diff options
| -rw-r--r-- | lib/pure/basic2d.nim | 65 |
1 files changed, 31 insertions, 34 deletions
diff --git a/lib/pure/basic2d.nim b/lib/pure/basic2d.nim index c315b6b00..e3ac4b0a1 100644 --- a/lib/pure/basic2d.nim +++ b/lib/pure/basic2d.nim @@ -35,10 +35,6 @@ import strutils ## var vec2:TVEctor2d=vec & m #concatenates vec with m and returns a new vector - - - - const DEG360* = PI * 2.0 ## 360 degrees in radians. @@ -93,13 +89,13 @@ proc point2d*(x,y:float):TPoint2d {.noInit,inline.} let - IDMATRIX2D*:TMatrix2d=matrix2d(1.0,0.0,0.0,1.0,0.0,0.0) + IDMATRIX*:TMatrix2d=matrix2d(1.0,0.0,0.0,1.0,0.0,0.0) ## Quick access to an identity matrix - ORIGO2D*:TPoint2d=Point2d(0.0,0.0) + ORIGO*:TPoint2d=Point2d(0.0,0.0) ## Quick acces to point (0,0) - XAXIS2D*:TVector2d=vector2d(1.0,0.0) + XAXIS*:TVector2d=vector2d(1.0,0.0) ## Quick acces to an 2d x-axis unit vector - YAXIS2D*:TVector2d=vector2d(0.0,1.0) + YAXIS*:TVector2d=vector2d(0.0,1.0) ## Quick acces to an 2d y-axis unit vector @@ -216,7 +212,7 @@ proc mirror*(v:TVector2d):TMatrix2d {.noInit.} = sqd=nd*(sqx-sqy) if nd==inf or nd==neginf: - return IDMATRIX2D #mirroring around a zero vector is arbitrary=>just use identity + return IDMATRIX #mirroring around a zero vector is arbitrary=>just use identity result.setElements( sqd,xy2, @@ -235,7 +231,7 @@ proc mirror*(v:TVector2d,org:TPoint2d):TMatrix2d {.noInit.} = sqd=nd*(sqx-sqy) if nd==inf or nd==neginf: - return IDMATRIX2D #mirroring around a zero vector is arbitrary=>just use identity + return IDMATRIX #mirroring around a zero vector is arbitrary=>just use identity result.setElements( sqd,xy2, @@ -314,7 +310,7 @@ proc `=~`*(m1,m2:TMatrix2d):bool= proc isIdentity*(m:TMatrix2d,tol=1.0e-6):bool= ## Checks is a matrix is approximately an identity matrix, ## using `tol` as tolerance for each element. - return equals(m,IDMATRIX2D,tol) + return equals(m,IDMATRIX,tol) @@ -412,13 +408,9 @@ proc tryNormalize*(v:var TVector2d):bool= if mag==0.0: return false - - let - newx=v.x/mag - newy=v.y/mag - - v.x=newx - v.y=newy + + v.x/=mag + v.y/=mag return true @@ -819,19 +811,23 @@ proc radToDeg*(rad:float):float= ## converts `rad` radians to degrees rad * RAD2DEGCONST - - -proc bisect*(v1,v2:TVector2d):tuple[vec:TVector2d,success:bool]= - ## Computes the bisector between v1 and v2 as a normalize vector `vec` - ## This can fail if any of `v1` or `v2` has zero length, in which - ## case `success` is set to false. - let +proc bisect*(v1,v2:TVector2d):TVector2d {.noInit.}= + ## Computes the bisector between v1 and v2 as a normalize vector + ## If one of the input vectors has zero length, a normalized verison + ## of the other is returned. + ## If both input vectors has zer length, an arbitrary normalize vector + ## is returned. + var vmag1=v1.len vmag2=v2.len - if vmag1==0.0 or vmag2==0.0: - result.success=false - return + # zero length vector equals arbitrary vector, just change to magnitude to one to + # avoid zero division + if vmag1==0.0: + if vmag2==0: #both are zero length return any normalized vector + return XAXIS + vmag1=1.0 + if vmag2==0.0: vmag2=1.0 let x1=v1.x/vmag1 @@ -839,12 +835,13 @@ proc bisect*(v1,v2:TVector2d):tuple[vec:TVector2d,success:bool]= x2=v2.x/vmag2 y2=v2.y/vmag2 + result.x=(x1 + x2) * 0.5 + result.y=(y1 + y2) * 0.5 - result=(vector2d((x1 + x2) * 0.5, (y1 + y2) * 0.5) , true) - - if not result.vec.tryNormalize(): + if not result.tryNormalize(): # This can happen if vectors are colinear. In this special case # there are actually two bisectors, we select just - # one of them (x1,y1 rotated 90 degrees). - result.vec=vector2d(y1,-x1) - + # one of them (x1,y1 rotated 90 degrees ccw). + result.x = -y1 + result.y = x1 + \ No newline at end of file |