diff --git a/src/main.cpp b/src/main.cpp
index 38751f0..d62d866 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -16,27 +16,110 @@ static void render() {
     glColor3f(0.0f, 0.0f, 1.0f);
     glVertex3f(0.5f, -0.5f, 0.0f);
     CHECK_GL(glEnd());
-    /* glBegin(GL_TRIANGLES); */
-    /* constexpr int n = 100; */
-    /* constexpr float pi = 3.1415926535897f; */
-    /* float radius = 0.5f; */
-    /* float inner_radius = 0.25f; */
-    /* static int x = 0; */
-    /* x++; */
-    /* if (x > n) */
-    /*     x -= n; */
-    /* for (int i = 0; i < x; i++) { */
-    /*     float angle = i / (float)n * pi * 2; */
-    /*     float angle_next = (i + 1) / (float)n * pi * 2; */
-    /*     glVertex3f(0.0f, 0.0f, 0.0f); */
-    /*     glVertex3f(radius * sinf(angle), radius * cosf(angle), 0.0f); */
-    /*     glVertex3f(radius * sinf(angle_next), radius * cosf(angle_next), 0.0f); */
-        /* glVertex3f(inner_radius * sinf(angle), inner_radius * cosf(angle), 0.0f); */
-        /* glVertex3f(inner_radius * sinf(angle_next), inner_radius * cosf(angle_next), 0.0f); */
-        /* glVertex3f(inner_radius * sinf(angle), inner_radius * cosf(angle), 0.0f); */
-        /* glVertex3f(radius * sinf(angle_next), radius * cosf(angle_next), 0.0f); */
-    /* } */
-    /* CHECK_GL(glEnd()); */
+}
+
+static void render_round() {
+     glBegin(GL_TRIANGLES); 
+     constexpr int n = 100; 
+     constexpr float pi = 3.1415926535897f; 
+     float radius = 0.5f; 
+     float inner_radius = 0.25f; 
+     static int x = 0; 
+     x++; 
+     if (x > n) 
+         x -= n; 
+     for (int i = 0; i < x; i++) { 
+         float angle = i / (float)n * pi * 2; 
+         float angle_next = (i + 1) / (float)n * pi * 2; 
+         glVertex3f(0.0f, 0.0f, 0.0f); 
+         glVertex3f(radius * sinf(angle), radius * cosf(angle), 0.0f); 
+         glVertex3f(radius * sinf(angle_next), radius * cosf(angle_next), 0.0f); 
+         glVertex3f(inner_radius * sinf(angle), inner_radius * cosf(angle), 0.0f); 
+         glVertex3f(inner_radius * sinf(angle_next), inner_radius * cosf(angle_next), 0.0f); 
+         glVertex3f(inner_radius * sinf(angle), inner_radius * cosf(angle), 0.0f); 
+         glVertex3f(radius * sinf(angle_next), radius * cosf(angle_next), 0.0f); 
+     } 
+     CHECK_GL(glEnd()); 
+}
+
+static void render_opencv() {
+    glBegin(GL_TRIANGLES);
+
+	constexpr int n = 360;
+	constexpr float pi = 3.1415926535897f;
+    constexpr float stopAngle = 11.0 / 12.0 * pi * 2;
+	float radius = 0.1f;
+    float far = 2 * radius;
+	float inner_radius = 0.06f;
+	/*static int x = 0;
+	x++;
+    if (x > n)
+        {return;}*/
+	for (int i = 0; i < n; i++) {
+		float angle = i / (float)n * pi * 2;
+		float angle_next = (i + 1) / (float)n * pi * 2;
+		//glVertex3f(0.0f, 0.0f, 0.0f);
+        // Բ1
+        if (0.f <= angle && 1.0f / 12.0f * pi * 2 > angle ||
+            11.0f / 12.0f * pi * 2 <= angle)
+        {
+            glColor3f(0.0f, 0.0f, 0.0f);
+        }
+        else {
+            glColor3f(0.0f, 0.0f, 1.0f);
+        }
+		glVertex3f(radius * sinf(angle) + far, radius * cosf(angle), 0.0f);
+		glVertex3f(radius * sinf(angle_next) + far, radius * cosf(angle_next), 0.0f);
+		glVertex3f(inner_radius * sinf(angle) + far, inner_radius * cosf(angle), 0.0f);
+		glVertex3f(inner_radius * sinf(angle_next) + far, inner_radius * cosf(angle_next), 0.0f);
+		glVertex3f(inner_radius * sinf(angle) + far, inner_radius * cosf(angle), 0.0f);
+		glVertex3f(radius * sinf(angle_next) + far, radius * cosf(angle_next), 0.0f);
+
+	}
+
+	for (int i = 0; i < n; i++) {
+		float angle = i / (float)n * pi * 2;
+		
+		float angle_next = (i + 1) / (float)n * pi * 2;
+		
+		// Բ2
+		if (1.0f / 12.0f * pi * 2 < angle && 3.0f / 12.0f * pi * 2 > angle)
+		{
+			glColor3f(0.0f, 0.0f, 0.0f);
+		}
+		else {
+			glColor3f(0.0f, 1.0f, 0.0f);
+		}
+        ;
+		glVertex3f(radius * sinf(angle) - far, radius * cosf(angle), 0.0f);
+		glVertex3f(radius * sinf(angle_next) - far, radius * cosf(angle_next), 0.0f);
+		glVertex3f(inner_radius * sinf(angle) - far, inner_radius * cosf(angle), 0.0f);
+		glVertex3f(inner_radius * sinf(angle_next) - far, inner_radius * cosf(angle_next), 0.0f);
+		glVertex3f(inner_radius * sinf(angle) - far, inner_radius * cosf(angle), 0.0f);
+		glVertex3f(radius * sinf(angle_next) - far, radius * cosf(angle_next), 0.0f);
+	}
+
+	for (int i = 0; i < n; i++) {
+		float angle = i / (float)n * pi * 2;
+		
+		float angle_next = (i + 1) / (float)n * pi * 2;
+
+		// Բ3
+		if (5.0f / 12.0f * pi * 2 < angle && 7.0f / 12.0f * pi * 2 > angle)
+		{
+            glColor3f(0.0f, 0.0f, 0.0f);
+		}
+		else {
+			glColor3f(1.0f, 0.0f, 0.0f);
+		}
+		glVertex3f(radius * sinf(angle) , radius * cosf(angle) + far, 0.0f);
+		glVertex3f(radius * sinf(angle_next) , radius * cosf(angle_next) + far, 0.0f);
+		glVertex3f(inner_radius * sinf(angle) , inner_radius * cosf(angle) + far, 0.0f);
+		glVertex3f(inner_radius * sinf(angle_next) , inner_radius * cosf(angle_next) + far, 0.0f);
+		glVertex3f(inner_radius * sinf(angle) , inner_radius * cosf(angle) + far, 0.0f);
+		glVertex3f(radius * sinf(angle_next) , radius * cosf(angle_next) + far, 0.0f);
+	}
+    CHECK_GL(glEnd());
 }
 
 int main() {
@@ -108,7 +191,7 @@ int main() {
     while (!glfwWindowShouldClose(window)) {
         // render graphics
         CHECK_GL(glClear(GL_COLOR_BUFFER_BIT));
-        render();
+        render_opencv();
         // refresh screen
         glfwSwapBuffers(window);
         glfwPollEvents();