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Please give me some idea how to detect a collision in a Commander Keen like side-scroller game. For example when the man goes to a stone, the stone must stop him. But I know only the POINT(X,Y) method, that's not good... The tiles are 16x16 pixel like in Commander Keen and Dangerous Dave. Any ideas how to detect the collision? :-?

how are you storing your map?

Oz~

I'm storing it in a 2D array

By the way, the game isn't a side scroller as I said, it's with static screens like Dangerous Dave I... but I thing that the collision detection is the same in side scrollers, isn't it?

and what are you trying to find out if you collide into it? The map? sprites?

if its the map, assuming it is something like MAP(x, y), this is what I'd suggest:

Code:
--Presudoe code

if key left THEN

 result = Map(x-1, y)

 If result = clear_space THEN

   'go ahead, and change coords

 END IF

end if

i don't have much time, so just do that sort of thing for every movement - reply if you have more trouble

Oz~

Depending on how the chracter x and ys are stored this cna be easy

If they are like the map array then you can compare the x and y's directly to the array and see if the coords are walkable
psuedocode:

Code:
IF map(guyx,guyy) = wall THEN dontmove

Here is the source:

Code:
DECLARE SUB PutSprite (PosX%, PosY%, SpriteType$, WhatToPut%)

DECLARE SUB LoadGraphics ()

DECLARE SUB LoadLevel (lev%)

DECLARE SUB PutTile (PosX%, PosY%, WhatToPut%)

DEFINT A-Z

CONST TRUE = -1

CONST FALSE = NOT TRUE

CONST Wall = 0

CONST Ground = 1

CONST Stone = 2

CONST Box = 3

CONST NICKY = 0

CONST NICKY2 = 2

CONST Arrow = 0

CONST MaxLives = 5

CONST StartLives = 3

CONST LastLevel = 2

CONST StartLevel = 1

CONST StartScore = 0

CONST MaxScore = 100000

CONST LevelX = 320

CONST LevelY = 176

CONST VisualPage = 0

CONST BufferPage = 1

CONST LevelPage = 2

UpArrow$ = CHR$(0) + "H"

DownArrow$ = CHR$(0) + "P"

LeftArrow$ = CHR$(0) + "K"

RightArrow$ = CHR$(0) + "M"

TYPE Objects

     ObjType AS INTEGER

     ObjName AS STRING * 10

     ObjX AS INTEGER

     ObjY AS INTEGER

END TYPE

DIM SHARED Tiles%(65, 5)

DIM SHARED LevelArray(1 TO 20, 1 TO 12) AS Objects

DIM SHARED NickySprites%(65, 3)

DIM SHARED Sprites%(65, 1)

DIM SHARED Lives%, Level%, Score&

DIM SHARED NickyX%, NickyY%, StartX%, StartY%, EndX%, EndY%, CurrentFrame%, Direction%, Motion%

DIM SHARED ExitTheLoop%

Lives% = StartLives

Score& = StartScore

Level% = StartLevel

CurrentFrame% = 1

Direction% = 1

Motion% = 2

LoadGraphics

LoadLevel 1

ExitTheLoop% = FALSE

DO

Keyb$ = INKEY$

SELECT CASE UCASE$(Keyb$)

       CASE RightArrow$: Direction% = 1: GOSUB MoveNicky

       CASE LeftArrow$: Direction% = -1: GOSUB MoveNicky

END SELECT

LOOP

WHILE INKEY$ = "": WEND

SCREEN 0: WIDTH 80, 25

END

MoveNicky:

LINE (NickyX%, NickyY%)-(NickyX% + 15, NickyY% + 15), 0, BF

IF CurrentFrame% = 2 THEN CurrentFrame% = 1 ELSE CurrentFrame% = 2

PutSprite NickyX%, NickyY%, "Nicky", (CurrentFrame% - 1) * 2

PCOPY BufferPage, VisualPage

WAIT &H3DA, 8

RETURN

SUB LoadGraphics

DEF SEG = VARSEG(Tiles%(0, 0))

BLOAD "TILES.DAT", VARPTR(Tiles%(0, 0))

DEF SEG = VARSEG(NickySprites%(0, 0))

BLOAD "NICKY.DAT", VARPTR(NickySprites%(0, 0))

DEF SEG = VARSEG(Sprites%(0, 0))

BLOAD "SPRITES.DAT", VARPTR(Sprites%(0, 0))

DEF SEG

END SUB

SUB LoadLevel (lev%)

SCREEN 7, 0, LevelPage, VisualPage

l$ = RTRIM$(LTRIM$(STR$(lev%)))

OPEN "LEVEL" + l$ + ".DAT" FOR INPUT AS #1

FOR Row% = 1 TO 12

LINE INPUT #1, LevRow$

FOR Col% = 1 TO 20

Object$ = MID$(LevRow$, Col%, 1)

TempX% = (Col% - 1) * 16

TempY% = (Row% - 1) * 16

SELECT CASE Object$

       CASE "W": LevelArray(Col%, Row%).ObjName = "WALL": LevelArray(Col%, Row%).ObjType = 1: PutTile TempX%, TempY%, Wall

       CASE "G": LevelArray(Col%, Row%).ObjName = "GROUND": LevelArray(Col%, Row%).ObjType = 1: PutTile TempX%, TempY%, Ground

       CASE "S": LevelArray(Col%, Row%).ObjName = "STONE": LevelArray(Col%, Row%).ObjType = 1: PutTile TempX%, TempY%, Stone

       CASE "B": LevelArray(Col%, Row%).ObjName = "BOX": LevelArray(Col%, Row%).ObjType = 1: PutTile TempX%, TempY%, Box

       CASE " ": LevelArray(Col%, Row%).ObjName = "NOTHING": LevelArray(Col%, Row%).ObjType = 0

END SELECT

LevelArray(Col%, Row%).ObjX = TempX

LevelArray(Col%, Row%).ObjY = TempY

NEXT Col%

NEXT Row%

PCOPY LevelPage, BufferPage

SCREEN 7, 0, BufferPage, VisualPage

INPUT #1, StartX%

INPUT #1, StartY%

INPUT #1, StartDir$

INPUT #1, EndX%

INPUT #1, EndY%

INPUT #1, ArrowDir$

NickyX% = StartX%

NickyY% = StartY%

PutSprite StartX%, StartY%, "Nicky", NICKY

PutSprite EndX%, EndY%, "Other", Arrow

PCOPY BufferPage, VisualPage

END SUB

SUB PutSprite (PosX%, PosY%, SpriteType$, WhatToPut%)

IF SpriteType$ = "Nicky" THEN

   PUT (PosX%, PosY%), NickySprites%(0, WhatToPut% + 1), AND

   PUT (PosX%, PosY%), NickySprites%(0, WhatToPut%), OR

ELSE

   PUT (PosX%, PosY%), Sprites%(0, 1), AND

   PUT (PosX%, PosY%), Sprites%(0, 0), OR

END IF

END SUB

SUB PutTile (PosX%, PosY%, WhatToPut%)

PUT (PosX%, PosY%), Tiles%(0, WhatToPut%), PSET

END SUB

Quote:Depending on how the chracter x and ys are stored this cna be easy

If they are like the map array then you can compare the x and y's directly to the array and see if the coords are walkable
psuedocode:

Code:
IF map(guyx,guyy) = wall THEN dontmove

=P

The char's x and y are stored as screen coordinates, not like the map Sad

Ok, this is Mit.

I have recently done collision detecting.
I came up with a quick eight IF calcs per 2 pics.

All you need is the pixel Top and Left of each pic (on the screen), and the Length and Height of each pic (in pixels) and it will tell you if they're touching no matter what system of storing your using.

Do you want it? I'll post it here if you ask me to.

Please post it Smile

http://www.gamedev.net/reference/article...cle735.asp

Its c code, but you should understand a simple c-ish if(foo==bar) Wink

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