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How do i disregard transparency when checking for collision with two sprites?
i did a search, and the one thread which had my question exactly dwindled to nothing.
http://forum.thegamecreators.com/?m=forum_view&t=133603&b=1
Hoping someone can help me with this,
Aralox

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Green Gandalf

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Playing: Malevolence:Sword of Ahkranox, Skyrim, Civ6.

Posted: 22nd Feb 2009 11:34

Did you try this?

sprite collision

I haven't tried it myself but at first sight it seems related to your problem.

[I found that link by doing a search for sprite collision.]

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Aralox

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Location: Melbourne

Posted: 23rd Feb 2009 08:18

hmm no, doesnt seem to work, i turned off offsetting on my sprites but still no. =(
do you think the advancedsprites plugin would help? i had a look, but i cant see any collision functions.

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Kira Vakaan

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Location: MI, United States

Posted: 24th Feb 2009 00:17

Doesn't seem to work? Well what are you trying to do?

Here, I've written a little example using my library. I just kinda pasted all the code at the end.

set display mode 1024,768,32,1
sync on

hide mouse

create bitmap 1,128,128
ink rgb(255,0,0),0
box 32,32,96,96
get image 1,0,0,128,128
ink rgb(0,255,0),0
box 32,32,96,96
get image 2,0,0,128,128
delete bitmap 1
`set current bitmap 0

ink rgb(255,255,255),0

sprite 1,mousex(),mousey(),1
sprite 2,(screen width()/2)-64,(screen height()/2)-64,2
set sprite priority 1,2
set sprite priority 2,1

do
   text 5,5,"Image 1:"
   paste image 1,25,25
   text 5,158,"Image 2:"
   paste image 2,25,178

sprite 1,mousex(),mousey(),1
   sprite 2,(screen width()/2)-64,(screen height()/2)-64,2

if SpriteCollide(1,2) then Result$="True" : else : Result$="False"
   text 5,330,"Sprites Colliding: "+Result$

sync
loop
end
remstart
      Library for Pixel Perfect Sprite Collision v0.8

by Kira Vakaan

Functions:

InitSpriteCollision()
   -This function sets up the dummy sprite used in sprite point collision detection as well as the transparent color
    used in all collisions.  Call this command before any other.

SpritePointCollide(x,y,spr)
   -Returns a one if the screen point (x,y) is colliding with sprite spr.  If spr is set to zero, the number of the sprite
    the point collides with is returned.  Supports sprite scaling and offsetting.

SpriteCollide(spr1,spr2)
   -Intended to replace the built-in command: sprite collision(spr1,spr2).  Currently does NOT support sprite scaling or
    offsetting.

SetTransparentColor(color as dword)
   -Sets the color to be ignored during collision detection.

GetTransparentColor()
   -...really..?

In the future (maybe):
   - Support for sprite scaling and offsetting during sprite on sprite collision detection.
   - Any suggestions from people.

remend

end

function InitSpriteCollision()
   #constant DUMMY   1000
   global Transparent as dword : Transparent=0

create bitmap DUMMY,1,1
   get image DUMMY,0,0,1,1
   delete bitmap DUMMY
   set current bitmap 0
   sprite DUMMY,0,0,DUMMY
   hide sprite DUMMY
endfunction

function SpritePointCollide(x,y,spr)
   sprite DUMMY,x,y,DUMMY
   Collision=sprite collision(DUMMY,spr)
   if not Collision then exitfunction 0
   if not spr then spr=Collision
   dec x,sprite x(spr)
   dec y,sprite y(spr)
   x=(x/(sprite scale x(spr)/100.0))+sprite offset x(spr)
   y=(y/(sprite scale y(spr)/100.0))+sprite offset y(spr)
   make memblock from image 255,sprite image(spr)
   Width=memblock dword(255,0)
   Height=memblock dword(255,4)
   if x<0 or y<0 or x=Width or y=Height then exitfunction 0
   if memblock dword(255,12+4*((x%%Width)+((y%%Width)*Width)))=Transparent then exitfunction 0
endfunction Collision

function SpriteCollide(spr1,spr2)
   Collision=sprite collision(spr1,spr2)
   if not Collision then exitfunction 0
   Color1 as dword
   Color2 as dword
   if not spr2 then spr2=Collision
   if sprite x(spr2)<sprite x(spr1)
      OverlapX=sprite x(spr1)
      OverlapWidth=sprite x(spr2)+sprite width(spr2)-sprite x(spr1)
   else
      OverlapX=sprite x(spr2)
      OverlapWidth=sprite x(spr1)+sprite width(spr1)-sprite x(spr2)
   endif
   if sprite y(spr2)<sprite y(spr1)
      OverlapY=sprite y(spr1)
      OverlapHeight=sprite y(spr2)+sprite height(spr2)-sprite y(spr1)
   else
      OverlapY=sprite y(spr2)
      OverlapHeight=sprite y(spr1)+sprite height(spr1)-sprite y(spr2)
   endif
   Spr1X=OverlapX-sprite x(spr1)
   Spr1Y=OverlapY-sprite y(spr1)
   Spr2X=OverlapX-sprite x(spr2)
   Spr2Y=OverlapY-sprite y(spr2)
   make memblock from image 255,sprite image(spr1)
   make memblock from image 256,sprite image(spr2)
   Spr1Width=memblock dword(255,0)
   Spr1Height=memblock dword(255,4)
   Spr2Width=memblock dword(256,0)
   Spr2Height=memblock dword(256,4)
   for y=1 to OverlapHeight
      for x=1 to OverlapWidth
         if Spr1X<0 or Spr1Y<0 or Spr1X>=Spr1Width or Spr1Y>=Spr1Height then goto continue
         if Spr2X<0 or Spr2Y<0 or Spr2X>=Spr2Width or Spr2Y>=Spr2Height then goto continue
         Color1=memblock dword(255,12+4*((Spr1X%%Spr1Width)+((Spr1Y%%Spr1Width)*Spr1Width)))
         Color2=memblock dword(256,12+4*((Spr2X%%Spr2Width)+((Spr2Y%%Spr2Width)*Spr2Width)))
         if Color1<>Transparent and Color2<>Transparent then exitfunction Collision
         continue:
         inc Spr1X
         inc Spr2X
      next x
      dec Spr1X,OverlapWidth
      dec Spr2X,OverlapWidth
      inc Spr1Y
      inc Spr2Y
   next y
endfunction 0

function SetTransparentColor(color as dword)
   Transparent=color
endfunction

function GetTransparentColor()
endfunction Transparent

set display mode 1024,768,32,1
sync on

hide mouse

create bitmap 1,128,128
ink rgb(255,0,0),0
box 32,32,96,96
get image 1,0,0,128,128
ink rgb(0,255,0),0
box 32,32,96,96
get image 2,0,0,128,128
delete bitmap 1
`set current bitmap 0

ink rgb(255,255,255),0

sprite 1,mousex(),mousey(),1
sprite 2,(screen width()/2)-64,(screen height()/2)-64,2
set sprite priority 1,2
set sprite priority 2,1

do
   text 5,5,"Image 1:"
   paste image 1,25,25
   text 5,158,"Image 2:"
   paste image 2,25,178

   sprite 1,mousex(),mousey(),1
   sprite 2,(screen width()/2)-64,(screen height()/2)-64,2

   if SpriteCollide(1,2) then Result$="True" : else : Result$="False"
   text 5,330,"Sprites Colliding: "+Result$

   sync
loop
end
remstart
      Library for Pixel Perfect Sprite Collision v0.8

                     by Kira Vakaan

Functions:

InitSpriteCollision()
   -This function sets up the dummy sprite used in sprite point collision detection as well as the transparent color
    used in all collisions.  Call this command before any other.

SpritePointCollide(x,y,spr)
   -Returns a one if the screen point (x,y) is colliding with sprite spr.  If spr is set to zero, the number of the sprite
    the point collides with is returned.  Supports sprite scaling and offsetting.

SpriteCollide(spr1,spr2)
   -Intended to replace the built-in command: sprite collision(spr1,spr2).  Currently does NOT support sprite scaling or
    offsetting.

SetTransparentColor(color as dword)
   -Sets the color to be ignored during collision detection.

GetTransparentColor()
   -...really..?

In the future (maybe):
   - Support for sprite scaling and offsetting during sprite on sprite collision detection.
   - Any suggestions from people.

remend

end

function InitSpriteCollision()
   #constant DUMMY   1000
   global Transparent as dword : Transparent=0

   create bitmap DUMMY,1,1
   get image DUMMY,0,0,1,1
   delete bitmap DUMMY
   set current bitmap 0
   sprite DUMMY,0,0,DUMMY
   hide sprite DUMMY
endfunction

function SpritePointCollide(x,y,spr)
   sprite DUMMY,x,y,DUMMY
   Collision=sprite collision(DUMMY,spr)
   if not Collision then exitfunction 0
   if not spr then spr=Collision
   dec x,sprite x(spr)
   dec y,sprite y(spr)
   x=(x/(sprite scale x(spr)/100.0))+sprite offset x(spr)
   y=(y/(sprite scale y(spr)/100.0))+sprite offset y(spr)
   make memblock from image 255,sprite image(spr)
   Width=memblock dword(255,0)
   Height=memblock dword(255,4)
   if x<0 or y<0 or x=Width or y=Height then exitfunction 0
   if memblock dword(255,12+4*((x%%Width)+((y%%Width)*Width)))=Transparent then exitfunction 0
endfunction Collision

function SpriteCollide(spr1,spr2)
   Collision=sprite collision(spr1,spr2)
   if not Collision then exitfunction 0
   Color1 as dword
   Color2 as dword
   if not spr2 then spr2=Collision
   if sprite x(spr2)<sprite x(spr1)
      OverlapX=sprite x(spr1)
      OverlapWidth=sprite x(spr2)+sprite width(spr2)-sprite x(spr1)
   else
      OverlapX=sprite x(spr2)
      OverlapWidth=sprite x(spr1)+sprite width(spr1)-sprite x(spr2)
   endif
   if sprite y(spr2)<sprite y(spr1)
      OverlapY=sprite y(spr1)
      OverlapHeight=sprite y(spr2)+sprite height(spr2)-sprite y(spr1)
   else
      OverlapY=sprite y(spr2)
      OverlapHeight=sprite y(spr1)+sprite height(spr1)-sprite y(spr2)
   endif
   Spr1X=OverlapX-sprite x(spr1)
   Spr1Y=OverlapY-sprite y(spr1)
   Spr2X=OverlapX-sprite x(spr2)
   Spr2Y=OverlapY-sprite y(spr2)
   make memblock from image 255,sprite image(spr1)
   make memblock from image 256,sprite image(spr2)
   Spr1Width=memblock dword(255,0)
   Spr1Height=memblock dword(255,4)
   Spr2Width=memblock dword(256,0)
   Spr2Height=memblock dword(256,4)
   for y=1 to OverlapHeight
      for x=1 to OverlapWidth
         if Spr1X<0 or Spr1Y<0 or Spr1X>=Spr1Width or Spr1Y>=Spr1Height then goto continue
         if Spr2X<0 or Spr2Y<0 or Spr2X>=Spr2Width or Spr2Y>=Spr2Height then goto continue
         Color1=memblock dword(255,12+4*((Spr1X%%Spr1Width)+((Spr1Y%%Spr1Width)*Spr1Width)))
         Color2=memblock dword(256,12+4*((Spr2X%%Spr2Width)+((Spr2Y%%Spr2Width)*Spr2Width)))
         if Color1<>Transparent and Color2<>Transparent then exitfunction Collision
         continue:
         inc Spr1X
         inc Spr2X
      next x
      dec Spr1X,OverlapWidth
      dec Spr2X,OverlapWidth
      inc Spr1Y
      inc Spr2Y
   next y
endfunction 0

function SetTransparentColor(color as dword)
   Transparent=color
endfunction

function GetTransparentColor()
endfunction Transparent

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Kira Vakaan

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Joined: 1st Dec 2008

Location: MI, United States

Posted: 24th Feb 2009 01:20

Oh, and I realize I didn't call my own InitSpriteCollision() function before using other commands from the library, as I said was necessary in the thread Green Gandalf gave the link to, but the initialization function is only necessary for "point on sprite" collisions and when a transparent color other than black is needed.

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Aralox

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Location: Melbourne

Posted: 24th Feb 2009 10:36

wow your example worked perfectly, even after i changed the box to a circle, and then replaced that with a png. thank you. however one thing i still need that the library doesnt support (i know youve mentioned this) is sprite offsetting. hmm how hard do you reckon it would be to impement this feature? ill give it a go

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Kira Vakaan

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Location: MI, United States

Posted: 24th Feb 2009 21:47 Edited at: 24th Feb 2009 21:49

Hm, I'll take a look. I don't suspect it'll be impossibly challenging. In the mean time, you could always just subtract the offset coordinates from the actual, every time you move the sprite.

Something like this:

sprite SpriteNumber,XPos-OffsetX,YPos-OffsetY,Img

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Aralox

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Posted: 24th Feb 2009 22:57

hey good idea ill try it

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Kira Vakaan

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Joined: 1st Dec 2008

Location: MI, United States

Posted: 24th Feb 2009 23:11

Actually, you needn't try it. I just revised the library to support offsetting. Maybe I'll give scaling another whack too...

Here's the new example:

set display mode 1024,768,32,1
sync on

`hide mouse

create bitmap 1,128,128
ink rgb(255,0,0),0
box 32,32,96,96
get image 1,0,0,128,128
ink rgb(0,255,0),0
box 32,32,96,96
get image 2,0,0,128,128
delete bitmap 1

ink rgb(255,255,255),0

sprite 1,mousex(),mousey(),1
sprite 2,(screen width()/2)-64,(screen height()/2)-64,2
set sprite priority 1,2
set sprite priority 2,1

offset sprite 1,64,64

do
   text 5,5,"Image 1:"
   paste image 1,25,25
   text 5,158,"Image 2:"
   paste image 2,25,178

sprite 1,mousex(),mousey(),1
   sprite 2,(screen width()/2)-64,(screen height()/2)-64,2

if SpriteCollide(1,2) then Result$="True" : else : Result$="False"
   text 5,330,"Sprites Colliding: "+Result$

sync
loop
end
remstart
      Library for Pixel Perfect Sprite Collision v0.9

by Kira Vakaan

Functions:

InitSpriteCollision()
   -This function sets up the dummy sprite used in sprite point collision detection as well as the transparent color
    used in all collisions.  Call this command before any other.

SpritePointCollide(x,y,spr)
   -Returns a one if the screen point (x,y) is colliding with sprite spr.  If spr is set to zero, the number of the sprite
    the point collides with is returned.  Supports sprite scaling and offsetting.

SpriteCollide(spr1,spr2)
   -Intended to replace the built-in command: sprite collision(spr1,spr2).  Currently does NOT support sprite scaling but
    DOES support sprite offsetting.

SetTransparentColor(color as dword)
   -Sets the color to be ignored during collision detection.

GetTransparentColor()
   -...really..?

In the future (maybe):
   - Support for sprite scaling during sprite on sprite collision detection.
   - Any suggestions from people.

remend

end

function InitSpriteCollision()
   #constant DUMMY   1000
   global Transparent as dword : Transparent=0

create bitmap DUMMY,1,1
   get image DUMMY,0,0,1,1
   delete bitmap DUMMY
   set current bitmap 0
   sprite DUMMY,0,0,DUMMY
   hide sprite DUMMY
endfunction

function SpritePointCollide(x,y,spr)
   sprite DUMMY,x,y,DUMMY
   Collision=sprite collision(DUMMY,spr)
   if not Collision then exitfunction 0
   if not spr then spr=Collision
   dec x,sprite x(spr)
   dec y,sprite y(spr)
   x=(x/(sprite scale x(spr)/100.0))+sprite offset x(spr)
   y=(y/(sprite scale y(spr)/100.0))+sprite offset y(spr)
   make memblock from image 255,sprite image(spr)
   Width=memblock dword(255,0)
   Height=memblock dword(255,4)
   if x<0 or y<0 or x=Width or y=Height then exitfunction 0
   if memblock dword(255,12+4*((x%%Width)+((y%%Width)*Width)))=Transparent then exitfunction 0
endfunction Collision

function SpriteCollide(spr1,spr2)
   Collision=sprite collision(spr1,spr2)
   if not Collision then exitfunction 0
   Color1 as dword
   Color2 as dword
   if not spr2 then spr2=Collision
   XPos1=sprite x(spr1)-sprite offset x(spr1) : YPos1=sprite y(spr1)-sprite offset y(spr1)
   XPos2=sprite x(spr2)-sprite offset x(spr2) : YPos2=sprite y(spr2)-sprite offset y(spr2)
   if XPos2<XPos1
      OverlapX=XPos1
      OverlapWidth=XPos2+sprite width(spr2)-XPos1
   else
      OverlapX=XPos2
      OverlapWidth=XPos1+sprite width(spr1)-XPos2
   endif
   if YPos2<YPos1
      OverlapY=YPos1
      OverlapHeight=YPos2+sprite height(spr2)-YPos1
   else
      OverlapY=YPos2
      OverlapHeight=YPos1+sprite height(spr1)-YPos2
   endif
   Spr1X=OverlapX-XPos1
   Spr1Y=OverlapY-YPos1
   Spr2X=OverlapX-XPos2
   Spr2Y=OverlapY-YPos2
   make memblock from image 255,sprite image(spr1)
   make memblock from image 256,sprite image(spr2)
   Spr1Width=memblock dword(255,0)
   Spr1Height=memblock dword(255,4)
   Spr2Width=memblock dword(256,0)
   Spr2Height=memblock dword(256,4)
   for y=1 to OverlapHeight
      for x=1 to OverlapWidth
         if Spr1X<0 or Spr1Y<0 or Spr1X>=Spr1Width or Spr1Y>=Spr1Height then goto continue
         if Spr2X<0 or Spr2Y<0 or Spr2X>=Spr2Width or Spr2Y>=Spr2Height then goto continue
         Color1=memblock dword(255,12+4*((Spr1X%%Spr1Width)+((Spr1Y%%Spr1Width)*Spr1Width)))
         Color2=memblock dword(256,12+4*((Spr2X%%Spr2Width)+((Spr2Y%%Spr2Width)*Spr2Width)))
         if Color1<>Transparent and Color2<>Transparent then exitfunction Collision
         continue:
         inc Spr1X
         inc Spr2X
      next x
      dec Spr1X,OverlapWidth
      dec Spr2X,OverlapWidth
      inc Spr1Y
      inc Spr2Y
   next y
endfunction 0

function SetTransparentColor(color as dword)
   Transparent=color
endfunction

function GetTransparentColor()
endfunction Transparent

set display mode 1024,768,32,1
sync on

`hide mouse

create bitmap 1,128,128
ink rgb(255,0,0),0
box 32,32,96,96
get image 1,0,0,128,128
ink rgb(0,255,0),0
box 32,32,96,96
get image 2,0,0,128,128
delete bitmap 1

ink rgb(255,255,255),0

sprite 1,mousex(),mousey(),1
sprite 2,(screen width()/2)-64,(screen height()/2)-64,2
set sprite priority 1,2
set sprite priority 2,1

offset sprite 1,64,64

do
   text 5,5,"Image 1:"
   paste image 1,25,25
   text 5,158,"Image 2:"
   paste image 2,25,178

   sprite 1,mousex(),mousey(),1
   sprite 2,(screen width()/2)-64,(screen height()/2)-64,2

   if SpriteCollide(1,2) then Result$="True" : else : Result$="False"
   text 5,330,"Sprites Colliding: "+Result$

   sync
loop
end
remstart
      Library for Pixel Perfect Sprite Collision v0.9

                     by Kira Vakaan

Functions:

InitSpriteCollision()
   -This function sets up the dummy sprite used in sprite point collision detection as well as the transparent color
    used in all collisions.  Call this command before any other.

SpritePointCollide(x,y,spr)
   -Returns a one if the screen point (x,y) is colliding with sprite spr.  If spr is set to zero, the number of the sprite
    the point collides with is returned.  Supports sprite scaling and offsetting.

SpriteCollide(spr1,spr2)
   -Intended to replace the built-in command: sprite collision(spr1,spr2).  Currently does NOT support sprite scaling but
    DOES support sprite offsetting.

SetTransparentColor(color as dword)
   -Sets the color to be ignored during collision detection.

GetTransparentColor()
   -...really..?

In the future (maybe):
   - Support for sprite scaling during sprite on sprite collision detection.
   - Any suggestions from people.

remend

end

function InitSpriteCollision()
   #constant DUMMY   1000
   global Transparent as dword : Transparent=0

   create bitmap DUMMY,1,1
   get image DUMMY,0,0,1,1
   delete bitmap DUMMY
   set current bitmap 0
   sprite DUMMY,0,0,DUMMY
   hide sprite DUMMY
endfunction

function SpritePointCollide(x,y,spr)
   sprite DUMMY,x,y,DUMMY
   Collision=sprite collision(DUMMY,spr)
   if not Collision then exitfunction 0
   if not spr then spr=Collision
   dec x,sprite x(spr)
   dec y,sprite y(spr)
   x=(x/(sprite scale x(spr)/100.0))+sprite offset x(spr)
   y=(y/(sprite scale y(spr)/100.0))+sprite offset y(spr)
   make memblock from image 255,sprite image(spr)
   Width=memblock dword(255,0)
   Height=memblock dword(255,4)
   if x<0 or y<0 or x=Width or y=Height then exitfunction 0
   if memblock dword(255,12+4*((x%%Width)+((y%%Width)*Width)))=Transparent then exitfunction 0
endfunction Collision

function SpriteCollide(spr1,spr2)
   Collision=sprite collision(spr1,spr2)
   if not Collision then exitfunction 0
   Color1 as dword
   Color2 as dword
   if not spr2 then spr2=Collision
   XPos1=sprite x(spr1)-sprite offset x(spr1) : YPos1=sprite y(spr1)-sprite offset y(spr1)
   XPos2=sprite x(spr2)-sprite offset x(spr2) : YPos2=sprite y(spr2)-sprite offset y(spr2)
   if XPos2<XPos1
      OverlapX=XPos1
      OverlapWidth=XPos2+sprite width(spr2)-XPos1
   else
      OverlapX=XPos2
      OverlapWidth=XPos1+sprite width(spr1)-XPos2
   endif
   if YPos2<YPos1
      OverlapY=YPos1
      OverlapHeight=YPos2+sprite height(spr2)-YPos1
   else
      OverlapY=YPos2
      OverlapHeight=YPos1+sprite height(spr1)-YPos2
   endif
   Spr1X=OverlapX-XPos1
   Spr1Y=OverlapY-YPos1
   Spr2X=OverlapX-XPos2
   Spr2Y=OverlapY-YPos2
   make memblock from image 255,sprite image(spr1)
   make memblock from image 256,sprite image(spr2)
   Spr1Width=memblock dword(255,0)
   Spr1Height=memblock dword(255,4)
   Spr2Width=memblock dword(256,0)
   Spr2Height=memblock dword(256,4)
   for y=1 to OverlapHeight
      for x=1 to OverlapWidth
         if Spr1X<0 or Spr1Y<0 or Spr1X>=Spr1Width or Spr1Y>=Spr1Height then goto continue
         if Spr2X<0 or Spr2Y<0 or Spr2X>=Spr2Width or Spr2Y>=Spr2Height then goto continue
         Color1=memblock dword(255,12+4*((Spr1X%%Spr1Width)+((Spr1Y%%Spr1Width)*Spr1Width)))
         Color2=memblock dword(256,12+4*((Spr2X%%Spr2Width)+((Spr2Y%%Spr2Width)*Spr2Width)))
         if Color1<>Transparent and Color2<>Transparent then exitfunction Collision
         continue:
         inc Spr1X
         inc Spr2X
      next x
      dec Spr1X,OverlapWidth
      dec Spr2X,OverlapWidth
      inc Spr1Y
      inc Spr2Y
   next y
endfunction 0

function SetTransparentColor(color as dword)
   Transparent=color
endfunction

function GetTransparentColor()
endfunction Transparent

Here's the new library:

remstart
      Library for Pixel Perfect Sprite Collision v0.9

by Kira Vakaan

Functions:

InitSpriteCollision()
   -This function sets up the dummy sprite used in sprite point collision detection as well as the transparent color
    used in all collisions.  Call this command before any other.

SpritePointCollide(x,y,spr)
   -Returns a one if the screen point (x,y) is colliding with sprite spr.  If spr is set to zero, the number of the sprite
    the point collides with is returned.  Supports sprite scaling and offsetting.

SpriteCollide(spr1,spr2)
   -Intended to replace the built-in command: sprite collision(spr1,spr2).  Currently does NOT support sprite scaling but
    DOES support sprite offsetting.

SetTransparentColor(color as dword)
   -Sets the color to be ignored during collision detection.

GetTransparentColor()
   -...really..?

In the future (maybe):
   - Support for sprite scaling during sprite on sprite collision detection.
   - Any suggestions from people.

remend

end

function InitSpriteCollision()
   #constant DUMMY   1000
   global Transparent as dword : Transparent=0

create bitmap DUMMY,1,1
   get image DUMMY,0,0,1,1
   delete bitmap DUMMY
   set current bitmap 0
   sprite DUMMY,0,0,DUMMY
   hide sprite DUMMY
endfunction

function SpritePointCollide(x,y,spr)
   sprite DUMMY,x,y,DUMMY
   Collision=sprite collision(DUMMY,spr)
   if not Collision then exitfunction 0
   if not spr then spr=Collision
   dec x,sprite x(spr)
   dec y,sprite y(spr)
   x=(x/(sprite scale x(spr)/100.0))+sprite offset x(spr)
   y=(y/(sprite scale y(spr)/100.0))+sprite offset y(spr)
   make memblock from image 255,sprite image(spr)
   Width=memblock dword(255,0)
   Height=memblock dword(255,4)
   if x<0 or y<0 or x=Width or y=Height then exitfunction 0
   if memblock dword(255,12+4*((x%%Width)+((y%%Width)*Width)))=Transparent then exitfunction 0
endfunction Collision

function SpriteCollide(spr1,spr2)
   Collision=sprite collision(spr1,spr2)
   if not Collision then exitfunction 0
   Color1 as dword
   Color2 as dword
   if not spr2 then spr2=Collision
   XPos1=sprite x(spr1)-sprite offset x(spr1) : YPos1=sprite y(spr1)-sprite offset y(spr1)
   XPos2=sprite x(spr2)-sprite offset x(spr2) : YPos2=sprite y(spr2)-sprite offset y(spr2)
   if XPos2<XPos1
      OverlapX=XPos1
      OverlapWidth=XPos2+sprite width(spr2)-XPos1
   else
      OverlapX=XPos2
      OverlapWidth=XPos1+sprite width(spr1)-XPos2
   endif
   if YPos2<YPos1
      OverlapY=YPos1
      OverlapHeight=YPos2+sprite height(spr2)-YPos1
   else
      OverlapY=YPos2
      OverlapHeight=YPos1+sprite height(spr1)-YPos2
   endif
   Spr1X=OverlapX-XPos1
   Spr1Y=OverlapY-YPos1
   Spr2X=OverlapX-XPos2
   Spr2Y=OverlapY-YPos2
   make memblock from image 255,sprite image(spr1)
   make memblock from image 256,sprite image(spr2)
   Spr1Width=memblock dword(255,0)
   Spr1Height=memblock dword(255,4)
   Spr2Width=memblock dword(256,0)
   Spr2Height=memblock dword(256,4)
   for y=1 to OverlapHeight
      for x=1 to OverlapWidth
         if Spr1X<0 or Spr1Y<0 or Spr1X>=Spr1Width or Spr1Y>=Spr1Height then goto continue
         if Spr2X<0 or Spr2Y<0 or Spr2X>=Spr2Width or Spr2Y>=Spr2Height then goto continue
         Color1=memblock dword(255,12+4*((Spr1X%%Spr1Width)+((Spr1Y%%Spr1Width)*Spr1Width)))
         Color2=memblock dword(256,12+4*((Spr2X%%Spr2Width)+((Spr2Y%%Spr2Width)*Spr2Width)))
         if Color1<>Transparent and Color2<>Transparent then exitfunction Collision
         continue:
         inc Spr1X
         inc Spr2X
      next x
      dec Spr1X,OverlapWidth
      dec Spr2X,OverlapWidth
      inc Spr1Y
      inc Spr2Y
   next y
endfunction 0

function SetTransparentColor(color as dword)
   Transparent=color
endfunction

function GetTransparentColor()
endfunction Transparent

remstart
      Library for Pixel Perfect Sprite Collision v0.9

                     by Kira Vakaan

Functions:

InitSpriteCollision()
   -This function sets up the dummy sprite used in sprite point collision detection as well as the transparent color
    used in all collisions.  Call this command before any other.

SpritePointCollide(x,y,spr)
   -Returns a one if the screen point (x,y) is colliding with sprite spr.  If spr is set to zero, the number of the sprite
    the point collides with is returned.  Supports sprite scaling and offsetting.

SpriteCollide(spr1,spr2)
   -Intended to replace the built-in command: sprite collision(spr1,spr2).  Currently does NOT support sprite scaling but
    DOES support sprite offsetting.

SetTransparentColor(color as dword)
   -Sets the color to be ignored during collision detection.

GetTransparentColor()
   -...really..?

In the future (maybe):
   - Support for sprite scaling during sprite on sprite collision detection.
   - Any suggestions from people.

remend

end

function InitSpriteCollision()
   #constant DUMMY   1000
   global Transparent as dword : Transparent=0

   create bitmap DUMMY,1,1
   get image DUMMY,0,0,1,1
   delete bitmap DUMMY
   set current bitmap 0
   sprite DUMMY,0,0,DUMMY
   hide sprite DUMMY
endfunction

function SpritePointCollide(x,y,spr)
   sprite DUMMY,x,y,DUMMY
   Collision=sprite collision(DUMMY,spr)
   if not Collision then exitfunction 0
   if not spr then spr=Collision
   dec x,sprite x(spr)
   dec y,sprite y(spr)
   x=(x/(sprite scale x(spr)/100.0))+sprite offset x(spr)
   y=(y/(sprite scale y(spr)/100.0))+sprite offset y(spr)
   make memblock from image 255,sprite image(spr)
   Width=memblock dword(255,0)
   Height=memblock dword(255,4)
   if x<0 or y<0 or x=Width or y=Height then exitfunction 0
   if memblock dword(255,12+4*((x%%Width)+((y%%Width)*Width)))=Transparent then exitfunction 0
endfunction Collision

function SpriteCollide(spr1,spr2)
   Collision=sprite collision(spr1,spr2)
   if not Collision then exitfunction 0
   Color1 as dword
   Color2 as dword
   if not spr2 then spr2=Collision
   XPos1=sprite x(spr1)-sprite offset x(spr1) : YPos1=sprite y(spr1)-sprite offset y(spr1)
   XPos2=sprite x(spr2)-sprite offset x(spr2) : YPos2=sprite y(spr2)-sprite offset y(spr2)
   if XPos2<XPos1
      OverlapX=XPos1
      OverlapWidth=XPos2+sprite width(spr2)-XPos1
   else
      OverlapX=XPos2
      OverlapWidth=XPos1+sprite width(spr1)-XPos2
   endif
   if YPos2<YPos1
      OverlapY=YPos1
      OverlapHeight=YPos2+sprite height(spr2)-YPos1
   else
      OverlapY=YPos2
      OverlapHeight=YPos1+sprite height(spr1)-YPos2
   endif
   Spr1X=OverlapX-XPos1
   Spr1Y=OverlapY-YPos1
   Spr2X=OverlapX-XPos2
   Spr2Y=OverlapY-YPos2
   make memblock from image 255,sprite image(spr1)
   make memblock from image 256,sprite image(spr2)
   Spr1Width=memblock dword(255,0)
   Spr1Height=memblock dword(255,4)
   Spr2Width=memblock dword(256,0)
   Spr2Height=memblock dword(256,4)
   for y=1 to OverlapHeight
      for x=1 to OverlapWidth
         if Spr1X<0 or Spr1Y<0 or Spr1X>=Spr1Width or Spr1Y>=Spr1Height then goto continue
         if Spr2X<0 or Spr2Y<0 or Spr2X>=Spr2Width or Spr2Y>=Spr2Height then goto continue
         Color1=memblock dword(255,12+4*((Spr1X%%Spr1Width)+((Spr1Y%%Spr1Width)*Spr1Width)))
         Color2=memblock dword(256,12+4*((Spr2X%%Spr2Width)+((Spr2Y%%Spr2Width)*Spr2Width)))
         if Color1<>Transparent and Color2<>Transparent then exitfunction Collision
         continue:
         inc Spr1X
         inc Spr2X
      next x
      dec Spr1X,OverlapWidth
      dec Spr2X,OverlapWidth
      inc Spr1Y
      inc Spr2Y
   next y
endfunction 0

function SetTransparentColor(color as dword)
   Transparent=color
endfunction

function GetTransparentColor()
endfunction Transparent

And the source file for the library is attached as well.

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Aralox

17

Years of Service

User Offline

Joined: 16th Jan 2007

Location: Melbourne

Posted: 25th Feb 2009 00:38 Edited at: 25th Feb 2009 00:44

Thank you, kira vakaan, it works beautifully!
except for one thing,

the sprite im checking collision for is constantly rotating.
hmm, ill try rotating it back to 0 degrees when checking collision, then rerotating it to its previous position. it should work, but will cause a drop in fps i think

EDIT: oh wait that wont do anything, itll still be checking the same sprite location. hmmmm

EDIT2: is there a way to check collision for the sprite, instead of the sprites image? wait that sounds silly even to me