1/*
2 * Copyright © 2000 SuSE, Inc.
3 * Copyright © 2007 Red Hat, Inc.
4 *
5 * Permission to use, copy, modify, distribute, and sell this software and its
6 * documentation for any purpose is hereby granted without fee, provided that
7 * the above copyright notice appear in all copies and that both that
8 * copyright notice and this permission notice appear in supporting
9 * documentation, and that the name of SuSE not be used in advertising or
10 * publicity pertaining to distribution of the software without specific,
11 * written prior permission.  SuSE makes no representations about the
12 * suitability of this software for any purpose.  It is provided "as is"
13 * without express or implied warranty.
14 *
15 * SuSE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SuSE
17 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
18 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
19 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
20 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 */
22
23#ifdef HAVE_CONFIG_H
24#include <config.h>
25#endif
26
27#include <stdlib.h>
28#include <stdio.h>
29#include <string.h>
30#include <assert.h>
31
32#include "pixman-private.h"
33
34static const pixman_color_t transparent_black = { 0, 0, 0, 0 };
35
36static void
37gradient_property_changed (pixman_image_t *image)
38{
39    gradient_t *gradient = &image->gradient;
40    int n = gradient->n_stops;
41    pixman_gradient_stop_t *stops = gradient->stops;
42    pixman_gradient_stop_t *begin = &(gradient->stops[-1]);
43    pixman_gradient_stop_t *end = &(gradient->stops[n]);
44
45    switch (gradient->common.repeat)
46    {
47    default:
48    case PIXMAN_REPEAT_NONE:
49	begin->x = INT32_MIN;
50	begin->color = transparent_black;
51	end->x = INT32_MAX;
52	end->color = transparent_black;
53	break;
54
55    case PIXMAN_REPEAT_NORMAL:
56	begin->x = stops[n - 1].x - pixman_fixed_1;
57	begin->color = stops[n - 1].color;
58	end->x = stops[0].x + pixman_fixed_1;
59	end->color = stops[0].color;
60	break;
61
62    case PIXMAN_REPEAT_REFLECT:
63	begin->x = - stops[0].x;
64	begin->color = stops[0].color;
65	end->x = pixman_int_to_fixed (2) - stops[n - 1].x;
66	end->color = stops[n - 1].color;
67	break;
68
69    case PIXMAN_REPEAT_PAD:
70	begin->x = INT32_MIN;
71	begin->color = stops[0].color;
72	end->x = INT32_MAX;
73	end->color = stops[n - 1].color;
74	break;
75    }
76}
77
78pixman_bool_t
79_pixman_init_gradient (gradient_t *                  gradient,
80                       const pixman_gradient_stop_t *stops,
81                       int                           n_stops)
82{
83    return_val_if_fail (n_stops > 0, FALSE);
84
85    /* We allocate two extra stops, one before the beginning of the stop list,
86     * and one after the end. These stops are initialized to whatever color
87     * would be used for positions outside the range of the stop list.
88     *
89     * This saves a bit of computation in the gradient walker.
90     *
91     * The pointer we store in the gradient_t struct still points to the
92     * first user-supplied struct, so when freeing, we will have to
93     * subtract one.
94     */
95    gradient->stops =
96	pixman_malloc_ab (n_stops + 2, sizeof (pixman_gradient_stop_t));
97    if (!gradient->stops)
98	return FALSE;
99
100    gradient->stops += 1;
101    memcpy (gradient->stops, stops, n_stops * sizeof (pixman_gradient_stop_t));
102    gradient->n_stops = n_stops;
103
104    gradient->common.property_changed = gradient_property_changed;
105
106    return TRUE;
107}
108
109void
110_pixman_image_init (pixman_image_t *image)
111{
112    image_common_t *common = &image->common;
113
114    pixman_region32_init (&common->clip_region);
115
116    common->alpha_count = 0;
117    common->have_clip_region = FALSE;
118    common->clip_sources = FALSE;
119    common->transform = NULL;
120    common->repeat = PIXMAN_REPEAT_NONE;
121    common->filter = PIXMAN_FILTER_NEAREST;
122    common->filter_params = NULL;
123    common->n_filter_params = 0;
124    common->alpha_map = NULL;
125    common->component_alpha = FALSE;
126    common->ref_count = 1;
127    common->property_changed = NULL;
128    common->client_clip = FALSE;
129    common->destroy_func = NULL;
130    common->destroy_data = NULL;
131    common->dirty = TRUE;
132}
133
134pixman_bool_t
135_pixman_image_fini (pixman_image_t *image)
136{
137    image_common_t *common = (image_common_t *)image;
138
139    common->ref_count--;
140
141    if (common->ref_count == 0)
142    {
143	if (image->common.destroy_func)
144	    image->common.destroy_func (image, image->common.destroy_data);
145
146	pixman_region32_fini (&common->clip_region);
147
148	free (common->transform);
149	free (common->filter_params);
150
151	if (common->alpha_map)
152	    pixman_image_unref ((pixman_image_t *)common->alpha_map);
153
154	if (image->type == LINEAR ||
155	    image->type == RADIAL ||
156	    image->type == CONICAL)
157	{
158	    if (image->gradient.stops)
159	    {
160		/* See _pixman_init_gradient() for an explanation of the - 1 */
161		free (image->gradient.stops - 1);
162	    }
163
164	    /* This will trigger if someone adds a property_changed
165	     * method to the linear/radial/conical gradient overwriting
166	     * the general one.
167	     */
168	    assert (
169		image->common.property_changed == gradient_property_changed);
170	}
171
172	if (image->type == BITS && image->bits.free_me)
173	    free (image->bits.free_me);
174
175	return TRUE;
176    }
177
178    return FALSE;
179}
180
181pixman_image_t *
182_pixman_image_allocate (void)
183{
184    pixman_image_t *image = malloc (sizeof (pixman_image_t));
185
186    if (image)
187	_pixman_image_init (image);
188
189    return image;
190}
191
192static void
193image_property_changed (pixman_image_t *image)
194{
195    image->common.dirty = TRUE;
196}
197
198/* Ref Counting */
199PIXMAN_EXPORT pixman_image_t *
200pixman_image_ref (pixman_image_t *image)
201{
202    image->common.ref_count++;
203
204    return image;
205}
206
207/* returns TRUE when the image is freed */
208PIXMAN_EXPORT pixman_bool_t
209pixman_image_unref (pixman_image_t *image)
210{
211    if (_pixman_image_fini (image))
212    {
213	free (image);
214	return TRUE;
215    }
216
217    return FALSE;
218}
219
220PIXMAN_EXPORT void
221pixman_image_set_destroy_function (pixman_image_t *            image,
222                                   pixman_image_destroy_func_t func,
223                                   void *                      data)
224{
225    image->common.destroy_func = func;
226    image->common.destroy_data = data;
227}
228
229PIXMAN_EXPORT void *
230pixman_image_get_destroy_data (pixman_image_t *image)
231{
232  return image->common.destroy_data;
233}
234
235void
236_pixman_image_reset_clip_region (pixman_image_t *image)
237{
238    image->common.have_clip_region = FALSE;
239}
240
241/* Executive Summary: This function is a no-op that only exists
242 * for historical reasons.
243 *
244 * There used to be a bug in the X server where it would rely on
245 * out-of-bounds accesses when it was asked to composite with a
246 * window as the source. It would create a pixman image pointing
247 * to some bogus position in memory, but then set a clip region
248 * to the position where the actual bits were.
249 *
250 * Due to a bug in old versions of pixman, where it would not clip
251 * against the image bounds when a clip region was set, this would
252 * actually work. So when the pixman bug was fixed, a workaround was
253 * added to allow certain out-of-bound accesses. This function disabled
254 * those workarounds.
255 *
256 * Since 0.21.2, pixman doesn't do these workarounds anymore, so now
257 * this function is a no-op.
258 */
259PIXMAN_EXPORT void
260pixman_disable_out_of_bounds_workaround (void)
261{
262}
263
264static void
265compute_image_info (pixman_image_t *image)
266{
267    pixman_format_code_t code;
268    uint32_t flags = 0;
269
270    /* Transform */
271    if (!image->common.transform)
272    {
273	flags |= (FAST_PATH_ID_TRANSFORM	|
274		  FAST_PATH_X_UNIT_POSITIVE	|
275		  FAST_PATH_Y_UNIT_ZERO		|
276		  FAST_PATH_AFFINE_TRANSFORM);
277    }
278    else
279    {
280	flags |= FAST_PATH_HAS_TRANSFORM;
281
282	if (image->common.transform->matrix[2][0] == 0			&&
283	    image->common.transform->matrix[2][1] == 0			&&
284	    image->common.transform->matrix[2][2] == pixman_fixed_1)
285	{
286	    flags |= FAST_PATH_AFFINE_TRANSFORM;
287
288	    if (image->common.transform->matrix[0][1] == 0 &&
289		image->common.transform->matrix[1][0] == 0)
290	    {
291		if (image->common.transform->matrix[0][0] == -pixman_fixed_1 &&
292		    image->common.transform->matrix[1][1] == -pixman_fixed_1)
293		{
294		    flags |= FAST_PATH_ROTATE_180_TRANSFORM;
295		}
296		flags |= FAST_PATH_SCALE_TRANSFORM;
297	    }
298	    else if (image->common.transform->matrix[0][0] == 0 &&
299	             image->common.transform->matrix[1][1] == 0)
300	    {
301		pixman_fixed_t m01 = image->common.transform->matrix[0][1];
302		pixman_fixed_t m10 = image->common.transform->matrix[1][0];
303
304		if (m01 == -pixman_fixed_1 && m10 == pixman_fixed_1)
305		    flags |= FAST_PATH_ROTATE_90_TRANSFORM;
306		else if (m01 == pixman_fixed_1 && m10 == -pixman_fixed_1)
307		    flags |= FAST_PATH_ROTATE_270_TRANSFORM;
308	    }
309	}
310
311	if (image->common.transform->matrix[0][0] > 0)
312	    flags |= FAST_PATH_X_UNIT_POSITIVE;
313
314	if (image->common.transform->matrix[1][0] == 0)
315	    flags |= FAST_PATH_Y_UNIT_ZERO;
316    }
317
318    /* Filter */
319    switch (image->common.filter)
320    {
321    case PIXMAN_FILTER_NEAREST:
322    case PIXMAN_FILTER_FAST:
323	flags |= (FAST_PATH_NEAREST_FILTER | FAST_PATH_NO_CONVOLUTION_FILTER);
324	break;
325
326    case PIXMAN_FILTER_BILINEAR:
327    case PIXMAN_FILTER_GOOD:
328    case PIXMAN_FILTER_BEST:
329	flags |= (FAST_PATH_BILINEAR_FILTER | FAST_PATH_NO_CONVOLUTION_FILTER);
330
331	/* Here we have a chance to optimize BILINEAR filter to NEAREST if
332	 * they are equivalent for the currently used transformation matrix.
333	 */
334	if (flags & FAST_PATH_ID_TRANSFORM)
335	{
336	    flags |= FAST_PATH_NEAREST_FILTER;
337	}
338	else if (
339	    /* affine and integer translation components in matrix ... */
340	    ((flags & FAST_PATH_AFFINE_TRANSFORM) &&
341	     !pixman_fixed_frac (image->common.transform->matrix[0][2] |
342				 image->common.transform->matrix[1][2])) &&
343	    (
344		/* ... combined with a simple rotation */
345		(flags & (FAST_PATH_ROTATE_90_TRANSFORM |
346			  FAST_PATH_ROTATE_180_TRANSFORM |
347			  FAST_PATH_ROTATE_270_TRANSFORM)) ||
348		/* ... or combined with a simple non-rotated translation */
349		(image->common.transform->matrix[0][0] == pixman_fixed_1 &&
350		 image->common.transform->matrix[1][1] == pixman_fixed_1 &&
351		 image->common.transform->matrix[0][1] == 0 &&
352		 image->common.transform->matrix[1][0] == 0)
353		)
354	    )
355	{
356	    /* FIXME: there are some affine-test failures, showing that
357	     * handling of BILINEAR and NEAREST filter is not quite
358	     * equivalent when getting close to 32K for the translation
359	     * components of the matrix. That's likely some bug, but for
360	     * now just skip BILINEAR->NEAREST optimization in this case.
361	     */
362	    pixman_fixed_t magic_limit = pixman_int_to_fixed (30000);
363	    if (image->common.transform->matrix[0][2] <= magic_limit  &&
364	        image->common.transform->matrix[1][2] <= magic_limit  &&
365	        image->common.transform->matrix[0][2] >= -magic_limit &&
366	        image->common.transform->matrix[1][2] >= -magic_limit)
367	    {
368		flags |= FAST_PATH_NEAREST_FILTER;
369	    }
370	}
371	break;
372
373    case PIXMAN_FILTER_CONVOLUTION:
374	break;
375
376    case PIXMAN_FILTER_SEPARABLE_CONVOLUTION:
377	flags |= FAST_PATH_SEPARABLE_CONVOLUTION_FILTER;
378	break;
379
380    default:
381	flags |= FAST_PATH_NO_CONVOLUTION_FILTER;
382	break;
383    }
384
385    /* Repeat mode */
386    switch (image->common.repeat)
387    {
388    case PIXMAN_REPEAT_NONE:
389	flags |=
390	    FAST_PATH_NO_REFLECT_REPEAT		|
391	    FAST_PATH_NO_PAD_REPEAT		|
392	    FAST_PATH_NO_NORMAL_REPEAT;
393	break;
394
395    case PIXMAN_REPEAT_REFLECT:
396	flags |=
397	    FAST_PATH_NO_PAD_REPEAT		|
398	    FAST_PATH_NO_NONE_REPEAT		|
399	    FAST_PATH_NO_NORMAL_REPEAT;
400	break;
401
402    case PIXMAN_REPEAT_PAD:
403	flags |=
404	    FAST_PATH_NO_REFLECT_REPEAT		|
405	    FAST_PATH_NO_NONE_REPEAT		|
406	    FAST_PATH_NO_NORMAL_REPEAT;
407	break;
408
409    default:
410	flags |=
411	    FAST_PATH_NO_REFLECT_REPEAT		|
412	    FAST_PATH_NO_PAD_REPEAT		|
413	    FAST_PATH_NO_NONE_REPEAT;
414	break;
415    }
416
417    /* Component alpha */
418    if (image->common.component_alpha)
419	flags |= FAST_PATH_COMPONENT_ALPHA;
420    else
421	flags |= FAST_PATH_UNIFIED_ALPHA;
422
423    flags |= (FAST_PATH_NO_ACCESSORS | FAST_PATH_NARROW_FORMAT);
424
425    /* Type specific checks */
426    switch (image->type)
427    {
428    case SOLID:
429	code = PIXMAN_solid;
430
431	if (image->solid.color.alpha == 0xffff)
432	    flags |= FAST_PATH_IS_OPAQUE;
433	break;
434
435    case BITS:
436	if (image->bits.width == 1	&&
437	    image->bits.height == 1	&&
438	    image->common.repeat != PIXMAN_REPEAT_NONE)
439	{
440	    code = PIXMAN_solid;
441	}
442	else
443	{
444	    code = image->bits.format;
445	    flags |= FAST_PATH_BITS_IMAGE;
446	}
447
448	if (!PIXMAN_FORMAT_A (image->bits.format)				&&
449	    PIXMAN_FORMAT_TYPE (image->bits.format) != PIXMAN_TYPE_GRAY		&&
450	    PIXMAN_FORMAT_TYPE (image->bits.format) != PIXMAN_TYPE_COLOR)
451	{
452	    flags |= FAST_PATH_SAMPLES_OPAQUE;
453
454	    if (image->common.repeat != PIXMAN_REPEAT_NONE)
455		flags |= FAST_PATH_IS_OPAQUE;
456	}
457
458	if (image->bits.read_func || image->bits.write_func)
459	    flags &= ~FAST_PATH_NO_ACCESSORS;
460
461	if (PIXMAN_FORMAT_IS_WIDE (image->bits.format))
462	    flags &= ~FAST_PATH_NARROW_FORMAT;
463	break;
464
465    case RADIAL:
466	code = PIXMAN_unknown;
467
468	/*
469	 * As explained in pixman-radial-gradient.c, every point of
470	 * the plane has a valid associated radius (and thus will be
471	 * colored) if and only if a is negative (i.e. one of the two
472	 * circles contains the other one).
473	 */
474
475        if (image->radial.a >= 0)
476	    break;
477
478	/* Fall through */
479
480    case CONICAL:
481    case LINEAR:
482	code = PIXMAN_unknown;
483
484	if (image->common.repeat != PIXMAN_REPEAT_NONE)
485	{
486	    int i;
487
488	    flags |= FAST_PATH_IS_OPAQUE;
489	    for (i = 0; i < image->gradient.n_stops; ++i)
490	    {
491		if (image->gradient.stops[i].color.alpha != 0xffff)
492		{
493		    flags &= ~FAST_PATH_IS_OPAQUE;
494		    break;
495		}
496	    }
497	}
498	break;
499
500    default:
501	code = PIXMAN_unknown;
502	break;
503    }
504
505    /* Alpha map */
506    if (!image->common.alpha_map)
507    {
508	flags |= FAST_PATH_NO_ALPHA_MAP;
509    }
510    else
511    {
512	if (PIXMAN_FORMAT_IS_WIDE (image->common.alpha_map->format))
513	    flags &= ~FAST_PATH_NARROW_FORMAT;
514    }
515
516    /* Both alpha maps and convolution filters can introduce
517     * non-opaqueness in otherwise opaque images. Also
518     * an image with component alpha turned on is only opaque
519     * if all channels are opaque, so we simply turn it off
520     * unconditionally for those images.
521     */
522    if (image->common.alpha_map						||
523	image->common.filter == PIXMAN_FILTER_CONVOLUTION		||
524        image->common.filter == PIXMAN_FILTER_SEPARABLE_CONVOLUTION     ||
525	image->common.component_alpha)
526    {
527	flags &= ~(FAST_PATH_IS_OPAQUE | FAST_PATH_SAMPLES_OPAQUE);
528    }
529
530    image->common.flags = flags;
531    image->common.extended_format_code = code;
532}
533
534void
535_pixman_image_validate (pixman_image_t *image)
536{
537    if (image->common.dirty)
538    {
539	compute_image_info (image);
540
541	/* It is important that property_changed is
542	 * called *after* compute_image_info() because
543	 * property_changed() can make use of the flags
544	 * to set up accessors etc.
545	 */
546	if (image->common.property_changed)
547	    image->common.property_changed (image);
548
549	image->common.dirty = FALSE;
550    }
551
552    if (image->common.alpha_map)
553	_pixman_image_validate ((pixman_image_t *)image->common.alpha_map);
554}
555
556PIXMAN_EXPORT pixman_bool_t
557pixman_image_set_clip_region32 (pixman_image_t *   image,
558                                pixman_region32_t *region)
559{
560    image_common_t *common = (image_common_t *)image;
561    pixman_bool_t result;
562
563    if (region)
564    {
565	if ((result = pixman_region32_copy (&common->clip_region, region)))
566	    image->common.have_clip_region = TRUE;
567    }
568    else
569    {
570	_pixman_image_reset_clip_region (image);
571
572	result = TRUE;
573    }
574
575    image_property_changed (image);
576
577    return result;
578}
579
580PIXMAN_EXPORT pixman_bool_t
581pixman_image_set_clip_region (pixman_image_t *   image,
582                              pixman_region16_t *region)
583{
584    image_common_t *common = (image_common_t *)image;
585    pixman_bool_t result;
586
587    if (region)
588    {
589	if ((result = pixman_region32_copy_from_region16 (&common->clip_region, region)))
590	    image->common.have_clip_region = TRUE;
591    }
592    else
593    {
594	_pixman_image_reset_clip_region (image);
595
596	result = TRUE;
597    }
598
599    image_property_changed (image);
600
601    return result;
602}
603
604PIXMAN_EXPORT void
605pixman_image_set_has_client_clip (pixman_image_t *image,
606                                  pixman_bool_t   client_clip)
607{
608    image->common.client_clip = client_clip;
609}
610
611PIXMAN_EXPORT pixman_bool_t
612pixman_image_set_transform (pixman_image_t *          image,
613                            const pixman_transform_t *transform)
614{
615    static const pixman_transform_t id =
616    {
617	{ { pixman_fixed_1, 0, 0 },
618	  { 0, pixman_fixed_1, 0 },
619	  { 0, 0, pixman_fixed_1 } }
620    };
621
622    image_common_t *common = (image_common_t *)image;
623    pixman_bool_t result;
624
625    if (common->transform == transform)
626	return TRUE;
627
628    if (!transform || memcmp (&id, transform, sizeof (pixman_transform_t)) == 0)
629    {
630	free (common->transform);
631	common->transform = NULL;
632	result = TRUE;
633
634	goto out;
635    }
636
637    if (common->transform &&
638	memcmp (common->transform, transform, sizeof (pixman_transform_t)) == 0)
639    {
640	return TRUE;
641    }
642
643    if (common->transform == NULL)
644	common->transform = malloc (sizeof (pixman_transform_t));
645
646    if (common->transform == NULL)
647    {
648	result = FALSE;
649
650	goto out;
651    }
652
653    memcpy (common->transform, transform, sizeof(pixman_transform_t));
654
655    result = TRUE;
656
657out:
658    image_property_changed (image);
659
660    return result;
661}
662
663PIXMAN_EXPORT void
664pixman_image_set_repeat (pixman_image_t *image,
665                         pixman_repeat_t repeat)
666{
667    if (image->common.repeat == repeat)
668	return;
669
670    image->common.repeat = repeat;
671
672    image_property_changed (image);
673}
674
675PIXMAN_EXPORT pixman_bool_t
676pixman_image_set_filter (pixman_image_t *      image,
677                         pixman_filter_t       filter,
678                         const pixman_fixed_t *params,
679                         int                   n_params)
680{
681    image_common_t *common = (image_common_t *)image;
682    pixman_fixed_t *new_params;
683
684    if (params == common->filter_params && filter == common->filter)
685	return TRUE;
686
687    if (filter == PIXMAN_FILTER_SEPARABLE_CONVOLUTION)
688    {
689	int width = pixman_fixed_to_int (params[0]);
690	int height = pixman_fixed_to_int (params[1]);
691	int x_phase_bits = pixman_fixed_to_int (params[2]);
692	int y_phase_bits = pixman_fixed_to_int (params[3]);
693	int n_x_phases = (1 << x_phase_bits);
694	int n_y_phases = (1 << y_phase_bits);
695
696	return_val_if_fail (
697	    n_params == 4 + n_x_phases * width + n_y_phases * height, FALSE);
698    }
699
700    new_params = NULL;
701    if (params)
702    {
703	new_params = pixman_malloc_ab (n_params, sizeof (pixman_fixed_t));
704	if (!new_params)
705	    return FALSE;
706
707	memcpy (new_params,
708	        params, n_params * sizeof (pixman_fixed_t));
709    }
710
711    common->filter = filter;
712
713    if (common->filter_params)
714	free (common->filter_params);
715
716    common->filter_params = new_params;
717    common->n_filter_params = n_params;
718
719    image_property_changed (image);
720    return TRUE;
721}
722
723PIXMAN_EXPORT void
724pixman_image_set_source_clipping (pixman_image_t *image,
725                                  pixman_bool_t   clip_sources)
726{
727    if (image->common.clip_sources == clip_sources)
728	return;
729
730    image->common.clip_sources = clip_sources;
731
732    image_property_changed (image);
733}
734
735/* Unlike all the other property setters, this function does not
736 * copy the content of indexed. Doing this copying is simply
737 * way, way too expensive.
738 */
739PIXMAN_EXPORT void
740pixman_image_set_indexed (pixman_image_t *        image,
741                          const pixman_indexed_t *indexed)
742{
743    bits_image_t *bits = (bits_image_t *)image;
744
745    if (bits->indexed == indexed)
746	return;
747
748    bits->indexed = indexed;
749
750    image_property_changed (image);
751}
752
753PIXMAN_EXPORT void
754pixman_image_set_alpha_map (pixman_image_t *image,
755                            pixman_image_t *alpha_map,
756                            int16_t         x,
757                            int16_t         y)
758{
759    image_common_t *common = (image_common_t *)image;
760
761    return_if_fail (!alpha_map || alpha_map->type == BITS);
762
763    if (alpha_map && common->alpha_count > 0)
764    {
765	/* If this image is being used as an alpha map itself,
766	 * then you can't give it an alpha map of its own.
767	 */
768	return;
769    }
770
771    if (alpha_map && alpha_map->common.alpha_map)
772    {
773	/* If the image has an alpha map of its own,
774	 * then it can't be used as an alpha map itself
775	 */
776	return;
777    }
778
779    if (common->alpha_map != (bits_image_t *)alpha_map)
780    {
781	if (common->alpha_map)
782	{
783	    common->alpha_map->common.alpha_count--;
784
785	    pixman_image_unref ((pixman_image_t *)common->alpha_map);
786	}
787
788	if (alpha_map)
789	{
790	    common->alpha_map = (bits_image_t *)pixman_image_ref (alpha_map);
791
792	    common->alpha_map->common.alpha_count++;
793	}
794	else
795	{
796	    common->alpha_map = NULL;
797	}
798    }
799
800    common->alpha_origin_x = x;
801    common->alpha_origin_y = y;
802
803    image_property_changed (image);
804}
805
806PIXMAN_EXPORT void
807pixman_image_set_component_alpha   (pixman_image_t *image,
808                                    pixman_bool_t   component_alpha)
809{
810    if (image->common.component_alpha == component_alpha)
811	return;
812
813    image->common.component_alpha = component_alpha;
814
815    image_property_changed (image);
816}
817
818PIXMAN_EXPORT pixman_bool_t
819pixman_image_get_component_alpha   (pixman_image_t       *image)
820{
821    return image->common.component_alpha;
822}
823
824PIXMAN_EXPORT void
825pixman_image_set_accessors (pixman_image_t *           image,
826                            pixman_read_memory_func_t  read_func,
827                            pixman_write_memory_func_t write_func)
828{
829    return_if_fail (image != NULL);
830
831    if (image->type == BITS)
832    {
833	image->bits.read_func = read_func;
834	image->bits.write_func = write_func;
835
836	image_property_changed (image);
837    }
838}
839
840PIXMAN_EXPORT uint32_t *
841pixman_image_get_data (pixman_image_t *image)
842{
843    if (image->type == BITS)
844	return image->bits.bits;
845
846    return NULL;
847}
848
849PIXMAN_EXPORT int
850pixman_image_get_width (pixman_image_t *image)
851{
852    if (image->type == BITS)
853	return image->bits.width;
854
855    return 0;
856}
857
858PIXMAN_EXPORT int
859pixman_image_get_height (pixman_image_t *image)
860{
861    if (image->type == BITS)
862	return image->bits.height;
863
864    return 0;
865}
866
867PIXMAN_EXPORT int
868pixman_image_get_stride (pixman_image_t *image)
869{
870    if (image->type == BITS)
871	return image->bits.rowstride * (int) sizeof (uint32_t);
872
873    return 0;
874}
875
876PIXMAN_EXPORT int
877pixman_image_get_depth (pixman_image_t *image)
878{
879    if (image->type == BITS)
880	return PIXMAN_FORMAT_DEPTH (image->bits.format);
881
882    return 0;
883}
884
885PIXMAN_EXPORT pixman_format_code_t
886pixman_image_get_format (pixman_image_t *image)
887{
888    if (image->type == BITS)
889	return image->bits.format;
890
891    return PIXMAN_null;
892}
893
894uint32_t
895_pixman_image_get_solid (pixman_implementation_t *imp,
896			 pixman_image_t *         image,
897                         pixman_format_code_t     format)
898{
899    uint32_t result;
900
901    if (image->type == SOLID)
902    {
903	result = image->solid.color_32;
904    }
905    else if (image->type == BITS)
906    {
907	if (image->bits.format == PIXMAN_a8r8g8b8)
908	    result = image->bits.bits[0];
909	else if (image->bits.format == PIXMAN_x8r8g8b8)
910	    result = image->bits.bits[0] | 0xff000000;
911	else if (image->bits.format == PIXMAN_a8)
912	    result = (*(uint8_t *)image->bits.bits) << 24;
913	else
914	    goto otherwise;
915    }
916    else
917    {
918	pixman_iter_t iter;
919
920    otherwise:
921	_pixman_implementation_src_iter_init (
922	    imp, &iter, image, 0, 0, 1, 1,
923	    (uint8_t *)&result,
924	    ITER_NARROW, image->common.flags);
925
926	result = *iter.get_scanline (&iter, NULL);
927    }
928
929    /* If necessary, convert RGB <--> BGR. */
930    if (PIXMAN_FORMAT_TYPE (format) != PIXMAN_TYPE_ARGB
931	&& PIXMAN_FORMAT_TYPE (format) != PIXMAN_TYPE_ARGB_SRGB)
932    {
933	result = (((result & 0xff000000) >>  0) |
934	          ((result & 0x00ff0000) >> 16) |
935	          ((result & 0x0000ff00) >>  0) |
936	          ((result & 0x000000ff) << 16));
937    }
938
939    return result;
940}
941