add bezier helpers

test/src/test_bezier.c

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c), Recep Aslantas.
+ *
+ * MIT License (MIT), http://opensource.org/licenses/MIT
+ * Full license can be found in the LICENSE file
+ */
+
+#include "test_common.h"
+
+CGLM_INLINE
+float
+test_bezier_plain(float s, float p0, float c0, float c1, float p1) {
+  float x, xx, xxx, ss, sss;
+
+  x   = 1.0f - s;
+  xx  = x * x;
+  xxx = xx * x;
+  ss  = s * s;
+  sss = ss * s;
+
+  return p0 * xxx + 3.0f * (c0 * s * xx + c1 * ss * x) + p1 * sss;
+}
+
+void
+test_bezier(void **state) {
+  float s, p0, p1, c0, c1, smc, Bs, Bs_plain;
+
+  s        = test_rand();
+  p0       = test_rand();
+  p1       = test_rand();
+  c0       = test_rand();
+  c1       = test_rand();
+
+  smc      = glm_smc(s, GLM_BEZIER_MAT, (vec4){p0, c0, c1, p1});
+  Bs       = glm_bezier(s, p0, c0, c1, p1);
+  Bs_plain = test_bezier_plain(s, p0, c0, c1, p1);
+
+  assert_true(glm_eq(Bs,  Bs_plain));
+  assert_true(glm_eq(smc, Bs_plain));
+  assert_true(glm_eq(Bs,  smc));
+}