loader.c

linux下开源图片codec

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "loader.h"

/* ----------------------------------------------------------------------- */

void load_bits_lsb(unsigned char *dst, unsigned char *src, int width,
		   int on, int off)
{
    int i,mask,bit;
    
    for (i = 0; i < width; i++) {
	mask = 1 << (i & 0x07);
	bit  = src[i>>3] & mask;
	dst[0] = bit ? on : off;
	dst[1] = bit ? on : off;
	dst[2] = bit ? on : off;
	dst += 3;
    }
}

void load_bits_msb(unsigned char *dst, unsigned char *src, int width,
		   int on, int off)
{
    int i,mask,bit;
    
    for (i = 0; i < width; i++) {
	mask = 1 << (7 - (i & 0x07));
	bit  = src[i>>3] & mask;
	dst[0] = bit ? on : off;
	dst[1] = bit ? on : off;
	dst[2] = bit ? on : off;
	dst += 3;
    }
}

void load_gray(unsigned char *dst, unsigned char *src, int width)
{
    int i;

    for (i = 0; i < width; i++) {
	dst[0] = src[0];
	dst[1] = src[0];
	dst[2] = src[0];
	dst += 3;
	src += 1;
    }
}

void load_graya(unsigned char *dst, unsigned char *src, int width)
{
    int i;

    for (i = 0; i < width; i++) {
	dst[0] = src[0];
	dst[1] = src[0];
	dst[2] = src[0];
	dst += 3;
	src += 2;
    }
}

void load_rgba(unsigned char *dst, unsigned char *src, int width)
{
    int i;

    for (i = 0; i < width; i++) {
	dst[0] = src[0];
	dst[1] = src[1];
	dst[2] = src[2];
	dst += 3;
	src += 4;
    }
}

/* ----------------------------------------------------------------------- */

int load_add_extra(struct ida_image_info *info, enum ida_extype type,
		   unsigned char *data, unsigned int size)
{
    struct ida_extra *extra;

    extra = malloc(sizeof(*extra));
    if (NULL == extra)
	return -1;
    memset(extra,0,sizeof(*extra));
    extra->data = malloc(size);
    if (NULL == extra->data) {
	free(extra);
	return -1;
    }
    extra->type = type;
    extra->size = size;
    memcpy(extra->data,data,size);
    extra->next = info->extra;
    info->extra = extra;
    return 0;
};

struct ida_extra* load_find_extra(struct ida_image_info *info,
				  enum ida_extype type)
{
    struct ida_extra *extra;

    for (extra = info->extra; NULL != extra; extra = extra->next)
	if (type == extra->type)
	    return extra;
    return NULL;
}

int load_free_extras(struct ida_image_info *info)
{
    struct ida_extra *next;

    while (NULL != info->extra) {
	next = info->extra->next;
	free(info->extra->data);
	free(info->extra);
	info->extra = next;
    }
    return 0;
}

/* ----------------------------------------------------------------------- */

LIST_HEAD(loaders);
LIST_HEAD(writers);

void load_register(struct ida_loader *loader)
{
    list_add_tail(&loader->list, &loaders);
}

#ifdef USE_X11
void write_register(struct ida_writer *writer)
{
    list_add_tail(&writer->list, &writers);
}
#endif