source: trunk/JPGPROC/source/gbmsrc/x.c@ 57

Last change on this file since 57 was 57, checked in by gyoung, 2 years ago

Fix errors reported by CPPCheck
File size: 2.8 KB
Line 
1static void
2
3GBM_ERR gbm_simple_scale(
4 const byte *s, int sw, int sh,
5 byte *d, int dw, int dh,
6 int bpp
7 )
8 {
9 int sst = ( (sw * bpp + 31) / 32 ) * 4;
10 int dst = ( (dw * bpp + 31) / 32 ) * 4;
11 int *xs, *ys, i;
12 void (*scaler)(const byte *s, byte *d, int dw, int xs[]);
13
14 /* Allocate memory for step arrays */
15
16 if ( (xs = malloc((size_t) ((dw+1+dh+1)*sizeof(int)))) == NULL )
17 return GBM_ERR_MEM;
18 ys = xs + (dw+1);
19
20 /* Make mapping to 0..dx from 0..sx (and same for y) */
21
22 for ( i = 0; i <= dw; i++ )
23 xs[i] = (i * sw) / dw;
24
25 for ( i = 0; i <= dh; i++ )
26 ys[i] = (i * sh) / dh;
27
28 /* Compute step coefficients */
29
30 for ( i = 0; i < dw; i++ )
31 xs[i] = xs[i+1] - xs[i];
32
33 for ( i = 0; i < dh; i++ )
34 ys[i] = ys[i+1] - ys[i];
35
36 /* Pick a scaling routine. Special optimisation to prevent
37 excessive work scaling horizontally if widths are the same.
38 Effectively reduces this code to a memcpy. */
39
40 if ( dw == sw )
41 switch ( bpp )
42 {
43 case 1 : scaler = fast_simple_scale_1 ; break;
44 case 4 : scaler = fast_simple_scale_4 ; break;
45 case 8 : scaler = fast_simple_scale_8 ; break;
46 case 24: scaler = fast_simple_scale_24; break;
47 }
48 else
49 switch ( bpp )
50 {
51 case 1 : scaler = simple_scale_1 ; break;
52 case 4 : scaler = simple_scale_4 ; break;
53 case 8 : scaler = simple_scale_8 ; break;
54 case 24: scaler = simple_scale_24; break;
55 }
56
57 /* Now do guts of scaling */
58
59 while ( dh-- > 0 )
60 {
61 (*scaler)(s, d, dw, xs);
62 d += dst;
63 s += (sst * *ys++);
64 }
65
66 free(xs);
67 return GBM_ERR_OK;
68 }
69
70static void expand(const byte *s, int sw, byte *d, int dw)
71 {
72 int n = 0, col = 0;
73 for ( ;; )
74 {
75 n += dw;
76 while ( n >= sw )
77 {
78 n -= sw;
79 *d++ =
80
81 col += *s++ * dw;
82 while (
83
84
85 for ( --
86
87 int i = 0, c = 0;
88 while ( i < sw * dw )
89 {
90 i += sw
91
92
93 int i = 0, col = 0;
94 while ( sw > 0 )
95 {
96 i += dx;
97 while ( i >= sx )
98 {
99 i -= sx;
100 col += *s++ * sx;
101 *d++ = (col / dx);
102 }
103 }
104
105 int i = 0, col = 0;
106 while ( dw > 0 )
107 {
108
109
110 if ( i <
111
112GBM_ERR gbm_scale_8(
113 const byte *s, int sw, int sh,
114 byte *d, int dw, int dh
115 )
116 {
117 int sst = ( (sw * 8 + 31) / 32 ) * 4;
118 int dst = ( (dw * 8 + 31) / 32 ) * 4;
119
120
121
122
123
124
125 int *xs, *ys, i;
126 void (*scaler)(const byte *s, byte *d, int dw, const int xs[]);
127
128 /* Allocate memory for step arrays */
129
130 if ( (xs = malloc((size_t) ((dw+dh)*sizeof(int)))) == NULL )
131 return GBM_ERR_MEM;
132 ys = xs + dw;
133
134 /* Make mapping to 0..dx-1 from 0..sx-1 (and same for y) */
135
136 for ( i = 0; i < dw; i++ )
137 xs[i] = (i * (sw-1) * 0x100) / (dw-1);
138
139 for ( i = 0; i < dh; i++ )
140 ys[i] = (i * (sh-1) * 0x100) / (dh-1);
141
142 /* Compute step coefficients */
143
144 for ( i = 0; i < dw; i++ )
145 xs[i] = xs[i+1] - xs[i];
146
147 for ( i = 0; i < dh; i++ )
148 ys[i] = ys[i+1] - ys[i];
149
150 }
151
152static void simple_scale_8(
153 const byte *s,
154 byte *d, int dw,
155 int xs[]
156 )
157 {
158 while ( dw-- > 0 )
159 {
160 *d++ = *s;
161 s += *xs++;
162 }
163 }
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