Sunday, March 5, 2017

Monkey-X - Collision - Line vs Oriented Rectangle - code example


' From the book '2d game collision detection'
' line vs oriented rectangle collision


Import mojo

' This is the collision class.
'
Class collision
    ' Collision function
    ' Here the line vs oriented rectangle collision 
    Function line_oriented_rectangle_collide:Bool(    l:line,
                                                    r:orientedrectangle)
        Local lr:rectangle
        lr = New rectangle(    New vector2d(0,0),    
                            multiply_vector(r.halfextend,2))
        
        Local l1:line = New line(    New vector2d(0,0),
                                    New vector2d(0,0))
        l1.base = subtract_vector(l.base,r.center)
        l1.base = rotate_vector(l1.base,-r.rotation)
        l1.base = add_vector(l1.base,r.halfextend)
        l1.direction = rotate_vector(l.direction,-r.rotation)
        
        Return line_rectangle_collide(l1,lr)
    End Function
    ' The rectangle vs Line Collision
    ' needed for line vs oriented rectangle collion
    Function line_rectangle_collide:Bool(l:line,r:rectangle)
        Local n:vector2d = rotate_vector_90(l.direction)
        
        Local dp1:Float,dp2:Float
        Local dp3:Float,dp4:Float
        
        Local c1:vector2d = r.origin
        Local c2:vector2d = add_vector(c1,r.size)
        Local c3:vector2d = New vector2d(c2.x,c1.y)
        Local c4:vector2d = New vector2d(c1.x,c2.y)
        
        c1 = subtract_vector(c1,l.base)
        c2 = subtract_vector(c2,l.base)
        c3 = subtract_vector(c3,l.base)
        c4 = subtract_vector(c4,l.base)                        
        
        dp1 = dot_product(n,c1)
        dp2 = dot_product(n,c2)
        dp3 = dot_product(n,c3)
        dp4 = dot_product(n,c4)
        
        Return     (dp1 * dp2 <= 0) Or
                (dp2 * dp3 <= 0) Or
                (dp3 * dp4 <= 0)
    End Function    
    '
    ' helper functions
    '

    Function dot_product:Float(a:vector2d,b:vector2d)
        Return a.x * b.x + a.y * b.y 
    End Function  
        
    Function rotate_vector_90:vector2d(v:vector2d)
        Local r:vector2d = New vector2d()
        r.x = -v.y
        r.y = v.x
        Return r
    End Function
        
    Function multiply_vector:vector2d(v:vector2d,scalar:Float)
        Local r:vector2d = New vector2d()
        r.x = v.x * scalar
        r.y = v.y * scalar
        Return r
    End Function

    ' Here is the function that rotates a vector. It returns the
    ' new rotated vector.
    '
    Function rotate_vector:vector2d(v:vector2d,degrees:Float)
        Local r:vector2d = New vector2d()
        r.x = v.x * Cos(degrees) - v.y * Sin(degrees)
        r.y = v.x * Sin(degrees) + v.y * Cos(degrees)
        Return r
    End Function  

    Function add_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d(0,0)
        r.x = a.x + b.x
        r.y = a.y + b.y
        Return r
    End Function            

    Function subtract_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d()
        r.x = a.x - b.x
        r.y = a.y - b.y
        Return r
    End Function

End Class

Class vector2d
    ' x and y hold the position of the vector
    Field x:Int,y:Int
    Method New(x:Int,y:Int)
        Self.x = x
        Self.y = y
    End Method
End Class

Class rectangle
    ' origin is a vector that holds the x and y coordinates
    ' of the rectangle
    Field origin:vector2d
    ' size is a vector that holds the x(width) and 
    ' y(height) of the rectangle
    Field size:vector2d
    Method New(origin:vector2d,size:vector2d)
        Self.origin = origin
        Self.size = size
    End Method
    Method draw()
        ' x1,y1,w,h are used to hold the rectangle
        ' location and size.
        Local x1:Int=origin.x
        Local y1:Int=origin.y
        Local w:Int=size.x
        Local h:Int=size.y
        DrawRect x1,y1,w,h
    End Method
End Class

Class line
    ' base is a vector which holds the origin
    ' of the line
    Field base:vector2d
    Field direction:vector2d
    Method New(base:vector2d,direction:vector2d)
        Self.base = base
        Self.direction = direction
    End Method
    Method draw()
        DrawLine base.x,base.y,direction.x,direction.y
    End Method    
End Class

Class orientedrectangle
    Field center:vector2d
    Field halfextend:vector2d
    Field rotation:Float
    Method New(center:vector2d,halfextend:vector2d,rotation:Float)
        Self.center = center
        Self.halfextend = halfextend
        Self.rotation = rotation
    End Method
    Method draw()
        Local v1:vector2d,v2:vector2d,v3:vector2d,v4:vector2d
        'topside
        v1 = New vector2d(-halfextend.x,-halfextend.y)
        v2 = New vector2d(halfextend.x,-halfextend.y)
        v1 = rotate_vector(v1,rotation)
        v2 = rotate_vector(v2,rotation)
        v1.x += center.x
        v1.y += center.y
        v2.x += center.x
        v2.y += center.y
        ' rightside
        v3 = New vector2d(halfextend.x,halfextend.y)
        v3 = rotate_vector(v3,rotation)
        v3.x += center.x
        v3.y += center.y
        ' bottom side
        v4 = New vector2d(-halfextend.x,halfextend.y)
        v4 = rotate_vector(v4,rotation)
        v4.x += center.x
        v4.y += center.y
        DrawLine v1.x,v1.y,v2.x,v2.y
        DrawLine v2.x,v2.y,v3.x,v3.y
        DrawLine v3.x,v3.y,v4.x,v4.y
        DrawLine v4.x,v4.y,v1.x,v1.y
    End Method    
    Function rotate_vector:vector2d(v:vector2d,degrees:Float)
        Local r:vector2d = New vector2d()
           r.x = v.x * Cos(degrees) - v.y * Sin(degrees)
            r.y = v.x * Sin(degrees) + v.y * Cos(degrees)
        Return r
    End Function    
End Class



' col is the caller of the class collision. 
' we use it to use the collision methods.
Global col:collision = New collision

Class MyGame Extends App
    Field angle:Float=0
    Method OnCreate()
        SetUpdateRate(60)
    End Method
    Method OnUpdate()
        angle+=1
        If angle > 360 Then angle=0
    End Method
    Method OnRender()
        Cls 0,0,0
        SetColor 255,255,255

        'set up the line
        Local line1:line = New line(    New vector2d(0,0),
                                        New vector2d(MouseX,MouseY))
        'set up the oriented rectangle (base, halfextend(size),angle)
        Local orect1:orientedrectangle
        orect1 = New orientedrectangle(    New vector2d(320,200),
                                        New vector2d(100,50),
                                        angle)

        ' Here we test for collision
        If col.line_oriented_rectangle_collide(line1,orect1)
            DrawText "Line vs Oriented Rectangle Collision",0,0
        Else
            DrawText "Line vs Oriented Rectangle NO Collision",0,0
        End If

        ' Here we draw the line and oriented
        ' rectangle.
        line1.draw
        orect1.draw
        
        DrawText "Move the Mouse to test for Collision",DeviceWidth/2,0
        
    End Method
End Class

Function Main()
    New MyGame()
End Function

Monkey-X - Collision - Line vs Line Segment - code example


' From the book '2d game collision detection'
' line vs line segment collision

#rem
If a line collides with a segment you only need to know
if the segments end points lie on the same side 
of the line. If they do then a collision is
impossible.
#end

Import mojo

' This is the collision class.
'
Class collision
    ' Collision function
    Function line_segment_collide:Bool(l:line,s:segment)
        Return Not on_one_side(l,s)
    End Function    

    '
    ' helper functions
    '
    Function on_one_side:Bool(axis:line,s:segment)
        Local d1:vector2d = subtract_vector(s.point1,axis.base)
        Local d2:vector2d = subtract_vector(s.point2,axis.base)
        Local n:vector2d = rotate_vector_90(axis.direction)
        Return dot_product(n,d1) * dot_product(n,d2) > 0
    End Function

    Function subtract_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d()
        r.x = a.x - b.x
        r.y = a.y - b.y
        Return r
    End Function

    Function dot_product:Float(a:vector2d,b:vector2d)
        Return a.x * b.x + a.y * b.y 
    End Function

    Function rotate_vector_90:vector2d(v:vector2d)
        Local r:vector2d = New vector2d()
        r.x = -v.y
        r.y = v.x
        Return r
    End Function

End Class

Class vector2d
    ' x and y hold the position of the vector
    Field x:Int,y:Int
    Method New(x:Int,y:Int)
        Self.x = x
        Self.y = y
    End Method
End Class

Class line
    ' base is a vector which holds the origin
    ' of the line
    Field base:vector2d
    Field direction:vector2d
    Method New(base:vector2d,direction:vector2d)
        Self.base = base
        Self.direction = direction
    End Method
    Method draw()
        DrawLine base.x,base.y,direction.x,direction.y
    End Method    
End Class

Class segment
    ' point1 and point2 are two vectors.
    ' A vector has a x and y coordinate.
    Field point1:vector2d
    Field point2:vector2d
    Method New(point1:vector2d,point2:vector2d)
        Self.point1 = point1
        Self.point2 = point2
    End Method
    Method draw()
        DrawLine point1.x,point1.y,point2.x,point2.y
    End Method
End Class



' col is the caller of the class collision. 
' we use it to use the collision methods.
Global col:collision = New collision

Class MyGame Extends App
    Method OnCreate()
        SetUpdateRate(60)
    End Method
    Method OnUpdate()
    End Method
    Method OnRender()
        Cls 0,0,0
        SetColor 255,255,255

        Local line1:line = New line(    New vector2d(0,0),
                                        New vector2d(MouseX,MouseY))
        Local segline1:segment = New segment(    New vector2d(100,200),
                                                New vector2d(400,100))

        ' Here we test for collision
        If col.line_segment_collide(line1,segline1)
            DrawText "Line vs Line Segment Collision",0,0
        Else
            DrawText "Line vs Line Segment NO Collision",0,0
        End If

        line1.draw
        segline1.draw
        
        DrawText "Move the Mouse to test for Collision",DeviceWidth/2,0
        
    End Method
End Class

Function Main()
    New MyGame()
End Function

Monkey -X - Collision - Point vs Oriented Rectangle - code example


' From the book '2d game collision detection'
' point vs oriented rectangle collision

Import mojo

' This is the collision class.
'
Class collision
    ' Collision function
    ' The point vs oriented rectangle collision
    Function oriented_rectangle_point_collide:Bool(    r:orientedrectangle,
                                                    p:vector2d)
        Local lr:rectangle
        lr = New rectangle(    New vector2d(0,0),
                            multiply_vector(r.halfextend,2))        
        Local lp:vector2d = subtract_vector(p,r.center)
        lp = rotate_vector(lp,-r.rotation)
        lp = add_vector(lp,r.halfextend)
        
        Return point_rectangle_collide(lp,lr) 
    End Function                                                    

    ' The point vs rectangle Collision
    ' needed for point in oriented rectangle collision
    Function point_rectangle_collide:Bool(p:vector2d,r:rectangle)
        Local left:Float = r.origin.x
        Local right:Float = left + r.size.x
        Local bottom:Float = r.origin.y
        Local top:Float = bottom + r.size.y        
        Return     left <= p.x And
                bottom <= p.y And
                p.x <= right And
                p.y <= top    
    End Function
    '
    ' helper functions
    '
    Function multiply_vector:vector2d(v:vector2d,scalar:Float)
        Local r:vector2d = New vector2d()
        r.x = v.x * scalar
        r.y = v.y * scalar
        Return r
    End Function

    Function subtract_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d()
        r.x = a.x - b.x
        r.y = a.y - b.y
        Return r
    End Function

    ' Here is the function that rotates a vector. It returns the
    ' new rotated vector.
    '
    Function rotate_vector:vector2d(v:vector2d,degrees:Float)
        Local r:vector2d = New vector2d()
        r.x = v.x * Cos(degrees) - v.y * Sin(degrees)
        r.y = v.x * Sin(degrees) + v.y * Cos(degrees)
        Return r
    End Function

    Function add_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d(0,0)
        r.x = a.x + b.x
        r.y = a.y + b.y
        Return r
    End Function   
        
End Class

Class vector2d
    ' x and y hold the position of the vector
    Field x:Int,y:Int
    Method New(x:Int,y:Int)
        Self.x = x
        Self.y = y
    End Method
End Class

Class rectangle
    ' origin is a vector that holds the x and y coordinates
    ' of the rectangle
    Field origin:vector2d
    ' size is a vector that holds the x(width) and 
    ' y(height) of the rectangle
    Field size:vector2d
    Method New(origin:vector2d,size:vector2d)
        Self.origin = origin
        Self.size = size
    End Method
    Method draw()
        ' x1,y1,w,h are used to hold the rectangle
        ' location and size.
        Local x1:Int=origin.x
        Local y1:Int=origin.y
        Local w:Int=size.x
        Local h:Int=size.y
        DrawRect x1,y1,w,h
    End Method
End Class

Class orientedrectangle
    Field center:vector2d
    Field halfextend:vector2d
    Field rotation:Float
    Method New(center:vector2d,halfextend:vector2d,rotation:Float)
        Self.center = center
        Self.halfextend = halfextend
        Self.rotation = rotation
    End Method
    Method draw()
        Local v1:vector2d,v2:vector2d,v3:vector2d,v4:vector2d
        'topside
        v1 = New vector2d(-halfextend.x,-halfextend.y)
        v2 = New vector2d(halfextend.x,-halfextend.y)
        v1 = rotate_vector(v1,rotation)
        v2 = rotate_vector(v2,rotation)
        v1.x += center.x
        v1.y += center.y
        v2.x += center.x
        v2.y += center.y
        ' rightside
        v3 = New vector2d(halfextend.x,halfextend.y)
        v3 = rotate_vector(v3,rotation)
        v3.x += center.x
        v3.y += center.y
        ' bottom side
        v4 = New vector2d(-halfextend.x,halfextend.y)
        v4 = rotate_vector(v4,rotation)
        v4.x += center.x
        v4.y += center.y
        DrawLine v1.x,v1.y,v2.x,v2.y
        DrawLine v2.x,v2.y,v3.x,v3.y
        DrawLine v3.x,v3.y,v4.x,v4.y
        DrawLine v4.x,v4.y,v1.x,v1.y
    End Method    
    Function rotate_vector:vector2d(v:vector2d,degrees:Float)
        Local r:vector2d = New vector2d()
           r.x = v.x * Cos(degrees) - v.y * Sin(degrees)
            r.y = v.x * Sin(degrees) + v.y * Cos(degrees)
        Return r
    End Function    
End Class


' col is the caller of the class collision. 
' we use it to use the collision methods.
Global col:collision = New collision

Class MyGame Extends App
    ' This variable we use to rotate
    ' the oriented rectangle.
    Field angle:Float=0
    Method OnCreate()
        SetUpdateRate(60)
    End Method
    Method OnUpdate()
        angle+=1
        If angle>359 Then angle = 0
    End Method
    Method OnRender()
        Cls 0,0,0
        SetColor 255,255,255

        Local center:vector2d = New vector2d(320,200)
        Local halfdivide:vector2d = New vector2d(100,50)
        Local orect1:orientedrectangle = New orientedrectangle(    center,
                                                                halfdivide,
                                                                angle)
    
        ' Here we create a vector with the mouse it's coordinates.
        ' We use this point to test collsion with the orect.
        Local point:vector2d = New vector2d(MouseX,MouseY)        

        ' Here we test for collision
        If col.oriented_rectangle_point_collide(    orect1,
                                                    point)
            DrawText "Point vs Oriented Rect Collision",0,0
        Else
            DrawText "Point vs Oriented Rect NO Collision",0,0
        End If
                    
        orect1.draw
    
        DrawText "Move the Mouse to test for Collision",DeviceWidth/2,0
        
    End Method
End Class

Function Main()
    New MyGame()
End Function

Saturday, March 4, 2017

Monkey-X - Collision - Rectangle vs Line Segment - code example


' From the book '2d game collision detection'
' rectangle vs Line segment collision

Import mojo

' This is the collision class.
'
Class collision
    ' Collision function
    ' Rectangle vs Line Segment Function
    Function rectangle_segment_collide:Bool(r:rectangle,s:segment)
        ' First we test the line vs rectangle collision
        Local sline:line = New line()
        sline.base = s.point1
        sline.direction = subtract_vector(    s.point2,
                                            s.point1)        
        If (Not line_rectangle_collide(sline,r)) Then
            Return False
        End If
        
        ' Here we test the ranges of the line
        ' with the rectangle
        
        Local rrange:range = New range()
        Local srange:range = New range()
        rrange.minimum = r.origin.x
        rrange.maximum = r.origin.x + r.size.x
        srange.minimum = s.point1.x
        srange.maximum = s.point2.x
        srange = sort_range(srange)
        If(Not overlapping_ranges(rrange,srange)) Then
            Return False
        End If

        rrange.minimum = r.origin.y
        rrange.maximum = r.origin.y + r.size.y
        srange.minimum = s.point1.y
        srange.maximum = s.point2.y
        srange = sort_range(srange)
        Return overlapping_ranges(rrange,srange)
                
    End Function
    
    ' The rectangle vs Line Collision
    ' needed for rectangle vs line segment
    Function line_rectangle_collide:Bool(l:line,r:rectangle)
        Local n:vector2d = rotate_vector_90(l.direction)
        
        Local dp1:Float,dp2:Float
        Local dp3:Float,dp4:Float
        
        Local c1:vector2d = r.origin
        Local c2:vector2d = add_vector(c1,r.size)
        Local c3:vector2d = New vector2d(c2.x,c1.y)
        Local c4:vector2d = New vector2d(c1.x,c2.y)
        
        c1 = subtract_vector(c1,l.base)
        c2 = subtract_vector(c2,l.base)
        c3 = subtract_vector(c3,l.base)
        c4 = subtract_vector(c4,l.base)                        
        
        dp1 = dot_product(n,c1)
        dp2 = dot_product(n,c2)
        dp3 = dot_product(n,c3)
        dp4 = dot_product(n,c4)
        
        Return     (dp1 * dp2 <= 0) Or
                (dp2 * dp3 <= 0) Or
                (dp3 * dp4 <= 0)
    End Function

    '
    ' helper functions
    '
    Function sort_range:range(r:range)
        Local sorted:range = r
        If (r.minimum > r.maximum)
            sorted.minimum = r.maximum
            sorted.maximum = r.minimum
        End If
        Return sorted
    End Function    

    Function overlapping_ranges:Bool(a:range,b:range)
        Return overlapping(    a.minimum,
                            a.maximum,
                            b.minimum,
                            b.maximum)
    End Function

    Function overlapping:Bool(mina:Float,maxa:Float,minb:Float,maxb:Float)
        Return minb <= maxa And mina <= maxb
    End Function  
    
    Function rotate_vector_90:vector2d(v:vector2d)
        Local r:vector2d = New vector2d()
        r.x = -v.y
        r.y = v.x
        Return r
    End Function

    Function add_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d(0,0)
        r.x = a.x + b.x
        r.y = a.y + b.y
        Return r
    End Function  

    Function subtract_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d()
        r.x = a.x - b.x
        r.y = a.y - b.y
        Return r
    End Function

    Function dot_product:Float(a:vector2d,b:vector2d)
        Return a.x * b.x + a.y * b.y 
    End Function    
            
End Class

Class vector2d
    ' x and y hold the position of the vector
    Field x:Int,y:Int
    Method New(x:Int,y:Int)
        Self.x = x
        Self.y = y
    End Method
End Class

Class line
    Field base:vector2d
    Field direction:vector2d
    Method New(base:vector2d,direction:vector2d)
        Self.base = base
        Self.direction = direction
    End Method
    Method draw()
        DrawLine base.x,base.y,direction.x,direction.y
    End Method
End Class

Class rectangle
    ' origin is a vector that holds the x and y coordinates
    ' of the rectangle
    Field origin:vector2d
    ' size is a vector that holds the x(width) and 
    ' y(height) of the rectangle
    Field size:vector2d
    Method New(origin:vector2d,size:vector2d)
        Self.origin = origin
        Self.size = size
    End Method
    Method draw()
        ' x1,y1,w,h are used to hold the rectangle
        ' location and size.
        Local x1:Int=origin.x
        Local y1:Int=origin.y
        Local w:Int=size.x
        Local h:Int=size.y
        DrawRect x1,y1,w,h
    End Method
End Class

Class range
    Field minimum:Float
    Field maximum:Float
    Method New(minimum:Float,maximum:Float)
        Self.minimum = minimum
        Self.maximum = maximum
    End Method
End Class

Class segment
    ' point1 and point2 are two vectors.
    ' A vector has a x and y coordinate.
    Field point1:vector2d
    Field point2:vector2d
    Method New(point1:vector2d,point2:vector2d)
        Self.point1 = point1
        Self.point2 = point2
    End Method
    Method draw()
        DrawLine point1.x,point1.y,point2.x,point2.y
    End Method
End Class

' col is the caller of the class collision. 
' we use it to use the collision methods.
Global col:collision = New collision

Class MyGame Extends App
    Field angle:Float
    Method OnCreate()
        SetUpdateRate(30)
    End Method
    Method OnUpdate()
        angle+=1
        If angle > 360 Then angle = 0  
    End Method
    Method OnRender()
        Cls 0,0,0 
        SetColor 255,255,255
        
        ' this is a line segment setup
        Local point1:vector2d = New vector2d(MouseX,MouseY)
        Local point2:vector2d = New vector2d(MouseX+100,MouseY+100)
        ' ls is short for line segment
        Local ls:segment = New segment(point1,point2)
        '
        ' This is the rectangle
        Local origin:vector2d = New vector2d(320,200)
        Local size:vector2d = New vector2d(100,50)
        Local rect1:rectangle = New rectangle(origin,size)

        ' Here we test for collision
        If col.rectangle_segment_collide(rect1,ls)
            DrawText "Rectangle vs Line Segment Collision",0,0
        Else
            DrawText "Rectangle vs Line Segment NO Collision",0,0
        End If

        ' Here we draw the line and rectangle
        ls.draw
        rect1.draw
                        
        DrawText "Move the Mouse to test for Collision",DeviceWidth/2,0
        
    End Method
End Class

Function Main()
    New MyGame()
End Function

Monkey-X - Collision - Rectangle vs Line - code example


' From the book '2d game collision detection'
' rectangle vs Line collision

Import mojo

' This is the collision class.
'
Class collision
    ' Collision function
    ' The rectangle vs Line Collision
    Function line_rectangle_collide:Bool(l:line,r:rectangle)
        Local n:vector2d = rotate_vector_90(l.direction)
        
        Local dp1:Float,dp2:Float
        Local dp3:Float,dp4:Float
        
        Local c1:vector2d = r.origin
        Local c2:vector2d = add_vector(c1,r.size)
        Local c3:vector2d = New vector2d(c2.x,c1.y)
        Local c4:vector2d = New vector2d(c1.x,c2.y)
        
        c1 = subtract_vector(c1,l.base)
        c2 = subtract_vector(c2,l.base)
        c3 = subtract_vector(c3,l.base)
        c4 = subtract_vector(c4,l.base)                        
        
        dp1 = dot_product(n,c1)
        dp2 = dot_product(n,c2)
        dp3 = dot_product(n,c3)
        dp4 = dot_product(n,c4)
        
        Return     (dp1 * dp2 <= 0) Or
                (dp2 * dp3 <= 0) Or
                (dp3 * dp4 <= 0)
    End Function

    '
    ' helper functions
    '
    Function rotate_vector_90:vector2d(v:vector2d)
        Local r:vector2d = New vector2d()
        r.x = -v.y
        r.y = v.x
        Return r
    End Function

    Function add_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d(0,0)
        r.x = a.x + b.x
        r.y = a.y + b.y
        Return r
    End Function  

    Function subtract_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d()
        r.x = a.x - b.x
        r.y = a.y - b.y
        Return r
    End Function

    Function dot_product:Float(a:vector2d,b:vector2d)
        Return a.x * b.x + a.y * b.y 
    End Function    
            
End Class

Class vector2d
    ' x and y hold the position of the vector
    Field x:Int,y:Int
    Method New(x:Int,y:Int)
        Self.x = x
        Self.y = y
    End Method
End Class

Class line
    Field base:vector2d
    Field direction:vector2d
    Method New(base:vector2d,direction:vector2d)
        Self.base = base
        Self.direction = direction
    End Method
    Method draw()
        DrawLine base.x,base.y,direction.x,direction.y
    End Method
End Class

Class rectangle
    ' origin is a vector that holds the x and y coordinates
    ' of the rectangle
    Field origin:vector2d
    ' size is a vector that holds the x(width) and 
    ' y(height) of the rectangle
    Field size:vector2d
    Method New(origin:vector2d,size:vector2d)
        Self.origin = origin
        Self.size = size
    End Method
    Method draw()
        ' x1,y1,w,h are used to hold the rectangle
        ' location and size.
        Local x1:Int=origin.x
        Local y1:Int=origin.y
        Local w:Int=size.x
        Local h:Int=size.y
        DrawRect x1,y1,w,h
    End Method
End Class


' col is the caller of the class collision. 
' we use it to use the collision methods.
Global col:collision = New collision

Class MyGame Extends App
    Field angle:Float
    Method OnCreate()
        SetUpdateRate(30)
    End Method
    Method OnUpdate()
        angle+=1
        If angle > 360 Then angle = 0  
    End Method
    Method OnRender()
        Cls 0,0,0 
        SetColor 255,255,255
        
        ' this is a line setup
        Local base:vector2d = New vector2d(0,0)
        Local direction:vector2d = New vector2d(MouseX,MouseY)
        Local line1:line = New line(base,direction)
        '
        ' This is the rectangle
        Local origin:vector2d = New vector2d(320,200)
        Local size:vector2d = New vector2d(100,100)
        Local rect1:rectangle = New rectangle(origin,size)

        ' Here we test for collision
        If col.line_rectangle_collide(line1,rect1)
            DrawText "Line vs Rectangle Collision",0,0
        Else
            DrawText "Line vs Rectangle NO Collision",0,0
        End If
        
        ' Here we draw the line and rectangle
        line1.draw
        rect1.draw
                        
        DrawText "Move the Mouse to test for Collision",DeviceWidth/2,0
        DrawText "Info : Lines are infinite in length.",DeviceWidth/2,20
        
    End Method
End Class

Function Main()
    New MyGame()
End Function

Monkey-X - Collision - Point vs Rectangle - code example


' From the book '2d game collision detection'
' point vs rectangle collision

Import mojo

' This is the collision class.
'
Class collision
    ' Collision function
    ' The point vs rectangle Collision
    Function point_rectangle_collide:Bool(p:vector2d,r:rectangle)
        Local left:Float = r.origin.x
        Local right:Float = left + r.size.x
        Local bottom:Float = r.origin.y
        Local top:Float = bottom + r.size.y        
        Return     left <= p.x And
                bottom <= p.y And
                p.x <= right And
                p.y <= top    
    End Function
End Class

Class vector2d
    ' x and y hold the position of the vector
    Field x:Int,y:Int
    Method New(x:Int,y:Int)
        Self.x = x
        Self.y = y
    End Method
End Class

Class rectangle
    ' origin is a vector that holds the x and y coordinates
    ' of the rectangle
    Field origin:vector2d
    ' size is a vector that holds the x(width) and 
    ' y(height) of the rectangle
    Field size:vector2d
    Method New(origin:vector2d,size:vector2d)
        Self.origin = origin
        Self.size = size
    End Method
    Method draw()
        ' x1,y1,w,h are used to hold the rectangle
        ' location and size.
        Local x1:Int=origin.x
        Local y1:Int=origin.y
        Local w:Int=size.x
        Local h:Int=size.y
        DrawRect x1,y1,w,h
    End Method
End Class


' col is the caller of the class collision. 
' we use it to use the collision methods.
Global col:collision = New collision

Class MyGame Extends App
    Field angle:Float
    Method OnCreate()
        SetUpdateRate(30)
    End Method
    Method OnUpdate()
        angle+=1
        If angle > 360 Then angle = 0  
    End Method
    Method OnRender()
        Cls 0,0,0 
        SetColor 255,255,255
        
        ' this is a point(vector) with the mouse coordinates
        Local point:vector2d = New vector2d(MouseX,MouseY)
        '
        ' This is the rectangle
        Local origin:vector2d = New vector2d(320,200)
        Local size:vector2d = New vector2d(100,100)
        Local rect1:rectangle = New rectangle(origin,size)

        ' Here we test for collision
        If col.point_rectangle_collide(point,rect1)
            DrawText "Point vs Rectangle Collision",0,0
        Else
            DrawText "Point vs Rectangle NO Collision",0,0
        End If
        
        rect1.draw
                        
        DrawText "Move the Mouse to test for Collision",DeviceWidth/2,0
        
    End Method
End Class

Function Main()
    New MyGame()
End Function

Monkey-X - Collision - Circle vs Oriented Rectangle - code example


' From the book '2d game collision detection'
' circle vs oriented rectangle collision

Import mojo

' This is the collision class.
'
Class collision
    ' Collision function
    ' the circle vs oriented rectangle collision
    
    Function circle_oriented_rectangle_collide:Bool(c:circle,
                                                    r:orientedrectangle)
        Local origin:vector2d = New vector2d(0,0)
        Local size:vector2d = New vector2d(0,0)
        Local lr:rectangle = New rectangle(origin,size)
        
        lr.size = multiply_vector(r.halfextend,2)
        
        Local center:vector2d = New vector2d(0,0)         
        Local lc:circle = New circle(center,c.radius)
        Local distance:vector2d = subtract_vector(c.center,r.center)
        distance = rotate_vector(distance,-r.rotation)
        lc.center = add_vector(distance,r.halfextend)
        
        Return circle_rectangle_collide(lc,lr)
        
    End Function
    
    ' needed for circle vs oriented rectangle collision
    Function circle_rectangle_collide:Bool(c:circle,r:rectangle)
        Local clamped:vector2d = clamp_on_rectangle(c.center,r)
        Return circle_point_collide(c,clamped)
    End Function

    ' Needed for circle_segment_collide
    Function circle_point_collide:Bool(c:circle,p:vector2d)
        Local distance:vector2d = subtract_vector(c.center,p)
        Return vector_length(distance) <= c.radius
    End Function

    ' Helper Functions ........
    '
    '
    Function multiply_vector:vector2d(v:vector2d,scalar:Float)
        Local r:vector2d = New vector2d()
        r.x = v.x * scalar
        r.y = v.y * scalar
        Return r
    End Function

    Function clamp_on_rectangle:vector2d(p:vector2d,r:rectangle)
        Local clamp:vector2d = New vector2d()
        clamp.x = Clamp(p.x,r.origin.x,r.origin.x+r.size.x)
        clamp.y = Clamp(p.y,r.origin.y,r.origin.y+r.size.y)
        Return clamp
    End Function
    
    Function vector_length:Float(v:vector2d)
        Return Sqrt(v.x * v.x + v.y * v.y)
    End Function

    Function subtract_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d()
        r.x = a.x - b.x
        r.y = a.y - b.y
        Return r
    End Function

    Function add_vector:vector2d(a:vector2d,b:vector2d)
        Local r:vector2d = New vector2d(0,0)
        r.x = a.x + b.x
        r.y = a.y + b.y
        Return r
    End Function   

    ' Here is the function that rotates a vector. It returns the
    ' new rotated vector.
    '
    Function rotate_vector:vector2d(v:vector2d,degrees:Float)
        Local r:vector2d = New vector2d()
        r.x = v.x * Cos(degrees) - v.y * Sin(degrees)
        r.y = v.x * Sin(degrees) + v.y * Cos(degrees)
        Return r
    End Function

End Class

Class vector2d
    ' x and y hold the position of the vector
    Field x:Int,y:Int
    Method New(x:Int,y:Int)
        Self.x = x
        Self.y = y
    End Method
End Class

Class rectangle
    ' origin is a vector that holds the x and y coordinates
    ' of the rectangle
    Field origin:vector2d
    ' size is a vector that holds the x(width) and 
    ' y(height) of the rectangle
    Field size:vector2d
    Method New(origin:vector2d,size:vector2d)
        Self.origin = origin
        Self.size = size
    End Method
    Method draw()
        ' x1,y1,w,h are used to hold the rectangle
        ' location and size.
        Local x1:Int=origin.x
        Local y1:Int=origin.y
        Local w:Int=size.x
        Local h:Int=size.y
        DrawRect x1,y1,w,h
    End Method
End Class

Class circle
    Field center:vector2d
    Field radius:Float
    Method New(center:vector2d,radius:Float)
        Self.center = center
        Self.radius = radius
    End Method
    Method draw()
        DrawCircle center.x,center.y,radius
    End Method
End Class

Class orientedrectangle
    Field center:vector2d
    Field halfextend:vector2d

    Field rotation:Float
    Method New(center:vector2d,halfextend:vector2d,rotation:Float)
        Self.center = center
        Self.halfextend = halfextend
        Self.rotation = rotation
    End Method
    Method draw()
        Local v1:vector2d,v2:vector2d,v3:vector2d,v4:vector2d
        'topside
        v1 = New vector2d(-halfextend.x,-halfextend.y)
        v2 = New vector2d(halfextend.x,-halfextend.y)
        v1 = rotate_vector(v1,rotation)
        v2 = rotate_vector(v2,rotation)
        v1.x += center.x
        v1.y += center.y
        v2.x += center.x
        v2.y += center.y
        ' rightside
        v3 = New vector2d(halfextend.x,halfextend.y)
        v3 = rotate_vector(v3,rotation)
        v3.x += center.x
        v3.y += center.y
        ' bottom side
        v4 = New vector2d(-halfextend.x,halfextend.y)
        v4 = rotate_vector(v4,rotation)
        v4.x += center.x
        v4.y += center.y
        DrawLine v1.x,v1.y,v2.x,v2.y
        DrawLine v2.x,v2.y,v3.x,v3.y
        DrawLine v3.x,v3.y,v4.x,v4.y
        DrawLine v4.x,v4.y,v1.x,v1.y
    End Method    
    Function rotate_vector:vector2d(v:vector2d,degrees:Float)
        Local r:vector2d = New vector2d()
           r.x = v.x * Cos(degrees) - v.y * Sin(degrees)
            r.y = v.x * Sin(degrees) + v.y * Cos(degrees)
        Return r
    End Function    
End Class

' col is the caller of the class collision. 
' we use it to use the collision methods.
Global col:collision = New collision

Class MyGame Extends App
    Field angle:Float
    Method OnCreate()
        SetUpdateRate(30)
    End Method
    Method OnUpdate()
        angle+=1
        If angle > 360 Then angle = 0  
    End Method
    Method OnRender()
        Cls 0,0,0 
        SetColor 255,255,255
        
        ' Here we set up the circle where we test
        ' the collision with
        Local cc:vector2d = New vector2d(320,200)
        Local r:Float = 50
        Local circle1:circle = New circle(cc,r)
        ' Here we set up the oriented rectangle
        Local orc:vector2d = New vector2d(MouseX,MouseY)
        Local ors:vector2d = New vector2d(100,50) 'size of the oriented rectangle
        Local orect:orientedrectangle = New orientedrectangle(orc,ors,angle)
        
        ' Collision test
        If col.circle_oriented_rectangle_collide(circle1,orect)
            DrawText "Circle vs Oriented rect Collide",0,0
        Else
            DrawText "Circle vs Oriented rect NO Collision",0,0
        End If
        
        orect.draw
        circle1.draw
        
        DrawText "Move the Mouse to test for Collision",DeviceWidth/2,0
        
    End Method
End Class

Function Main()
    New MyGame()
End Function