How do you create animated textures with Texture2D.Apply with any regularity?

Questions & Answers
1

I've noticed that one cannot really dynamically modify textures and expect them to animate with any sort of regularity. This may be an Editor specific issue. I am hoping that I can create a "paint" tool in unity but I don't seem to be able to draw reliably. I'm hoping it's just something I'm missing.

Here's my code:

using UnityEditor;
using UnityEngine;
using System.Collections;

public class TestEditor : EditorWindow {

    [MenuItem("Editor/TestEditor")]
    static void ShowWindow ()
    {
        EditorWindow.GetWindow<TestEditor> ();
    }

    Texture2D canvas;
    Color[] colors;
    bool isInitialized = false;
    bool penDown =false;

    int offset =0;
    public TestEditor() 
    {

    }

    int count =0;
    public void OnGUI()
    {
        this.wantsMouseMove = true;

        canvas = getWhiteCanvas(canvas, (int)(position.width/2), (int)( position.height/2));
        colors = canvas.GetPixels();
        GUI.Box (new Rect(0,0,canvas.width, canvas.height), canvas);

        Event current = Event.current;

        switch(current.type)
        {
        case EventType.Repaint:
            Debug.Log("Repaint:" +count++);
            //if(penDown == true)
            {

                /*
                int x = (int) current.mousePosition.x;
                int y = (int) ((float)(canvas.height) - current.mousePosition.y);
                //Debug.Log("MouseMove:" + x + ":" + y);

                if (x < canvas.width && y < canvas.height) 
                {
                    colors[y * canvas.width + x] = Color.blue;
                    canvas.SetPixels(colors);
                    canvas.Apply();
                }
                */
            }
            break;
        case EventType.MouseDown:
            //Debug.Log("MouseDown:" + current.mousePosition.x + ":" + current.mousePosition.y);
            penDown = true;         
            break;
        case EventType.MouseUp:
            //Debug.Log("MouseUp:" + current.mousePosition.x + ":" + current.mousePosition.y);
            penDown = false;
            break;
        }
    }

    public void Update()
    {
                // Fill the texture with Sierpinski's fractal pattern!
                int y = 0;
                while (y < canvas.height) {
                    int x = 0;
                    while (x < canvas.width) {
                        Color color = ((x+offset & y+offset) == 0)?Color.white:Color.gray;
                        canvas.SetPixel(x, y, color);
                        ++x;
                    }
                    ++y;
                }
                canvas.Apply();
                offset = offset + 1 % canvas.width;

    }

    //-----------------------------------------------------------------------------
    public Texture2D getWhiteCanvas(Texture2D current, int width, int height)
    {
        Texture2D canvas = current;
        if (canvas == null)
        {   
            canvas = new Texture2D(width, height, TextureFormat.ARGB32, false);
            for(int x = 0; x < width; x++)
                for(int y = 0; y < height; y++)
                    canvas.SetPixel(x,y,Color.white);
        }
        else if (canvas.width != width || canvas.height != height)
        {
            canvas = new Texture2D(width, height, TextureFormat.ARGB32, false);
            int oldWidth = (current.width < width) ? current.width : width;
            int oldHeight = (current.height < height) ? current.height : height;
            for(int x = 0; x < oldWidth; x++)
                for(int y = 0; y < oldHeight; y++)
                    canvas.SetPixel(x,y,current.GetPixel(x,y));
        }
        canvas.Apply();
        return canvas;

    }

}
2

If you use FixedUpdate() instead of Update() does it help the regularity? Update() is frame-dependent, but FixedUpdate runs on a fixed timestep.