From 32a3560bc33fb97809586062f10ba3189fc151e8 Mon Sep 17 00:00:00 2001
From: Johan Malm <jgm323@gmail.com>
Date: Tue, 21 Jul 2020 21:07:47 +0100
Subject: [PATCH] Add tools/hex/hex-color-average.c

---
 tools/hex/.gitignore          |  2 ++
 tools/hex/Makefile            |  4 +++
 tools/hex/hex-color-average.c | 58 +++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 tools/hex/.gitignore
 create mode 100644 tools/hex/Makefile
 create mode 100644 tools/hex/hex-color-average.c

diff --git a/tools/hex/.gitignore b/tools/hex/.gitignore
new file mode 100644
index 00000000..ccf9afa3
--- /dev/null
+++ b/tools/hex/.gitignore
@@ -0,0 +1,2 @@
+hex-color-average
+hex-color-average.o
diff --git a/tools/hex/Makefile b/tools/hex/Makefile
new file mode 100644
index 00000000..e62fee0a
--- /dev/null
+++ b/tools/hex/Makefile
@@ -0,0 +1,4 @@
+hex-color-average: hex-color-average.o
+
+clean:
+	rm -f hex-color-average
diff --git a/tools/hex/hex-color-average.c b/tools/hex/hex-color-average.c
new file mode 100644
index 00000000..f6150404
--- /dev/null
+++ b/tools/hex/hex-color-average.c
@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int hexval(int c)
+{
+	int ret = -1;
+	switch (c) {
+	case '0'...'9':
+		ret = c - '0';
+		break;
+	case 'a'...'f':
+		ret = c - 'a' + 10;
+		break;
+	case 'A'...'F':
+		ret = c - 'A' + 10;
+		break;
+	}
+	return ret;
+}
+
+int hex2dec(const char *hexstring)
+{
+	int value = 0, pos = 0, hex;
+	while ((hex = hexval(hexstring[pos++])) != -1)
+		value = (value << 4) + hex;
+	return value;
+}
+
+void usage(const char *command)
+{
+	printf("Usage: %s <rrggbb> <rrggbb>\n", command);
+	exit(1);
+}
+int main(int argc, char **argv)
+{
+	double col[6] = { 0 };
+
+	if (argc < 3)
+		usage(argv[0]);
+
+	for (int j = 1; j < argc; j++) {
+		int len = strlen(argv[j]);
+		for (int i = 0; i < len / 2; i++) {
+			char buf[3] = { 0 };
+			buf[0] = argv[j][i * 2];
+			buf[1] = argv[j][i * 2 + 1];
+			col[(j - 1) * 3 + i] = hex2dec(buf) / 255.0;
+		}
+	}
+	printf("[%s] { %.2f, %.2f, %.2f }\n", argv[1], col[0], col[1], col[2]);
+	printf("[%s] { %.2f, %.2f, %.2f }\n", argv[2], col[3], col[4], col[5]);
+	printf("[ mean ] { %.2f, %.2f, %.2f }\n",
+	       (col[0] + col[3]) / 2.0,
+	       (col[1] + col[4]) / 2.0,
+	       (col[2] + col[5]) / 2.0);
+}
+