Caching charts

[Munken]

As mentioned early some charts are quite slow to render. Some of this can be solved by rendering to an image an then just have CN1 draw this.

Currently I use this code to achieve it:

    private static Image g(GraphicalView g, int w, int h) {
        Image buf = Image.createImage(w, h, 0xF0F0F0);
        buf.getGraphics().setClip(0, 0, w, h);

        Canvas canvas = new Canvas();
        Paint paint = new Paint();
        canvas.g = buf.getGraphics();
        Paint.g = buf.getGraphics();
        g.getChart().draw(canvas, 0, 0, w, h, paint);

        return buf;
    }

There should however be a way to invalidate the cache or it should detect automatically.

[Munken]

Here is some code that relies entirely on the pisces pipeline to render the chart. Please note that it is note complete. Needs scaling, translation, rotation and other stuff.

https://gist.github.com/Munken/6fae6ec805fabc626c9f

[shannah]

Have you found that this gives better performance?

[Munken]

Before it would scroll heavily when scrolling a tab that contained a chart. With caching it as an image scrolling is fluent.

The Pisces canvas solves the rest