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c18a2c36 SS |
1 | /* |
2 | * SDL_zoom_template - surface scaling | |
3 | * | |
4 | * Copyright (c) 2009 Citrix Systems, Inc. | |
5 | * | |
6 | * Derived from: SDL_rotozoom, LGPL (c) A. Schiffler from the SDL_gfx library. | |
7 | * Modifications by Stefano Stabellini. | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL version 2. | |
10 | * See the COPYING file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
14 | #if BPP == 16 | |
15 | #define SDL_TYPE Uint16 | |
16 | #elif BPP == 32 | |
17 | #define SDL_TYPE Uint32 | |
18 | #else | |
19 | #error unsupport depth | |
20 | #endif | |
21 | ||
22 | /* | |
23 | * Simple helper functions to make the code looks nicer | |
24 | * | |
25 | * Assume spf = source SDL_PixelFormat | |
26 | * dpf = dest SDL_PixelFormat | |
27 | * | |
28 | */ | |
29 | #define getRed(color) (((color) & spf->Rmask) >> spf->Rshift) | |
30 | #define getGreen(color) (((color) & spf->Gmask) >> spf->Gshift) | |
31 | #define getBlue(color) (((color) & spf->Bmask) >> spf->Bshift) | |
32 | #define getAlpha(color) (((color) & spf->Amask) >> spf->Ashift) | |
33 | ||
34 | #define setRed(r, pcolor) do { \ | |
35 | *pcolor = ((*pcolor) & (~(dpf->Rmask))) + \ | |
36 | (((r) & (dpf->Rmask >> dpf->Rshift)) << dpf->Rshift); \ | |
37 | } while (0); | |
38 | ||
39 | #define setGreen(g, pcolor) do { \ | |
40 | *pcolor = ((*pcolor) & (~(dpf->Gmask))) + \ | |
41 | (((g) & (dpf->Gmask >> dpf->Gshift)) << dpf->Gshift); \ | |
42 | } while (0); | |
43 | ||
44 | #define setBlue(b, pcolor) do { \ | |
45 | *pcolor = ((*pcolor) & (~(dpf->Bmask))) + \ | |
46 | (((b) & (dpf->Bmask >> dpf->Bshift)) << dpf->Bshift); \ | |
47 | } while (0); | |
48 | ||
49 | #define setAlpha(a, pcolor) do { \ | |
50 | *pcolor = ((*pcolor) & (~(dpf->Amask))) + \ | |
51 | (((a) & (dpf->Amask >> dpf->Ashift)) << dpf->Ashift); \ | |
52 | } while (0); | |
53 | ||
cc69bda6 | 54 | static void glue(sdl_zoom_rgb, BPP)(SDL_Surface *src, SDL_Surface *dst, int smooth, |
c18a2c36 SS |
55 | SDL_Rect *dst_rect) |
56 | { | |
57 | int x, y, sx, sy, *sax, *say, *csax, *csay, csx, csy, ex, ey, t1, t2, sstep, sstep_jump; | |
58 | SDL_TYPE *c00, *c01, *c10, *c11, *sp, *csp, *dp; | |
59 | int d_gap; | |
60 | SDL_PixelFormat *spf = src->format; | |
61 | SDL_PixelFormat *dpf = dst->format; | |
62 | ||
63 | if (smooth) { | |
64 | /* For interpolation: assume source dimension is one pixel. | |
65 | * Smaller here to avoid overflow on right and bottom edge. | |
66 | */ | |
67 | sx = (int) (65536.0 * (float) (src->w - 1) / (float) dst->w); | |
68 | sy = (int) (65536.0 * (float) (src->h - 1) / (float) dst->h); | |
69 | } else { | |
70 | sx = (int) (65536.0 * (float) src->w / (float) dst->w); | |
71 | sy = (int) (65536.0 * (float) src->h / (float) dst->h); | |
72 | } | |
73 | ||
cc69bda6 MA |
74 | sax = g_new(int, dst->w + 1); |
75 | say = g_new(int, dst->h + 1); | |
c18a2c36 SS |
76 | |
77 | sp = csp = (SDL_TYPE *) src->pixels; | |
78 | dp = (SDL_TYPE *) (dst->pixels + dst_rect->y * dst->pitch + | |
79 | dst_rect->x * dst->format->BytesPerPixel); | |
80 | ||
81 | csx = 0; | |
82 | csax = sax; | |
83 | for (x = 0; x <= dst->w; x++) { | |
84 | *csax = csx; | |
85 | csax++; | |
86 | csx &= 0xffff; | |
87 | csx += sx; | |
88 | } | |
89 | csy = 0; | |
90 | csay = say; | |
91 | for (y = 0; y <= dst->h; y++) { | |
92 | *csay = csy; | |
93 | csay++; | |
94 | csy &= 0xffff; | |
95 | csy += sy; | |
96 | } | |
97 | ||
98 | d_gap = dst->pitch - dst_rect->w * dst->format->BytesPerPixel; | |
99 | ||
100 | if (smooth) { | |
101 | csay = say; | |
102 | for (y = 0; y < dst_rect->y; y++) { | |
103 | csay++; | |
104 | sstep = (*csay >> 16) * src->pitch; | |
105 | csp = (SDL_TYPE *) ((Uint8 *) csp + sstep); | |
106 | } | |
107 | ||
108 | /* Calculate sstep_jump */ | |
109 | csax = sax; | |
110 | sstep_jump = 0; | |
111 | for (x = 0; x < dst_rect->x; x++) { | |
112 | csax++; | |
113 | sstep = (*csax >> 16); | |
114 | sstep_jump += sstep; | |
115 | } | |
116 | ||
117 | for (y = 0; y < dst_rect->h ; y++) { | |
118 | /* Setup colour source pointers */ | |
119 | c00 = csp + sstep_jump; | |
120 | c01 = c00 + 1; | |
121 | c10 = (SDL_TYPE *) ((Uint8 *) csp + src->pitch) + sstep_jump; | |
122 | c11 = c10 + 1; | |
123 | csax = sax + dst_rect->x; | |
124 | ||
125 | for (x = 0; x < dst_rect->w; x++) { | |
126 | ||
127 | /* Interpolate colours */ | |
128 | ex = (*csax & 0xffff); | |
129 | ey = (*csay & 0xffff); | |
130 | t1 = ((((getRed(*c01) - getRed(*c00)) * ex) >> 16) + | |
131 | getRed(*c00)) & (dpf->Rmask >> dpf->Rshift); | |
132 | t2 = ((((getRed(*c11) - getRed(*c10)) * ex) >> 16) + | |
133 | getRed(*c10)) & (dpf->Rmask >> dpf->Rshift); | |
134 | setRed((((t2 - t1) * ey) >> 16) + t1, dp); | |
135 | t1 = ((((getGreen(*c01) - getGreen(*c00)) * ex) >> 16) + | |
136 | getGreen(*c00)) & (dpf->Gmask >> dpf->Gshift); | |
137 | t2 = ((((getGreen(*c11) - getGreen(*c10)) * ex) >> 16) + | |
138 | getGreen(*c10)) & (dpf->Gmask >> dpf->Gshift); | |
139 | setGreen((((t2 - t1) * ey) >> 16) + t1, dp); | |
140 | t1 = ((((getBlue(*c01) - getBlue(*c00)) * ex) >> 16) + | |
141 | getBlue(*c00)) & (dpf->Bmask >> dpf->Bshift); | |
142 | t2 = ((((getBlue(*c11) - getBlue(*c10)) * ex) >> 16) + | |
143 | getBlue(*c10)) & (dpf->Bmask >> dpf->Bshift); | |
144 | setBlue((((t2 - t1) * ey) >> 16) + t1, dp); | |
145 | t1 = ((((getAlpha(*c01) - getAlpha(*c00)) * ex) >> 16) + | |
146 | getAlpha(*c00)) & (dpf->Amask >> dpf->Ashift); | |
147 | t2 = ((((getAlpha(*c11) - getAlpha(*c10)) * ex) >> 16) + | |
148 | getAlpha(*c10)) & (dpf->Amask >> dpf->Ashift); | |
149 | setAlpha((((t2 - t1) * ey) >> 16) + t1, dp); | |
150 | ||
151 | /* Advance source pointers */ | |
152 | csax++; | |
153 | sstep = (*csax >> 16); | |
154 | c00 += sstep; | |
155 | c01 += sstep; | |
156 | c10 += sstep; | |
157 | c11 += sstep; | |
158 | /* Advance destination pointer */ | |
159 | dp++; | |
160 | } | |
161 | /* Advance source pointer */ | |
162 | csay++; | |
163 | csp = (SDL_TYPE *) ((Uint8 *) csp + (*csay >> 16) * src->pitch); | |
164 | /* Advance destination pointers */ | |
165 | dp = (SDL_TYPE *) ((Uint8 *) dp + d_gap); | |
166 | } | |
167 | ||
168 | ||
169 | } else { | |
170 | csay = say; | |
171 | ||
172 | for (y = 0; y < dst_rect->y; y++) { | |
173 | csay++; | |
174 | sstep = (*csay >> 16) * src->pitch; | |
175 | csp = (SDL_TYPE *) ((Uint8 *) csp + sstep); | |
176 | } | |
177 | ||
178 | /* Calculate sstep_jump */ | |
179 | csax = sax; | |
180 | sstep_jump = 0; | |
181 | for (x = 0; x < dst_rect->x; x++) { | |
182 | csax++; | |
183 | sstep = (*csax >> 16); | |
184 | sstep_jump += sstep; | |
185 | } | |
186 | ||
187 | for (y = 0 ; y < dst_rect->h ; y++) { | |
188 | sp = csp + sstep_jump; | |
189 | csax = sax + dst_rect->x; | |
190 | ||
191 | for (x = 0; x < dst_rect->w; x++) { | |
192 | ||
193 | /* Draw */ | |
194 | *dp = *sp; | |
195 | ||
196 | /* Advance source pointers */ | |
197 | csax++; | |
198 | sstep = (*csax >> 16); | |
199 | sp += sstep; | |
200 | ||
201 | /* Advance destination pointer */ | |
202 | dp++; | |
203 | } | |
204 | /* Advance source pointers */ | |
205 | csay++; | |
206 | sstep = (*csay >> 16) * src->pitch; | |
207 | csp = (SDL_TYPE *) ((Uint8 *) csp + sstep); | |
208 | ||
209 | /* Advance destination pointer */ | |
210 | dp = (SDL_TYPE *) ((Uint8 *) dp + d_gap); | |
211 | } | |
212 | } | |
213 | ||
cc69bda6 MA |
214 | g_free(sax); |
215 | g_free(say); | |
c18a2c36 SS |
216 | } |
217 | ||
218 | #undef SDL_TYPE | |
219 |