ref: 8f2d8d661e4230e61e095e336f1b14c739b62ba0
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. $Id$ */ #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 JBIG2_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; }