my code doesn't seem to respond to key presses but it keeps redrawing the frog which it should only do after a key press. any help you can provide would be great


Code:

To fix the redraw, do this:


Code:


Not sure about the keys not registering though...

I think the problem is here:


Code:

If the user didn't press the key, then it would jump back to the loop. See if this would help: Instead of:

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Do:

Code:

/me hopes I was any help with Asm.

well, now it responds to keypresses, first one clears the sprite, second one redraws it. no change in coordinates.

new code:


Code:

I noticed the program only modifies xcoord not ycoord. Also, I read in Ion Guru that LargeSprite XORs the sprite to the screen, so maybe just output the same frog sprite to the same place instead of using a blank sprite. Either that or clear the graph buffer.

hmmm.

Well, notice where XCoord and YCoord are located and remember how many bytes HL is.

plus that still doesn't explain why it isn't moving.



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Here's how XOR works: in essence, drawing it one time makes it, and drawing the exact same thing in the same place erases it again. You must call the iLargeSprite routine AFTER you know a key has been pressed but BEFORE you change coordinates to erase it.

yeah. I know how XOR works.

also, digi's been helping out with some optimizations, but Im still getting that effect.


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Hmm, that code looks absolutely fine to me.

I thought so too.

Actually, wait. WTF is with the cp after the dec/inc? just do the jp no matter what.

in the keypressing?

Im attempting to see if it will draw offscreen and prevent that. let me see if that helps though.

[edit]
yeah it moves now

[edit2]
slaps self. i had the c's and nc's reversed

[edit3]

now just some issues with encountering the edge.


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coolness. Why not do more conventional loading into a and then or a or cp 95 or cp 63?

look how it works. I never have to load the coordinates anywhere other than HL, (xcoord) and a brief stay in the stack while drawing.

Change all your c/nc's to z's. See how that works.

I already got it to move fine. I'll see if that helps with it getting one draw cycle off when it hits the edge though.

I just found my last bug.

In a keypress that was at the edge of the screen and therefore not moving the sprite I was jumping back to loop instead of loop2, thus XORing the sprite and throwing everything off a drawing cycle.

final code:


Code:

Alright Elfprince, you're well on your way.

My only regret is that I couldn't have been on here earlier to help. By the time I signed in, everything was pretty much fixed.

Glad to see you're becoming a member of the ASM club. Our only rule is that no n00bs are allowed (and that is only because if you can get asm working....you're not a n00b ).

thank you.

the debugging time on this was actually a lot shorter than the amount of time I spent on my first 400 byte Basic program...this comes in at around 300.

Cool Do you have any plans for upcoming ASM programs? Have you had any ideas for programs that just weren't feasable in BASIC (due to speed, etc) that you will now bring to fruition?

Please don't take offense to my comments on BASIC, but there are somethings that are better left to faster languages (not that you can't make them in BASIC, as you have clearly shown time and time again).