add xortex.c

audiovisual/xortex.c

@@ -0,0 +1,35 @@
+/* xor texture generator */
+#include <stdio.h>
+#include <stdint.h>
+
+size_t
+strlen(const char *);
+
+int
+main(int argc, char **argv)
+{
+	const char palette_def[] = "WO0KXkxocl;:*,'.";
+	const char *palette = palette_def;
+
+	int w = 48, h = 48;
+	if (argc > 2) {
+		w = atoi(argv[1]);
+		h = atoi(argv[2]);
+	}
+	if (argc > 3)
+		palette = argv[3];
+	int palette_len = strlen(palette);
+	if (palette_len == 0 || palette_len & (palette_len - 1)) {
+		fputs("palette length must be a power of two\n", stderr);
+		return 1;
+	}
+
+	for (int y = 0; y < h; ++y) {
+		for (int x = 0; x < w; ++x) {
+			uint8_t c = (x>>1) ^ (y>>1);
+			putchar(palette[c & (palette_len-1)]);
+		}
+		putchar('\n');
+	}
+	return 0;
+}