CyanMan

[iCon]

I'm working on a minor game and have a few problems:

1) Where should I make 'onground = false' so the gravity doesn't turn off after the first platform.

2)How can I make 'sub gameover' print gameover before it ends the program.

3)How to improve left/right collision detection? (It is possible to go through the platforms from the sides if entered at the right height from the platform)

4)How to stop the program from lagging every time a platform spawns?

You'll have to use your own images, here's the code:


textmode (TEXT_BUFFERED)

'sets how many frames the cyanman sprite is
dim cyanman (texstripframes ("files\cyanman.png")- 1)
'the variable the animation frames will be loaded into
dim walk (9), stand
dim ploop 'platform loop
dim cl 'collision loop
dim onground = false
const maxplatforms = 99

'loads the imagestrip into cyanman
cyanman = loadtexstrip ("files\cyanman.png")

'Loads the cyanman frames
stand = cyanman (0)

walk (0) = cyanman (8)
walk (1) = cyanman (1)
walk (2) = cyanman (2)
walk (3) = cyanman (3)
walk (4) = cyanman (4)
walk (5) = cyanman (0)
walk (6) = cyanman (5)
walk (7) = cyanman (6)
walk (8) = cyanman (7)
walk (9) = cyanman (0)

'Sets the starting player image
dim sprite
sprite = newsprite (stand)
sprsetpos (320, 241)

'Sets the 1st purple platform
dim platform (maxplatforms), plxsize, plysize
platform (1) = newsprite (loadtex ("files\platform.png"))
sprsetsize (200, 32)
sprsetpos (320, 432)
sprsetyvel (-1)

'spawns platforms in a subroutine
sub platformspawn (platformcount)
   dim x = rnd () % 640 + 1
   dim xsize = rnd () % 320 + 100
   platform (platformcount) = newsprite (loadtex ("files\platform.png"))
   sprsetsize (xsize , 32)
   sprsetpos (x, 480)
   sprsetyvel (-1)
endsub

'GAMEOVER Subroutine
sub gameover ()
   locate 16, 12: print "GAME OVER"
   end
endsub

'Main animation loop
while true
   'Player Control
   bindsprite (1)
   if scankeydown (VK_RIGHT) then
       sprsettextures (walk)
       sprsetanimspeed (0.2)
       sprsetxflip (false)
       sprsetvel (1, 0)
   elseif scankeydown (VK_LEFT) then
       sprsettextures (walk)
       sprsetanimspeed (0.2)
       sprsetxflip (true)
       sprsetvel (-1, 0)
   else
       sprsettexture (stand)
       sprsetvel (0, 0)
   endif
   
   'Stops the player going off screen
   if sprleft (1) = -10 and scankeydown (VK_LEFT) then
       sprsetxvel (0)
   endif
   
   if sprright (1) = spriteareawidth () + 10 and scankeydown (VK_RIGHT) then
       sprsetxvel (0)
   endif
   
   'platform spawn
   for ploop = 2 to maxplatforms
       if sprbottom (ploop) = 400 then
           platformspawn (ploop + 1)
       endif
   next

   'Platform Collision Detection
   for cl = 2 to maxplatforms
   'Platform top
       if sprx (1) < sprx (cl) + (sprxsize (cl)/2) and sprx (1) > sprx (cl) - (sprxsize (cl)/2) and sprbottom (1) = sprtop (cl) + 3 then
           bindsprite (1)
           sprsetyvel (-1)
           onground = true
       endif
       'Platform left
       if sprtop (1) < spry (cl) + (sprysize (cl)/2) and sprbottom (1) > spry (cl) - (sprysize (cl)/2) and sprright (1) - 16 = sprleft (cl) and scankeydown (VK_RIGHT) then
           bindsprite (1)
           sprsetxvel (0)
       endif
       'Platform right
       if sprtop (1) < spry (cl) + (sprysize (cl)/2) and sprbottom (1) > spry (cl) - (sprysize (cl)/2) and sprleft (1) + 16 = sprright (cl) and scankeydown (VK_LEFT) then
           bindsprite (1)
           sprsetxvel (0)
       endif
   next
   
   'deletes platforms when they reach the top
   for cl = 2 to maxplatforms
       if sprtop (cl) < 0 then
           deletesprite (cl)
       endif
   next
   
   'gravity
   if onground = false then
       bindsprite (1)
       sprsetyvel (1)
   endif
   
   'Game Over
   if sprbottom (1) < 0 then
       gameover ()
   elseif sprtop (1) > 480 then
       gameover ()
   endif
   
   'Animate the sprites
   animatesprites()
   drawtext ()
   waittimer (20)

wend


[matthew]

Regarding the Collision Detection there is a thread here that might help.

As for the lag whenever a new platform is created. It's probably because you're loading the texture every time you call the subroutine. There's no-need to do that just load the texture once at the beginning of your program & use NewSprite() to generate a new platform.

[iCon]

Here's the updated code, with questions 3 and 4 answered. Right now the most important thing is gravity. Updated bits in bold.

'Cyan Man
textmode (TEXT_BUFFERED)

'sets how many frames the cyanman sprite is
dim cyanman (texstripframes ("files\cyanman.png")- 1)
'the variable the animation frames will be loaded into
dim walk (9), stand
dim ploop 'platform loop
dim cl 'collision loop
dim onground = false
[b]dim xvel = 2[\b]
const maxplatforms = 99

'loads the imagestrip into cyanman
cyanman = loadtexstrip ("files\cyanman.png")

'platform textures
dim ptex = loadtex ("files\platform.png")

'Loads the cyanman frames
stand = cyanman (0)

walk (0) = cyanman (8)
walk (1) = cyanman (1)
walk (2) = cyanman (2)
walk (3) = cyanman (3)
walk (4) = cyanman (4)
walk (5) = cyanman (0)
walk (6) = cyanman (5)
walk (7) = cyanman (6)
walk (8) = cyanman (7)
walk (9) = cyanman (0)

'Sets the starting player image
dim sprite
sprite = newsprite (stand)
sprsetpos (320, 241)

'Sets the 1st purple platform
dim platform (maxplatforms), plxsize, plysize
platform (1) = newsprite (ptex)
sprsetsize (200, 32)
sprsetpos (320, 432)
sprsetyvel (-1)

'spawns platforms in a subroutine
sub platformspawn (platformcount)
   dim x = rnd () % 640 + 1
   dim xsize = rnd () % 280 + 100
   platform (platformcount) = newsprite (ptex)
   sprsetsize (xsize , 32)
   sprsetpos (x, [b]500)'sets the platform 20 units below the screen[/b]    sprsetyvel (-1)
endsub

'GAMEOVER Subroutine
sub gameover ()
   locate 16, 12: print "GAME OVER"
   end
endsub

'Main animation loop
while true
   'Player Control
   bindsprite (1)
   if scankeydown (VK_RIGHT) then
       sprsettextures (walk)
       sprsetanimspeed (0.2)
       sprsetxflip (false)
       sprsetxvel [b](xvel)[/b]
   elseif scankeydown (VK_LEFT) then
       sprsettextures (walk)
       sprsetanimspeed (0.2)
       sprsetxflip (true)
       sprsetxvel [b](-xvel)[/b]
  else
       sprsettexture (stand)
       sprsetvel (0, 0)
   endif
   
   'Stops the player going off screen
   if sprleft (1) [b]<= [/b]-10 and scankeydown (VK_LEFT) then
       sprsetxvel (0)
   endif
   
   if sprright (1)[b] >=[/b] spriteareawidth () + 10 and scankeydown (VK_RIGHT) then
       sprsetxvel (0)
   endif
   
   'platform spawn
   for ploop = 2 to maxplatforms
       if sprbottom (ploop) = 400 then
           platformspawn (ploop + 1)
       endif
   next

   'Platform Collision Detection
   for cl = 2 to maxplatforms
   'Platform top
       if sprx (1) < sprx (cl) + (sprxsize (cl)/2) and sprx (1) > sprx (cl) - (sprxsize (cl)/2) and sprbottom (1) >= sprtop (cl) and sprtop (1) + 5 <= sprbottom (cl) then
           bindsprite (1)
           sprsetyvel (-1)
           onground = true
       endif
       'Platform left
       if sprtop (1) < spry (cl) + (sprysize (cl)/2) and sprbottom (1) > spry (cl) - (sprysize (cl)/2) and sprright (1) - 16 >= sprleft (cl)[b] and sprleft (1) < sprleft (cl) then[/b]
          bindsprite (1)
           [b]sprsetx (sprleft (cl) - 2)[/b]
           [b]sprsetyvel (1)[/b]
      endif
       'Platform right
       if sprtop (1) < spry (cl) + (sprysize (cl)/2) and sprbottom (1) > spry (cl) - (sprysize (cl)/2) and sprleft (1) + 16 <= sprright (cl) [b]and sprright (1) > sprright (cl)[/b] then
           bindsprite (1)
           [b]sprsetx (sprright (cl) + 2)[/b]
           [b]sprsetyvel (1)[/b]
       endif
   next
   
   'deletes platforms when they reach the top
   for cl = 2 to maxplatforms
       if sprtop (cl) < [b]-40 then 'deletes any platforms off the screen[/b]            deletesprite (cl)
       endif
   next
   
   'gravity
   if onground = false then
       bindsprite (1)
       sprsetyvel (1)
       [b]xvel = 1[/b]
  else
       [b]xvel = 2[/b]
   endif
   
   'Game Over
   if sprbottom (1) < 0 then
       gameover ()
   elseif sprtop (1) > 480 then
       gameover ()
   endif
   
   'Animate the sprites
   animatesprites()
   drawtext ()
   waittimer (20)

wend


[matthew]

Some time ago I developed a Platformer in another language & found this tutorial extremely useful. You'll find the section on Gravity & Jumping at the bottom of the page.

[iCon]

Huzzah!

Now the program checks every platform to see if Cyanman is on it then it uses this to determine whether gravity is true or not.

The only things left to do is to balance the game, add some minor stuff in and Q2.

Here's the code, change the textures and play.

'Cyan Man
textmode (TEXT_BUFFERED)

'sets how many frames the cyanman sprite is
dim cyanman (texstripframes ("files\cyanman.png")- 1)
'the variable the animation frames will be loaded into
dim walk (9), stand
dim ploop 'platform loop
dim cl 'collision loop
dim notonplat = 1
dim onground = false
dim xvel = 2
const maxplatforms = 99

'loads the imagestrip into cyanman
cyanman = loadtexstrip ("files\cyanman.png")

'platform textures
dim ptex = loadtex ("files\platform.png")

'Loads the cyanman frames
stand = cyanman (0)

walk (0) = cyanman (8)
walk (1) = cyanman (1)
walk (2) = cyanman (2)
walk (3) = cyanman (3)
walk (4) = cyanman (4)
walk (5) = cyanman (0)
walk (6) = cyanman (5)
walk (7) = cyanman (6)
walk (8) = cyanman (7)
walk (9) = cyanman (0)

'Sets the starting player image
dim sprite
sprite = newsprite (stand)
sprsetpos (320, 241)

'Sets the 1st purple platform
dim platform (maxplatforms), plxsize, plysize
platform (1) = newsprite (ptex)
sprsetsize (200, 32)
sprsetpos (320, 480)
sprsetyvel (-1)

'spawns platforms in a subroutine
sub platformspawn (platformcount)
   dim x = rnd () % 640 + 1
   dim xsize = rnd () % 280 + 100
   platform (platformcount) = newsprite (ptex)
   sprsetsize (xsize , 32)
   sprsetpos (x, 500)'sets the platform 20 units below the screen
   sprsetyvel (-1)
endsub

'GAMEOVER Subroutine
sub gameover ()
   locate 16, 12: print "GAME OVER"
   end
endsub

'Main animation loop
while true
   'Player Control
   bindsprite (1)
   if scankeydown (VK_RIGHT) then
       sprsettextures (walk)
       sprsetanimspeed (0.2)
       sprsetxflip (false)
       sprsetxvel (xvel)
   elseif scankeydown (VK_LEFT) then
       sprsettextures (walk)
       sprsetanimspeed (0.2)
       sprsetxflip (true)
       sprsetxvel (-xvel)
   else
       sprsettexture (stand)
       sprsetvel (0, 0)
   endif
   
   'Stops the player going off screen
   if sprleft (1) <= -10 and scankeydown (VK_LEFT) then
       sprsetxvel (0)
   endif
   
   if sprright (1) >= spriteareawidth () + 10 and scankeydown (VK_RIGHT) then
       sprsetxvel (0)
   endif
   
   'platform spawn
   for ploop = 2 to maxplatforms
       if sprbottom (ploop) = 450 then
           platformspawn (ploop + 1)
       endif
   next

   'Platform Collision Detection
   for cl = 2 to maxplatforms
   'Platform top
       if sprx (1) < sprx (cl) + (sprxsize (cl)/2) and sprx (1) > sprx (cl) - (sprxsize (cl)/2) and sprbottom (1) - 3 >= sprtop (cl) and sprtop (1) + 5 <= sprbottom (cl) then
           bindsprite (1)
           sprsetyvel (-1)
           onground = true
       else
           notonplat = notonplat + 1
       endif
       'Platform left
       if sprtop (1) < spry (cl) + (sprysize (cl)/2) and sprbottom (1) > spry (cl) - (sprysize (cl)/2) and sprright (1) - 16 >= sprleft (cl) and sprleft (1) < sprleft (cl) then
           bindsprite (1)
           sprsetx (sprleft (cl) - 2)
           sprsetyvel (0.2)
       endif
       'Platform right
       if sprtop (1) < spry (cl) + (sprysize (cl)/2) and sprbottom (1) > spry (cl) - (sprysize (cl)/2) and sprleft (1) + 16 <= sprright (cl) and sprright (1) > sprright (cl) then
           bindsprite (1)
           sprsetx (sprright (cl) + 2)
           sprsetyvel (0.2)
       endif
   next
   
   'if Cyanman isn't on a single platform notonplat = 99, if Cyanman is, notonplat = 98
   if notonplat = 99 then
       onground = false
   endif
   
   'deletes platforms when they reach the top
   for cl = 2 to maxplatforms
       if sprtop (cl) < -40 then 'deletes any platforms off the screen
           deletesprite (cl)
       endif
   next
   
   'gravity
   if onground = false then
       bindsprite (1)
       sprsetyvel (1)
       xvel = 1
   endif
   
   'Game Over
   if sprbottom (1) < 0 then
       gameover ()
   elseif sprtop (1) > 480 then
       gameover ()
   endif
   
   'Animate the sprites
   animatesprites()
   drawtext ()
   waittimer (20)
   notonplat = 1

wend