Substantial simplification of dochar(). The logic is the same, but

macros and the removal of a gratuitous array of structures make it
much less verbose.

diff --git a/bedstead.c b/bedstead.c
index 5835572a773dcfadb11adca48c7bd2e97b5d331a..feaa377e3831a17d1ed087547d23039165a54807 100644 (file)
--- a/bedstead.c
+++ b/bedstead.c
@@ -104,6 +104,7 @@
 
 #include <assert.h>
 #include <ctype.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -114,10 +115,6 @@
 #define XPIX 100
 #define YPIX 100
 
-struct corner {
-       int tl, tr, bl, br;
-};
-
 void doprologue(void);
 void dochar(char data[YSIZE], unsigned flags);
 
@@ -1112,85 +1109,48 @@ whitepixel(int x, int y, int bl, int br, int tr, int tl)
 void
 dochar(char data[YSIZE], unsigned flags)
 {
-       struct corner corner[XSIZE][YSIZE] = { };
        int x, y;
 
 #define GETPIX(x,y) (getpix(data, (x), (y), flags))
+#define L GETPIX(x-1, y)
+#define R GETPIX(x+1, y)
+#define U GETPIX(x, y-1)
+#define D GETPIX(x, y+1)
+#define UL GETPIX(x-1, y-1)
+#define UR GETPIX(x+1, y-1)
+#define DL GETPIX(x-1, y+1)
+#define DR GETPIX(x+1, y+1)
 
        clearpath();
        for (x = 0; x < XSIZE; x++) {
                for (y = 0; y < YSIZE; y++) {
                        if (GETPIX(x, y)) {
+                               bool tl, tr, bl, br;
+
                                /* Assume filled in */
-                               corner[x][y].tl = 1;
-                               corner[x][y].tr = 1;
-                               corner[x][y].bl = 1;
-                               corner[x][y].br = 1;
+                               tl = tr = bl = br = true;
                                /* Check for diagonals */
-                               if ((GETPIX(x-1, y) == 0 &&
-                                    GETPIX(x, y-1) == 0 &&
-                                    GETPIX(x-1, y-1) == 1) ||
-                                   (GETPIX(x+1, y) == 0 &&
-                                    GETPIX(x, y+1) == 0 &&
-                                    GETPIX(x+1, y+1) == 1)) {
-                                       corner[x][y].tr = 0;
-                                       corner[x][y].bl = 0;
-                               }
-                               if ((GETPIX(x+1, y) == 0 &&
-                                    GETPIX(x, y-1) == 0 &&
-                                    GETPIX(x+1, y-1) == 1) ||
-                                   (GETPIX(x-1, y) == 0 &&
-                                    GETPIX(x, y+1) == 0 &&
-                                    GETPIX(x-1, y+1) == 1)) {
-                                       corner[x][y].tl = 0;
-                                       corner[x][y].br = 0;
-                               }
+                               if ((UL && !U && !L) || (DR && !D && !R))
+                                       tr = bl = false;
+                               if ((UR && !U && !R) || (DL && !D && !L))
+                                       tl = br = false;
                                /* Avoid odd gaps */
-                               if (GETPIX(x-1, y) == 1 ||
-                                   GETPIX(x-1, y-1) == 1 ||
-                                   GETPIX(x, y-1) == 1)
-                                       corner[x][y].tl = 1;
-                               if (GETPIX(x+1, y) == 1 ||
-                                   GETPIX(x+1, y-1) == 1 ||
-                                   GETPIX(x, y-1) == 1)
-                                       corner[x][y].tr = 1;
-                               if (GETPIX(x-1, y) == 1 ||
-                                   GETPIX(x-1, y+1) == 1 ||
-                                   GETPIX(x, y+1) == 1)
-                                       corner[x][y].bl = 1;
-                               if (GETPIX(x+1, y) == 1 ||
-                                   GETPIX(x+1, y+1) == 1 ||
-                                   GETPIX(x, y+1) == 1)
-                                       corner[x][y].br = 1;
-                               blackpixel(x, YSIZE - y - 1,
-                                   corner[x][y].bl, corner[x][y].br,
-                                   corner[x][y].tr, corner[x][y].tl);
+                               if (L || UL || U) tl = true;
+                               if (R || UR || U) tr = true;
+                               if (L || DL || D) bl = true;
+                               if (R || DR || D) br = true;
+                               blackpixel(x, YSIZE - y - 1, bl, br, tr, tl);
                        } else {
+                               bool tl, tr, bl, br;
+
                                /* Assume clear */
-                               corner[x][y].tl = 0;
-                               corner[x][y].tr = 0;
-                               corner[x][y].bl = 0;
-                               corner[x][y].br = 0;
+                               tl = tr = bl = br = false;
                                /* white pixel -- just diagonals */
-                               if (GETPIX(x-1, y) == 1 &&
-                                   GETPIX(x, y-1) == 1 &&
-                                   GETPIX(x-1, y-1) == 0)
-                                       corner[x][y].tl = 1;
-                               if (GETPIX(x+1, y) == 1 &&
-                                   GETPIX(x, y-1) == 1 &&
-                                   GETPIX(x+1, y-1) == 0)
-                                       corner[x][y].tr = 1;
-                               if (GETPIX(x-1, y) == 1 &&
-                                   GETPIX(x, y+1) == 1 &&
-                                   GETPIX(x-1, y+1) == 0)
-                                       corner[x][y].bl = 1;
-                               if (GETPIX(x+1, y) == 1 &&
-                                   GETPIX(x, y+1) == 1 &&
-                                   GETPIX(x+1, y+1) == 0)
-                                       corner[x][y].br = 1;
-                               whitepixel(x, YSIZE - y - 1,
-                                   corner[x][y].bl, corner[x][y].br,
-                                   corner[x][y].tr, corner[x][y].tl);
+                               if (L && U && !UL) tl = true;
+                               if (R && U && !UR) tr = true;
+                               if (L && D && !DL) bl = true;
+                               if (R && D && !DR) br = true;
+                               whitepixel(x, YSIZE - y - 1, bl, br, tr, tl);
                        }
                }
        }