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/* image-type.c
*
* Copyright (C) 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include <libguile.h>
static scm_t_bits image_tag;
struct image {
int width, height;
char *pixels;
/* The name of this image */
SCM name;
/* A function to call when this image is
modified, e.g., to update the screen,
or SCM_BOOL_F if no action necessary */
SCM update_func;
};
static SCM
make_image (SCM name, SCM s_width, SCM s_height)
{
SCM smob;
struct image *image;
int width = scm_to_int (s_width);
int height = scm_to_int (s_height);
/* Step 1: Allocate the memory block.
*/
image = (struct image *) scm_gc_malloc (sizeof (struct image), "image");
/* Step 2: Initialize it with straight code.
*/
image->width = width;
image->height = height;
image->pixels = NULL;
image->name = SCM_BOOL_F;
image->update_func = SCM_BOOL_F;
/* Step 3: Create the smob.
*/
SCM_NEWSMOB (smob, image_tag, image);
/* Step 4: Finish the initialization.
*/
image->name = name;
image->pixels = scm_gc_malloc (width * height, "image pixels");
return smob;
}
SCM
clear_image (SCM image_smob)
{
int area;
struct image *image;
scm_assert_smob_type (image_tag, image_smob);
image = (struct image *) SCM_SMOB_DATA (image_smob);
area = image->width * image->height;
memset (image->pixels, 0, area);
/* Invoke the image's update function.
*/
if (scm_is_true (image->update_func))
scm_call_0 (image->update_func);
scm_remember_upto_here_1 (image_smob);
return SCM_UNSPECIFIED;
}
static SCM
mark_image (SCM image_smob)
{
/* Mark the image's name and update function. */
struct image *image = (struct image *) SCM_SMOB_DATA (image_smob);
scm_gc_mark (image->name);
return image->update_func;
}
static size_t
free_image (SCM image_smob)
{
struct image *image = (struct image *) SCM_SMOB_DATA (image_smob);
scm_gc_free (image->pixels, image->width * image->height, "image pixels");
scm_gc_free (image, sizeof (struct image), "image");
return 0;
}
static int
print_image (SCM image_smob, SCM port, scm_print_state *pstate)
{
struct image *image = (struct image *) SCM_SMOB_DATA (image_smob);
scm_puts ("#<image ", port);
scm_display (image->name, port);
scm_puts (">", port);
/* non-zero means success */
return 1;
}
void
init_image_type (void)
{
image_tag = scm_make_smob_type ("image", sizeof (struct image));
scm_set_smob_mark (image_tag, mark_image);
scm_set_smob_free (image_tag, free_image);
scm_set_smob_print (image_tag, print_image);
scm_c_define_gsubr ("clear-image", 1, 0, 0, clear_image);
scm_c_define_gsubr ("make-image", 3, 0, 0, make_image);
}
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