parser for 10deg

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 71 insertions, 0 deletions

diff --git a/src/parse_10deg.c b/src/parse_10deg.c
new file mode 100644
index 0000000..0b34050
--- /dev/null
+++ b/src/parse_10deg.c
@@ -0,0 +1,71 @@
+/**
+ * Copyright © 2016  Mattias Andrée <maandree@member.fsf.org>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <math.h>
+#include <sys/stat.h>
+
+#define HIGHEST  40000
+#define LOWEST   1000
+#define DELTA    100
+#define EXPECTED_ELEMENTS  ((HIGHEST - LOWEST) / DELTA + 1)
+
+
+
+static void
+ciexyy_to_srgb(double x, double y, double Y, double *r, double *g, double *b)
+{
+#define SRGB(C)  (((C) <= 0.0031308) ? (12.92 * (C)) : ((1.0 + 0.055) * pow((C), 1.0 / 2.4) - 0.055))
+	double X, Z;
+
+	/* Convert CIE xyY to CIE XYZ. */
+	X = Y * (y == 0 ? 0 : (x / y));
+	Z = Y * (y == 0 ? 0 : ((1 - x - y) / y));
+
+	/* Convert CIE XYZ to [0, 1] linear RGB. (ciexyz_to_linear) */
+	*r = ( 3.240450 * X) + (-1.537140 * Y) + (-0.4985320 * Z);
+	*g = (-0.969266 * X) + ( 1.876010 * Y) + ( 0.0415561 * Z);
+	*b = (0.0556434 * X) + (-0.204026 * Y) + ( 1.0572300 * Z);
+
+	/* Convert [0, 1] linear RGB to [0, 1] sRGB. */
+	SRGB(*r), SRGB(*g), SRGB(*b);
+}
+
+
+int main(void)
+{
+	double xyrgb[5];
+	struct stat attr;
+
+	while (fscanf(stdin, "%lf %lf\n", xyrgb + 0, xyrgb + 1) == 2) {
+		ciexyy_to_srgb(xyrgb[0], xyrgb[1], 1.0, xyrgb + 2, xyrgb + 3, xyrgb + 4);
+		if (write(1, xyrgb, sizeof(xyrgb)) < (ssize_t)sizeof(xyrgb))
+			return perror(""), 1;
+	}
+	if (fstat(1, &attr))
+		return perror(""), 1;
+	if ((size_t)(attr.st_size) != EXPECTED_ELEMENTS * 5 * sizeof(double))
+		return 1;
+
+	return 0;
+}
+