added render target and bezier classes, added stroke settings panel

engine/util.cpp

@@ -13,3 +13,23 @@ glm::vec4 rand_color()
     float b = (rand() % 256) / 256.f;
     return { r, g, b, 1.f };
 }
+
+glm::vec3 convert_hsv2rgb(const glm::vec3 c)
+{
+    glm::vec4 K = glm::vec4(1.0f, 2.0f / 3.0f, 1.0f / 3.0f, 3.0f);
+    glm::vec3 p = glm::abs(glm::fract(glm::vec3(c.xxx + K.xyz)) * 6.0f - K.www);
+    auto tmp = glm::clamp(glm::vec3(p - K.xxx), 0.0f, 1.0f);
+    return c.z * glm::mix(glm::vec3(K.xxx), tmp, c.y);
+}
+
+glm::vec3 convert_rgb2hsv(const glm::vec3 c)
+{
+    glm::vec4 K = glm::vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+    //glm::vec4 p = mix(glm::vec4(c.bg, K.wz), glm::vec4(c.gb, K.xy), glm::step(c.b, c.g));
+    //glm::vec4 q = mix(glm::vec4(p.xyw, c.r), glm::vec4(c.r, p.yzx), glm::step(p.x, c.r));
+    glm::vec4 p = c.g < c.b ? glm::vec4(c.bg, K.wz) : glm::vec4(c.gb, K.xy);
+    glm::vec4 q = c.r < p.x ? glm::vec4(p.xyw, c.r) : glm::vec4(c.r, p.yzx);
+    float d = q.x - glm::min(q.w, q.y);
+    float e = 1.0e-10f;
+    return glm::vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+}