diff --git a/zadanie-4/circle_vs.glsl b/zadanie-4/circle_vs.glsl
index e300ae1..026cdc8 100644
--- a/zadanie-4/circle_vs.glsl
+++ b/zadanie-4/circle_vs.glsl
@@ -1,10 +1,10 @@
 #version 330 core
-layout (location = 0) in vec2 aPos;
+layout (location = 0) in vec3 aPos;
 
 uniform mat4 model;
 uniform mat4 view;
 uniform mat4 projection;
 
 void main() {
-    gl_Position = projection * view * model * vec4(aPos, 0.0, 1.0);
+    gl_Position = projection * view * model * vec4(aPos, 1.0);
 }
diff --git a/zadanie-4/main.cpp b/zadanie-4/main.cpp
index f1a5538..87384a1 100644
--- a/zadanie-4/main.cpp
+++ b/zadanie-4/main.cpp
@@ -56,14 +56,18 @@ GLuint bezierVAO, bezierVBO;
 GLuint sphereVAO, sphereVBO, sphereEBO;
 
 std::vector<glm::vec3> controlPoints = {
-        glm::vec3(-1.0f, 0.0f, 0.0f),
-        glm::vec3(-0.5f, 5.0f, 0.0f),
-        glm::vec3(0.5f, -5.0f, 0.0f),
-        glm::vec3(1.0f, 3.0f, 0.0f)
+        glm::vec3(-1.0f, -1.0f, 0.0f),
+        glm::vec3(-0.5f, 4.0f, 0.0f),
+        glm::vec3(0.5f, -6.0f, 0.0f),
+        glm::vec3(1.0f, 2.0f, 0.0f)
 };
 
 float easingFn(float t) {
-    return pow(t, 3);
+//    return 1 - pow(1 - t, 3);
+    return t < 0.5
+    ? (1 - pow(1 - 2*t, 3)) / 2
+    : (pow(2*t - 1, 3) + 1) / 2;
+
 }
 
 glm::vec3 cubicBezier(const glm::vec3& P0, const glm::vec3& P1, const glm::vec3& P2, const glm::vec3& P3, float t) {