ref: 55a01f747fb2b992f7b777f1a2d7ee8cac1e13af
dir: /jbig2_image.c/
/*
jbig2dec
Copyright (c) 2001-2002 artofcode LLC.
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 of the License, or
(at your option) any later version.
$Id: jbig2_image.c,v 1.11 2002/07/03 14:56:15 giles Exp $
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#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) >> 5) + 1) << 2; /* generate a word-aligned stride */
image->data = (uint32_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 w, h;
int src_stride, dst_stride;
int leftword, rightword;
int leftbits, rightbits;
int row, word, shift, i;
uint32_t *s, *d;
uint32_t mask, highmask;
if (op != JBIG2_COMPOSE_OR) {
jbig2_error(ctx, JBIG2_SEVERITY_WARNING, -1,
"non-OR composition modes NYI");
}
/* clip */
w = src->width;
h = src->height;
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;
fprintf(stderr, "composting %dx%d at (%d, %d) afer clipping\n",
w, h, x, y);
/* special case complete/strip replacement */
if ((x == 0) && (w == src->width)) {
memcpy(dst->data + y*dst->stride, src->data, h*src->stride);
return 0;
}
/* general case */
leftword = x >> 5;
leftbits = x & 31;
rightword = (x + w) >> 5;
rightbits = (x + w) & 31;
shift = 0;
while (leftbits >= 1 << shift) shift++;
mask = 0;
if (leftbits) for (i = 0; i < leftbits; i++)
mask = mask << 1 | 1;
highmask = 1;
if (rightbits) for (i = 0; i < rightbits; i++)
highmask = highmask << 1 | 1;
/* word strides */
src_stride = src->stride >> 2;
dst_stride = dst->stride >> 2;
fprintf(stderr, "leftword = %d leftbits = %d rightword = %d rightbits=%d shift=%d\n",
leftword, leftbits, rightword, rightbits, shift);
fprintf(stderr, "mask = 0x%08x highmask = 0x%08x\n", mask, highmask);
if (leftword == rightword) {
for (row = 0; row < h; row++) {
s = src->data + row*src_stride;
d = dst->data + (y + row)*dst_stride + leftword;
*d |= (*s & mask) << leftbits;
}
} else {
mask = 0;
for (i = 0; i < 32 - leftbits; i++)
mask = mask << 1 | 1;
for (row = 0; row < h; row++) {
s = src->data + row*src_stride;
d = dst->data + (y + row)*dst_stride + leftword;
*d++ |= (*s & mask) << leftbits;
for(word = leftword; word < rightword; word++) {
*d |= (*s++ & ~mask) >> (32 - leftbits);
*d++ |= (*s & mask) << leftbits;
}
*d |= (*++s & highmask) << (32 - rightbits);
}
}
return 0;
}