correct the type of the im_decode_exif() data parameter
[imager.git] / rotate.im
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1/*
2=head1 NAME
3
999f4294 4 rotate.im - implements image rotations
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5
6=head1 SYNOPSIS
7
8 i_img *i_rotate90(i_img *src, int degrees)
9
10=head1 DESCRIPTION
11
12Implements basic 90 degree rotations of an image.
13
14Other rotations will be added as tuits become available.
15
16=cut
17*/
18
92bda632 19#include "imager.h"
13c9a303 20#include "imageri.h"
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21#include <math.h> /* for floor() */
22
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23#define ROT_DEBUG(x)
24
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25i_img *i_rotate90(i_img *src, int degrees) {
26 i_img *targ;
8d14daab 27 i_img_dim x, y;
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28
29 i_clear_error();
30
31 if (degrees == 180) {
32 /* essentially the same as flipxy(..., 2) except that it's not
33 done in place */
34 targ = i_sametype(src, src->xsize, src->ysize);
35 if (src->type == i_direct_type) {
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36#code src->bits <= 8
37 IM_COLOR *vals = mymalloc(src->xsize * sizeof(IM_COLOR));
38 for (y = 0; y < src->ysize; ++y) {
39 IM_COLOR tmp;
40 IM_GLIN(src, 0, src->xsize, y, vals);
41 for (x = 0; x < src->xsize/2; ++x) {
42 tmp = vals[x];
43 vals[x] = vals[src->xsize - x - 1];
44 vals[src->xsize - x - 1] = tmp;
45 }
46 IM_PLIN(targ, 0, src->xsize, src->ysize - y - 1, vals);
faa9b3e7 47 }
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48 myfree(vals);
49#/code
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50 }
51 else {
52 i_palidx *vals = mymalloc(src->xsize * sizeof(i_palidx));
53
54 for (y = 0; y < src->ysize; ++y) {
55 i_palidx tmp;
56 i_gpal(src, 0, src->xsize, y, vals);
57 for (x = 0; x < src->xsize/2; ++x) {
58 tmp = vals[x];
59 vals[x] = vals[src->xsize - x - 1];
60 vals[src->xsize - x - 1] = tmp;
61 }
62 i_ppal(targ, 0, src->xsize, src->ysize - y - 1, vals);
63 }
64
65 myfree(vals);
66 }
67
68 return targ;
69 }
70 else if (degrees == 270 || degrees == 90) {
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71 i_img_dim tx, txstart, txinc;
72 i_img_dim ty, tystart, tyinc;
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73
74 if (degrees == 270) {
75 txstart = 0;
76 txinc = 1;
77 tystart = src->xsize-1;
78 tyinc = -1;
79 }
80 else {
81 txstart = src->ysize-1;
82 txinc = -1;
83 tystart = 0;
84 tyinc = 1;
85 }
86 targ = i_sametype(src, src->ysize, src->xsize);
87 if (src->type == i_direct_type) {
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88#code src->bits <= 8
89 IM_COLOR *vals = mymalloc(src->xsize * sizeof(IM_COLOR));
90
91 tx = txstart;
92 for (y = 0; y < src->ysize; ++y) {
93 IM_GLIN(src, 0, src->xsize, y, vals);
94 ty = tystart;
95 for (x = 0; x < src->xsize; ++x) {
96 IM_PPIX(targ, tx, ty, vals+x);
97 ty += tyinc;
98 }
99 tx += txinc;
faa9b3e7 100 }
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101 myfree(vals);
102#/code
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103 }
104 else {
105 i_palidx *vals = mymalloc(src->xsize * sizeof(i_palidx));
106
107 tx = txstart;
108 for (y = 0; y < src->ysize; ++y) {
109 i_gpal(src, 0, src->xsize, y, vals);
110 ty = tystart;
111 for (x = 0; x < src->xsize; ++x) {
112 i_ppal(targ, tx, tx+1, ty, vals+x);
113 ty += tyinc;
114 }
115 tx += txinc;
116 }
117 myfree(vals);
118 }
119 return targ;
120 }
121 else {
122 i_push_error(0, "i_rotate90() only rotates at 90, 180, or 270 degrees");
123 return NULL;
124 }
125}
126
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127/* linear interpolation */
128static i_color interp_i_color(i_color before, i_color after, double pos,
129 int channels) {
130 i_color out;
131 int ch;
132
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133 if (channels == 1 || channels == 3) {
134 for (ch = 0; ch < channels; ++ch)
289d65f4 135 out.channel[ch] = ((1-pos) * before.channel[ch] + pos * after.channel[ch]) + 0.5;
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136 }
137 else {
138 int total_cover = (1-pos) * before.channel[channels-1]
139 + pos * after.channel[channels-1];
140
141 total_cover = I_LIMIT_8(total_cover);
142 if (total_cover) {
143 double before_alpha = before.channel[channels-1] / 255.0;
144 double after_alpha = after.channel[channels-1] / 255.0;
145 double total_alpha = before_alpha * (1-pos) + after_alpha * pos;
146
147 for (ch = 0; ch < channels-1; ++ch) {
148 int out_level = ((1-pos) * before.channel[ch] * before_alpha +
ef74691a 149 pos * after.channel[ch] * after_alpha) / total_alpha + 0.5;
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150
151 out.channel[ch] = I_LIMIT_8(out_level);
152 }
153 }
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154 else {
155 for (ch = 0; ch < channels-1; ++ch)
156 out.channel[ch] = 0;
157 }
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158
159 out.channel[channels-1] = total_cover;
160 }
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161
162 return out;
163}
164
165/* hopefully this will be inlined (it is with -O3 with gcc 2.95.4) */
166/* linear interpolation */
167static i_fcolor interp_i_fcolor(i_fcolor before, i_fcolor after, double pos,
168 int channels) {
169 i_fcolor out;
170 int ch;
171
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172 if (channels == 1 || channels == 3) {
173 for (ch = 0; ch < channels; ++ch)
174 out.channel[ch] = (1-pos) * before.channel[ch] + pos * after.channel[ch];
175 }
176 else {
177 double total_cover = (1-pos) * before.channel[channels-1]
178 + pos * after.channel[channels-1];
179
180 total_cover = I_LIMIT_DOUBLE(total_cover);
181 if (total_cover) {
182 double before_alpha = before.channel[channels-1];
183 double after_alpha = after.channel[channels-1];
184 double total_alpha = before_alpha * (1-pos) + after_alpha * pos;
185
186 for (ch = 0; ch < channels-1; ++ch) {
187 double out_level = ((1-pos) * before.channel[ch] * before_alpha +
188 pos * after.channel[ch] * after_alpha) / total_alpha;
189
190 out.channel[ch] = I_LIMIT_DOUBLE(out_level);
191 }
192 }
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193 else {
194 for (ch = 0; ch < channels-1; ++ch)
195 out.channel[ch] = 0;
196 }
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197
198 out.channel[channels-1] = total_cover;
199 }
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200
201 return out;
202}
203
8d14daab 204i_img *i_matrix_transform_bg(i_img *src, i_img_dim xsize, i_img_dim ysize, const double *matrix,
97ac0a96 205 const i_color *backp, const i_fcolor *fbackp) {
faa9b3e7 206 i_img *result = i_sametype(src, xsize, ysize);
8d14daab 207 i_img_dim x, y;
faa9b3e7 208 int ch;
8d14daab 209 i_img_dim i, j;
faa9b3e7 210 double sx, sy, sz;
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211
212 if (src->type == i_direct_type) {
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213#code src->bits <= 8
214 IM_COLOR *vals = mymalloc(xsize * sizeof(IM_COLOR));
215 IM_COLOR back;
faa9b3e7 216
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217#ifdef IM_EIGHT_BIT
218 if (backp) {
219 back = *backp;
220 }
221 else if (fbackp) {
222 for (ch = 0; ch < src->channels; ++ch) {
0a53238e 223 i_fsample_t fsamp;
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224 fsamp = fbackp->channel[ch];
225 back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
faa9b3e7 226 }
faa9b3e7 227 }
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228#else
229#define interp_i_color interp_i_fcolor
230 if (fbackp) {
231 back = *fbackp;
232 }
233 else if (backp) {
234 for (ch = 0; ch < src->channels; ++ch)
235 back.channel[ch] = backp->channel[ch] / 255.0;
236 }
237#endif
faa9b3e7 238 else {
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239 for (ch = 0; ch < src->channels; ++ch)
240 back.channel[ch] = 0;
241 }
faa9b3e7 242
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243 for (y = 0; y < ysize; ++y) {
244 for (x = 0; x < xsize; ++x) {
245 /* dividing by sz gives us the ability to do perspective
246 transforms */
247 sz = x * matrix[6] + y * matrix[7] + matrix[8];
248 if (fabs(sz) > 0.0000001) {
249 sx = (x * matrix[0] + y * matrix[1] + matrix[2]) / sz;
250 sy = (x * matrix[3] + y * matrix[4] + matrix[5]) / sz;
251 }
252 else {
253 sx = sy = 0;
254 }
255
256 /* anything outside these ranges is either a broken co-ordinate
257 or outside the source */
258 if (fabs(sz) > 0.0000001
259 && sx >= -1 && sx < src->xsize
260 && sy >= -1 && sy < src->ysize) {
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261 double fsx = floor(sx);
262 double fsy = floor(sy);
263 i_img_dim bx = fsx;
264 i_img_dim by = fsy;
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265
266 ROT_DEBUG(fprintf(stderr, "map " i_DFp " to %g,%g\n", i_DFcp(x, y), sx, sy));
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267 if (sx != fsx) {
268 double dx = sx - fsx;
269 if (sy != fsy) {
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270 IM_COLOR c[2][2];
271 IM_COLOR ci2[2];
8cf47973 272 double dy = sy - fsy;
289d65f4 273 ROT_DEBUG(fprintf(stderr, " both non-int\n"));
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274 for (i = 0; i < 2; ++i)
275 for (j = 0; j < 2; ++j)
1e9de315 276 if (IM_GPIX(src, bx+i, by+j, &c[j][i]))
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277 c[j][i] = back;
278 for (j = 0; j < 2; ++j)
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279 ci2[j] = interp_i_color(c[j][0], c[j][1], dx, src->channels);
280 vals[x] = interp_i_color(ci2[0], ci2[1], dy, src->channels);
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281 }
282 else {
283 IM_COLOR ci2[2];
289d65f4 284 ROT_DEBUG(fprintf(stderr, " y int, x non-int\n"));
999f4294 285 for (i = 0; i < 2; ++i)
1e9de315 286 if (IM_GPIX(src, bx+i, sy, ci2+i))
999f4294 287 ci2[i] = back;
8cf47973 288 vals[x] = interp_i_color(ci2[0], ci2[1], dx, src->channels);
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289 }
290 }
291 else {
8cf47973 292 if (sy != fsy) {
999f4294 293 IM_COLOR ci2[2];
8cf47973 294 double dy = sy - fsy;
289d65f4 295 ROT_DEBUG(fprintf(stderr, " x int, y non-int\n"));
999f4294 296 for (i = 0; i < 2; ++i)
1e9de315 297 if (IM_GPIX(src, bx, by+i, ci2+i))
999f4294 298 ci2[i] = back;
8cf47973 299 vals[x] = interp_i_color(ci2[0], ci2[1], dy, src->channels);
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300 }
301 else {
289d65f4 302 ROT_DEBUG(fprintf(stderr, " both int\n"));
999f4294 303 /* all the world's an integer */
8cf47973 304 if (IM_GPIX(src, bx, by, vals+x))
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305 vals[x] = back;
306 }
307 }
308 }
309 else {
310 vals[x] = back;
311 }
faa9b3e7 312 }
999f4294 313 IM_PLIN(result, 0, xsize, y, vals);
faa9b3e7 314 }
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315 myfree(vals);
316#undef interp_i_color
317#/code
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318 }
319 else {
320 /* don't interpolate for a palette based image */
321 i_palidx *vals = mymalloc(xsize * sizeof(i_palidx));
0d3b936e 322 i_palidx back = 0;
0d3b936e 323 int minval = 256 * 4;
8d14daab 324 i_img_dim ix, iy;
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325 i_color want_back;
326 i_fsample_t fsamp;
faa9b3e7 327
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328 if (backp) {
329 want_back = *backp;
330 }
331 else if (fbackp) {
332 for (ch = 0; ch < src->channels; ++ch) {
333 fsamp = fbackp->channel[ch];
334 want_back.channel[ch] = fsamp < 0 ? 0 : fsamp > 1 ? 255 : fsamp * 255;
335 }
336 }
337 else {
338 for (ch = 0; ch < src->channels; ++ch)
339 want_back.channel[ch] = 0;
340 }
341
342 /* find the closest color */
343 for (i = 0; i < i_colorcount(src); ++i) {
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344 i_color temp;
345 int tempval;
346 i_getcolors(src, i, &temp, 1);
347 tempval = 0;
348 for (ch = 0; ch < src->channels; ++ch) {
0d3b936e 349 tempval += abs(want_back.channel[ch] - temp.channel[ch]);
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350 }
351 if (tempval < minval) {
0d3b936e 352 back = i;
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353 minval = tempval;
354 }
355 }
356
357 for (y = 0; y < ysize; ++y) {
358 for (x = 0; x < xsize; ++x) {
359 /* dividing by sz gives us the ability to do perspective
360 transforms */
361 sz = x * matrix[6] + y * matrix[7] + matrix[8];
362 if (abs(sz) > 0.0000001) {
363 sx = (x * matrix[0] + y * matrix[1] + matrix[2]) / sz;
364 sy = (x * matrix[3] + y * matrix[4] + matrix[5]) / sz;
365 }
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366 else {
367 sx = sy = 0;
368 }
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369
370 /* anything outside these ranges is either a broken co-ordinate
371 or outside the source */
372 if (abs(sz) > 0.0000001
373 && sx >= -0.5 && sx < src->xsize-0.5
374 && sy >= -0.5 && sy < src->ysize-0.5) {
375
376 /* all the world's an integer */
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377 ix = (i_img_dim)(sx+0.5);
378 iy = (i_img_dim)(sy+0.5);
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379 if (!i_gpal(src, ix, ix+1, iy, vals+x))
380 vals[i] = back;
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381 }
382 else {
0d3b936e 383 vals[x] = back;
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384 }
385 }
386 i_ppal(result, 0, xsize, y, vals);
387 }
388 myfree(vals);
389 }
390
391 return result;
392}
393
8d14daab 394i_img *i_matrix_transform(i_img *src, i_img_dim xsize, i_img_dim ysize, const double *matrix) {
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395 return i_matrix_transform_bg(src, xsize, ysize, matrix, NULL, NULL);
396}
397
35891892 398static void
97ac0a96 399i_matrix_mult(double *dest, const double *left, const double *right) {
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400 int i, j, k;
401 double accum;
402
403 for (i = 0; i < 3; ++i) {
404 for (j = 0; j < 3; ++j) {
405 accum = 0.0;
406 for (k = 0; k < 3; ++k) {
407 accum += left[3*i+k] * right[3*k+j];
408 }
409 dest[3*i+j] = accum;
410 }
411 }
412}
413
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414#define numfmt "%23g"
415
1e9de315 416ROT_DEBUG(static void dump_mat(const char *name, double *f) {
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417 fprintf(stderr, "%s:\n " numfmt " " numfmt " " numfmt "\n"
418 " " numfmt " " numfmt " " numfmt "\n"
419 " " numfmt " " numfmt " " numfmt "\n",
420 name, f[0], f[1], f[2], f[3], f[4], f[5], f[6], f[7], f[8]);
421 })
422
0d3b936e 423i_img *i_rotate_exact_bg(i_img *src, double amount,
97ac0a96 424 const i_color *backp, const i_fcolor *fbackp) {
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425 double xlate1[9] = { 0 };
426 double rotate[9];
427 double xlate2[9] = { 0 };
428 double temp[9], matrix[9];
8d14daab 429 i_img_dim x1, x2, y1, y2, newxsize, newysize;
faa9b3e7 430
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431 ROT_DEBUG(fprintf(stderr, "rotate angle %.20g\n", amount));
432
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433 /* first translate the centre of the image to (0,0) */
434 xlate1[0] = 1;
289d65f4 435 xlate1[2] = (src->xsize-1)/2.0;
faa9b3e7 436 xlate1[4] = 1;
289d65f4 437 xlate1[5] = (src->ysize-1)/2.0;
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438 xlate1[8] = 1;
439
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440 ROT_DEBUG(dump_mat("xlate1", xlate1));
441
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442 /* rotate around (0.0) */
443 rotate[0] = cos(amount);
444 rotate[1] = sin(amount);
445 rotate[2] = 0;
446 rotate[3] = -rotate[1];
447 rotate[4] = rotate[0];
448 rotate[5] = 0;
449 rotate[6] = 0;
450 rotate[7] = 0;
451 rotate[8] = 1;
452
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453 ROT_DEBUG(dump_mat("rotate", rotate));
454
455 ROT_DEBUG(fprintf(stderr, "cos %g sin %g\n", rotate[0], rotate[1]));
456
457 x1 = ceil(fabs(src->xsize * rotate[0] + src->ysize * rotate[1]) - 0.0001);
458 x2 = ceil(fabs(src->xsize * rotate[0] - src->ysize * rotate[1]) - 0.0001);
459 y1 = ceil(fabs(src->xsize * rotate[3] + src->ysize * rotate[4]) - 0.0001);
460 y2 = ceil(fabs(src->xsize * rotate[3] - src->ysize * rotate[4]) - 0.0001);
461 ROT_DEBUG(fprintf(stderr, "x1 y1 " i_DFp " x2 y2 " i_DFp "\n", i_DFcp(x1, y1), i_DFcp(x2, y2)));
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462 newxsize = x1 > x2 ? x1 : x2;
463 newysize = y1 > y2 ? y1 : y2;
464 /* translate the centre back to the center of the image */
465 xlate2[0] = 1;
289d65f4 466 xlate2[2] = -(newxsize-1)/2.0;
faa9b3e7 467 xlate2[4] = 1;
289d65f4 468 xlate2[5] = -(newysize-1)/2.0;
faa9b3e7 469 xlate2[8] = 1;
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470
471 ROT_DEBUG(dump_mat("xlate2", xlate2));
472
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473 i_matrix_mult(temp, xlate1, rotate);
474 i_matrix_mult(matrix, temp, xlate2);
475
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476 ROT_DEBUG(dump_mat("matrxi", matrix));
477
0d3b936e 478 return i_matrix_transform_bg(src, newxsize, newysize, matrix, backp, fbackp);
faa9b3e7 479}
b8c2033e 480
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481i_img *i_rotate_exact(i_img *src, double amount) {
482 return i_rotate_exact_bg(src, amount, NULL, NULL);
483}
484
485
b8c2033e
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486/*
487=back
488
489=head1 AUTHOR
490
491Tony Cook <tony@develop-help.com>
492
493=head1 SEE ALSO
494
495Imager(3)
496
497=cut
498*/