Scale and colour a bitmap image at the same time

3543362 3 days ago

Hello,

I've been playing around with the drawBitmap2 and drawScaledBitmap functions to achieve the goal of using only one bitmap to scale across devices of different sizes (which drawScaledBitmap does) and colour the bitmap (which drawBitmap2 does).

But is there a trick to get them both done at the same time? Please advise if at all possible.

0 flocsy🤠 3 days ago

Where does the bitmap come from? Isn't it a drawable resource compiled in the app? If it is then why bother scaling it at runtime when it can be done at compilation time?

0 the-ninth 3 days ago

3543362 said:
But is there a trick to get them both done at the same time? Please advise if at all possible.

One approach you can try is to create a BufferedBitmap with the target dimensions. Then, use drawScaledBitmap to draw onto the Dc of the BufferedBitmap, and finally use drawBitmap2 to render the BufferedBitmap to the screen.

0 3543362 3 days ago in reply to flocsy🤠

It's a PNG file that I would like sized and coloured depending on the type of device.

0 3543362 3 days ago in reply to the-ninth

Thanks for your helpful response. I understand the creation of the buffered bitmap, but the documentation does not demonstrate how to draw into the buffered bitmap, at least not that I am aware of. Do you know how to do that?

0 the-ninth 3 days ago in reply to 3543362

3543362 said:
It's a PNG file that I would like sized and coloured depending on the type of device.

One option—if it suits your use case—is to define the image as a resource and use scaleX and/or scaleY as a percentage of the screen width. This allows for flexible scaling across devices.

3543362 said:
Thanks for your helpful response. I understand the creation of the buffered bitmap, but the documentation does not demonstrate how to draw into the buffered bitmap, at least not that I am aware of. Do you know how to do that?

You can draw into a BufferedBitmap by calling getDc() on it. That returns a Dc object, which you can then draw to using methods like drawScaledBitmap().

0 flocsy🤠 3 days ago in reply to 3543362

Then do it at compile time