Use CIE XYZ instead of sRGB

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 57 insertions, 0 deletions

diff --git a/src/vu-colour-srgb.c b/src/vu-colour-srgb.c
new file mode 100644
index 0000000..164c6ae
--- /dev/null
+++ b/src/vu-colour-srgb.c
@@ -0,0 +1,57 @@
+/* See LICENSE file for copyright and license details. */
+#include "arg.h"
+#include "util.h"
+
+static void
+usage(void)
+{
+	eprintf("usage: %s [-d depth] [-l] red green blue\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned long long int max;
+	double red, green, blue, X, Y, Z;
+	int depth = 8;
+	int linear = 0;
+
+	ARGBEGIN {
+	case 'd':
+		if (toi(EARGF(usage()), 1, 64, &depth))
+			eprintf("argument of -d must be an integer in [1, 64]\n");
+		break;
+	case 'l':
+		linear = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc != 3)
+		usage();
+
+	if (tolf(argv[0], &red))
+		eprintf("the X value must be a floating-point value\n");
+	if (tolf(argv[1], &green))
+		eprintf("the Y value must be a floating-point value\n");
+	if (tolf(argv[2], &blue))
+		eprintf("the Z value must be a floating-point value\n");
+
+	max    = 1ULL << (depth - 1);
+	max   |= max - 1;
+	red   /= max;
+	green /= max;
+	blue  /= max;
+	if (!linear) {
+		red   = srgb_decode(red);
+		green = srgb_decode(green);
+		blue  = srgb_decode(blue);
+	}
+
+	srgb_to_ciexyz(red, green, blue, &X, &Y, &Z);
+	printf("%lf %lf %lf\n", X, Y, Z);
+	efshut(stdout, "<stdout>");
+
+	return 0;
+}