Add 2020 source files for real

2020/ferguson1/termcaps.c

@@ -0,0 +1,133 @@
+/* This will imperfectly:
+ 
+   (1)	Test if terminal supports the features Snake uses.
+   (2)	Report terminal (and playing) size(s).
+   (3)	Estimates the minimum number of columns to play unhindered (based on the
+ 	size, max size and growth rate).
+   (4)	Reports the max size of the Snake and the number of bugs required to
+ 	reach that size (doesn't use shedding).
+ */
+
+#include <curses.h>
+#include <term.h>
+#include <stdlib.h>
+#define f(a,b) ((a)<(b)?(a):(b))
+static char *v;
+static size_t Y=997,X=5, S=5, rows,N, K;
+static int x, y;
+struct caps
+{
+    char *caps, *sup, *desc;
+    int fatal;
+};
+static size_t b(size_t n)
+{
+    size_t i=n/10, j=1;
+    while (i)
+    {
+        i/=10;
+        ++j;
+    }
+    return j;
+}
+static size_t a(int n)
+{
+    int i=n/10;
+    size_t j=1;
+    while (i)
+    {
+        i/=10;
+        ++j;
+    }
+    return j;
+}
+
+static struct caps caps[] =
+{
+    { "cup", NULL, "cursor movement", 1 },
+    { "civis", NULL, "making cursor invisible", 0 },
+    { "bold", NULL, "bold", 0 },
+    { NULL, NULL, NULL, 0 }
+};
+
+static size_t c(size_t M, size_t V)
+{
+    size_t i;
+
+    if (!S) S = 5;
+
+    for (i=0; V<M; ++i)
+	V += S;
+
+    return i;
+}
+int main(void)
+{
+    int i, j, k = 0, f = 0;
+    if (!initscr())
+    {
+	fprintf(stderr, "FATAL: couldn't initialise curses\n");
+	return -1;
+    } 
+    j = has_colors();
+    k += !j;
+    getmaxyx(stdscr, y, x);
+    endwin();
+
+    if (y < 10 || x < 10)
+    {
+	fprintf(stderr, "FATAL: terminal size must be at least 10 lines and 10 columns\n");
+	return -1;
+    }
+   
+    for (i = 0; i[caps].caps; ++i)
+    {
+	i[caps].sup = tigetstr(caps[i].caps);
+	/* tigetstr() returns (char *)-1 if the capability name isn't
+	 * recognised; check for this before suggesting it's supported: */
+	if (caps[i].sup == (char *)-1)
+	    caps[i].sup = NULL;
+	if (!caps[i].sup) ++k;
+    }
+
+    for (i = 0; i[caps].caps; ++i)
+    {
+	printf("terminal%s support%s %s", caps[i].sup?"":" does not",caps[i].sup?"s":"", caps[i].desc);
+	if (caps[i].fatal && !caps[i].sup)
+	{
+	    ++f;
+	    printf(" (fatal)");
+	}
+	puts("");
+    }
+    printf("terminal%s support%s colours\n\n",j?"":" does not",j?"s":"");
+    printf("terminal rows %3d (%-3d playable)\n", y, y - 3);
+    printf("terminal cols %3d (%-3d playable)\n\n", x, x - 2);
+
+    K = (size_t)((y-3)*(x-3));;
+
+    v = getenv("MAXSIZE");
+    if (v) Y = strtoul(v, NULL, 0);
+    Y = f(K,Y);
+    v = getenv("GROW");
+    if (v) S = strtoul(v, NULL, 0);
+    v = getenv("SIZE");
+    if (v) X = strtoul(v, NULL, 0);
+    N = c(Y,X);
+    printf("snake size: %5zu (max size: %zu)\n", Y, K);
+    printf("      bugs: %5zu (max size: %zu)\n\n", N, c(K,X));
+
+    rows = 14 + b(Y)*2 + a(y)*2 + a(x)*2 + b(N);
+    if (x < (int)rows + 1) ++k;
+    printf("at least %zu columns recommended for snake size %-5zu (is %d)\n", rows+1,Y, x);
+
+    rows = 14 + b(K)*2 + a(y)*2 + a(x)*2 + b(c(K,X));
+    printf("at least %zu columns recommended for snake size %-5zu (is %d)\n\n", rows + 1, K, x);
+
+
+    if (!k)
+	printf("No problems detected.\n");
+    else printf("%d problem%s detected (%d fatal).\n", k, k!=1?"s":"", f);
+
+    return f?-1:k;
+}