[pjmlp]

I am developing a game and would like to use a png image with all the required tiles for the game.

However, looking to the J2ME(MIDP 1.0) and Nokia UI, I don't find a way to copy a subset of the image to the screen.

Basically I would like to do some form of blitting where I give the source and destination rectangle for the blit.

Thanks in advance,
Paulo Pinto

[shmoove]

If you don't care about a little less speed then you can use a clipping method:
http://nkn.forum.nokia.com/forum/sho...ove+setclip%2A
If you want to keep the speed but don't care about losing transparency then you can create new smaller images from the big one:

Image newImage = Image.createImage(newWidth,newHeight);
newImage.getGraphics().drawImage(original,-xOffsetOfTheNewImageInTheBigOne,-sameForYOffset,Graphics.TOP|Graphics.LEFT);

If you want to keep transparency, then you'll need to look into DirectGraphics and it's methods from the Nokia UI API.

shmoove

[pjmlp]

Thanks I will have a look into it.

[dfun]

I had already figured out on my own the negative arguments trick for drawImage, and it has been working fine on a Nokia 7210: to create a new w x h image that contains a w x h clip of a bigger image, starting at (startX, startY) on the bigger image, you simply create the new w x h image, get a Graphics for it, and then call drawImage(sourceImage, -startX, -startY, Graphics.TOP | Graphics.LEFT).

However, I have now started porting the application on a Nokia 3410 and it seems this is not working any more - sometimes I only get a few lines of the original image copied and the rest left blank. (For now, I have just tried it with the 1.0 emulator - not on the phone yet.)

Does anyone (maybe from Nokia staff) know whether calls to Graphics.drawImage with negative values for the x and y parameters are valid and supported on all Nokia phones? Or does anyone know an alternate solution in MIDP 1.0?