CODEWITHSUNDEEP
androidbitmap
matfr
matfr

Reputation: 109

Drawing to a new Bitmap and then using that in my onDraw

I would like to display several rings with different coloured sections (see below). The colour of the sections, however, cannot be know in advance, so I will need to draw these dynamically.

Coloured ring

I know I could draw directly to the canvas but, once I have them, I would like to animate these rings, rotate them, have them overlap etc. It seemed, therefore, that the easiest and possibly least expensive approach would be to create them in advance, in memory, as transparent pngs and then just draw them in onDraw.

My problem is the only methods I can find to do this are setPixel. Is there not a way I could use drawing tools, like in Canvas, to draw to an empty bitmap, once, then use that bitmap with my canvas in onDraw?

I feel like I am missing a piece in the puzzle. Any help would be greatly appreciated.

Upvotes: 0

Views: 568

Answers (1)

CaseyB
CaseyB

Reputation: 25058

You can create a Bitmap that is the size you want the ring to be and then create a Canvas the same size. Call setBitmap() on the Canvas and it will draw on to that for you. Then you can build your circle and have a bitmap to hold onto and use just like any other resource.

Upvotes: 1

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