From e0311c85cf6c178849344f572aaad0428df1137c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cenk=20G=C3=BCndo=C4=9Fan?= <cnkgndgn@gmail.com>
Date: Sat, 13 Feb 2016 23:00:05 +0100
Subject: [PATCH] color: add hex2color, color2hex, str2rgb, rgb2str

---
 sys/color/color.c   | 50 ++++++++++++++++++++++++++++++++++++++++++++-
 sys/include/color.h | 44 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 92 insertions(+), 2 deletions(-)

diff --git a/sys/color/color.c b/sys/color/color.c
index ddd273def..f6a57b412 100644
--- a/sys/color/color.c
+++ b/sys/color/color.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014 Freie Universität Berlin
+ * Copyright (C) 2014 - 2016 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser General
  * Public License v2.1. See the file LICENSE in the top level directory for more
@@ -14,12 +14,15 @@
  * @brief       Implementation of color module
  *
  * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ * @author      Cenk Gündoğan <mail@cgundogan.de>
  *
  * @}
  */
 
 #include "color.h"
 
+#define ENABLE_DEBUG    (0)
+#include "debug.h"
 
 void color_rgb2hsv(color_rgb_t *rgb, color_hsv_t *hsv)
 {
@@ -127,3 +130,48 @@ void color_hsv2rgb(color_hsv_t *hsv, color_rgb_t *rgb)
             break;
     }
 }
+
+void color_hex2rgb(const uint32_t hex, color_rgb_t *rgb)
+{
+    rgb->r = ((hex >> 16UL) & 0xFF);
+    rgb->g = ((hex >> 8UL) & 0xFF);
+    rgb->b = (hex & 0xFF);
+}
+
+void color_rgb2hex(const color_rgb_t *rgb, uint32_t *hex)
+{
+    *hex = (((uint32_t) rgb->r) << 16UL) | (rgb->g << 8UL) | (rgb->b);
+}
+
+void color_str2rgb(const char* str, color_rgb_t *rgb)
+{
+    rgb->r = (((str[0] > '9') ? (str[0] &~ 0x20) - 'A' + 10 : (str[0] - '0')) << 4) | /* R */
+             (((str[1] > '9') ? (str[1] &~ 0x20) - 'A' + 10 : (str[1] - '0')) << 0) ; /* R */
+    rgb->g = (((str[2] > '9') ? (str[2] &~ 0x20) - 'A' + 10 : (str[2] - '0')) << 4) | /* G */
+             (((str[3] > '9') ? (str[3] &~ 0x20) - 'A' + 10 : (str[3] - '0')) << 0) ; /* G */
+    rgb->b = (((str[4] > '9') ? (str[4] &~ 0x20) - 'A' + 10 : (str[4] - '0')) << 4) | /* B */
+             (((str[5] > '9') ? (str[5] &~ 0x20) - 'A' + 10 : (str[5] - '0')) << 0) ; /* B */
+}
+
+void color_rgb2str(const color_rgb_t *rgb, char* str)
+{
+    uint8_t tmp;
+
+    /* RR */
+    tmp = rgb->r >> 4;
+    str[0] = (tmp > 9) ? ('A' - 10 + tmp) : ('0' + tmp);
+    tmp = rgb->r & 0x0F;
+    str[1] = (tmp > 9) ? ('A' - 10 + tmp) : ('0' + tmp);
+
+    /* GG */
+    tmp = rgb->g >> 4;
+    str[2] = (tmp > 9) ? ('A' - 10 + tmp) : ('0' + tmp);
+    tmp = rgb->g & 0x0F;
+    str[3] = (tmp > 9) ? ('A' - 10 + tmp) : ('0' + tmp);
+
+    /* BB */
+    tmp = rgb->b >> 4;
+    str[4] = (tmp > 9) ? ('A' - 10 + tmp) : ('0' + tmp);
+    tmp = rgb->b & 0x0F;
+    str[5] = (tmp > 9) ? ('A' - 10 + tmp) : ('0' + tmp);
+}
diff --git a/sys/include/color.h b/sys/include/color.h
index 4188b150d..b20e03d16 100644
--- a/sys/include/color.h
+++ b/sys/include/color.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2014 Freie Universität Berlin
+ * Copyright (C) 2014 - 2016 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser General
  * Public License v2.1. See the file LICENSE in the top level directory for more
@@ -16,6 +16,7 @@
  * @brief       Headers for the color handling module
  *
  * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ * @author      Cenk Gündoğan <mail@cgundogan.de>
  */
 
 #ifndef __COLOR_H
@@ -62,6 +63,47 @@ void color_rgb2hsv(color_rgb_t *rgb, color_hsv_t *hsv);
  */
 void color_hsv2rgb(color_hsv_t *hsv, color_rgb_t *rgb);
 
+/**
+ * @brief Convert a @p hex value of the form 0x00RRGGBB to an RGB color struct
+ *
+ * @note                the two most significant bytes of @p hex will be ignored
+ *
+ * @param[in] hex       Input color encoded in hex
+ * @param[out] rgb      Output color encoded in RGB space
+ */
+void color_hex2rgb(const uint32_t hex, color_rgb_t *rgb);
+
+/**
+ * @brief Convert a @p rgb struct to a @p hex value of the form 0x00RRGGBB
+ *
+ * @note                the two most significant bytes of @p hex will be 0
+ *
+ * @param[in] rgb       Input color encoded in RGB space
+ * @param[out] hex      Output color encoded in hex
+ */
+void color_rgb2hex(const color_rgb_t *rgb, uint32_t *hex);
+
+/**
+ * @brief Convert a hex color string of the form 'RRGGBB' to a color_rgb_t struct
+ *
+ * @note                @p str MUST contain only hexadecimal digits.
+ *                      Expect unexpected behaviour, otherwise.
+ *
+ * @param[in] str       Input color encoded as string of the form 'RRGGBB'
+ * @param[out] rgb      Output color encoded in RGB space
+ */
+void color_str2rgb(const char *str, color_rgb_t *color);
+
+/**
+ * @brief Convert a color_rgb_t struct to a hex color string of the form 'RRGGBB'
+ *
+ * @note                @p str MUST be big enough to hold 6 characters
+ *
+ * @param[in] rgb       Input color encoded in RGB space
+ * @param[out] str      Output color encoded as string of the form 'RRGGBB'
+ */
+void color_rgb2str(const color_rgb_t *rgb, char *str);
+
 #ifdef __cplusplus
 }
 #endif