Assembler playfield

[whisperer_in_darkness]

For some reason I'm having difficulties finding books which would show me a good way to draw a playfield / levels for a simple 2d game with Assembler.

 

Many books describe how to write your own character set though. Is that the best way to do it? Can you recommend any books or articles?

 

I would imagine this is something almost every game programmer has done. Strange that i can't find any examples.

[Wrathchild]

The pinned development books thread might help as I'm sure this has been covered many times in the past. Personally, a combination of De Re Atari and the Compute!'s First and Second Book of Graphics were an OK grounding

[+therealbountybob]

Are you after a character set and level designer tool for certain graphics modes (which mode)? I've used Envision (the Atari version) for Ramp Rage but probably others can advise on this better.

 

I've found Atari Graphics & Arcade Game Design a great book - http://www.atariarchives.org/

 

[whisperer_in_darkness]

Thanks for the tips! I think I'm going to try out some of the level design tools next. I'm not after anything specific. The problem I have with the old books is that there may be a chapter "this is how you create a custom character set" but I'd be more interested about "this is how I build levels with the custom character set". So I guess I'm more interested about the overall process and game design since that is still a bit vague to me, but maybe that's just me.

[Irgendwer]

If you are somewhat familiar with BASIC, study the code of BASIC games. The principle in assembler is very similar.

Archives of type-in-listings makes the access very easy.

E.g. examine page 3 & 4 of this listing:

http://ataribasiclistings.mygamesonline.org/Computronic/Computronic-12-87.pdf

...and you get an idea how level data is applied...

Edited June 6, 2017 by Irgendwer

[Wrathchild]

Similarly, if you do take a look at the Envision tool and the examples that come with it, it wasn't clear whether you are looking to develop something with static or scrolling screens which would have an impact on design. Another thing to try would be to examine games that are similar to what you want to try and achieve and study their inner workings via the debugger in Altirra, typically starting with the ".dumpdlist" command and looking at the DLI routine(s) pointed to by address $200.

[whisperer_in_darkness]

Good tips again. I'll look into it, Thanks!

Edited June 6, 2017 by whisperer_in_darkness

[peteym5]

What I did was create my own mini programming codes for drawing levels, screens, etc. like SET (character), CHR(character), HLN (horizontal line), VLN (vertical line), BLK (block). It will be in a format like dta HLN,5,5,10, which draws the a line of 10 characters at screen position 5,5. It is known as procedural screen drawing. Have a ENS for End Screen Draw. I am able to draw hundreds of screens in very little memory space with this programming.

Get_Screen_Positions
        ldy Read_Pointer 
        lda (Read_NDX),Y    
        sta Screen_X
        iny
        lda (Read_NDX),Y
        tax        
        iny
        STY Read_Pointer
        LDA Screen_X
        CLC
        ADC :MULT48LO,X    
        STA SCRPOS + 0
        LDA :MULT48HI,X
        ADC #$00
        STA SCRPOS + 1
        RTS
    
Get_Rectangle_Dimensions    
        clc
        sta temp
        and #$0F
        adc #$01
        sta Rec_Width  
        lda Temp
        lsr @        
        lsr @        
        lsr @            
        lsr @            
        clc                
        adc #$01    
        sta Rec_Height
        rts                  

Draw_Horizontal_Line
       LDA Draw_Character
Horizontal_Line_Loop
       DEY
       STA (SCRPOS), Y
       BNE Horizontal_Line_Loop
       RTS

Edited June 6, 2017 by peteym5

[snicklin]

Spindizzy used the procedural method for drawing its screens, hence why there were over 300 over the screens.

[vitoco]

I did the same in my BASIC tenliner ORUGA. It uses a FOR-NEXT loop to draw 8 walls, 4 of them are fixed for every level and 4 that appears in some levels according to a "magic formula": they act like bits: 4 bits have 16 combinations ---> 16 different levels.

[whisperer_in_darkness]

Yes, procedural levels would make sense. It's funny...as a kid I used to think I would be the best ever level designer. Later I have come to conclusion I'm actually pretty horrible level designer. Actually fun levels are not something I can produce with ease.

[+therealbountybob]

What sort of game are you working on or thinking about w_i_d - a platformer?

 

Take Mr.Robot - It's funny that sometimes other people find unusual ways of arranging things or using "features" of the elements to produce some really different levels - a recent HSC round played a couple of our home brew sets.

[whisperer_in_darkness]

I think I'll try to make a simple top down "collect things, evade monsters" type of game to get started. I was also thinking about platformer, but there have been so many so good platformers that I think it would be difficult to make one that isn't horrible.

[Avram]

Look at modern game design books. Or level design articles at gamasutra.com. Or videos on the GDC vault: http://www.gdcvault.com/play/1023282/Empowering-the-Player-Level-Design

[+therealbountybob]

I think I'll try to make a simple top down "collect things, evade monsters" type of game to get started. I was also thinking about platformer, but there have been so many so good platformers that I think it would be difficult to make one that isn't horrible.

Sounds a good idea, these games are usually fun. If you get even a working demo you could enter it into the abbuc software contest