ref: 6aa746d4788e43727f93ed58581ef13f45f5e4b1
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 1.19 2002/07/20 17:23:15 giles 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 /* special case complete/strip replacement */ if ((x == 0) && (w == src->width)) { memcpy(dst->data + y*dst->stride, src->data, h*src->stride); return 0; } 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; }