From ad3bf7a91fe79fb85486e33abfdb8d8080325201 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 31 Dec 2000 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2000-12-31

---
 bitsy/gamma.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 bitsy/gamma.c

diff --git a/bitsy/gamma.c b/bitsy/gamma.c
new file mode 100644
index 0000000000000000000000000000000000000000..489c39bfa43b5cdef482130de7e5669154df215f
--- /dev/null
+++ b/bitsy/gamma.c
@@ -0,0 +1,51 @@
+#include <u.h>
+#include <libc.h>
+#include <stdio.h>
+
+double	gamma = 1.6;
+
+int
+remap5(int i)
+{
+	double v;
+
+	v = (double)i/31.0;
+	return 31.0*pow(v, gamma);
+}
+
+int
+remap6(int i)
+{
+	double v;
+
+	v = (double)i/63.0;
+	return 63.0*pow(v, gamma);
+}
+
+int
+remap(int i)
+{
+	int r, g, b;
+
+	b = i & 0x1F;
+	g = (i>>5) & 0x3F;
+	r = (i>>11) & 0x1F;
+	return (remap5(r)<<11) | (remap6(g)<<5) | (remap5(b)<<0);
+}
+
+void
+main(void)
+{
+	int i;
+
+	printf("/* gamma = %.2f */\n", gamma);
+	printf("ushort gamma[65536] = {\n");
+	for(i=0; i<65536; i++){
+		if((i%8) == 0)
+			printf("\t");
+		printf("0x%.4x, ", remap(i));
+		if((i%8) == 7)
+			printf("\n");
+	}
+	printf("};\n");
+}