Climb rope, move upstairs - GameCreators Forum

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Tattered brush

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Posted: 12th Dec 2008 17:38

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Hi guys

I am creating a 2d platform like adventure game. The screen does not scroll, the background image is just replaced when the sprite walks off screen.
I have come to a point where I want my character to climb a rope or move up some stairs and I am not sure how I would code this.
I just want the character to be able to "jump" up the rope, so every jump takes him further up the rope. Any advice on how I would do this?

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zenassem

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Posted: 12th Dec 2008 23:41 Edited at: 12th Dec 2008 23:56

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Well since you have no scrolling going on you could literally hardcode your jump/climbing areas. But If you don't want to do it that way you could, use a second bitmap image (that is not seen) to draw your collision/climbing zones. I might have to draw up something in paint to have this make sense. But anyway, you use the second image to test what should occur.

(Forgive me for the ugly example I am about to post)
The first image is the level the player sees. The second is a collision map of the level. You just check the sprites position against the collision map, and depending on the color you code the action.

Red=Player collides
Green=Player moves through
Yellow=Player Climbs

visible level

invisible collision map for level

~Zenassem

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Tattered brush

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Posted: 13th Dec 2008 14:25

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Thanks for taking the time to illustrate my problem, it is much clearer and it seems this is just what i am looking for.
Would it be possible for you show this in code please? Are there any examples of collision maps out there?
I want the player to be able to move through the stairs until the sprite jumps, making the player land on the first stair etc.
Thanks for your help so far.

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RUCCUS

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Posted: 13th Dec 2008 15:28

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If you want to make your life easier, you should work on a level editor. You could program it to allow you to import your background image, then draw collision boxes ontop of it and set the boxe's properties (stop the user, allow them to climb up, etc). Using this method you could go one step further and set collision boxes to hurt the user and place them over something like lava, boxes to win the game when entered so you could program doors easily by drawing a enter collision box overtop of it, etc.

The level editor wouldn't be too hard to make since it's 2D. Id recommend you get familiar with user-defined types and arrays if you're not already. You could save the collision boxes in an array, and store their properties in a UDT. For example;

+ Code Snippet

#CONSTANT CLIMB 1
collisionbox(1).x# = 4
collisionbox(1).y# = 100
collisionbox(1).reaction = CLIMB

And then to check for collision you could easily loop through every box and react accordingly;

+ Code Snippet

boxes = ARRAY COUNT(collisionbox(0))
x# = user's x position
y# = user's y position

FOR b = 1 TO boxes
   IF x# > collisionbox(b).x# AND x# < collisionbox(b).x# + collisionbox(b).width#
      IF y# > collisionbox(b).y# AND y# < collisionbox(b).y# + collisionbox(b).height#
         IF collisionbox(b).reaction = DENSE
            // Stop the user
         ENDIF
         IF collisionbox(b).reaction = CLIMB
            // Climb code
         ENDIF
      ENDIF
   ENDIF
NEXT b

You'll need to familiarize yourself with the file commands as well so you can load the collision maps into your game. Its a little more work but once you have a decent level editor you can make maps easily, and improve it to allow you to place spawn points, weapons, etc.

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zenassem

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Posted: 13th Dec 2008 22:28

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I can write some code later, but the idea is to make a memblock from the collision image. Then just create a function that grabs the right pixel info based on the sprites X,Y position on the actual background.

Here is a tutorial on how the make memblock from image works. You can sink your brain into that until i can code an example later.

~Zenassem

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Tattered brush

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Posted: 15th Dec 2008 10:22

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Thanks for the support guys. Looks like there's alot to learn. I like the idea of creating collision boxes just need to understand UDTs and arrays more thoroughly.
Can a UDT hold a sprite image. For example if I define an array for objects, can one of the properties be the sprite that represents that object in the game world?

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zenassem

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Posted: 15th Dec 2008 10:43

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Sorry I totally dropped the ball on you. Didn't mean to do that. I will provide that sample code when I get back this morning.

as for your question... In a way the answer is yes.

One of the indexes of the array could store the sprite number, which would refer to the sprite. You could aslo store a pointer to the beginning of the memblock containing the image data.

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zenassem

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Posted: 16th Dec 2008 21:10 Edited at: 17th Dec 2008 02:49

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I'll have this finished tonight. The example will cover 3 methods.

1. Hard coded collision boxes
2. Using an image as a collision map
3. Building the world out of tiles and using one layer as a collision map

preview:

EDIT:
Here is the Media for 3. (Srym photobucket converted them to .jpg so you may need to re flood fill the black. I'll try to fix it later)
man

block

ladder

Here is 3. (It's a crude as can be)

rem BARE BONES TILEWORLD MAP with BUILT IN COLLISION

rem Setup Display 
sync on
sync rate 30

set display mode 640,480,32

rem Load Media
load image "Block.bmp",1,1
paste image 1,0,0,1
get image 2,0,0,63,63,1
delete image 1
cls

load image "ladder.bmp",1,1
paste image 1,0,0,1
get image 3,0,0,63,63,1
delete image 1
cls

load image "Man.bmp",1,1
paste image 1,0,0,1
get image 9,0,0,63,63,1
delete image 1
cls

rem Create an Array to hold our world info that is stored in Data statements 
dim TileWorld(10,7,4)

rem Set the read pointer to the beginning of the Data statements
restore WorldDat

rem fill our World Array with the info from the Data statements
for z=0 to 3 
    for y=0 to 6
        for x=0 to 9
            read arval
            imgnum=arval
            TileWorld(x,y,z)=imgnum
        next x
    next y
next z

rem set player inital world coordinates
PlayerX=2
PlayerY=5

rem MAIN LOOP
do
cls 0

rem read the TileWorld Array, and Paste the right image to the screen
for z=0 to 3
    for y=0 to 6
        for x=0 to 9
            imgnum = TileWorld(x,y,z)
            rem if an element's value don't paste an image
            if imgnum<>0 
                paste image imgnum,x*64,y*64,1
            endif
        next x
    next y
next z

rem update players position
paste image 9, PlayerX*64,PlayerY*64,1

rem Get user input
rem if the player presses right and the tile next to him is clear (=0) then move player right as long as he is not at the right max.
if rightkey()=1 and TileWorld(PlayerX+1,PlayerY,2)=0 and PlayerX<6
    inc PlayerX, 1
endif
rem if player presses left and the tile next to him is clear (=0) then move player left. As long he is not at the left min.
if leftkey()=1 and TileWorld(PlayerX-1,PlayerY,2)=0 and PlayerX<>0
    dec PlayerX, 1
endif
rem if player presses up, see if a ladder is present behind him (=3) on the layer above the blocks
if upkey()=1 and TileWorld(PlayerX,PlayerY,3)=3
    dec PlayerY,1
endif
rem if player presses down, see if there is a ladder present below his current position
if downkey()=1 and TileWorld(PlayerX,PlayerY+1,3)=3 
    inc PlayerY, 1
endif

rem if the tile under a player is not a block AND the player is not on a ladder make him fall down until there is one
if TileWorld(PlayerX,PlayerY+1,2)=0 and TileWorld(PlayerX,PlayerY,3)<>3
    inc PlayerY, 1   
endif

sync
loop
end

rem layer 0
WorldDat:
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0

rem layer 1
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0

rem layer 2
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,2,2,2,2,0,0,0,0
data 0,0,0,0,0,0,0,0,0,2
data 0,2,2,2,0,0,0,2,2,2
data 0,0,0,0,0,0,2,2,2,2
data 2,2,2,2,2,2,2,2,2,2

rem layer 3
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0

+ Code Snippet

rem BARE BONES TILEWORLD MAP with BUILT IN COLLISION

rem Setup Display 
sync on
sync rate 30

set display mode 640,480,32

rem Load Media
load image "Block.bmp",1,1
paste image 1,0,0,1
get image 2,0,0,63,63,1
delete image 1
cls

load image "ladder.bmp",1,1
paste image 1,0,0,1
get image 3,0,0,63,63,1
delete image 1
cls

load image "Man.bmp",1,1
paste image 1,0,0,1
get image 9,0,0,63,63,1
delete image 1
cls

rem Create an Array to hold our world info that is stored in Data statements 
dim TileWorld(10,7,4)

rem Set the read pointer to the beginning of the Data statements
restore WorldDat

rem fill our World Array with the info from the Data statements
for z=0 to 3 
    for y=0 to 6
        for x=0 to 9
            read arval
            imgnum=arval
            TileWorld(x,y,z)=imgnum
        next x
    next y
next z

rem set player inital world coordinates
PlayerX=2
PlayerY=5

rem MAIN LOOP
do
cls 0

rem read the TileWorld Array, and Paste the right image to the screen
for z=0 to 3
    for y=0 to 6
        for x=0 to 9
            imgnum = TileWorld(x,y,z)
            rem if an element's value don't paste an image
            if imgnum<>0 
                paste image imgnum,x*64,y*64,1
            endif
        next x
    next y
next z

rem update players position
paste image 9, PlayerX*64,PlayerY*64,1

rem Get user input
rem if the player presses right and the tile next to him is clear (=0) then move player right as long as he is not at the right max.
if rightkey()=1 and TileWorld(PlayerX+1,PlayerY,2)=0 and PlayerX<6
    inc PlayerX, 1
endif
rem if player presses left and the tile next to him is clear (=0) then move player left. As long he is not at the left min.
if leftkey()=1 and TileWorld(PlayerX-1,PlayerY,2)=0 and PlayerX<>0
    dec PlayerX, 1
endif
rem if player presses up, see if a ladder is present behind him (=3) on the layer above the blocks
if upkey()=1 and TileWorld(PlayerX,PlayerY,3)=3
    dec PlayerY,1
endif
rem if player presses down, see if there is a ladder present below his current position
if downkey()=1 and TileWorld(PlayerX,PlayerY+1,3)=3 
    inc PlayerY, 1
endif

rem if the tile under a player is not a block AND the player is not on a ladder make him fall down until there is one
if TileWorld(PlayerX,PlayerY+1,2)=0 and TileWorld(PlayerX,PlayerY,3)<>3
    inc PlayerY, 1   
endif

sync
loop
end

rem layer 0
WorldDat:
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0

rem layer 1
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0

rem layer 2
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,2,2,2,2,0,0,0,0
data 0,0,0,0,0,0,0,0,0,2
data 0,2,2,2,0,0,0,2,2,2
data 0,0,0,0,0,0,2,2,2,2
data 2,2,2,2,2,2,2,2,2,2

rem layer 3
data 0,0,0,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,3,0,0,0,0,0,0,0
data 0,0,0,0,0,0,0,0,0,0

=====================
Next I'll do 1. and 2. and edit them in

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RUCCUS

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Posted: 17th Dec 2008 21:08

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He was reffering to UDTs Zen.

The answer is yes. UDTs allow you to create named locations within arrays. So yes you could have a UDT that stored the sprite number. Look them up and you'll figure out how useful they are.

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