tests: Add a test for the RGB <-> HSL functions

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 32d67c2bf40641b2d1d30fa2d994013c3e6ce5bc)

tests/conform/Makefile.am

@@ -29,6 +29,7 @@ test_sources = \
 	test-blend-strings.c \
 	test-blend.c \
 	test-depth-test.c \
+	test-color-hsl.c \
 	test-color-mask.c \
 	test-backface-culling.c \
 	test-just-vertex-shader.c \

tests/conform/test-color-hsl.c

@@ -0,0 +1,45 @@
+#include <math.h>
+#include <string.h>
+
+#include <cogl/cogl.h>
+
+#include "test-utils.h"
+
+#define cogl_assert_float(a, b)         \
+  do {                                  \
+    if (fabsf ((a) - (b)) >= 0.0001f)   \
+      g_assert_cmpfloat ((a), ==, (b)); \
+  } while (0)
+
+void
+test_color_hsl (void)
+{
+  CoglColor color;
+  float hue, saturation, luminance;
+
+  cogl_color_init_from_4ub(&color, 108, 198, 78, 255);
+  cogl_color_to_hsl(&color, &hue, &saturation, &luminance);
+
+  cogl_assert_float(hue, 105.f);
+  cogl_assert_float(saturation, 0.512821);
+  cogl_assert_float(luminance, 0.541176);
+
+  memset(&color, 0, sizeof (CoglColor));
+  cogl_color_init_from_hsl(&color, hue, saturation, luminance);
+
+  g_assert_cmpint (color.red, ==, 108);
+  g_assert_cmpint (color.green, ==, 198);
+  g_assert_cmpint (color.blue, ==, 78);
+  g_assert_cmpint (color.alpha, ==, 255);
+
+  memset(&color, 0, sizeof (CoglColor));
+  cogl_color_init_from_hsl(&color, hue, 0, luminance);
+
+  cogl_assert_float(color.red / 255.0f, luminance);
+  cogl_assert_float(color.green / 255.0f, luminance);
+  cogl_assert_float(color.blue / 255.0f, luminance);
+  cogl_assert_float(color.alpha / 255.0f, 1.0f);
+
+  if (cogl_test_verbose ())
+    g_print ("OK\n");
+}

tests/conform/test-conform-main.c

@@ -135,6 +135,7 @@ main (int argc, char **argv)
             0);
 
   ADD_TEST (test_euler_quaternion, 0, 0);
+  ADD_TEST (test_color_hsl, 0, 0);
 
   ADD_TEST (test_fence, TEST_REQUIREMENT_FENCE, 0);