ref: c51afb6cce1f14340b7ec8476c64949b469614a7
dir: /jbig2_image.c/
/*
jbig2dec
Copyright (c) 2001-2003 artofcode LLC.
This software is distributed under license and may not
be copied, modified or distributed except as expressly
authorized under the terms of the license contained in
the file LICENSE in this distribution.
For information on commercial licensing, go to
http://www.artifex.com/licensing/ or contact
Artifex Software, Inc., 101 Lucas Valley Road #110,
San Rafael, CA 94903, U.S.A., +1(415)492-9861.
$Id$
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "os_types.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h> /* memcpy() */
#include "jbig2.h"
#include "jbig2_priv.h"
#include "jbig2_image.h"
/* allocate a Jbig2Image structure and its associated bitmap */
Jbig2Image* jbig2_image_new(Jbig2Ctx *ctx, int width, int height)
{
Jbig2Image *image;
int stride;
image = (Jbig2Image *)jbig2_alloc(ctx->allocator, sizeof(*image));
if (image == NULL) {
jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1,
"could not allocate image structure");
return NULL;
}
stride = ((width - 1) >> 3) + 1; /* generate a byte-aligned stride */
image->data = (uint8_t *)jbig2_alloc(ctx->allocator, stride*height);
if (image->data == NULL) {
jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1,
"could not allocate image data buffer! [%d bytes]\n", stride*height);
jbig2_free(ctx->allocator, image);
return NULL;
}
image->width = width;
image->height = height;
image->stride = stride;
image->refcount = 1;
return image;
}
/* clone an image pointer by bumping its reference count */
Jbig2Image* jbig2_image_clone(Jbig2Ctx *ctx, Jbig2Image *image)
{
image->refcount++;
return image;
}
/* release an image pointer, freeing it it appropriate */
void jbig2_image_release(Jbig2Ctx *ctx, Jbig2Image *image)
{
image->refcount--;
if (!image->refcount) jbig2_image_free(ctx, image);
}
/* free a Jbig2Image structure and its associated memory */
void jbig2_image_free(Jbig2Ctx *ctx, Jbig2Image *image)
{
jbig2_free(ctx->allocator, image->data);
jbig2_free(ctx->allocator, image);
}
/* composite one jbig2_image onto another */
int jbig2_image_compose(Jbig2Ctx *ctx, Jbig2Image *dst, Jbig2Image *src,
int x, int y, Jbig2ComposeOp op)
{
int i, j;
int w, h;
int leftbyte, rightbyte;
int shift;
uint8_t *s, *ss;
uint8_t *d, *dd;
uint8_t mask, rightmask;
if (op != JBIG2_COMPOSE_OR) {
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, -1,
"non-OR composition modes NYI");
}
/* clip */
w = src->width;
h = src->height;
ss = src->data;
/* FIXME: this isn't sufficient for the < 0 cases */
if (x < 0) { w += x; x = 0; }
if (y < 0) { h += y; y = 0; }
w = (x + w < dst->width) ? w : dst->width - x;
h = (y + h < dst->height) ? h : dst->height - y;
#ifdef JBIG2_DEBUG
jbig2_error(ctx, JBIG2_SEVERITY_DEBUG, -1,
"composting %dx%d at (%d, %d) afer clipping\n",
w, h, x, y);
#endif
#if 0
/* special case complete/strip replacement */
/* disabled because it's only safe to do when the destination
buffer is all-blank. */
if ((x == 0) && (w == src->width)) {
memcpy(dst->data + y*dst->stride, src->data, h*src->stride);
return 0;
}
#endif
leftbyte = x >> 3;
rightbyte = (x + w - 1) >> 3;
shift = x & 7;
/* general OR case */
s = ss;
d = dd = dst->data + y*dst->stride + leftbyte;
if (leftbyte == rightbyte) {
mask = 0x100 - (0x100 >> w);
for (j = 0; j < h; j++) {
*d |= (*s & mask) >> shift;
d += dst->stride;
s += src->stride;
}
} else if (shift == 0) {
for (j = 0; j < h; j++) {
for (i = leftbyte; i <= rightbyte; i++)
*d++ |= *s++;
d = (dd += dst->stride);
s = (ss += src->stride);
}
} else {
mask = 0x100 - (1 << shift);
if (((w + 7) >> 3) < ((x + w + 7) >> 3) - (x >> 3))
rightmask = (0x100 - (0x100 >> ((x + w) & 7))) >> (8 - shift);
else
rightmask = 0x100 - (0x100 >> (w & 7));
for (j = 0; j < h; j++) {
*d++ |= (*s & mask) >> shift;
for(i = leftbyte; i < rightbyte - 1; i++) {
*d |= ((*s++ & ~mask) << (8 - shift));
*d++ |= ((*s & mask) >> shift);
}
if (((w + 7) >> 3) < ((x + w + 7) >> 3) - (x >> 3))
*d |= (s[0] & rightmask) << (8 - shift);
else
*d |= ((s[0] & ~mask) << (8 - shift)) |
((s[1] & rightmask) >> shift);
d = (dd += dst->stride);
s = (ss += src->stride);
}
}
return 0;
}
/* look up a pixel value in an image.
returns 0 outside the image frame for the convenience of
the template code
*/
int jbig2_image_get_pixel(Jbig2Image *image, int x, int y)
{
const int w = image->width;
const int h = image->height;
const int byte = (x >> 3) + y*image->stride;
const int bit = 7 - (x & 7);
if ((x < 0) || (x >= w)) return 0;
if ((y < 0) || (y >= h)) return 0;
return ((image->data[byte]>>bit) & 1);
}
/* set an individual pixel value in an image */
int jbig2_image_set_pixel(Jbig2Image *image, int x, int y, bool value)
{
const int w = image->width;
const int h = image->height;
int i, scratch, mask;
int bit, byte;
if ((x < 0) || (x >= w)) return 0;
if ((y < 0) || (y >= h)) return 0;
byte = (x >> 3) + y*image->stride;
bit = 7 - (x & 7);
mask = (1 << bit) ^ 0xff;
scratch = image->data[byte] & mask;
image->data[byte] = scratch | (value << bit);
return 1;
}