TheGameCreators - CodeBase - PickObject() function for DBC

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Category: Miscellaneous

Version: 1.0

Information

Uploaded: 27th Jan 2006 11:06

Modified: 1st Jan 1970 01:00

Author: Relativity

Summary

This function uses Sparky's .DLL to pick an object from a 2D point, such as the mouse position.

Full Description

This program will allow the user to see if a vector extending from a 2D point on the screen into 3D space will pass through an object. It incorporates Sparky's .DLL with my PickScreen() function. Sparky's .DLL has been uploaded; check the bottom of the Code page to download it. Syntax: PickObject(XPoint,YPoint,Distance#) XPoint - 2D X-Coordinate on the screen YPoint - 2D Y-Coordinate on the screen Distance# - Maximum distance to check for objects IMPORTANT: -This code requires Sparky's .DLL to run. -Enhanced version of DarkBASIC is required to run this function WARNING: -The Box Collision in Sparky's .DLL is bugged; do not use it unless the object you are using it on will never be behind another object when using this function INSTRUCTIONS: -Declare all objects you want to be detected by the function as Sparky's .DLL requires (see the Command List) -Whenever an object is moved or rotated use Sparky's updateObjectDBC() function -Make sure you paste all the function required for Sparky's .DLL to the bottom of your program. The PickObject() function is the first of the functions listed. Sparky's .DLL has been uploaded; check the bottom of the Code page to download it.

DarkBASIC Source Code

` This code was downloaded from The Game Creators

` It is reproduced here with full permission

` http://www.thegamecreators.com

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

`PickObject() EXAMPLE PROGRAM

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

`PickScreen() CODE WRITTEN BY:  SITHSPAWN (SEE CODEBASE)

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

`RAYCASTING .DLL WRITTEN BY:  SPARKY

`(DOWNLOAD AT http://sparky152.homestead.com/files/DBCcollisions_v1.05.zip)

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

`ARRANGED BY:  SITHSPAWN

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

`I M P O R T A N T:  SPARKY'S DLL IS REQUIRED FOR THIS FUNCTION TO WORK!!!  (SEE DOWNLOAD INFORMATION AT THE TOP OF THIS PROGRAM)

`ALSO  I M P O R T A N T:  DarkBASIC ENHANCED IS REQUIRED FOR THIS FUNCTION!!!

`AGAIN,  I M P O R T A N T:  YOU MUST DECLARE ALL OBJECTS AS SPARKY'S .DLL REQUIRES.  SEE SPARKY'S .DLL COMMAND LIST.

`LAST  I M P O R T A N T:  ANY CHANGES TO THE OBJECT YOU ARE PICKING (I.E. MOVEMENT, ROTATION) MUST BE ACCOUNTED FOR WITH

`SPARKY'S updateObjectDBC() function.

`W A R N I N G:  SPARKY'S BOX COLLISION IS BUGGED.  THEREFORE, IT IS STRONGLY ADVISED THAT YOU STAY AWAY FROM USING IT UNLESS YOU KNOW THAT

`THE OBJECT WILL NEVER BE BEHIND ANOTHER OBJECT FROM THE CAMERA'S PERSPECTIVE.

`INITIAL SETUP

SYNC ON

AUTOCAM OFF

SET DISPLAY MODE 800,600,16

RANDOMIZE TIMER()

`MAKE MATRIX FOR BASIS FOR COMPARISON

MAKE MATRIX 1,200,200,10,10

SET MATRIX WIREFRAME ON 1

`MAKE OBJECTS

MAKE OBJECT PLAIN 1,0,0

POSITION OBJECT 1,0,10,0

MAKE OBJECT CUBE 2,30

MAKE OBJECT SPHERE 3,50

MAKE OBJECT CONE 4,70

FOR OBJECT=2 TO 4

COLOR OBJECT OBJECT,RGB(RND(255),RND(255),RND(255))

POSITION OBJECT OBJECT,RND(200),RND(100),RND(200)

ROTATE OBJECT OBJECT,RND(359),RND(359),RND(359)

NEXT OBJECT

`DECLARE OBJECTS WITH SPARKY'S .DLL

setupObjectDBC(2,0,0)

setupObjectDBC(3,0,1)

setupComplexObjectDBC(4,0,2)

`DECLARE AN ARRAY FOR USE WITH THE PICKSCREEN FUNCTION

DIM VECTOR#(2)

`MAIN LOOP

`  CAMERA MOVEMENT

IF UPKEY()=1 THEN MOVE OBJECT 1,3

IF DOWNKEY()=1 THEN MOVE OBJECT 1,-3

IF MOUSELOOK=1

IF LEFTKEY()=1 OR RIGHTKEY()=1

IF LEFTKEY()=1 THEN MLOOKY2#=WRAPVALUE(MLOOKY#-90)

IF RIGHTKEY()=1 THEN MLOOKY2#=WRAPVALUE(MLOOKY#+90)

ROTATE OBJECT 1,0,MLOOKY2#,0:MOVE OBJECT 1,3

ROTATE OBJECT 1,MLOOKX#,MLOOKY#,0

ENDIF

POSITION MOUSE 400,300

MLOOKX#=WRAPVALUE(MLOOKX#+MOUSEMOVEY())

MLOOKY#=WRAPVALUE(MLOOKY#+MOUSEMOVEX())

IF MLOOKX#>180 AND MLOOKX#<270 THEN MLOOKX#=270

IF MLOOKX#<180 AND MLOOKX#>90 THEN MLOOKX#=90

ROTATE OBJECT 1,MLOOKX#,MLOOKY#,0

IF MOUSECLICK()=2 AND WAITMOUSE>5

WAITMOUSE=0

MOUSELOOK=0

SHOW MOUSE

ENDIF

ELSE

IF LEFTKEY()=1 THEN ROTATE OBJECT 1,OBJECT ANGLE X(1),WRAPVALUE(OBJECT ANGLE Y(1)-3),0

IF RIGHTKEY()=1 THEN ROTATE OBJECT 1,OBJECT ANGLE X(1),WRAPVALUE(OBJECT ANGLE Y(1)+3),0

IF MOUSECLICK()=2 AND WAITMOUSE>5

WAITMOUSE=0

MOUSELOOK=1

HIDE MOUSE

MLOOKX#=OBJECT ANGLE X(1) : MLOOKY#=OBJECT ANGLE Y(1)

IF OBJECT_SELECTED>0

updateObjectDBC(OBJECT_SELECTED)

OBJECT_SELECTED=0

ENDIF

`***********************************

`PICKING THE OBJECT (THE GOOD STUFF)

`***********************************

IF MOUSECLICK()=1 AND WAITSELECT>5

WAITSELECT=0

IF OBJECT_SELECTED=0

OBJECT_SELECTED=PICKOBJECT(MOUSEX(),MOUSEY(),1000.0)

IF OBJECT_SELECTED>0 THEN DISTANCE#=DISTANCETOCAM(OBJECT_SELECTED)

ELSE

updateObjectDBC(OBJECT_SELECTED)

OBJECT_SELECTED=0

ENDIF

IF OBJECT_SELECTED>0

PICKSCREEN(MOUSEX(),MOUSEY(),DISTANCE#)

PRINT VECTOR#(0),VECTOR#(1),VECTOR#(2)

POSITION OBJECT OBJECT_SELECTED,VECTOR#(0),VECTOR#(1),VECTOR#(2)

ENDIF

INC WAITMOUSE

INC WAITSELECT

POSITION CAMERA OBJECT POSITION X(1),OBJECT POSITION Y(1),OBJECT POSITION Z(1)

ROTATE CAMERA OBJECT ANGLE X(1),OBJECT ANGLE Y(1),OBJECT ANGLE Z(1)

SET CURSOR 0,0

PRINT "Select an object with the mouse to move it."

PRINT "Click the right mouse button to use mouse look."

PRINT "Use the arrow keys to move."

PRINT "Object Selected> ",OBJECT_SELECTED

IF OBJECT_SELECTED>0

PRINT "X POS> ",OBJECT POSITION X(OBJECT_SELECTED)," Y POS> ",OBJECT POSITION Y(OBJECT_SELECTED)," Z POS> ",OBJECT POSITION Z(OBJECT_SELECTED)

ENDIF

SYNC

LOOP

`I M P O R T A N T:  SPARKY'S DLL IS REQUIRED FOR THIS FUNCTION TO WORK!!!  (SEE DOWNLOAD INFORMATION AT THE TOP OF THIS PROGRAM)

`ALSO  I M P O R T A N T:  DarkBASIC ENHANCED IS REQUIRED FOR THIS FUNCTION!!!

`AGAIN,  I M P O R T A N T:  YOU MUST DECLARE ALL OBJECTS AS SPARKY'S .DLL REQUIRES.  SEE SPARKY'S .DLL COMMAND LIST.

`W A R N I N G:  SPARKY'S BOX COLLISION IS BUGGED.  THEREFORE, IT IS STRONGLY ADVISED THAT YOU STAY AWAY FROM USING IT UNLESS YOU KNOW THAT

`THE OBJECT WILL NEVER BE BEHIND ANOTHER OBJECT FROM THE CAMERA'S PERSPECTIVE.

`THIS FUNCTION WILL GIVE YOU A POINT IN 3D SPACE A CERTAIN DISTANCE AWAY FROM THE CAMERA

`THAT CORRESPONDS TO A 2D POINT ON YOUR SCREEN.

`SYNTAX: XPOINT# IS THE 2D X POINT ON YOUR SCREEN

`        YPOINT# IS THE 2D Y POINT ON YOUR SCREEN

`        DISTANCE# IS THE MAX DISTANCE AWAY FROM THE CAMERA YOU WANT TO CALCULATE PICK OBJECT

`W A R N I N G:  THERE MUST EXIST AN OBJECT DECLARED WITH SPARKY'S .DLL OR ELSE THIS FUNCTION WILL FAIL

`RESULTS WILL BE OUTPUT BY THE FUNCTION.  THE NUMBER OF THE CLOSEST OBJECT SELECTED WILL BE OUTPUT.

`A RESULT OF 0 MEANS THAT NO OBJECT IS SELECTED

FUNCTION PICKOBJECT(XPOINT,YPOINT,DISTANCE#)

DIM PICKOBJECTVECTOR#(2)

`  CALCULATE HALF THE SCREEN WIDTH AND HEIGHT

`  SUBTRACT 1 BECAUSE POINTS START AT (0,0), NOT (1,1)

HALFSW#=(SCREEN WIDTH()-1)

HALFSW#=HALFSW#/2

HALFSH#=(SCREEN HEIGHT()-1)

HALFSH#=HALFSH#/2

`  CALCULATE THE RATIO CONSTANTS.  REMEMBER, HEIGHT CONSTANT IS ALWAYS .6

SW#=SCREEN WIDTH()

SH#=SCREEN HEIGHT()

WIDTHCONSTANT#=SW#/SH#

WIDTHCONSTANT#=.6*WIDTHCONSTANT#

`  CALCULATE 3D COORDINATE OF SCREEN POINT ASSUMING CAMERA ISN'T ROTATED AND IS AT POSITION 0,0,0

XPOINT#=XPOINT

YPOINT#=YPOINT

XPOINT#=XPOINT-HALFSW#

YPOINT#=HALFSH#-YPOINT

XVEC#=WIDTHCONSTANT#*(XPOINT#/HALFSW#)

YVEC#=.6*(YPOINT#/HALFSH#)

ZVEC#=1

`  CALCULATE LENGTH FROM CAMERA POINT TO 3D SCREEN POINT

LENGTH#=SQRT((XVEC#*XVEC#)+(YVEC#*YVEC#)+(ZVEC#*ZVEC#))

`  MAKE VECTOR A UNIT VECTOR

XVEC#=(XVEC#/LENGTH#)

YVEC#=(YVEC#/LENGTH#)

ZVEC#=(ZVEC#/LENGTH#)

`  CALCULATE POINT ON VECTOR AT DESIRED DISTANCE FROM CAMERA

XVEC#=DISTANCE#*XVEC#

YVEC#=DISTANCE#*YVEC#

ZVEC#=DISTANCE#*ZVEC#

`  CALULATE X-AXIS ROTATION RELATIVE TO CAMERA

OLDY#=YVEC#

OLDZ#=ZVEC#

YVEC#=(OLDY#*COS(CAMERA ANGLE X()))-(OLDZ#*SIN(CAMERA ANGLE X()))

ZVEC#=(OLDY#*SIN(CAMERA ANGLE X()))+(OLDZ#*COS(CAMERA ANGLE X()))

`  CALCULATE Y-AXIS ROTATION RELATIVE TO CAMERA

OLDX#=XVEC#

OLDZ#=ZVEC#

XVEC#=(OLDX#*COS(CAMERA ANGLE Y()))+(OLDZ#*SIN(CAMERA ANGLE Y()))

ZVEC#=(OLDZ#*COS(CAMERA ANGLE Y()))-(OLDX#*SIN(CAMERA ANGLE Y()))

`  CALCULATE Z-AXIS ROTATION RELATIVE TO CAMERA

OLDX#=XVEC#

OLDY#=YVEC#

XVEC#=(OLDX#*COS(CAMERA ANGLE Z()))-(OLDY#*SIN(CAMERA ANGLE Z()))

YVEC#=(OLDX#*SIN(CAMERA ANGLE Z()))+(OLDY#*COS(CAMERA ANGLE Z()))

`  CALCULATE THE VECTOR RELATIVE TO THE STANDARD AXIS RATHER THAN RELATIVE TO THE CAMERA

VECTOR#(0)=XVEC#+CAMERA POSITION X()

VECTOR#(1)=YVEC#+CAMERA POSITION Y()

VECTOR#(2)=ZVEC#+CAMERA POSITION Z()

`  CALCULATE RAYCASTING USING SPARKY'S .DLL (N O T E:  IF USING GROUPS, SET THE GROUP FLAG TO 1)

OBJECT_SELECTED=intersectObjectDBC(0,0,CAMERA POSITION X(),CAMERA POSITION Y(),CAMERA POSITION Z(),VECTOR#(0),VECTOR#(1),VECTOR#(2),0)

UNDIM PICKOBJECTVECTOR#(2)

ENDFUNCTION OBJECT_SELECTED

`MY PICKSCREEN FUNCTION

FUNCTION PICKSCREEN(XPOINT,YPOINT,DISTANCE#)

`  CALCULATE HALF THE SCREEN WIDTH AND HEIGHT

`  SUBTRACT 1 BECAUSE POINTS START AT (0,0), NOT (1,1)

HALFSW#=(SCREEN WIDTH()-1)

HALFSW#=HALFSW#/2

HALFSH#=(SCREEN HEIGHT()-1)

HALFSH#=HALFSH#/2

`  CALCULATE THE RATIO CONSTANTS.  REMEMBER, HEIGHT CONSTANT IS ALWAYS .6

SW#=SCREEN WIDTH()

SH#=SCREEN HEIGHT()

WIDTHCONSTANT#=SW#/SH#

WIDTHCONSTANT#=.6*WIDTHCONSTANT#

`  CALCULATE 3D COORDINATE OF SCREEN POINT ASSUMING CAMERA ISN'T ROTATED AND IS AT POSITION 0,0,0

XPOINT#=XPOINT

YPOINT#=YPOINT

XPOINT#=XPOINT-HALFSW#

YPOINT#=HALFSH#-YPOINT

XVEC#=WIDTHCONSTANT#*(XPOINT#/HALFSW#)

YVEC#=.6*(YPOINT#/HALFSH#)

ZVEC#=1

`  CALCULATE LENGTH FROM CAMERA POINT TO 3D SCREEN POINT

LENGTH#=SQRT((XVEC#*XVEC#)+(YVEC#*YVEC#)+(ZVEC#*ZVEC#))

`  MAKE VECTOR A UNIT VECTOR

XVEC#=(XVEC#/LENGTH#)

YVEC#=(YVEC#/LENGTH#)

ZVEC#=(ZVEC#/LENGTH#)

`  CALCULATE POINT ON VECTOR AT DESIRED DISTANCE FROM CAMERA

XVEC#=DISTANCE#*XVEC#

YVEC#=DISTANCE#*YVEC#

ZVEC#=DISTANCE#*ZVEC#

`  CALULATE X-AXIS ROTATION RELATIVE TO CAMERA

OLDY#=YVEC#

OLDZ#=ZVEC#

YVEC#=(OLDY#*COS(CAMERA ANGLE X()))-(OLDZ#*SIN(CAMERA ANGLE X()))

ZVEC#=(OLDY#*SIN(CAMERA ANGLE X()))+(OLDZ#*COS(CAMERA ANGLE X()))

`  CALCULATE Y-AXIS ROTATION RELATIVE TO CAMERA

OLDX#=XVEC#

OLDZ#=ZVEC#

XVEC#=(OLDX#*COS(CAMERA ANGLE Y()))+(OLDZ#*SIN(CAMERA ANGLE Y()))

ZVEC#=(OLDZ#*COS(CAMERA ANGLE Y()))-(OLDX#*SIN(CAMERA ANGLE Y()))

`  CALCULATE Z-AXIS ROTATION RELATIVE TO CAMERA

OLDX#=XVEC#

OLDY#=YVEC#

XVEC#=(OLDX#*COS(CAMERA ANGLE Z()))-(OLDY#*SIN(CAMERA ANGLE Z()))

YVEC#=(OLDX#*SIN(CAMERA ANGLE Z()))+(OLDY#*COS(CAMERA ANGLE Z()))

`  CALCULATE THE VECTOR RELATIVE TO THE STANDARD AXIS RATHER THAN RELATIVE TO THE CAMERA

VECTOR#(0)=XVEC#+CAMERA POSITION X()

VECTOR#(1)=YVEC#+CAMERA POSITION Y()

VECTOR#(2)=ZVEC#+CAMERA POSITION Z()

ENDFUNCTION

`MY OBJECT DISTANCE TO CAMERA FUNCTION

FUNCTION DISTANCETOCAM(OBJNUM)

DISTANCE#=SQRT((OBJECT POSITION X(OBJNUM)-CAMERA POSITION X())^2+(OBJECT POSITION Y(OBJNUM)-CAMERA POSITION Y())^2+(OBJECT POSITION Z(OBJNUM)-CAMERA POSITION Z())^2)

ENDFUNCTION DISTANCE#

`SPARKY'S .DLL FUNCTIONS

function setupObjectDBC(objNum,groupNum,objectType)

commonSetup(objNum)

vertData = get memblock ptr(254)

objectData = get memblock ptr(255)

call dll 1,"setupObject",objNum,groupNum,objectType,vertData,objectData

delete memblock 254

endfunction

function setupComplexObjectDBC(objNum,groupNum,facesPerNode)

commonSetup(objNum)

vertData = get memblock ptr(254)

objectData = get memblock ptr(255)

call dll 1,"setupComplexObject",objNum,groupNum,facesPerNode,vertData,objectData

delete memblock 254

endfunction

function commonSetup(objNum)

if dll exist(1)=0 then load dll "DBCcollision.dll",1

if memblock exist(255)=0 then make memblock 255,24

x#=object position x(objNum)

y#=object position y(objNum)

z#=object position z(objNum)

angx#=object angle x(objNum)

angy#=object angle y(objNum)

angz#=object angle z(objNum)

write memblock float 255,0,x#

write memblock float 255,4,y#

write memblock float 255,8,z#

write memblock float 255,12,angx#

write memblock float 255,16,angy#

write memblock float 255,20,angz#

position object objNum,0,0,0

rotate object objNum,0,0,0

make mesh from object 255,objNum

make memblock from mesh 254,255

delete mesh 255

position object objNum,x#,y#,z#

rotate object objNum,angx#,angy#,angz#

endfunction

function updateObjectDBC(objNum)

if memblock exist(255)=0 then make memblock 255,24

write memblock float 255,0,object position x(objNum)

write memblock float 255,4,object position y(objNum)

write memblock float 255,8,object position z(objNum)

write memblock float 255,12,object angle x(objNum)

write memblock float 255,16,object angle y(objNum)

write memblock float 255,20,object angle z(objNum)

objectData = get memblock ptr(255)

call dll 1,"updateObject",objNum,objectData

endfunction

function intersectObjectDBC(objNum,groupFlag,oldx#,oldy#,oldz#,x#,y#,z#,excludeObj)

collide=call dll(1,"intersectObject",objNum,groupFlag,oldx#,oldy#,oldz#,x#,y#,z#,excludeObj)

endfunction collide

function setObjectCollisionOnDBC(objNum)

call dll 1,"set_object_collision_on",objNum

endfunction

function setObjectCollisionOffDBC(objNum)

call dll 1,"set_object_collision_off",objNum

endfunction

function collisionStatusDBC(objNum)

result=call dll(1,"collisionstatus",objNum)

endfunction result

function getStaticCollisionX()

result#=call dll(1,"getStaticCollisionX")

endfunction result#

function getStaticCollisionY()

result#=call dll(1,"getStaticCollisionY")

endfunction result#

function getStaticCollisionZ()

result#=call dll(1,"getStaticCollisionZ")

endfunction result#

function getCollisionNormalX()

result#=call dll(1,"getCollisionNormalX")

endfunction result#

function getCollisionNormalY()

result#=call dll(1,"getCollisionNormalY")

endfunction result#

function getCollisionNormalZ()

result#=call dll(1,"getCollisionNormalZ")

endfunction result#

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Author Name:	Relativity
CodeBase Entries:	2

CodeBase - PickObject() function for DBC

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DarkBASIC Source Code

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