From d89bc07ca149a8518ab105f55b939b0e9dbd7a91 Mon Sep 17 00:00:00 2001
From: Mateusz Salamon <mateusz@msalamon.pl>
Date: Thu, 25 Oct 2018 22:22:23 +0100
Subject: [PATCH] Color correciton function.

---
 Inc/ws2812b.h |  3 +++
 Src/ws2812b.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/Inc/ws2812b.h b/Inc/ws2812b.h
index 1614dda..64c7d83 100644
--- a/Inc/ws2812b.h
+++ b/Inc/ws2812b.h
@@ -25,4 +25,7 @@ void WS2812B_SetDiodeRGB(int16_t diode_id, uint8_t R, uint8_t G, uint8_t B);
 void WS2812B_SetDiodeHSV(int16_t diode_id, uint16_t Hue, uint8_t Saturation, uint8_t Brightness);
 void WS2812B_Refresh();
 
+// color correction
+uint8_t sine8(uint8_t x);
+uint8_t gamma8(uint8_t x);
 #endif /* WS2812B_H_ */
diff --git a/Src/ws2812b.c b/Src/ws2812b.c
index 0957215..020583e 100644
--- a/Src/ws2812b.c
+++ b/Src/ws2812b.c
@@ -224,3 +224,49 @@ void HAL_SPI_TxCpltCallback(SPI_HandleTypeDef *hspi)
 	}
 
 }
+
+static const uint8_t _sineTable[256] = {
+  128,131,134,137,140,143,146,149,152,155,158,162,165,167,170,173,
+  176,179,182,185,188,190,193,196,198,201,203,206,208,211,213,215,
+  218,220,222,224,226,228,230,232,234,235,237,238,240,241,243,244,
+  245,246,248,249,250,250,251,252,253,253,254,254,254,255,255,255,
+  255,255,255,255,254,254,254,253,253,252,251,250,250,249,248,246,
+  245,244,243,241,240,238,237,235,234,232,230,228,226,224,222,220,
+  218,215,213,211,208,206,203,201,198,196,193,190,188,185,182,179,
+  176,173,170,167,165,162,158,155,152,149,146,143,140,137,134,131,
+  128,124,121,118,115,112,109,106,103,100, 97, 93, 90, 88, 85, 82,
+   79, 76, 73, 70, 67, 65, 62, 59, 57, 54, 52, 49, 47, 44, 42, 40,
+   37, 35, 33, 31, 29, 27, 25, 23, 21, 20, 18, 17, 15, 14, 12, 11,
+   10,  9,  7,  6,  5,  5,  4,  3,  2,  2,  1,  1,  1,  0,  0,  0,
+    0,  0,  0,  0,  1,  1,  1,  2,  2,  3,  4,  5,  5,  6,  7,  9,
+   10, 11, 12, 14, 15, 17, 18, 20, 21, 23, 25, 27, 29, 31, 33, 35,
+   37, 40, 42, 44, 47, 49, 52, 54, 57, 59, 62, 65, 67, 70, 73, 76,
+   79, 82, 85, 88, 90, 93, 97,100,103,106,109,112,115,118,121,124};
+
+static const uint8_t _gammaTable[256] = {
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  2,  2,  2,  2,  2,  2,  2,  2,  3,  3,  3,  3,
+    3,  3,  4,  4,  4,  4,  5,  5,  5,  5,  5,  6,  6,  6,  6,  7,
+    7,  7,  8,  8,  8,  9,  9,  9, 10, 10, 10, 11, 11, 11, 12, 12,
+   13, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20,
+   20, 21, 21, 22, 22, 23, 24, 24, 25, 25, 26, 27, 27, 28, 29, 29,
+   30, 31, 31, 32, 33, 34, 34, 35, 36, 37, 38, 38, 39, 40, 41, 42,
+   42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
+   58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 69, 70, 71, 72, 73, 75,
+   76, 77, 78, 80, 81, 82, 84, 85, 86, 88, 89, 90, 92, 93, 94, 96,
+   97, 99,100,102,103,105,106,108,109,111,112,114,115,117,119,120,
+  122,124,125,127,129,130,132,134,136,137,139,141,143,145,146,148,
+  150,152,154,156,158,160,162,164,166,168,170,172,174,176,178,180,
+  182,184,186,188,191,193,195,197,199,202,204,206,209,211,213,215,
+  218,220,223,225,227,230,232,235,237,240,242,245,247,250,252,255};
+
+uint8_t sine8(uint8_t x)
+{
+	return _sineTable[x];
+}
+
+uint8_t gamma8(uint8_t x)
+{
+	return _gammaTable[x];
+}