1 /* image-type.c
2 *
3 * Copyright (C) 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2, or (at your option)
8 * any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this software; see the file COPYING. If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301 USA
19 */
20
21 #include <stdlib.h>
22 #include <libguile.h>
23
24 static scm_t_bits image_tag;
25
26 struct image {
27 int width, height;
28 char *pixels;
29
30 /* The name of this image */
31 SCM name;
32
33 /* A function to call when this image is
34 modified, e.g., to update the screen,
35 or SCM_BOOL_F if no action necessary */
36 SCM update_func;
37 };
38
39 static SCM
make_image(SCM name,SCM s_width,SCM s_height)40 make_image (SCM name, SCM s_width, SCM s_height)
41 {
42 SCM smob;
43 struct image *image;
44 int width = scm_to_int (s_width);
45 int height = scm_to_int (s_height);
46
47 /* Step 1: Allocate the memory block.
48 */
49 image = (struct image *) scm_gc_malloc (sizeof (struct image), "image");
50
51 /* Step 2: Initialize it with straight code.
52 */
53 image->width = width;
54 image->height = height;
55 image->pixels = NULL;
56 image->name = SCM_BOOL_F;
57 image->update_func = SCM_BOOL_F;
58
59 /* Step 3: Create the smob.
60 */
61 SCM_NEWSMOB (smob, image_tag, image);
62
63 /* Step 4: Finish the initialization.
64 */
65 image->name = name;
66 image->pixels = scm_gc_malloc (width * height, "image pixels");
67
68 return smob;
69 }
70
71 SCM
clear_image(SCM image_smob)72 clear_image (SCM image_smob)
73 {
74 int area;
75 struct image *image;
76
77 scm_assert_smob_type (image_tag, image_smob);
78
79 image = (struct image *) SCM_SMOB_DATA (image_smob);
80 area = image->width * image->height;
81 memset (image->pixels, 0, area);
82
83 /* Invoke the image's update function.
84 */
85 if (scm_is_true (image->update_func))
86 scm_call_0 (image->update_func);
87
88 scm_remember_upto_here_1 (image_smob);
89
90 return SCM_UNSPECIFIED;
91 }
92
93 static SCM
mark_image(SCM image_smob)94 mark_image (SCM image_smob)
95 {
96 /* Mark the image's name and update function. */
97 struct image *image = (struct image *) SCM_SMOB_DATA (image_smob);
98
99 scm_gc_mark (image->name);
100 return image->update_func;
101 }
102
103 static size_t
free_image(SCM image_smob)104 free_image (SCM image_smob)
105 {
106 struct image *image = (struct image *) SCM_SMOB_DATA (image_smob);
107
108 scm_gc_free (image->pixels, image->width * image->height, "image pixels");
109 scm_gc_free (image, sizeof (struct image), "image");
110
111 return 0;
112 }
113
114 static int
print_image(SCM image_smob,SCM port,scm_print_state * pstate)115 print_image (SCM image_smob, SCM port, scm_print_state *pstate)
116 {
117 struct image *image = (struct image *) SCM_SMOB_DATA (image_smob);
118
119 scm_puts ("#<image ", port);
120 scm_display (image->name, port);
121 scm_puts (">", port);
122
123 /* non-zero means success */
124 return 1;
125 }
126
127 void
init_image_type(void)128 init_image_type (void)
129 {
130 image_tag = scm_make_smob_type ("image", sizeof (struct image));
131 scm_set_smob_mark (image_tag, mark_image);
132 scm_set_smob_free (image_tag, free_image);
133 scm_set_smob_print (image_tag, print_image);
134
135 scm_c_define_gsubr ("clear-image", 1, 0, 0, clear_image);
136 scm_c_define_gsubr ("make-image", 3, 0, 0, make_image);
137 }
138