From a23fed6fbeaf4187ba2c2fd473d6270607d2d655 Mon Sep 17 00:00:00 2001
From: Neale Pickett <neale@woozle.org>
Date: Tue, 10 May 2016 20:25:53 -0600
Subject: [PATCH] Built-in foreground color selection

Now that I'm doing it in the right order, it turns out the built-in function for picking a legible foreground color works just dandy. Pulled my custom function back out and using that.
---
 src/main.c | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/src/main.c b/src/main.c
index 42c1809..f431fb6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -20,20 +20,6 @@ GPoint center;
 
 bool bt_connected;
 
-static GColor8 visible_against(GColor8 bg) {
-  uint8_t r = (bg.argb >> 4) & 0b11;
-  uint8_t g = (bg.argb >> 2) & 0b11;
-  uint8_t b = (bg.argb >> 0) & 0b11;
-  uint16_t a = (299*r + 587*g + 114*b);
-  
-  // Counting the perceptive luminance - human eye favors green color... 
-  if (a < 1500) {
-    return GColorWhite;
-  } else {
-    return GColorBlack;
-  }
-}
-
 static GPoint point_of_polar(int32_t theta, int r) {
   GPoint ret = {
     .x = (int16_t)(sin_lookup(theta) * r / TRIG_MAX_RATIO) + center.x,
@@ -186,11 +172,10 @@ static void init() {
     argb = rand() % 0b00111111;
   }
   accent_color = (GColor8){ .argb = argb + 0b11000000 };
-  text_color = visible_against(accent_color);
 #else
   accent_color = GColorWhite;
-  text_color = GColorBlack;
 #endif
+  text_color = gcolor_legible_over(accent_color);
   
   s_day_buffer[0] = '\0';