StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POAndroid scrolling background of bitmap tiles
text
Body
copied!<p>I'm tried to determine the "best" way to scroll a background comprised of tiled Bitmaps on an Android SurfaceView. I've actually been successful in doing so, but wanted to determine if there is a more efficient technique, or if my technique might not work on all Android phones.</p> <p>Basically, I create a new, mutable Bitmap to be slightly larger than the dimensions of my SurfaceView. Specifically, my Bitmap accomodates an extra line of tiles on the top, bottom, left, and right. I create a canvas around my new bitmap, and draw my bitmap tiles to it. Then, I can scroll up to a tile in any direction simply by drawing a "Surfaceview-sized" subset of my background Bitmap to the SurfaceHolder's canvas.</p> <p>My questions are:</p> <ol> <li><p>Is there a better bit blit technique than drawing a background bitmap to the canvas of my SurfaceHolder? </p></li> <li><p>What is the best course of action when I scroll to the edge of my background bitmap, and wish to shift the map one tile length? As I see it, my options are to:</p></li> </ol> <p>a. Redraw all the tiles in my background individually, shifted a tile length in one direction. (This strikes me as being inefficient, as it would entail many small Bitmap draws).</p> <p>b. Simply make the background bitmap so large that it will encompass the entire scrolling world. (This could require an extremely large bitmap, yet it would only need to be created once.)</p> <p>c. Copy the background bitmap, draw it onto itself but shifted a tile length in the direction we are scrolling, and draw the newly revealed row or column of tiles with a few individual bitmap draws. (Here I am making the assumption that one large bitmap draw is more efficient than multiple small ones covering the same expanse.)</p> <p>Thank you for reading all this, and I would be most grateful for any advice.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload