ref: 43fcbcd7acbd0b2d64a770ca39590e2356df4337
dir: /jbig2_image.c/
/*
jbig2dec
Copyright (c) 2001-2002 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: jbig2_image.c,v 1.21 2003/02/07 05:06:46 raph Exp $
*/
#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;
return 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 DEBUG
fprintf(stderr, "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)) |
((*(++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;
}