT(1) - FIXEDPOINT_FRACTION(sx);
95 if (xportion > sx2 - sx1)
96 {
97 xportion = sx2 - sx1;
98 }
99 pcontribution = xportion * yportion;
100 sx = FIXEDPOINT_FLOOR (sx);
101 }
102 else if (sx == FIXEDPOINT_FLOOR (sx2))
103 {
104 xportion = FIXEDPOINT_FRACTION(sx2);
105 pcontribution = xportion * yportion;
106 }
107 else
108 {
109 xportion = INT_TO_FIXEDPOINT(1);
110 pcontribution = xportion * yportion;
111 }
112 /* Color depth specific code begin */
113 p = *(uint32_t *)(pu8SrcLine + FIXEDPOINT_TO_INT(sx) * 4);
114 /* Color depth specific code end */
115 red += trueColorGetRed (p) * pcontribution;
116 green += trueColorGetGreen (p) * pcontribution;
117 blue += trueColorGetBlue (p) * pcontribution;
118
119 sx += INT_TO_FIXEDPOINT(1);
120 } while (sx < sx2);
121
122 sy += INT_TO_FIXEDPOINT(1);
123 } while (sy < sy2);
124
125 if (spixels != 0)
126 {
127 red /= spixels;
128 green /= spixels;
129 blue /= spixels;
130 }
131 /* Clamping to allow for rounding errors above */
132 if (red > 255)
133 {
134 red = 255;
135 }
136 if (green > 255)
137 {
138 green = 255;
139 }
140 if (blue > 255)
141 {
142 blue = 255;
143 }
144 imageSetPixel (dst,
145 x, y,
146 ( ((int) red) << 16) + (((int) green) << 8) + ((int) blue),
147 dstW);
148 }
149 }
150}
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