Can you read or change the contents of any screen?

[luisp]

Hi,


Can you read or change the contents of any screen programmatically?

So you can change the levels (only the blocks) of an explosion (a la bomberman)?

Thanks,
Luis.

[AndyJF]

There's a bit of code that you can use to read blocks here -

www.youtube.com/watch?v=0pGcwYh9hOs&t=156s

Maybe you could combine it with the putblock command?

[luisp]

Thanks, that sound great.

[Jonathan Cauldwell]

That code is fine for AGDx but you'll have to enter it differently if using AGD.

For MPAGD you can use GETBLOCK X Y and the block type at the specified coordinates will be returned in the BLOCK variable. To change the block type at a screen coordinate simply use PUTBLOCK Z where Z is the block number.

An example from the MPAGD manual:
GETBLOCK X Y                ; top left of sprite
IF BLOCK = FODDERBLOCK      ; is it fodder?
   LET LINE = X
   LET COLUMN = Y
   DIVIDE LINE BY 8
   DIVIDE COLUMN BY 8
   PUTBLOCK 0              ; put a space there
ENDIF


If you want the block to stay like that when the player leaves and re-enters the screen you will need to use adventure mode

[roolandoo]

Jonathan, How do I activate Adventure Mode in MPAGD?

[Jonathan Cauldwell]

If you're developing for the Spectrum, go to the Suite ZX subdirectory, you should see some batch files in there. You need to edit build.bat and export.bat in Notepad. In each you should see a line that has the command CompilerZX %1. Just add -a to the end of this line and adventure mode will be activated.

I'll record a YouTube tips video to clarify.

[roolandoo]

Thank you very much, Jonathan.