Fixed off-by one bug on hsl to rgb conversion

includes/colors.c

@@ -33,11 +33,11 @@ void cvt_rgb(struct Rgb *dest, const struct Hls const *src) {
        (0 > src -> l && src -> l > 1)) {
         return;
     }
-    float hue = src -> h;
     float r, g, b;
+    float hue = src -> h;
     float chroma = (1 - fabs(2 * (src -> l) - 1)) * (src -> s);
     float x = chroma * (1 - fabs((int)(hue/60) % 2 - 1));
-    float m = (src -> l) - chroma/2;
+    float m = (src -> l) - (chroma/2);
     if (0 <= hue && hue < 60) {
         r = chroma;
         g = x;
@@ -67,9 +67,9 @@ void cvt_rgb(struct Rgb *dest, const struct Hls const *src) {
         g = 0;
         b = 0;
     }
-    dest -> r = (r + m) * 255;
-    dest -> g = (g + m) * 255;
-    dest -> b = (b + m) * 255;
+    dest -> r = ceil((r + m) * 255);
+    dest -> g = ceil((g + m) * 255);
+    dest -> b = ceil((b + m) * 255);
 }
 
 void cvt_hls(struct Hls *dest, const struct Rgb const *src) {
@@ -242,4 +242,21 @@ int main() {
     testconversion(128, 0, 128);
     testconversion(0, 128, 128);
     testconversion(0, 0, 128);
-}
+    testconvhls(0, 0, 0);
+    testconvhls(0, 0, 1);
+    testconvhls(0, 1, 0.5);
+    testconvhls(120, 1, 0.5);
+    testconvhls(240, 1, 0.5);
+    testconvhls(60, 1, 0.5);
+    testconvhls(180, 1, 0.5);
+    testconvhls(300, 1, 0.5);
+    testconvhls(0, 0, 0.75);
+    testconvhls(0, 0, 0.5);
+    testconvhls(0, 1, 0.25);
+    testconvhls(60, 1, 0.25);
+    testconvhls(120, 1, 0.25);
+    testconvhls(300, 1, 0.25);
+    testconvhls(180, 1, 0.25);
+    testconvhls(240, 1, 0.25);
+}
+