TheGameCreators - CodeBase - Check if an object is infront of another

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Category: Collision

Version: 1.0

Information

Uploaded: 25th May 2012 16:14

Modified: 25th May 2012 16:15

Author: Chris Tate

Summary

Check if an object is in front of another using collision followed by intersection check. (Or vise-versa if you wish)

Full Description

DarkBASIC Professional Source Code

` This code was downloaded from The Game Creators

` It is reproduced here with full permission

` http://www.thegamecreators.com

`%Project Title%

`CheckIfInFrontOfObject.dba

`======================

` Make Player

PlayerObject = 1

Make Object Cube PlayerObject, 3.0

Color Object PlayerObject, Rgb(0, 255, 255)

Set Object Emissive PlayerObject, Rgb(0, 255, 255)

Position Object PlayerObject, -10,0,-10

` Make level object to collide into

LevelObject = 2

Make Object Cone LevelObject, 3.0

Set Object Cull LevelObject, 0          ` Now we can see the back of the cone

XRotate Object LevelObject, 90

Fix Object Pivot LevelObject    ` Now the X angle is zero, but the cone mesh has been rotated

Color Object LevelObject, Rgb(255, 0,0)

Set Object Emissive LevelObject, Rgb(255, 0, 0)

` Make matrix guide

Make Matrix 1, 40,40,10,10

Position Matrix 1, -20, 0, -20

Position Camera 0,20,-20

Point Camera 0,0,0

Sync On : Sync Rate 60

` Make sure we can see the object

If Object In Screen( PlayerObject ) = 0

Point Camera Object Position X( PlayerObject ), Object Position Y( PlayerObject ), Object Position Z( PlayerObject )

Endif

` Provide keyboard movement

ControlObject( PlayerObject, UpKey() - Downkey(), RightKey() - LeftKey(), 0.25, 5.0)

` Rotate the level object slowly

ControlObject( LevelObject, 0, 0.25, 0, 1.0)

If ObjectInFrontOf( PlayerObject, LevelObject, 5 )

Color Object LevelObject, Rgb(255,0,0)

Set Object Emissive PlayerObject, Rgb(255,0, 0)

Else

Color Object LevelObject, Rgb(0,255,0)

Set Object Emissive PlayerObject, Rgb(0, 255, 255)

Endif

Text 0,0,"Collide in front of this cone to make it green"

Sync

Loop

Function ControlObject( iObject, fForwardForce#, fClockwiseForce#, fMovementSpeed#, fRotateSpeed#)

Move Object iObject, fForwardForce# * fMovementSpeed#

Turn Object Right iObject, fClockwiseForce# * fRotateSpeed#

Endfunction

Function ObjectInFrontOf( iObject, iInFrontOfObject, fDistance# )

` Check if object is colliding before checking if it is in front

If Object Collision( iObject, iInFrontOfObject )

x1# = Object Position X( iInFrontOfObject )

y1# = Object Position Y( iInFrontOfObject )

z1# = Object Position Z( iInFrontOfObject )

` Cast a ray infront

x2# = NewXValue( x1#, Object Angle Y( iInFrontOfObject ), fDistance# )

y2# = y1#       ` In this scenario, the player cannot move up or down

` Use this otherwise: Object Position Y( iObject )

` If you wanted to check if the object is pointing upwards towards the player

` aswell, use this: NewYValue( y1#, Object Angle X( iInFrontOfObject ), fDistance# )

z2# = NewZValue( z1#, Object Angle Y( iInFrontOfObject ), fDistance# )

If Intersect Object( iObject, x1#, y1#, z1#, x2#, y2#, z2# ) > 0 Then ExitFunction 1

CodeBase - Check if an object is infront of another

Information

Summary

Full Description

DarkBASIC Professional Source Code

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Author Name:	Chris Tate
CodeBase Entries:	2