1 /* Xviewer -- Affine Transformations
2 *
3 * Copyright (C) 2003-2009 The Free Software Foundation
4 *
5 * Portions based on code from libart_lgpl by Raph Levien.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 */
21
22 #ifdef HAVE_CONFIG_H
23 #include <config.h>
24 #endif
25
26 #include <time.h>
27 #include <stdlib.h>
28 #include <math.h>
29 #include <gtk/gtk.h>
30 #include <cairo/cairo.h>
31
32 #include "xviewer-transform.h"
33 #include "xviewer-jobs.h"
34
35 /* The number of progress updates per transformation */
36 #define XVIEWER_TRANSFORM_N_PROG_UPDATES 20
37
38 struct _XviewerTransformPrivate {
39 cairo_matrix_t affine;
40 };
41
42 typedef struct {
43 gdouble x;
44 gdouble y;
45 } XviewerPoint;
46
47 /* Convert degrees into radians */
48 #define XVIEWER_DEG_TO_RAD(degree) ((degree) * (G_PI/180.0))
49
G_DEFINE_TYPE_WITH_PRIVATE(XviewerTransform,xviewer_transform,G_TYPE_OBJECT)50 G_DEFINE_TYPE_WITH_PRIVATE (XviewerTransform, xviewer_transform, G_TYPE_OBJECT)
51
52 static void
53 xviewer_transform_init (XviewerTransform *trans)
54 {
55 trans->priv = xviewer_transform_get_instance_private (trans);
56 }
57
58 static void
xviewer_transform_class_init(XviewerTransformClass * klass)59 xviewer_transform_class_init (XviewerTransformClass *klass)
60 {
61
62 }
63
64 /**
65 * xviewer_transform_apply:
66 * @trans: a #XviewerTransform
67 * @pixbuf: a #GdkPixbuf
68 * @job: a #XviewerJob
69 *
70 * Applies the transformation in @trans to @pixbuf, setting its progress in @job.
71 *
72 * Returns: (transfer full): A new #GdkPixbuf with the transformation applied.
73 **/
74 GdkPixbuf*
xviewer_transform_apply(XviewerTransform * trans,GdkPixbuf * pixbuf,XviewerJob * job)75 xviewer_transform_apply (XviewerTransform *trans, GdkPixbuf *pixbuf, XviewerJob *job)
76 {
77 XviewerPoint dest_top_left;
78 XviewerPoint dest_bottom_right;
79 XviewerPoint vertices[4] = { {0, 0}, {1, 0}, {1, 1}, {0, 1} };
80 double r_det;
81 int inverted [6];
82 XviewerPoint dest;
83
84 int src_width;
85 int src_height;
86 int src_rowstride;
87 int src_n_channels;
88 guchar *src_buffer;
89
90 GdkPixbuf *dest_pixbuf;
91 int dest_width;
92 int dest_height;
93 int dest_rowstride;
94 int dest_n_channels;
95 guchar *dest_buffer;
96
97 guchar *src_pos;
98 guchar *dest_pos;
99 int dx, dy, sx, sy;
100 int i, x, y;
101
102 int progress_delta;
103
104 g_return_val_if_fail (pixbuf != NULL, NULL);
105
106 g_object_ref (pixbuf);
107
108 src_width = gdk_pixbuf_get_width (pixbuf);
109 src_height = gdk_pixbuf_get_height (pixbuf);
110 src_rowstride = gdk_pixbuf_get_rowstride (pixbuf);
111 src_n_channels = gdk_pixbuf_get_n_channels (pixbuf);
112 src_buffer = gdk_pixbuf_get_pixels (pixbuf);
113
114 /* find out the dimension of the destination pixbuf */
115 dest_top_left.x = 100000;
116 dest_top_left.y = 100000;
117 dest_bottom_right.x = -100000;
118 dest_bottom_right.y = -100000;
119
120 for (i = 0; i < 4; i++) {
121 dest.x = vertices[i].x * (src_width - 1);
122 dest.y = vertices[i].y * (src_height -1);
123
124 cairo_matrix_transform_point (&trans->priv->affine,
125 &dest.x, &dest.y);
126
127 dest_top_left.x = MIN (dest_top_left.x, dest.x);
128 dest_top_left.y = MIN (dest_top_left.y, dest.y);
129
130 dest_bottom_right.x = MAX (dest_bottom_right.x, dest.x);
131 dest_bottom_right.y = MAX (dest_bottom_right.y, dest.y);
132 }
133
134 /* create the resulting pixbuf */
135 dest_width = abs (dest_bottom_right.x - dest_top_left.x + 1);
136 dest_height = abs (dest_bottom_right.y - dest_top_left.y + 1);
137
138 dest_pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
139 gdk_pixbuf_get_has_alpha (pixbuf),
140 gdk_pixbuf_get_bits_per_sample (pixbuf),
141 dest_width,
142 dest_height);
143 dest_rowstride = gdk_pixbuf_get_rowstride (dest_pixbuf);
144 dest_n_channels = gdk_pixbuf_get_n_channels (dest_pixbuf);
145 dest_buffer = gdk_pixbuf_get_pixels (dest_pixbuf);
146
147 /* invert the matrix so that we can compute the source pixel
148 from the target pixel and convert the values to integer
149 ones (faster!) FIXME: Maybe we can do some more
150 improvements by using special mmx/3dnow features if
151 available.
152 */
153 r_det = 1.0 / (trans->priv->affine.xx * trans->priv->affine.yy - trans->priv->affine.yx * trans->priv->affine.xy);
154 inverted[0] = trans->priv->affine.yy * r_det;
155 inverted[1] = -trans->priv->affine.yx * r_det;
156 inverted[2] = -trans->priv->affine.xy * r_det;
157 inverted[3] = trans->priv->affine.xx * r_det;
158 inverted[4] = -trans->priv->affine.x0 * inverted[0] - trans->priv->affine.y0 * inverted[2];
159 inverted[5] = -trans->priv->affine.x0 * inverted[1] - trans->priv->affine.y0 * inverted[3];
160
161 progress_delta = MAX (1, dest_height / XVIEWER_TRANSFORM_N_PROG_UPDATES);
162
163 /*
164 * for every destination pixel (dx,dy) compute the source pixel (sx, sy)
165 * and copy the color values
166 */
167 for (y = 0, dy = dest_top_left.y; y < dest_height; y++, dy++) {
168 for (x = 0, dx = dest_top_left.x; x < dest_width; x++, dx++) {
169
170 sx = dx * inverted[0] + dy * inverted[2] + inverted[4];
171 sy = dx * inverted[1] + dy * inverted[3] + inverted[5];
172
173 if (sx >= 0 && sx < src_width && sy >= 0 && sy < src_height) {
174 src_pos = src_buffer + sy * src_rowstride + sx * src_n_channels;
175 dest_pos = dest_buffer + y * dest_rowstride + x * dest_n_channels;
176
177 for (i = 0; i < src_n_channels; i++) {
178 dest_pos[i] = src_pos[i];
179 }
180 }
181 }
182
183 if (job != NULL && y % progress_delta == 0) {
184 gfloat progress;
185
186 progress = (gfloat) (y + 1.0) / (gfloat) dest_height;
187
188 xviewer_job_set_progress (job, progress);
189 }
190 }
191
192 g_object_unref (pixbuf);
193
194 if (job != NULL) {
195 xviewer_job_set_progress (job, 1.0);
196 }
197
198 return dest_pixbuf;
199 }
200
201 static void
_xviewer_cairo_matrix_copy(const cairo_matrix_t * src,cairo_matrix_t * dest)202 _xviewer_cairo_matrix_copy (const cairo_matrix_t *src, cairo_matrix_t *dest)
203 {
204 cairo_matrix_init (dest, src->xx, src->yx, src->xy, src->yy, src->x0, src->y0);
205 }
206
207 #define DOUBLE_EQUAL_MAX_DIFF 1e-6
208 #define DOUBLE_EQUAL(a,b) (fabs (a - b) < DOUBLE_EQUAL_MAX_DIFF)
209 /* art_affine_equal modified to work with cairo_matrix_t */
210 static gboolean
_xviewer_cairo_matrix_equal(const cairo_matrix_t * a,const cairo_matrix_t * b)211 _xviewer_cairo_matrix_equal (const cairo_matrix_t *a, const cairo_matrix_t *b)
212 {
213 return (DOUBLE_EQUAL (a->xx, b->xx) && DOUBLE_EQUAL (a->yx, b->yx) &&
214 DOUBLE_EQUAL (a->xy, b->xy) && DOUBLE_EQUAL (a->yy, b->yy) &&
215 DOUBLE_EQUAL (a->x0, b->x0) && DOUBLE_EQUAL (a->y0, b->y0) );
216 }
217
218 /* art_affine_flip modified to work with cairo_matrix_t */
219 static void
_xviewer_cairo_matrix_flip(cairo_matrix_t * dst,const cairo_matrix_t * src,gboolean horiz,gboolean vert)220 _xviewer_cairo_matrix_flip (cairo_matrix_t *dst, const cairo_matrix_t *src, gboolean horiz, gboolean vert)
221 {
222 dst->xx = horiz ? -src->xx : src->xx;
223 dst->yx = horiz ? -src->yx : src->yx;
224 dst->xy = vert ? -src->xy : src->xy;
225 dst->yy = vert ? -src->yy : src->yy;
226 dst->x0 = horiz ? -src->x0 : src->x0;
227 dst->y0 = vert ? -src->y0 : src->y0;
228 }
229
230 /**
231 * xviewer_transform_reverse:
232 * @trans: a #XviewerTransform
233 *
234 * Creates the reverse transformation of @trans
235 *
236 * Returns: (transfer full): a new transformation
237 **/
238 XviewerTransform*
xviewer_transform_reverse(XviewerTransform * trans)239 xviewer_transform_reverse (XviewerTransform *trans)
240 {
241 XviewerTransform *reverse;
242
243 g_return_val_if_fail (XVIEWER_IS_TRANSFORM (trans), NULL);
244
245 reverse = XVIEWER_TRANSFORM (g_object_new (XVIEWER_TYPE_TRANSFORM, NULL));
246
247 _xviewer_cairo_matrix_copy (&trans->priv->affine, &reverse->priv->affine);
248
249 g_return_val_if_fail (cairo_matrix_invert (&reverse->priv->affine) == CAIRO_STATUS_SUCCESS, reverse);
250
251 return reverse;
252 }
253
254 /**
255 * xviewer_transform_compose:
256 * @trans: a #XviewerTransform
257 * @compose: another #XviewerTransform
258 *
259 *
260 *
261 * Returns: (transfer full): a new transform
262 **/
263 XviewerTransform*
xviewer_transform_compose(XviewerTransform * trans,XviewerTransform * compose)264 xviewer_transform_compose (XviewerTransform *trans, XviewerTransform *compose)
265 {
266 XviewerTransform *composition;
267
268 g_return_val_if_fail (XVIEWER_IS_TRANSFORM (trans), NULL);
269 g_return_val_if_fail (XVIEWER_IS_TRANSFORM (compose), NULL);
270
271 composition = XVIEWER_TRANSFORM (g_object_new (XVIEWER_TYPE_TRANSFORM, NULL));
272
273 cairo_matrix_multiply (&composition->priv->affine,
274 &trans->priv->affine,
275 &compose->priv->affine);
276
277 return composition;
278 }
279
280 gboolean
xviewer_transform_is_identity(XviewerTransform * trans)281 xviewer_transform_is_identity (XviewerTransform *trans)
282 {
283 static const cairo_matrix_t identity = { 1, 0, 0, 1, 0, 0 };
284
285 g_return_val_if_fail (XVIEWER_IS_TRANSFORM (trans), FALSE);
286
287 return _xviewer_cairo_matrix_equal (&identity, &trans->priv->affine);
288 }
289
290 XviewerTransform*
xviewer_transform_identity_new(void)291 xviewer_transform_identity_new (void)
292 {
293 XviewerTransform *trans;
294
295 trans = XVIEWER_TRANSFORM (g_object_new (XVIEWER_TYPE_TRANSFORM, NULL));
296
297 cairo_matrix_init_identity (&trans->priv->affine);
298
299 return trans;
300 }
301
302 XviewerTransform*
xviewer_transform_rotate_new(int degree)303 xviewer_transform_rotate_new (int degree)
304 {
305 XviewerTransform *trans;
306
307 trans = XVIEWER_TRANSFORM (g_object_new (XVIEWER_TYPE_TRANSFORM, NULL));
308
309 cairo_matrix_init_rotate (&trans->priv->affine, XVIEWER_DEG_TO_RAD(degree));
310
311 return trans;
312 }
313
314 XviewerTransform*
xviewer_transform_flip_new(XviewerTransformType type)315 xviewer_transform_flip_new (XviewerTransformType type)
316 {
317 XviewerTransform *trans;
318 gboolean horiz, vert;
319
320 trans = XVIEWER_TRANSFORM (g_object_new (XVIEWER_TYPE_TRANSFORM, NULL));
321
322 cairo_matrix_init_identity (&trans->priv->affine);
323
324 horiz = (type == XVIEWER_TRANSFORM_FLIP_HORIZONTAL);
325 vert = (type == XVIEWER_TRANSFORM_FLIP_VERTICAL);
326
327 _xviewer_cairo_matrix_flip (&trans->priv->affine,
328 &trans->priv->affine,
329 horiz, vert);
330
331 return trans;
332 }
333
334 XviewerTransform*
xviewer_transform_new(XviewerTransformType type)335 xviewer_transform_new (XviewerTransformType type)
336 {
337 XviewerTransform *trans = NULL;
338 XviewerTransform *temp1 = NULL, *temp2 = NULL;
339
340 switch (type) {
341 case XVIEWER_TRANSFORM_NONE:
342 trans = xviewer_transform_identity_new ();
343 break;
344 case XVIEWER_TRANSFORM_FLIP_HORIZONTAL:
345 trans = xviewer_transform_flip_new (XVIEWER_TRANSFORM_FLIP_HORIZONTAL);
346 break;
347 case XVIEWER_TRANSFORM_ROT_180:
348 trans = xviewer_transform_rotate_new (180);
349 break;
350 case XVIEWER_TRANSFORM_FLIP_VERTICAL:
351 trans = xviewer_transform_flip_new (XVIEWER_TRANSFORM_FLIP_VERTICAL);
352 break;
353 case XVIEWER_TRANSFORM_TRANSPOSE:
354 temp1 = xviewer_transform_rotate_new (90);
355 temp2 = xviewer_transform_flip_new (XVIEWER_TRANSFORM_FLIP_HORIZONTAL);
356 trans = xviewer_transform_compose (temp1, temp2);
357 g_object_unref (temp1);
358 g_object_unref (temp2);
359 break;
360 case XVIEWER_TRANSFORM_ROT_90:
361 trans = xviewer_transform_rotate_new (90);
362 break;
363 case XVIEWER_TRANSFORM_TRANSVERSE:
364 temp1 = xviewer_transform_rotate_new (90);
365 temp2 = xviewer_transform_flip_new (XVIEWER_TRANSFORM_FLIP_VERTICAL);
366 trans = xviewer_transform_compose (temp1, temp2);
367 g_object_unref (temp1);
368 g_object_unref (temp2);
369 break;
370 case XVIEWER_TRANSFORM_ROT_270:
371 trans = xviewer_transform_rotate_new (270);
372 break;
373 default:
374 trans = xviewer_transform_identity_new ();
375 break;
376 }
377
378 return trans;
379 }
380
381 XviewerTransformType
xviewer_transform_get_transform_type(XviewerTransform * trans)382 xviewer_transform_get_transform_type (XviewerTransform *trans)
383 {
384 cairo_matrix_t affine, a1, a2;
385 XviewerTransformPrivate *priv;
386
387 g_return_val_if_fail (XVIEWER_IS_TRANSFORM (trans), XVIEWER_TRANSFORM_NONE);
388
389 priv = trans->priv;
390
391 cairo_matrix_init_rotate (&affine, XVIEWER_DEG_TO_RAD(90));
392 if (_xviewer_cairo_matrix_equal (&affine, &priv->affine)) {
393 return XVIEWER_TRANSFORM_ROT_90;
394 }
395
396 cairo_matrix_init_rotate (&affine, XVIEWER_DEG_TO_RAD(180));
397 if (_xviewer_cairo_matrix_equal (&affine, &priv->affine)) {
398 return XVIEWER_TRANSFORM_ROT_180;
399 }
400
401 cairo_matrix_init_rotate (&affine, XVIEWER_DEG_TO_RAD(270));
402 if (_xviewer_cairo_matrix_equal (&affine, &priv->affine)) {
403 return XVIEWER_TRANSFORM_ROT_270;
404 }
405
406 cairo_matrix_init_identity (&affine);
407 _xviewer_cairo_matrix_flip (&affine, &affine, TRUE, FALSE);
408 if (_xviewer_cairo_matrix_equal (&affine, &priv->affine)) {
409 return XVIEWER_TRANSFORM_FLIP_HORIZONTAL;
410 }
411
412 cairo_matrix_init_identity (&affine);
413 _xviewer_cairo_matrix_flip (&affine, &affine, FALSE, TRUE);
414 if (_xviewer_cairo_matrix_equal (&affine, &priv->affine)) {
415 return XVIEWER_TRANSFORM_FLIP_VERTICAL;
416 }
417
418 cairo_matrix_init_rotate (&a1, XVIEWER_DEG_TO_RAD(90));
419 cairo_matrix_init_identity (&a2);
420 _xviewer_cairo_matrix_flip (&a2, &a2, TRUE, FALSE);
421 cairo_matrix_multiply(&affine, &a1, &a2);
422 if (_xviewer_cairo_matrix_equal (&affine, &priv->affine)) {
423 return XVIEWER_TRANSFORM_TRANSPOSE;
424 }
425
426 /* A transversion is a 180° rotation followed by a transposition */
427 /* Reuse the transposition from the previous step for this. */
428 cairo_matrix_init_rotate (&a1, XVIEWER_DEG_TO_RAD(180));
429 cairo_matrix_multiply(&a2, &a1, &affine);
430 if (_xviewer_cairo_matrix_equal (&a2, &priv->affine)) {
431 return XVIEWER_TRANSFORM_TRANSVERSE;
432 }
433
434 return XVIEWER_TRANSFORM_NONE;
435 }
436
437 gboolean
xviewer_transform_get_affine(XviewerTransform * trans,cairo_matrix_t * affine)438 xviewer_transform_get_affine (XviewerTransform *trans, cairo_matrix_t *affine)
439 {
440 g_return_val_if_fail (XVIEWER_IS_TRANSFORM (trans), FALSE);
441
442 _xviewer_cairo_matrix_copy (&trans->priv->affine, affine);
443
444 return TRUE;
445 }
446
447