UnityEngine.Graphics.DrawTexture(UnityEngine.Rect, UnityEngine.Texture)

private void RunAddnewLife() 
    {
        GL.PushMatrix();
        GL.LoadPixelMatrix(0, renderTexture.width, renderTexture.height, 0);

        RenderTexture.active = renderTexture;
        int positionx, positiony;
        positionx = Random.Range(0, renderTexture.width + newLife.width + newLife.width) - newLife.width;
        positiony = Random.Range(0, renderTexture.height + newLife.height + newLife.height) - newLife.height;
        Graphics.DrawTexture(new Rect(positionx, positiony, newLife.width, newLife.height), newLife);
        RenderTexture.active = null;

        GL.PopMatrix();
    }

void BrushPaint() 
    {
        GL.PushMatrix();
        GL.LoadPixelMatrix(0, renderTexture.width, renderTexture.height, 0);

        RenderTexture.active = renderTexture;

        int positionx = x - ((int)slider.value);
        int positiony = y - ((int)slider.value);
        Graphics.DrawTexture(new Rect(positionx, positiony, (int)slider.value * 2, (int)slider.value * 2), Brush);

        RenderTexture.active = null;

        GL.PopMatrix();
    }

void ClearPaint() 
    {
        GL.PushMatrix();
        GL.LoadPixelMatrix(0, renderTexture.width, renderTexture.height, 0);

        RenderTexture.active = renderTexture;

        int positionx = x - ((int)slider.value);
        int positiony = y - ((int)slider.value);
        Graphics.DrawTexture(new Rect(positionx, positiony, (int)slider.value * 2, (int)slider.value * 2), Clear);

        RenderTexture.active = null;

        GL.PopMatrix();
    }

void PencilPaint() 
    {
        GL.PushMatrix();
        GL.LoadPixelMatrix(0, renderTexture.width, renderTexture.height, 0);

        RenderTexture.active = renderTexture;

        Texture2D tex = new Texture2D(1, 1);
        tex.ReadPixels(new Rect(x, y, 1, 1), 0, 0);
        tex.Apply();

        float r = tex.GetPixel(0, 0).r;
        r += 1 / sliderMax.value;

        tex.SetPixel(0, 0, new Color(r, 1, 1, 1));
        tex.Apply();

        Graphics.DrawTexture(new Rect(x, y, 1, 1), tex);

        RenderTexture.active = null;

        GL.PopMatrix();
    }

static void _gpu_scale(Texture2D src, int width, int height, FilterMode fmode)
    {
        //We need the source texture in VRAM because we render with it
        src.filterMode = fmode;
        src.Apply(true);

        //Using RTT for best quality and performance. Thanks, Unity 5
        RenderTexture rtt = new RenderTexture(width, height, 32);

        //Set the RTT in order to render to it
        Graphics.SetRenderTarget(rtt);

        //Setup 2D matrix in range 0..1, so nobody needs to care about sized
        GL.LoadPixelMatrix(0, 1, 1, 0);

        //Then clear & draw the texture to fill the entire RTT.
        GL.Clear(true, true, new Color(0, 0, 0, 0));
        Graphics.DrawTexture(new Rect(0, 0, 1, 1), src);
    }

public override void OnMonitorGUI(Rect r)
        {
            if (Event.current.type == EventType.Repaint)
            {
                // If m_MonitorAreaRect isn't set the preview was just opened so refresh the render to get the histogram data
                if (Mathf.Approximately(m_MonitorAreaRect.width, 0) && Mathf.Approximately(m_MonitorAreaRect.height, 0))
                    InternalEditorUtility.RepaintAllViews();

                // Sizing
                float width = m_HistogramTexture != null
                    ? Mathf.Min(m_HistogramTexture.width, r.width - 65f)
                    : r.width;
                float height = m_HistogramTexture != null
                    ? Mathf.Min(m_HistogramTexture.height, r.height - 45f)
                    : r.height;

                m_MonitorAreaRect = new Rect(
                        Mathf.Floor(r.x + r.width / 2f - width / 2f),
                        Mathf.Floor(r.y + r.height / 2f - height / 2f - 5f),
                        width, height
                        );

                if (m_HistogramTexture != null)
                {
                    Graphics.DrawTexture(m_MonitorAreaRect, m_HistogramTexture);

                    var color = Color.white;
                    const float kTickSize = 5f;

                    // Rect, lines & ticks points
                    if (m_MonitorSettings.histogramMode == HistogramMode.RGBSplit)
                    {
                        //  A B C D E
                        //  N       F
                        //  M       G
                        //  L K J I H

                        var A = new Vector3(m_MonitorAreaRect.x - 1f, m_MonitorAreaRect.y - 1f);
                        var E = new Vector3(A.x + m_MonitorAreaRect.width + 2f, m_MonitorAreaRect.y - 1f);
                        var H = new Vector3(E.x, E.y + m_MonitorAreaRect.height + 2f);
                        var L = new Vector3(A.x, H.y);

                        var N = new Vector3(A.x, A.y + (L.y - A.y) / 3f);
                        var M = new Vector3(A.x, A.y + (L.y - A.y) * 2f / 3f);
                        var F = new Vector3(E.x, E.y + (H.y - E.y) / 3f);
                        var G = new Vector3(E.x, E.y + (H.y - E.y) * 2f / 3f);

                        var C = new Vector3(A.x + (E.x - A.x) / 2f, A.y);
                        var J = new Vector3(L.x + (H.x - L.x) / 2f, L.y);

                        var B = new Vector3(A.x + (C.x - A.x) / 2f, A.y);
                        var D = new Vector3(C.x + (E.x - C.x) / 2f, C.y);
                        var I = new Vector3(J.x + (H.x - J.x) / 2f, J.y);
                        var K = new Vector3(L.x + (J.x - L.x) / 2f, L.y);

                        // Borders
                        Handles.color = color;
                        Handles.DrawLine(A, E);
                        Handles.DrawLine(E, H);
                        Handles.DrawLine(H, L);
                        Handles.DrawLine(L, new Vector3(A.x, A.y - 1f));

                        // Vertical ticks
                        Handles.DrawLine(A, new Vector3(A.x - kTickSize, A.y));
                        Handles.DrawLine(N, new Vector3(N.x - kTickSize, N.y));
                        Handles.DrawLine(M, new Vector3(M.x - kTickSize, M.y));
                        Handles.DrawLine(L, new Vector3(L.x - kTickSize, L.y));

                        Handles.DrawLine(E, new Vector3(E.x + kTickSize, E.y));
                        Handles.DrawLine(F, new Vector3(F.x + kTickSize, F.y));
                        Handles.DrawLine(G, new Vector3(G.x + kTickSize, G.y));
                        Handles.DrawLine(H, new Vector3(H.x + kTickSize, H.y));

                        // Horizontal ticks
                        Handles.DrawLine(A, new Vector3(A.x, A.y - kTickSize));
                        Handles.DrawLine(B, new Vector3(B.x, B.y - kTickSize));
                        Handles.DrawLine(C, new Vector3(C.x, C.y - kTickSize));
                        Handles.DrawLine(D, new Vector3(D.x, D.y - kTickSize));
                        Handles.DrawLine(E, new Vector3(E.x, E.y - kTickSize));

                        Handles.DrawLine(L, new Vector3(L.x, L.y + kTickSize));
                        Handles.DrawLine(K, new Vector3(K.x, K.y + kTickSize));
                        Handles.DrawLine(J, new Vector3(J.x, J.y + kTickSize));
                        Handles.DrawLine(I, new Vector3(I.x, I.y + kTickSize));
                        Handles.DrawLine(H, new Vector3(H.x, H.y + kTickSize));

                        // Separators
                        Handles.DrawLine(N, F);
                        Handles.DrawLine(M, G);

                        // Labels
                        GUI.color = color;
                        GUI.Label(new Rect(L.x - 15f, L.y + kTickSize - 4f, 30f, 30f), "0.0", FxStyles.tickStyleCenter);
                        GUI.Label(new Rect(J.x - 15f, J.y + kTickSize - 4f, 30f, 30f), "0.5", FxStyles.tickStyleCenter);
                        GUI.Label(new Rect(H.x - 15f, H.y + kTickSize - 4f, 30f, 30f), "1.0", FxStyles.tickStyleCenter);
                    }
                    else
                    {
                        //  A B C D E
                        //  P       F
                        //  O       G
                        //  N       H
                        //  M L K J I

                        var A = new Vector3(m_MonitorAreaRect.x, m_MonitorAreaRect.y);
                        var E = new Vector3(A.x + m_MonitorAreaRect.width + 1f, m_MonitorAreaRect.y);
                        var I = new Vector3(E.x, E.y + m_MonitorAreaRect.height + 1f);
                        var M = new Vector3(A.x, I.y);

                        var C = new Vector3(A.x + (E.x - A.x) / 2f, A.y);
                        var G = new Vector3(E.x, E.y + (I.y - E.y) / 2f);
                        var K = new Vector3(M.x + (I.x - M.x) / 2f, M.y);
                        var O = new Vector3(A.x, A.y + (M.y - A.y) / 2f);

                        var P = new Vector3(A.x, A.y + (O.y - A.y) / 2f);
                        var F = new Vector3(E.x, E.y + (G.y - E.y) / 2f);
                        var N = new Vector3(A.x, O.y + (M.y - O.y) / 2f);
                        var H = new Vector3(E.x, G.y + (I.y - G.y) / 2f);

                        var B = new Vector3(A.x + (C.x - A.x) / 2f, A.y);
                        var L = new Vector3(M.x + (K.x - M.x) / 2f, M.y);
                        var D = new Vector3(C.x + (E.x - C.x) / 2f, A.y);
                        var J = new Vector3(K.x + (I.x - K.x) / 2f, M.y);

                        // Borders
                        Handles.color = color;
                        Handles.DrawLine(A, E);
                        Handles.DrawLine(E, I);
                        Handles.DrawLine(I, M);
                        Handles.DrawLine(M, new Vector3(A.x, A.y - 1f));

                        // Vertical ticks
                        Handles.DrawLine(A, new Vector3(A.x - kTickSize, A.y));
                        Handles.DrawLine(P, new Vector3(P.x - kTickSize, P.y));
                        Handles.DrawLine(O, new Vector3(O.x - kTickSize, O.y));
                        Handles.DrawLine(N, new Vector3(N.x - kTickSize, N.y));
                        Handles.DrawLine(M, new Vector3(M.x - kTickSize, M.y));

                        Handles.DrawLine(E, new Vector3(E.x + kTickSize, E.y));
                        Handles.DrawLine(F, new Vector3(F.x + kTickSize, F.y));
                        Handles.DrawLine(G, new Vector3(G.x + kTickSize, G.y));
                        Handles.DrawLine(H, new Vector3(H.x + kTickSize, H.y));
                        Handles.DrawLine(I, new Vector3(I.x + kTickSize, I.y));

                        // Horizontal ticks
                        Handles.DrawLine(A, new Vector3(A.x, A.y - kTickSize));
                        Handles.DrawLine(B, new Vector3(B.x, B.y - kTickSize));
                        Handles.DrawLine(C, new Vector3(C.x, C.y - kTickSize));
                        Handles.DrawLine(D, new Vector3(D.x, D.y - kTickSize));
                        Handles.DrawLine(E, new Vector3(E.x, E.y - kTickSize));

                        Handles.DrawLine(M, new Vector3(M.x, M.y + kTickSize));
                        Handles.DrawLine(L, new Vector3(L.x, L.y + kTickSize));
                        Handles.DrawLine(K, new Vector3(K.x, K.y + kTickSize));
                        Handles.DrawLine(J, new Vector3(J.x, J.y + kTickSize));
                        Handles.DrawLine(I, new Vector3(I.x, I.y + kTickSize));

                        // Labels
                        GUI.color = color;
                        GUI.Label(new Rect(A.x - kTickSize - 34f, A.y - 15f, 30f, 30f), "1.0", FxStyles.tickStyleRight);
                        GUI.Label(new Rect(O.x - kTickSize - 34f, O.y - 15f, 30f, 30f), "0.5", FxStyles.tickStyleRight);
                        GUI.Label(new Rect(M.x - kTickSize - 34f, M.y - 15f, 30f, 30f), "0.0", FxStyles.tickStyleRight);

                        GUI.Label(new Rect(E.x + kTickSize + 4f, E.y - 15f, 30f, 30f), "1.0", FxStyles.tickStyleLeft);
                        GUI.Label(new Rect(G.x + kTickSize + 4f, G.y - 15f, 30f, 30f), "0.5", FxStyles.tickStyleLeft);
                        GUI.Label(new Rect(I.x + kTickSize + 4f, I.y - 15f, 30f, 30f), "0.0", FxStyles.tickStyleLeft);

                        GUI.Label(new Rect(M.x - 15f, M.y + kTickSize - 4f, 30f, 30f), "0.0", FxStyles.tickStyleCenter);
                        GUI.Label(new Rect(K.x - 15f, K.y + kTickSize - 4f, 30f, 30f), "0.5", FxStyles.tickStyleCenter);
                        GUI.Label(new Rect(I.x - 15f, I.y + kTickSize - 4f, 30f, 30f), "1.0", FxStyles.tickStyleCenter);
                    }
                }
            }
        }

public override void OnMonitorGUI(Rect r)
        {
            if (Event.current.type == EventType.Repaint)
            {
                // If m_MonitorAreaRect isn't set the preview was just opened so refresh the render to get the waveform data
                if (Mathf.Approximately(m_MonitorAreaRect.width, 0) && Mathf.Approximately(m_MonitorAreaRect.height, 0))
                    InternalEditorUtility.RepaintAllViews();

                // Sizing
                float width = m_WaveformTexture != null
                    ? Mathf.Min(m_WaveformTexture.width, r.width - 65f)
                    : r.width;
                float height = m_WaveformTexture != null
                    ? Mathf.Min(m_WaveformTexture.height, r.height - 45f)
                    : r.height;

                m_MonitorAreaRect = new Rect(
                        Mathf.Floor(r.x + r.width / 2f - width / 2f),
                        Mathf.Floor(r.y + r.height / 2f - height / 2f - 5f),
                        width, height
                        );

                if (m_WaveformTexture != null)
                {
                    m_Material.SetFloat("_Exposure", m_MonitorSettings.paradeExposure);

                    var oldActive = RenderTexture.active;
                    Graphics.Blit(null, m_WaveformTexture, m_Material, 0);
                    RenderTexture.active = oldActive;

                    Graphics.DrawTexture(m_MonitorAreaRect, m_WaveformTexture);

                    var color = Color.white;
                    const float kTickSize = 5f;

                    // Rect, lines & ticks points
                    //  A O B P C Q D
                    //  N           E
                    //  M           F
                    //  L           G
                    //  K T J S I R H

                    var A = new Vector3(m_MonitorAreaRect.x, m_MonitorAreaRect.y);
                    var D = new Vector3(A.x + m_MonitorAreaRect.width + 1f, m_MonitorAreaRect.y);
                    var H = new Vector3(D.x, D.y + m_MonitorAreaRect.height + 1f);
                    var K = new Vector3(A.x, H.y);

                    var F = new Vector3(D.x, D.y + (H.y - D.y) / 2f);
                    var M = new Vector3(A.x, A.y + (K.y - A.y) / 2f);

                    var B = new Vector3(A.x + (D.x - A.x) / 3f, A.y);
                    var C = new Vector3(A.x + (D.x - A.x) * 2f / 3f, A.y);
                    var I = new Vector3(K.x + (H.x - K.x) * 2f / 3f, K.y);
                    var J = new Vector3(K.x + (H.x - K.x) / 3f, K.y);

                    var N = new Vector3(A.x, A.y + (M.y - A.y) / 2f);
                    var L = new Vector3(A.x, M.y + (K.y - M.y) / 2f);
                    var E = new Vector3(D.x, D.y + (F.y - D.y) / 2f);
                    var G = new Vector3(D.x, F.y + (H.y - F.y) / 2f);

                    var O = new Vector3(A.x + (B.x - A.x) / 2f, A.y);
                    var P = new Vector3(B.x + (C.x - B.x) / 2f, B.y);
                    var Q = new Vector3(C.x + (D.x - C.x) / 2f, C.y);

                    var R = new Vector3(I.x + (H.x - I.x) / 2f, I.y);
                    var S = new Vector3(J.x + (I.x - J.x) / 2f, J.y);
                    var T = new Vector3(K.x + (J.x - K.x) / 2f, K.y);

                    // Borders
                    Handles.color = color;
                    Handles.DrawLine(A, D);
                    Handles.DrawLine(D, H);
                    Handles.DrawLine(H, K);
                    Handles.DrawLine(K, new Vector3(A.x, A.y - 1f));

                    Handles.DrawLine(B, J);
                    Handles.DrawLine(C, I);

                    // Vertical ticks
                    Handles.DrawLine(A, new Vector3(A.x - kTickSize, A.y));
                    Handles.DrawLine(N, new Vector3(N.x - kTickSize, N.y));
                    Handles.DrawLine(M, new Vector3(M.x - kTickSize, M.y));
                    Handles.DrawLine(L, new Vector3(L.x - kTickSize, L.y));
                    Handles.DrawLine(K, new Vector3(K.x - kTickSize, K.y));

                    Handles.DrawLine(D, new Vector3(D.x + kTickSize, D.y));
                    Handles.DrawLine(E, new Vector3(E.x + kTickSize, E.y));
                    Handles.DrawLine(F, new Vector3(F.x + kTickSize, F.y));
                    Handles.DrawLine(G, new Vector3(G.x + kTickSize, G.y));
                    Handles.DrawLine(H, new Vector3(H.x + kTickSize, H.y));

                    // Horizontal ticks
                    Handles.DrawLine(A, new Vector3(A.x, A.y - kTickSize));
                    Handles.DrawLine(B, new Vector3(B.x, B.y - kTickSize));
                    Handles.DrawLine(C, new Vector3(C.x, C.y - kTickSize));
                    Handles.DrawLine(D, new Vector3(D.x, D.y - kTickSize));
                    Handles.DrawLine(O, new Vector3(O.x, O.y - kTickSize));
                    Handles.DrawLine(P, new Vector3(P.x, P.y - kTickSize));
                    Handles.DrawLine(Q, new Vector3(Q.x, Q.y - kTickSize));

                    Handles.DrawLine(H, new Vector3(H.x, H.y + kTickSize));
                    Handles.DrawLine(I, new Vector3(I.x, I.y + kTickSize));
                    Handles.DrawLine(J, new Vector3(J.x, J.y + kTickSize));
                    Handles.DrawLine(K, new Vector3(K.x, K.y + kTickSize));
                    Handles.DrawLine(R, new Vector3(R.x, R.y + kTickSize));
                    Handles.DrawLine(S, new Vector3(S.x, S.y + kTickSize));
                    Handles.DrawLine(T, new Vector3(T.x, T.y + kTickSize));

                    // Labels
                    GUI.color = color;
                    GUI.Label(new Rect(A.x - kTickSize - 34f, A.y - 15f, 30f, 30f), "1.0", FxStyles.tickStyleRight);
                    GUI.Label(new Rect(M.x - kTickSize - 34f, M.y - 15f, 30f, 30f), "0.5", FxStyles.tickStyleRight);
                    GUI.Label(new Rect(K.x - kTickSize - 34f, K.y - 15f, 30f, 30f), "0.0", FxStyles.tickStyleRight);

                    GUI.Label(new Rect(D.x + kTickSize + 4f, D.y - 15f, 30f, 30f), "1.0", FxStyles.tickStyleLeft);
                    GUI.Label(new Rect(F.x + kTickSize + 4f, F.y - 15f, 30f, 30f), "0.5", FxStyles.tickStyleLeft);
                    GUI.Label(new Rect(H.x + kTickSize + 4f, H.y - 15f, 30f, 30f), "0.0", FxStyles.tickStyleLeft);
                }
            }
        }

public override void OnMonitorGUI(Rect r)
        {
            if (Event.current.type == EventType.Repaint)
            {
                // If m_MonitorAreaRect isn't set the preview was just opened so refresh the render to get the vectoscope data
                if (Mathf.Approximately(m_MonitorAreaRect.width, 0) && Mathf.Approximately(m_MonitorAreaRect.height, 0))
                    InternalEditorUtility.RepaintAllViews();

                // Sizing
                float size = 0f;

                if (r.width < r.height)
                {
                    size = m_VectorscopeTexture != null
                        ? Mathf.Min(m_VectorscopeTexture.width, r.width - 35f)
                        : r.width;
                }
                else
                {
                    size = m_VectorscopeTexture != null
                        ? Mathf.Min(m_VectorscopeTexture.height, r.height - 25f)
                        : r.height;
                }

                m_MonitorAreaRect = new Rect(
                        Mathf.Floor(r.x + r.width / 2f - size / 2f),
                        Mathf.Floor(r.y + r.height / 2f - size / 2f - 5f),
                        size, size
                        );

                if (m_VectorscopeTexture != null)
                {
                    m_Material.SetFloat("_Exposure", m_MonitorSettings.vectorscopeExposure);

                    var oldActive = RenderTexture.active;
                    Graphics.Blit(null, m_VectorscopeTexture, m_Material, m_MonitorSettings.vectorscopeShowBackground ? 0 : 1);
                    RenderTexture.active = oldActive;

                    Graphics.DrawTexture(m_MonitorAreaRect, m_VectorscopeTexture);

                    var color = Color.white;
                    const float kTickSize = 10f;
                    const int kTickCount = 24;

                    float radius = m_MonitorAreaRect.width / 2f;
                    float midX = m_MonitorAreaRect.x + radius;
                    float midY = m_MonitorAreaRect.y + radius;
                    var center = new Vector2(midX, midY);

                    // Cross
                    color.a *= 0.5f;
                    Handles.color = color;
                    Handles.DrawLine(new Vector2(midX, m_MonitorAreaRect.y), new Vector2(midX, m_MonitorAreaRect.y + m_MonitorAreaRect.height));
                    Handles.DrawLine(new Vector2(m_MonitorAreaRect.x, midY), new Vector2(m_MonitorAreaRect.x + m_MonitorAreaRect.width, midY));

                    if (m_MonitorAreaRect.width > 100f)
                    {
                        color.a = 1f;

                        // Ticks
                        Handles.color = color;
                        for (int i = 0; i < kTickCount; i++)
                        {
                            float a = (float)i / (float)kTickCount;
                            float theta = a * (Mathf.PI * 2f);
                            float tx = Mathf.Cos(theta + (Mathf.PI / 2f));
                            float ty = Mathf.Sin(theta - (Mathf.PI / 2f));
                            var innerVec = center + new Vector2(tx, ty) * (radius - kTickSize);
                            var outerVec = center + new Vector2(tx, ty) * radius;
                            Handles.DrawAAPolyLine(3f, innerVec, outerVec);
                        }

                        // Labels (where saturation reaches 75%)
                        color.a = 1f;
                        var oldColor = GUI.color;
                        GUI.color = color * 2f;

                        var point = new Vector2(-0.254f, -0.750f) * radius + center;
                        var rect = new Rect(point.x - 10f, point.y - 10f, 20f, 20f);
                        GUI.Label(rect, "[R]", FxStyles.tickStyleCenter);

                        point = new Vector2(-0.497f, 0.629f) * radius + center;
                        rect = new Rect(point.x - 10f, point.y - 10f, 20f, 20f);
                        GUI.Label(rect, "[G]", FxStyles.tickStyleCenter);

                        point = new Vector2(0.750f, 0.122f) * radius + center;
                        rect = new Rect(point.x - 10f, point.y - 10f, 20f, 20f);
                        GUI.Label(rect, "[B]", FxStyles.tickStyleCenter);

                        point = new Vector2(-0.750f, -0.122f) * radius + center;
                        rect = new Rect(point.x - 10f, point.y - 10f, 20f, 20f);
                        GUI.Label(rect, "[Y]", FxStyles.tickStyleCenter);

                        point = new Vector2(0.254f, 0.750f) * radius + center;
                        rect = new Rect(point.x - 10f, point.y - 10f, 20f, 20f);
                        GUI.Label(rect, "[C]", FxStyles.tickStyleCenter);

                        point = new Vector2(0.497f, -0.629f) * radius + center;
                        rect = new Rect(point.x - 10f, point.y - 10f, 20f, 20f);
                        GUI.Label(rect, "[M]", FxStyles.tickStyleCenter);
                        GUI.color = oldColor;
                    }
                }
            }
        }

public override void OnMonitorGUI(Rect r)
        {
            if (Event.current.type == EventType.Repaint)
            {
                // If m_MonitorAreaRect isn't set the preview was just opened so refresh the render to get the waveform data
                if (Mathf.Approximately(m_MonitorAreaRect.width, 0) && Mathf.Approximately(m_MonitorAreaRect.height, 0))
                    InternalEditorUtility.RepaintAllViews();

                // Sizing
                float width = m_WaveformTexture != null
                    ? Mathf.Min(m_WaveformTexture.width, r.width - 65f)
                    : r.width;
                float height = m_WaveformTexture != null
                    ? Mathf.Min(m_WaveformTexture.height, r.height - 45f)
                    : r.height;

                m_MonitorAreaRect = new Rect(
                        Mathf.Floor(r.x + r.width / 2f - width / 2f),
                        Mathf.Floor(r.y + r.height / 2f - height / 2f - 5f),
                        width, height
                        );

                if (m_WaveformTexture != null)
                {
                    m_Material.SetFloat("_Exposure", m_MonitorSettings.waveformExposure);

                    var oldActive = RenderTexture.active;
                    Graphics.Blit(null, m_WaveformTexture, m_Material, 0);
                    RenderTexture.active = oldActive;

                    Graphics.DrawTexture(m_MonitorAreaRect, m_WaveformTexture);

                    var color = Color.white;
                    const float kTickSize = 5f;

                    // Rect, lines & ticks points
                    //  A B C D E
                    //  P       F
                    //  O       G
                    //  N       H
                    //  M L K J I

                    var A = new Vector3(m_MonitorAreaRect.x, m_MonitorAreaRect.y);
                    var E = new Vector3(A.x + m_MonitorAreaRect.width + 1f, m_MonitorAreaRect.y);
                    var I = new Vector3(E.x, E.y + m_MonitorAreaRect.height + 1f);
                    var M = new Vector3(A.x, I.y);

                    var C = new Vector3(A.x + (E.x - A.x) / 2f, A.y);
                    var G = new Vector3(E.x, E.y + (I.y - E.y) / 2f);
                    var K = new Vector3(M.x + (I.x - M.x) / 2f, M.y);
                    var O = new Vector3(A.x, A.y + (M.y - A.y) / 2f);

                    var P = new Vector3(A.x, A.y + (O.y - A.y) / 2f);
                    var F = new Vector3(E.x, E.y + (G.y - E.y) / 2f);
                    var N = new Vector3(A.x, O.y + (M.y - O.y) / 2f);
                    var H = new Vector3(E.x, G.y + (I.y - G.y) / 2f);

                    var B = new Vector3(A.x + (C.x - A.x) / 2f, A.y);
                    var L = new Vector3(M.x + (K.x - M.x) / 2f, M.y);
                    var D = new Vector3(C.x + (E.x - C.x) / 2f, A.y);
                    var J = new Vector3(K.x + (I.x - K.x) / 2f, M.y);

                    // Borders
                    Handles.color = color;
                    Handles.DrawLine(A, E);
                    Handles.DrawLine(E, I);
                    Handles.DrawLine(I, M);
                    Handles.DrawLine(M, new Vector3(A.x, A.y - 1f));

                    // Vertical ticks
                    Handles.DrawLine(A, new Vector3(A.x - kTickSize, A.y));
                    Handles.DrawLine(P, new Vector3(P.x - kTickSize, P.y));
                    Handles.DrawLine(O, new Vector3(O.x - kTickSize, O.y));
                    Handles.DrawLine(N, new Vector3(N.x - kTickSize, N.y));
                    Handles.DrawLine(M, new Vector3(M.x - kTickSize, M.y));

                    Handles.DrawLine(E, new Vector3(E.x + kTickSize, E.y));
                    Handles.DrawLine(F, new Vector3(F.x + kTickSize, F.y));
                    Handles.DrawLine(G, new Vector3(G.x + kTickSize, G.y));
                    Handles.DrawLine(H, new Vector3(H.x + kTickSize, H.y));
                    Handles.DrawLine(I, new Vector3(I.x + kTickSize, I.y));

                    // Horizontal ticks
                    Handles.DrawLine(A, new Vector3(A.x, A.y - kTickSize));
                    Handles.DrawLine(B, new Vector3(B.x, B.y - kTickSize));
                    Handles.DrawLine(C, new Vector3(C.x, C.y - kTickSize));
                    Handles.DrawLine(D, new Vector3(D.x, D.y - kTickSize));
                    Handles.DrawLine(E, new Vector3(E.x, E.y - kTickSize));

                    Handles.DrawLine(M, new Vector3(M.x, M.y + kTickSize));
                    Handles.DrawLine(L, new Vector3(L.x, L.y + kTickSize));
                    Handles.DrawLine(K, new Vector3(K.x, K.y + kTickSize));
                    Handles.DrawLine(J, new Vector3(J.x, J.y + kTickSize));
                    Handles.DrawLine(I, new Vector3(I.x, I.y + kTickSize));

                    // Labels
                    GUI.color = color;
                    GUI.Label(new Rect(A.x - kTickSize - 34f, A.y - 15f, 30f, 30f), "1.0", FxStyles.tickStyleRight);
                    GUI.Label(new Rect(O.x - kTickSize - 34f, O.y - 15f, 30f, 30f), "0.5", FxStyles.tickStyleRight);
                    GUI.Label(new Rect(M.x - kTickSize - 34f, M.y - 15f, 30f, 30f), "0.0", FxStyles.tickStyleRight);

                    GUI.Label(new Rect(E.x + kTickSize + 4f, E.y - 15f, 30f, 30f), "1.0", FxStyles.tickStyleLeft);
                    GUI.Label(new Rect(G.x + kTickSize + 4f, G.y - 15f, 30f, 30f), "0.5", FxStyles.tickStyleLeft);
                    GUI.Label(new Rect(I.x + kTickSize + 4f, I.y - 15f, 30f, 30f), "0.0", FxStyles.tickStyleLeft);

                    GUI.Label(new Rect(M.x - 15f, M.y + kTickSize - 4f, 30f, 30f), "0.0", FxStyles.tickStyleCenter);
                    GUI.Label(new Rect(K.x - 15f, K.y + kTickSize - 4f, 30f, 30f), "0.5", FxStyles.tickStyleCenter);
                    GUI.Label(new Rect(I.x - 15f, I.y + kTickSize - 4f, 30f, 30f), "1.0", FxStyles.tickStyleCenter);
                }
            }
        }

static void _gpu_scale(Texture2D src, Rect? srcRect, int width, int height, FilterMode fmode)
    {
        //We need the source texture in VRAM because we render with it
        src.filterMode = fmode;
        src.Apply(true);

        //Using RTT for best quality and performance. Thanks, Unity 5
        RenderTexture rtt = new RenderTexture(width, height, 32);

        //Set the RTT in order to render to it
        Graphics.SetRenderTarget(rtt);

        //Setup 2D matrix in range 0..1, so nobody needs to care about sized
        GL.LoadPixelMatrix(0, 1, 1, 0);

        //Then clear & draw the texture to fill the entire RTT.
        GL.Clear(true, true, new Color(0, 0, 0, 0));
        if (srcRect.HasValue)
        {
            //srcRect.Value.AsNormalizedUv(src.width, src.height)
            Graphics.DrawTexture(new Rect(0, 0, 1, 1), src, srcRect.Value.AsNormalizedUv(src.width, src.height), 0, 0, 0, 0);
        }
        else
        {
            Graphics.DrawTexture(new Rect(0, 0, 1, 1), src);
        }
    }