/* Copyright (C) 2001-2015 Peter Selinger. This file is part of Potrace. It is free software and it is covered by the GNU General Public License. See the file COPYING for details. */ #ifndef GREYMAP_H #define GREYMAP_H #include #include /* internal format for greymaps. Note: in this format, rows are ordered from bottom to top. The pixels in each row are given from left to right. */ struct greymap_s { int w; /* width, in pixels */ int h; /* height, in pixels */ signed short int *map; /* raw data, w*h values */ }; typedef struct greymap_s greymap_t; /* macros for accessing pixel at index (x,y). Note that the origin is in the *lower* left corner. U* macros omit the bounds check. */ #define gm_index(gm, x, y) (&(gm)->map[(x)+(y)*(ssize_t)(gm)->w]) #define gm_safe(gm, x, y) ((int)(x)>=0 && (int)(x)<(gm)->w && (int)(y)>=0 && (int)(y)<(gm)->h) #define gm_bound(x, m) ((x)<0 ? 0 : (x)>=(m) ? (m)-1 : (x)) #define GM_UGET(gm, x, y) (*gm_index(gm, x, y)) #define GM_UINC(gm, x, y, b) (*gm_index(gm, x, y) += (short int)(b)) #define GM_UINV(gm, x, y) (*gm_index(gm, x, y) = 255 - *gm_index(gm, x, y)) #define GM_UPUT(gm, x, y, b) (*gm_index(gm, x, y) = (short int)(b)) #define GM_GET(gm, x, y) (gm_safe(gm, x, y) ? GM_UGET(gm, x, y) : 0) #define GM_INC(gm, x, y, b) (gm_safe(gm, x, y) ? GM_UINC(gm, x, y, b) : 0) #define GM_INV(gm, x, y) (gm_safe(gm, x, y) ? GM_UINV(gm, x, y) : 0) #define GM_PUT(gm, x, y, b) (gm_safe(gm, x, y) ? GM_UPUT(gm, x, y, b) : 0) #define GM_BGET(gm, x, y) GM_UGET(gm, gm_bound(x, gm->w), gm_bound(y, gm->h)) /* modes for cutting off out-of-range values. The following names refer to winding numbers. I.e., make a pixel black if winding number is nonzero, odd, or positive, respectively. We assume that 0 winding number corresponds to white (255). */ #define GM_MODE_NONZERO 1 #define GM_MODE_ODD 2 #define GM_MODE_POSITIVE 3 #define GM_MODE_NEGATIVE 4 extern char *gm_read_error; greymap_t *gm_new(int w, int h); greymap_t *gm_dup(greymap_t *gm); void gm_free(greymap_t *gm); void gm_clear(greymap_t *gm, int b); int gm_read(FILE *f, greymap_t **gmp); int gm_writepgm(FILE *f, greymap_t *gm, char *comment, int raw, int mode, double gamma); int gm_print(FILE *f, greymap_t *gm); #endif /* GREYMAP_H */