I've forgotten how to dim correctly

[Retro Lord]

It's been ages since I made any games. And I just started again and I realised I've forgot how to dim.

 

The situation is like this:

You are a car, driving along, avoiding other cars and running over zombies, when a car or zombie leaves the screen a counter goes up and it gradually turns into night. When it's night you go to a separate screen that gives you 100 bonus points. Now, it is at this point I need the dim that makes the car/zombie that is player1 to move faster.

 

The skeletal structure is:

if r=0 then player1y=player1y-1

if r=1 then player1y=player1y-2

if r=2 then player1y=player1y-3

if r=3 then r=0

 

Any pointers?

 

.bas = default.bas

 

The code should be easely understandable, but if you want me too clearify things just tell me to.

  rem CODE INSPIRED BY Atarius Maximus at http://www.atariage.com/forums/index.php?showtopic=109288

 set kernel_option no_blank_lines

newstart

 s=0
  player0x = 70
  player0y = 70

 f=10
main
  rem POSSIBLY INEFFICIENT CODE, SEPARATE COLOR INFO FOR EACH FRAME...
  if f = 10 then player0:
        %00000000
        %00111100
        %10111101
        %10100101
        %11100111
        %10100101
        %10100101
        %00111100
        %00111100
        %00011000
        %00011000
        %01011010
        %01011010
        %01111110
        %01011010
        %01011010
end


 COLUP0=$1E

  if g = 10 then player1:
        %00000000
        %00111100
        %10111101
        %10100101
        %11100111
        %10100101
        %10100101
        %00111100
        %00111100
        %00011000
        %00011000
        %01011010
        %01011010
        %01111110
        %01011010
        %01011010
end


  if g = 20 then player1:
        %00000000
        %00100100
        %00100100
        %00100100
        %00100100
        %00011000
        %00011000
        %01011010
        %01011010
        %01111110
        %00000000
        %00011000
        %00011000
        %00011000
        %00000000
        %00000000
end

 if g = 30 then player1:
        %00011000
        %00011000
        %00011000
        %00011000
        %01111110
        %01111110
        %00011000
        %00011000
        %00000000
        %00000000
        %00000000
        %00000000
        %00000000
        %00000000
        %00000000
        %00000000
end

 if g=10 then COLUP1=$86
 if g=20 then COLUP1=$D8
 if g=30 then COLUP1=rand

 COLUPF=$04

 playfield:
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
 .........XXXXXXXXXXXXXX.........
end



 a=a+1

  drawscreen

 if r=0 then player1y=player1y+1
 if r=1 then player1y=player1y+2
 if r=2 then player1y=player1y+3

 if s=0 then COLUBK=$DE
 if s=1 then COLUBK=$DC
 if s=2 then COLUBK=$DA
 if s=3 then COLUBK=$D8
 if s=4 then COLUBK=$D6
 if s=5 then COLUBK=$D4
 if s=6 then COLUBK=$D2
 if s=7 then COLUBK=$D0
 if s=8 then COLUBK=$00
 if s=9 then goto WIN : r=r+1

 if player1y>90 then s=s+1 : score=score+1 : b=(rand&2) : player1y=10 : player1x=rand

 if player1x<70 then player1x=rand : player1y=0
 if player1x>95 then player1x=rand : player1y=0

 if g=20 && collision(player0,player1) then score=score+10 : b=(rand&2) : player1y=10 : player1x=rand

 if g=10 && collision(player0,player1) then goto LOSE

 if b=0 then g=10
 if b=1 then g=10
 if b=2 then g=20


  if joy0right then player0x = player0x + 1
  if joy0left then player0x = player0x - 1
  if joy0up then player0y = player0y - 1
  if joy0down then player0y = player0y + 1

  goto main

LOSE

 COLUPF=$04
 COLUBK=rand

 drawscreen

 if switchreset then reboot

 goto LOSE




WIN

 COLUPF=$04
 COLUBK=rand

 q=q+1

 drawscreen

 if q=60 then score=score+100
 if q=120 then goto newstart

 goto WIN

[graywest]

Dim allows you to set a descriptive name for a variable.

 

dim Something = a

 

Something = Something + 1

a = a + 1

 

The last two lines do the same thing if you use the "dim" statement to assign the name "Something" to variable a.

[+Random Terrain]

Dim allows you to set a descriptive name for a variable.

 

dim Something = a

 

Something = Something + 1

a = a + 1

 

The last two lines do the same thing if you use the "dim" statement to assign the name "Something" to variable a.

 

I think he might be talking about this:

 

randomterrain.com/atari-2600-memories-batari-basic-commands.html#fixedpoint

[Retro Lord]

Thank you all for the help, got things the way I want now, you'r awesome =)

[freshbrood]

Hi everyone.

 

I was unclear on how to use dim.

 

So, if I'm clear; it's only real purpose is to let us keep track of variables easier- instead of remember what "a" or "e" was keeping track of..

 

Is that right? And, if so.. wouldn't excessive use of dim commands actually INCREASE code size slightly?

I mean "a" obviously uses less characters/bytes than "something". Yes?

[RevEng]

The variable names don't contribute to the ROM usage. There's only one effect of using more descriptive variable names - your source code becomes easier to read.

[+Random Terrain]

The variable names don't contribute to the ROM usage. There's only one effect of using more descriptive variable names - your source code becomes easier to read.

 

Added that to the bB page:

 

randomterrain.com/atari-2600-memories-batari-basic-commands.html#dim_descriptive_names