Random position on playfield?

+Random Terrain · June 1, 2013

I really don't understand counters either.

Take a look at this 27 second video where kids are playing Don't Spill the Beans and watch what happens about 16 seconds into it:

www.youtube.com/watch?v=yx-cewdfTpo

http://www.youtube.com/watch?v=yx-cewdfTpo

A normal bB variable is similar to the pot in Don't Spill the Beans and numbers can be thought of as beans. The pot can hold up to 255 beans. If you try to add more than 255 beans, the pot will tip over and you'll be left with zero beans in the pot. If you try to subtract when there are zero beans in the pot, 255 beans will magically hop back up into the pot.

A counter isn't special, it's just a regular old variable. Counters are only called counters because they are used for counting. You probably already know that the drawscreen command must run 60 times a second for NTSC programs, so if you wanted something to happen once a second, you'd want your counter to stop every time it contains 60 beans. Here's an example using the variable c as a counter:

  c = c + 1 : rem * A bean is tossed into the pot.

  if c = 60 then c = 0 : rem * You dump the beans out of the pot, then do whatever it is you wanted to do here.

The example above will keep doing whatever it is you want to do every second (60 = one second). If you wanted something to happen every 2 seconds, you'd change 60 to 120.

Rabbit 2600 · June 1, 2013

That was one of the best explanations I ever heard. I understand completely! You rock Random Terrain!

Let's see. To get the effect of a pixel appearing every second. Then I would set it up like this?

c = c + 1
  if c = 60 then c = 0 : pfpixel temp5 temp6 on

  temp5 = (rand&31) : temp6 = (rand&7) + (rand/64)
  pfpixel temp5 temp6 off

Edited June 1, 2013 by Rabbit 2600

+Random Terrain · June 1, 2013

That was one of the best explanations I ever heard. I understand completely! You rock Random Terrain!

Let's see. To get the effect of a pixel appearing every second. Then I would set it up like this?
  c = c + 1
  if c = 60 then c = 0 then pfpixel temp5 temp6 on
  temp5 = (rand&31) : temp6 = (rand&7) + (rand/64)

Almost. You have an extra then. You could do this:

  c = c + 1
  if c = 60 then c = 0 : temp5 = (rand&31) : temp6 = (rand&7) + (rand/64) : pfpixel temp5 temp6 on

Or if you are afraid the line is getting too long, you can do this trick:

  c = c + 1

  if c < 60 then goto __Skip_60_Count
  c = 0
  temp5 = (rand&31) : temp6 = (rand&7) + (rand/64)
  pfpixel temp5 temp6 on

__Skip_60_Count

That last one lets you use a lot of code on as many lines as you want without using gosub. I learned that from batari.

Rabbit 2600 · June 1, 2013

Cool that I almost had it^^ Thank you once again. Now I got it to work perfectly!

Rabbit 2600 · June 1, 2013

Hm, having some trouble with player0 and pfpixel collision again The player dosn't get any score when touching the pixels.

p = 0
if p then if collision(player0, playfield) then p = 0: score = score+10

Edited June 1, 2013 by Rabbit 2600

+Random Terrain · June 1, 2013

Hm, having some trouble with player0 and pfpixel collision again The player dosn't get any score when touching the pixels.
  p = 0
 if p then if collision(player0, playfield) then p = 0: score = score+10

If you use "p = 0" right before an if-then that requires p to be greater than zero, guess what will happen? That's right. You guessed it. Nothing will happen.

Rabbit 2600 · June 1, 2013

Ah! What a silly misstake! It's obviously suppose to be p = 1! Thank you once again =)

bogax · June 1, 2013

That last one lets you use a lot of code on as many lines as you want without using gosub. I learned that from batari.

I'll add that I've been using gosubs for things you might

not normally use a gosub for, just to get player defintions

and the like out of the way, to make it easier to see what

the code is doing.

you'd (probably) normally use a gosub where you want to

reuse a piece of code but don't want to take up space with

another copy of the code.

but gosubs use extra time and code/memory compared to say,

a goto especially if you're jumping around in diferent banks.

Rabbit 2600 · June 1, 2013

Ahh, neat!

Now score is working as it should. Trying to get the pixel that player0 touches to get destroyed but it's not going well. Is a goto function that bypasses this code the right thing to do?

if c = 60 then c = 0 : temp5 = (rand&31) : temp6 = (rand&7) + (rand/64) : pfpixel temp5 temp6 on

Edited June 1, 2013 by Rabbit 2600

+Random Terrain · June 1, 2013

Ahh, neat!

Now score is working as it should. Trying to get the pixel that player0 touches to get destroyed but it's not going well. Is a goto function that bypasses this code the right thing to do?
if c = 60 then c = 0 : temp5 = (rand&31) : temp6 = (rand&7) + (rand/64) : pfpixel temp5 temp6 on

If you want to destroy a playfield pixel that a sprite touches, you have to convert the sprite coordinates to playfield coordinates, but if your sprite is larger than a playfield pixel, it can be hard to tell where that playfield pixel actually is. It's not something that beginners would normally be able to do without someone just doing it for them.

Rabbit 2600 · June 1, 2013

Mm'kay. I'm sure I'll figure it out eventually. I have two great examples to work by, both have the features I need. I just need to find a way to combine them. It's quite interesting trying to figure out what makes things work in what way.:

  if c = 60 then c = 0 : goto skippixel
  temp5 = (rand&31) : temp6 = (rand&7) + (rand/64)
  pfpixel temp5 temp6 on
skippixel

And

 p = 0
 if p then if collision(player0, playfield) then p = 0

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

 if p then Skip_Pixel
 pfpixel s t off
 s = (rand&31) : t = rand/2 : t = ((t/2 + t)/4 + t)/16
 pfpixel s t on
 if joy0fire then p = 1

Skip_Pixel

Edited June 1, 2013 by Rabbit 2600

bogax · June 1, 2013

here's some code that will

show you sprite and pfpixel

positions

fire switches between them

sprite_v_pf.bas

Edited June 1, 2013 by bogax

Rabbit 2600 · June 1, 2013

Mama Mia, that's alot of code. I'll dive into it =)

Rabbit 2600 · June 1, 2013

Is there any way to do collision with pixels without converting player0's position into pixel position?

bogax · June 1, 2013

Mama Mia, that's alot of code. I'll dive into it =)

You can if you want

If you have questions, ask

It's really just to show pfpixel

positions versus player positions.

The reason I said the player-playfield

collision code is probably not what you

want is because in it there's only one

pfpixel it can be and it doesn't care

which direction you're going.

That simplifies things greatly

But I expect most of the time you'd need

to figure out which of several/many

pfpixels your player is colliding with

you have to do that by position.

And it could be that this corner of the

player is colliding with that pfpixel and

that corner of the player is colliding

with this pfpixel.

hmm maybe I should rig it to show when an actual

collision is detected.

It's only when an actual player pixel overlaps

a playfield pixel that you get a collision.

I used a box for the player so if it overlaps

at all you'd get a collision but if the player

was say a single pixel you could have player

pixels that you defined as off overlapping

pfpixels without a collision and that complicates

figuring by position which is colliding with what.

Edited June 1, 2013 by bogax

Rabbit 2600 · June 1, 2013

I can't do it. I can't convert player0 positin to pixel position =/

Edited June 2, 2013 by Rabbit 2600

Rabbit 2600 · June 2, 2013

Okay, I came up with a solution that works!

I'm having problems with a screen. When the player has cleaned up 5 spots a screen showing "CLEAN!" should appear. But the games moves to that screen directly from the title instead of the playfield screen. What am I doing wrong?

rem Generated 2013-05-31 20:37:14 by Visual bB Version 1.0.0.554
rem **********************************
rem *					 *
rem *				 *
rem *						*
rem *				 *
rem *					 *
rem **********************************
set kernel_options player1colors playercolors pfcolors

set smartbranching on


dim rand16 = z

dim Master_Counter = a

dim timer = b


dim _P1_L_R = player1x.a
dim _P1_U_D = player1y.b

dim _P0_L_R = player0x.a
dim _P0_U_D = player0y.b

dim _player0a = a
dim _player0b = b


scorecolor = $20

player0x = 50
player0y = 50
p = 1
player1x = 70
player1y = 70

ballx = rand&127
bally = rand&63
ballheight = 4
c = 0

player0color:
$F4;
$F4;
$0E;
$0E;
$0E;
$0E;
$2E;
$2E;
$2E;
$2E;
$2E;
$06;
$06;
$06;
$0E;
$0E;
end

player1color:
$A2;
$A2;
$A2;
$A2;
$A2;
$20;
$20;
$20;
$20;
$20;
$2E;
$2E;
$2E;
$2E;
$0E;
$0E;
end

playfield:
.....X.X..XX..X..X.XXX.XXXX.....
.....X.X.X..X.X..X.X...X........
.....XXX.X..X.X..X.XXX.XXXX.....
.....X.X.X..X.X..X...X.X........
.....X.X..XX...XX..XXX.XXXX.....
................................
.X..X.XXXX.XXXX.XX..X.X..X.XXXX.
.X.X..X....X....X.X.X.XX.X.X....
.XX...XXXX.XXXX.XX..X.X.XX.X.XX.
.X.X..X....X....X...X.X..X.X..X.
.X..X.XXXX.XXXX.X...X.X..X.XXXX.
end

title
pfcolors:
$2E
$2C
$2C
$2A
$2A
$28
$28
$26
$26
$24
$24
$24
end
drawscreen
if joy0fire || joy1fire then goto skiptitle
goto title

screen1
skiptitle

playfield:
X.............XXXXX............X
X.............X...X............X
XXXXXXXXXXXXXXX...XXXXXXXXXXXXXX
X..............................X
X..............................X
X..............................X
X..............................X
X..............................X
X..............................X
X..............................X
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
end

main
f=f+1 : if f = 20 then f = 0
if f = 0 then gosub f0
if f = 10 then gosub f1

rem POSSIBLY INEFFICIENT CODE, SEPARATE COLOR INFO FOR EACH FRAME...

if joy0right then r = 0
if joy0left then r = 8

REFP0 = r

pfcolors:
$2E
$2C
$2C
$2A
$2A
$28
$28
$26
$26
$24
$24
$24
end

drawscreen

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

if _P1_U_D < _P0_U_D then _P1_U_D = _P1_U_D + 0.30
if _P1_U_D > _P0_U_D then _P1_U_D = _P1_U_D - 0.30
if _P1_L_R < _P0_L_R then _P1_L_R = _P1_L_R + 0.30
if _P1_L_R > _P0_L_R then _P1_L_R = _P1_L_R - 0.30

if p = 1 then if collision(player0, ball) then p = 0: score = score+10: p = 1:bally=rand&63:ballx=rand&127: c = c + 1
if c = 5 then goto clean



playfield:
................................
................................
................................
.....XXX.X...XXX..X..X..X.X.....
.....X...X...X...X.X.XX.X.X.....
.....X...X...XXX.XXX.X.XX.X.....
.....X...X...X...X.X.X..X.......
.....XX..XXX.XXX.X.X.X..X.X.....
................................
................................
................................
end


clean
pfcolors:
$2E
$2C
$2C
$2A
$2A
$28
$28
$26
$26
$24
$24
$24
end
drawscreen
if joy0fire || joy1fire then goto skiptitle
goto clean

screen2





goto main



f0
player0:
%00100110
%00000110
%00110010
%00110010
%01100100
%00000100
%00111000
%01001000
%00100000
%01110000
%01010000
%01110000
%11000000
%11000000
%00000000
%00000000
end
return

f1
player0:
%10010111
%01000001
%00110001
%00110001
%01100010
%00000010
%00011100
%00100100
%00010000
%00111000
%00101000
%00111000
%01100000
%01100000
%00000000
%00000000
end


player1:
%00000100
%01100100
%00100100
%00101000
%00111000
%00000000
%10111000
%10111000
%11111100
%00111010
%00000001
%00111001
%00101001
%00111000
%00000000
%00000000
end


player1:
%00101000
%00101000
%00101000
%00101000
%00111000
%01000000
%01011000
%01011000
%01111100
%00111010
%00000010
%00111010
%00101010
%00111000
%00000000
%00000000
end




return

Edited June 2, 2013 by Rabbit 2600

bogax · June 2, 2013

Okay, I came up with a solution that works!

I'm having problems with a screen. When the player has cleaned up 5 spots a screen showing "CLEAN!" should appear. But the games moves to that screen directly from the title instead of the playfield screen. What am I doing wrong?

You skip the clean ! playfield statement when c = 5

Rabbit 2600 · June 2, 2013

Cheers! Got it working =D

And, I almost got the code working that makes you go back to the playfield after the "clean!" screen. Only thing is the player0 and ball is missing. How do I fix it?

   rem Generated 2013-05-31 20:37:14 by Visual bB Version 1.0.0.554
   rem **********************************
   rem *					  *
   rem *				   *
   rem *						*
   rem *				  *
   rem *					   *
   rem **********************************
   set kernel_options player1colors playercolors pfcolors

   set smartbranching on


   dim rand16 = z

   dim Master_Counter = a

 dim timer = b


     dim _P1_L_R = player1x.a
     dim _P1_U_D = player1y.b

     dim _P0_L_R = player0x.a
     dim _P0_U_D = player0y.b

     dim _player0a = a
     dim _player0b = b


   scorecolor = $20

   player0x = 50
   player0y = 50
   p = 1
 player1x = 70
 player1y = 70

 ballx = rand&127
 bally = rand&63
 ballheight = 4
 c = 0

   player0color:
   $F4;
   $F4;
   $0E;
   $0E;
   $0E;
   $0E;
   $2E;
   $2E;
   $2E;
   $2E;
   $2E;
   $06;
   $06;
   $06;
   $0E;
   $0E;
end

       player1color:
       $A2;
       $A2;
       $A2;
       $A2;
       $A2;
       $20;
       $20;
       $20;
       $20;
       $20;
       $2E;
       $2E;
       $2E;
       $2E;
       $0E;
       $0E;
end

 playfield:
 .....X.X..XX..X..X.XXX.XXXX.....
 .....X.X.X..X.X..X.X...X........
 .....XXX.X..X.X..X.XXX.XXXX.....
 .....X.X.X..X.X..X...X.X........
 .....X.X..XX...XX..XXX.XXXX.....
 ................................
 .X..X.XXXX.XXXX.XX..X.X..X.XXXX.
 .X.X..X....X....X.X.X.XX.X.X....
 .XX...XXXX.XXXX.XX..X.X.XX.X.XX.
 .X.X..X....X....X...X.X..X.X..X.
 .X..X.XXXX.XXXX.X...X.X..X.XXXX.
end

title
   pfcolors:
   $2E
   $2C
   $2C
   $2A
   $2A
   $28
   $28
   $26
   $26
   $24
   $24
   $24
end
   drawscreen
   if joy0fire || joy1fire then goto skiptitle
   goto title

screen1
skiptitle

 playfield:
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 XXXXXXXXXXXXXXX...XXXXXXXXXXXXXX
 XXXXXXXXXXXXXXX...XXXXXXXXXXXXXX
 X..............................X
 X..............................X
 X..............................X
 X..............................X
 X..............................X
 X..............................X
 X..............................X
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
end




main
   f=f+1 : if f = 20 then f = 0
   if f = 0 then gosub f0
   if f = 10 then gosub f1

   rem POSSIBLY INEFFICIENT CODE, SEPARATE COLOR INFO FOR EACH FRAME...
   
   if joy0right then r = 0
   if joy0left then r = 8

   REFP0 = r

   pfcolors:
   $2E
   $2C
   $2C
   $2A
   $2A
   $28
   $28
   $26
   $26
   $24
   $24
   $24
end

   drawscreen

   if joy0right then player0x = player0x + 1
   if joy0left then player0x = player0x - 1
   if joy0up then player0y = player0y - 1
   if joy0down then player0y = player0y + 1
 
 if _P1_U_D < _P0_U_D then _P1_U_D = _P1_U_D + 0.30
 if _P1_U_D > _P0_U_D then _P1_U_D = _P1_U_D - 0.30
 if _P1_L_R < _P0_L_R then _P1_L_R = _P1_L_R + 0.30
 if _P1_L_R > _P0_L_R then _P1_L_R = _P1_L_R - 0.30

   if p = 1 then if collision(player0, ball) then p = 0: score = score+10: p = 1:bally=rand&63:ballx=rand&127: c = c + 1
   if c = 5 then goto __Clean_Screen_Loop
 if collision(ball,playfield) then bally=rand&63:ballx=rand&127




   goto main

__Clean_Screen_Loop

                   rem  ****************************************************************
                   rem  *
                   rem  *  Playfield colors.
                   rem  *
                   rem  ````````````````````````````````````````````````````````````````
                   rem  `
                   COLUBK = 0 : COLUPF = $30

   ballx = 255 : bally = 255
   player0x = 255 : player0y = 255
   player1x = 255 : player1y = 255
   missile0x = 255 : missile0y = 255
   missile1x = 255 : missile1y = 255

                   rem  ****************************************************************
                   rem  *
                   rem  *  Draws the screen.
                   rem  *
                   rem  ````````````````````````````````````````````````````````````````
                   rem  `
               playfield:
 ................................
 ................................
 ................................
 .....XXX.X...XXX..X..X..X.X.....
 .....X...X...X...X.X.XX.X.X.....
 .....X...X...XXX.XXX.X.XX.X.....
 .....X...X...X...X.X.X..X.......
 .....XX..XXX.XXX.X.X.X..X.X.....
 ................................
 ................................
 ................................
end

                   drawscreen

                   if joy0fire || joy1fire then c = 0: goto title
                   goto __Clean_Screen_Loop


f0
   player0:
   %00100110
   %00000110
   %00110010
   %00110010
   %01100100
   %00000100
   %00111000
   %01001000
   %00100000
   %01110000
   %01010000
   %01110000
   %11000000
   %11000000
   %00000000
   %00000000
end
 return

f1
   player0:
   %10010111
   %01000001
   %00110001
   %00110001
   %01100010
   %00000010
   %00011100
   %00100100
   %00010000
   %00111000
   %00101000
   %00111000
   %01100000
   %01100000
   %00000000
   %00000000
end


               player1:
               %00000100
               %01100100
               %00100100
               %00101000
               %00111000
               %00000000
               %10111000
               %10111000
               %11111100
               %00111010
               %00000001
               %00111001
               %00101001
               %00111000
               %00000000
               %00000000
end


               player1:
               %00101000
               %00101000
               %00101000
               %00101000
               %00111000
               %01000000
               %01011000
               %01011000
               %01111100
               %00111010
               %00000010
               %00111010
               %00101010
               %00111000
               %00000000
               %00000000
end

 return

Edited June 2, 2013 by Rabbit 2600

bogax · June 5, 2013

hmm maybe I should rig it to show when an actual

collision is detected.

Heh, I don't suppose anybody cares but..

I added a collision indication.

The player color changes.

I added a few different player shapes

which you can step through using left

and right when the player is yellow.

Step through the functions using fire.

The functions are:

move the playfield block,

move the player,

change the player shape.

Scorecolor follows function.

scr_positions.bas

Rabbit 2600 · June 5, 2013

Nice! That'll come in handy for me =)

Random position on playfield?

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