void DrawCustomToneCurve()

in unity/Assets/PostProcessingV2/Editor/Effects/ColorGradingEditor.cs [384:464]
64 lines of code
8 McCabe index (conditional complexity)

        void DrawCustomToneCurve()
        {
            EditorGUILayout.Space();

            // Reserve GUI space
            using (new GUILayout.HorizontalScope())
            {
                GUILayout.Space(EditorGUI.indentLevel * 15f);
                m_CustomToneCurveRect = GUILayoutUtility.GetRect(128, 80);
            }

            if (Event.current.type != EventType.Repaint)
                return;

            // Prepare curve data
            float toeStrength = m_ToneCurveToeStrength.value.floatValue;
            float toeLength = m_ToneCurveToeLength.value.floatValue;
            float shoulderStrength = m_ToneCurveShoulderStrength.value.floatValue;
            float shoulderLength = m_ToneCurveShoulderLength.value.floatValue;
            float shoulderAngle = m_ToneCurveShoulderAngle.value.floatValue;
            float gamma = m_ToneCurveGamma.value.floatValue;
            m_HableCurve.Init(
                toeStrength,
                toeLength,
                shoulderStrength,
                shoulderLength,
                shoulderAngle,
                gamma
            );

            float endPoint = m_HableCurve.whitePoint;

            // Background
            m_RectVertices[0] = PointInRect(0f, 0f, endPoint);
            m_RectVertices[1] = PointInRect(endPoint, 0f, endPoint);
            m_RectVertices[2] = PointInRect(endPoint, k_CustomToneCurveRangeY, endPoint);
            m_RectVertices[3] = PointInRect(0f, k_CustomToneCurveRangeY, endPoint);
            Handles.DrawSolidRectangleWithOutline(m_RectVertices, Color.white * 0.1f, Color.white * 0.4f);

            // Vertical guides
            if (endPoint < m_CustomToneCurveRect.width / 3)
            {
                int steps = Mathf.CeilToInt(endPoint);
                for (var i = 1; i < steps; i++)
                    DrawLine(i, 0, i, k_CustomToneCurveRangeY, 0.4f, endPoint);
            }

            // Label
            Handles.Label(m_CustomToneCurveRect.position + Vector2.right, "Custom Tone Curve", EditorStyles.miniLabel);

            // Draw the acual curve
            var vcount = 0;
            while (vcount < k_CustomToneCurveResolution)
            {
                float x = endPoint * vcount / (k_CustomToneCurveResolution - 1);
                float y = m_HableCurve.Eval(x);

                if (y < k_CustomToneCurveRangeY)
                {
                    m_CurveVertices[vcount++] = PointInRect(x, y, endPoint);
                }
                else
                {
                    if (vcount > 1)
                    {
                        // Extend the last segment to the top edge of the rect.
                        var v1 = m_CurveVertices[vcount - 2];
                        var v2 = m_CurveVertices[vcount - 1];
                        var clip = (m_CustomToneCurveRect.y - v1.y) / (v2.y - v1.y);
                        m_CurveVertices[vcount - 1] = v1 + (v2 - v1) * clip;
                    }
                    break;
                }
            }

            if (vcount > 1)
            {
                Handles.color = Color.white * 0.9f;
                Handles.DrawAAPolyLine(2f, vcount, m_CurveVertices);
            }
        }