fix HSL

Author: profezzorn

common/color.h

@@ -172,6 +172,14 @@ class HSL {
   HSL rotate(float angle) {
     return HSL(fract(H + angle), S, L);
   }
+  void printTo(Print& p) {
+    p.print("HSL:");
+    p.print(H);
+    p.write(',');
+    p.print(S);
+    p.write(',');
+    p.print(L);
+  }
   float H; // 0 - 1.0
   float S; // 0 - 1.0
   float L; // 0 - 1.0
@@ -305,23 +313,23 @@ class Color16 {
     int MAX = std::max(r, std::max(g, b));
     int MIN = std::min(r, std::min(g, b));
     int C = MAX - MIN;
-    int H;
+    float H;
     // Note 16384 = 60 degrees.
     if (C == 0) {
       H = 0;
     } else if (r == MAX) {
       // r is biggest
-      H = 16384 * (g - b) / C;
+      H = (g - b) / (float)C;
     } else if (g == MAX) {
       // g is biggest
-      H = 16384 * (b - r) / C + 16384 * 2;
+      H = (b - r) / (float)C + 2.0f;
     } else {
       // b is biggest
-      H = 16384 * (r - g) / C + 16384 * 4;
+      H = (r - g) / (float)C + 4.0f;
     }
     int L = MIN + MAX;
     float S = (MAX*2 - L) / (float)std::min<int>(L, 131072 - L);
-    return HSL(H / 98304.0, S, L / 131070.0);
+    return HSL(fract(H / 6.0f), S, L / 131070.0);
   }
 
   explicit Color16(HSL hsl) {

common/tests.cpp

@@ -127,6 +127,12 @@ BladeConfig* current_config;
   if (fabs(x_ - y_) > D) { std::cerr << #X << " (" << x_ << ") ~!= " << #Y << " (" << y_ << ") line " << __LINE__ << std::endl;  exit(1); } \
 } while(0)
 
+#define CHECK_NEAR_MSG(X, Y, D, MSG) do {					\
+  auto x_ = (X);                                                                \
+  auto y_ = (Y);                                                                \
+  if (fabs(x_ - y_) > D) { STDOUT << #X << " (" << x_ << ") ~!= " << #Y << " (" << y_ << ") " << MSG << " line " << __LINE__ << "\n";  exit(1); } \
+} while(0)
+
 #define CHECK_LT(X, Y) do {                                             \
   auto x_ = (X);                                                                \
   auto y_ = (Y);                                                                \
@@ -326,6 +332,17 @@ void test_rotate(Color16 c, int angle) {
 
   // Test HSL
   HSL hsl = c.toHSL();
+  CHECK_LE(0.0, hsl.H);
+  CHECK_LE(0.0, hsl.S);
+  CHECK_LE(0.0, hsl.L);
+  CHECK_LE(hsl.H, 1.0);
+  CHECK_LE(hsl.S, 1.0);
+  CHECK_LE(hsl.L, 1.0);
+  Color16 result3(hsl);
+  CHECK_NEAR_MSG(result3.r, c.r, 1, " in:" << c << " out:" << result3 << " hsl:" << hsl);
+  CHECK_NEAR_MSG(result3.g, c.g, 1, " in:" << c << " out:" << result3 << " hsl:" << hsl);
+  CHECK_NEAR_MSG(result3.b, c.b, 1, " in:" << c << " out:" << result3 << " hsl:" << hsl);
+
   hsl = hsl.rotate(angle / (float)(32768 * 3));
 //  fprintf(stderr, "Angle = %d HSL={%f,%f,%f} RGB=%d,%d,%d\n", angle, hsl.H, hsl.S, hsl.L, c.r, c.g, c.b);
   CHECK_LE(0.0, hsl.H);