added render target and bezier classes, added stroke settings panel

engine/util.h

@@ -9,3 +9,5 @@ uint16_t constexpr const_hash(const char* input)
 
 bool point_in_rect(const glm::vec2& point, const glm::vec4& rect);
 glm::vec4 rand_color();
+glm::vec3 convert_hsv2rgb(const glm::vec3 c);
+glm::vec3 convert_rgb2hsv(const glm::vec3 c);