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Diffstat (limited to 'plug-ins/selection-to-path/bitmap.h')
| -rw-r--r-- | plug-ins/selection-to-path/bitmap.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/plug-ins/selection-to-path/bitmap.h b/plug-ins/selection-to-path/bitmap.h new file mode 100644 index 0000000..98c89ac --- /dev/null +++ b/plug-ins/selection-to-path/bitmap.h @@ -0,0 +1,112 @@ +/* bitmap.h: definition for a bitmap type. No packing is done by + * default; each pixel is represented by an entire byte. Among other + * things, this means the type can be used for both grayscale and binary + * images. + * + * Copyright (C) 1992 Free Software Foundation, Inc. + * + * 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 3, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#ifndef BITMAP_H +#define BITMAP_H + +#include <stdio.h> +#include "bounding-box.h" +#include "types.h" + + +/* If the bitmap holds 8-bit values, rather than one-bit, the + definition of BLACK here is wrong. So don't use it in that case! */ +#define WHITE 0 +#define BLACK 1 + + +/* The basic structure and macros to access it. */ +typedef struct +{ + dimensions_type dimensions; + one_byte *bitmap; +} bitmap_type; + +/* The dimensions of the bitmap, in pixels. */ +#define BITMAP_DIMENSIONS(b) ((b).dimensions) + +/* The pixels, represented as an array of bytes (in contiguous storage). + Each pixel is a single byte, even for binary fonts. */ +#define BITMAP_BITS(b) ((b).bitmap) + +/* These are convenient abbreviations for getting inside the members. */ +#define BITMAP_WIDTH(b) DIMENSIONS_WIDTH (BITMAP_DIMENSIONS (b)) +#define BITMAP_HEIGHT(b) DIMENSIONS_HEIGHT (BITMAP_DIMENSIONS (b)) + +/* This is the address of the first pixel in the row ROW. */ +#define BITMAP_ROW(b, row) (BITMAP_BITS (b) + (row) * BITMAP_WIDTH (b)) + +/* This is the pixel at [ROW,COL]. */ +#define BITMAP_PIXEL(b, row, col) \ + (*(BITMAP_BITS (b) + (row) * BITMAP_WIDTH (b) + (col))) + +#define BITMAP_VALID_PIXEL(b, row, col) \ + (0 <= (row) && (row) < BITMAP_HEIGHT (b) \ + && 0 <= (col) && (col) < BITMAP_WIDTH (b)) + +/* Assume that the pixel at [ROW,COL] itself is black. */ + +#define BITMAP_INTERIOR_PIXEL(b, row, col) \ + (0 != (row) && (row) != BITMAP_HEIGHT (b) - 1 \ + && 0 != (col) && (col) != BITMAP_WIDTH (b) - 1 \ + && BITMAP_PIXEL (b, row - 1, col - 1) == BLACK \ + && BITMAP_PIXEL (b, row - 1, col) == BLACK \ + && BITMAP_PIXEL (b, row - 1, col + 1) == BLACK \ + && BITMAP_PIXEL (b, row, col - 1) == BLACK \ + && BITMAP_PIXEL (b, row, col + 1) == BLACK \ + && BITMAP_PIXEL (b, row + 1, col - 1) == BLACK \ + && BITMAP_PIXEL (b, row + 1, col) == BLACK \ + && BITMAP_PIXEL (b, row + 1, col + 1) == BLACK) + +/* Allocate storage for the bits, set them all to white, and return an + initialized structure. */ +extern bitmap_type new_bitmap (dimensions_type); + +/* Free that storage. */ +extern void free_bitmap (bitmap_type *); + +/* Make a fresh copy of BITMAP in a new structure, and return it. */ +extern bitmap_type copy_bitmap (bitmap_type bitmap); + +/* Return the pixels in the bitmap B enclosed by the bounding box BB. + The result is put in newly allocated storage. */ +extern bitmap_type extract_subbitmap (bitmap_type b, bounding_box_type bb); + +/* Consider the dimensions of a bitmap as a bounding box. The bounding + box returned is in bitmap coordinates, rather than Cartesian, and + refers to pixels, rather than edges. Specifically, this means that + the maximum column is one less than results from `dimensions_to_bb + (BITMAP_DIMENSIONS ())'. */ +extern bounding_box_type bitmap_to_bb (const bitmap_type); + +/* Return a vector of zero-based column numbers marking transitions from + black to white or white to black in ROW, which is of length WIDTH. + The end of the vector is marked with an element of length WIDTH + 1. + The first element always marks a white-to-black transition (or it's + 0, if the first pixel in ROW is black). */ +extern unsigned *bitmap_find_transitions (const one_byte *row, unsigned width); + +/* Print part of or all of a bitmap. */ +extern void print_bounded_bitmap (FILE *, bitmap_type, bounding_box_type); +extern void print_bitmap (FILE *, bitmap_type); + +#endif /* not BITMAP_H */ + |