1 files changed, 51 insertions(+), 0 deletions(-)

A 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");
+}