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Updated from manual.

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This commit is contained in:
Marius Vollmer 2004-09-24 02:11:03 +00:00
parent 48d8f65992
commit 43631debba
1 changed files with 29 additions and 18 deletions
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47
doc/example-smob/image-type.c
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@ -1,6 +1,6 @@
/* image-type.c
*
* Copyright (C) 1998, 2000 Free Software Foundation, Inc.
* Copyright (C) 1998, 2000, 2004 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
@ -39,42 +39,53 @@ struct image {
static SCM
make_image (SCM name, SCM s_width, SCM s_height)
{
SCM smob;
struct image *image;
int width, height;
int width = scm_to_int (s_width);
int height = scm_to_int (s_height);
SCM_ASSERT (SCM_STRINGP (name), name, SCM_ARG1, "make-image");
SCM_ASSERT (SCM_INUMP (s_width), s_width, SCM_ARG2, "make-image");
SCM_ASSERT (SCM_INUMP (s_height), s_height, SCM_ARG3, "make-image");
width = SCM_INUM (s_width);
height = SCM_INUM (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 = scm_gc_malloc (width * height, "image pixels");
image->name = name;
image->pixels = NULL;
image->name = SCM_BOOL_F;
image->update_func = SCM_BOOL_F;
SCM_RETURN_NEWSMOB (image_tag, image);
/* 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;
}
static SCM
SCM
clear_image (SCM image_smob)
{
int area;
struct image *image;
SCM_ASSERT (SCM_SMOB_PREDICATE (image_tag, image_smob),
image_smob, SCM_ARG1, "clear-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 (image->update_func != SCM_BOOL_F)
scm_apply (image->update_func, SCM_EOL, SCM_EOL);
/* 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;
}