This code allows you to calculate the X/Y step values between two sets of coordinates, allowing you to move between the two.
// --------------------------------- //
// Project: TestLineMove
// Start: Monday, January 19, 2009
// IDE Version: 6.138
TYPE tMoveAlongLine
ax
ay
ex
ey
bx
by
ix
iy
numSteps
maxDistance
ENDTYPE
FUNCTION _dummy:
ENDFUNCTION
INLINE
#include "math.h"
extern double atan2 ( double y, double x );
ENDINLINE
FUNCTION setTo:x,y
moveAlongLine.ax=x
moveAlongLine.ay=y
ENDFUNCTION
FUNCTION changeTo:bx,by
moveTo(moveAlongLine.ax,moveAlongLine.ay,bx,by)
ENDFUNCTION
FUNCTION angleBetweenPoints:ax,ay,ex,ey
INLINE
double angle;
angle=atan2(ex-ax,ey-ay);
if (angle<0.0)
{
angle=180.0+(180.0+angle);
}
return angle;
ENDINLINE
ENDFUNCTION
FUNCTION moveTo:sx,sy,fx,fy,mDistance=-1.0
LOCAL dx
LOCAL dy
moveAlongLine.ax=sx
moveAlongLine.ay=sy
moveAlongLine.ex=fx
moveAlongLine.ey=dy
dx=fx-sx
dy=fy-sy
moveAlongLine.bx=ABS(dx)
moveAlongLine.by=ABS(dy)
IF moveAlongLine.bx>moveAlongLine.by
moveAlongLine.numSteps=moveAlongLine.bx
ELSE
moveAlongLine.numSteps=moveAlongLine.by
ENDIF
moveAlongLine.maxDistance=mDistance
moveAlongLine.ix=dx/moveAlongLine.numSteps
moveAlongLine.iy=dy/moveAlongLine.numSteps
ENDFUNCTION
FUNCTION process%:speed
IF moveAlongLine.numSteps<=0.0
RETURN FALSE
ELSE
INC moveAlongLine.ax,moveAlongLine.ix*speed
INC moveAlongLine.ay,moveAlongLine.iy*speed
DEC moveAlongLine.numSteps,speed
IF moveAlongLine.maxDistance>0.0
DEC moveAlongLine.maxDistance,speed
IF moveAlongLine.maxDistance<=0.0
moveAlongLine.numSteps=0.0
moveAlongLine.maxDistance=0.0
RETURN FALSE
ENDIF
ENDIF
ENDIF
RETURN TRUE
ENDFUNCTION
The angle between two points code needs changing as its inaccurate, but the rest works fine.
The test code :
GLOBAL moveAlongLine AS tMoveAlongLine
SETSCREEN 1024,768,0
moveTo(0,0,200,100)
DEBUG "Angle : "+angleBetweenPoints(100,100,10,20)+"\n"
WHILE TRUE
DEBUG "X:"+moveAlongLine.ax+"\n"
DEBUG "Y:"+moveAlongLine.ay+"\n"
DEBUG moveAlongLine.numSteps+"\n"
DRAWLINE moveAlongLine.ax,moveAlongLine.ay,1,1,RGB(255,255,255)
SHOWSCREEN
process(0.25)
WEND
If anyone has a better routine for calculating the angle between two coordinates, let me know
