Libraries.Game.Collision.BoundingBox2D

This class represents a 2D box that bounds an 2D item. The box approximates the size of the 2D items. The box is defined by two Vector2 objects which represent the maximum and minimum points of the item. This class is used throughout the Collision libraries to monitor collisions. The box is not allowed to rotate, therefore, we call these boxes "axis-aligned bounding boxes".

Example Code

use Libraries.Game.Collision.BoundingBox2D
use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    output "The center of the bounding box is (" + boundingBox:GetCenterX() 
            + ", " + boundingBox:GetCenterY() + ") "

This action re-calculates the center and the dimensions of the BoundingBox2D. This action is used internally. Note that center and dimensions are calculated when minimum and maximum are set.

This action will clear out the values of the BoundingBox2D, resetting all of its values to zero.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum

    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()
    
    boundingBox:Clear()
    
    output "After clearing, the box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

This action combines two given boundingBox to create the bounds of this BoundingBox2D. CalculateDimensions() should be called after this action to get center, width, and height.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

    BoundingBox2D addition
    Vector2 minimum2
    Vector2 maximum2
    minimum:Set(2, 2)
    maximum:Set(0.9, 0.9)
    addition:Set(minimum, maximum)

    output "The second box is centered at (" + addition:GetCenterX() 
        + ", " + addition:GetCenterY() + ") with a width of " 
        +  addition:GetWidth() + " and a height of " + addition:GetHeight()

    BoundingBox2D result
    result:Combine(boundingBox, addition)
    result:CalculateDimensions()

    output "The box, resulting from the combination, is centered at (" + result:GetCenterX() 
        + ", " + result:GetCenterY() + ") with a width of " 
        +  result:GetWidth() + " and a height of " + result:GetHeight()

This action compares two object hash codes and returns an integer. The result is larger if this hash code is larger than the object passed as a parameter, smaller, or equal. In this case, -1 means smaller, 0 means equal, and 1 means larger. This action was changed in Quorum 7 to return an integer, instead of a CompareResult object, because the previous implementation was causing efficiency issues.

Example Code

Object o
        Object t
        integer result = o:Compare(t) //1 (larger), 0 (equal), or -1 (smaller)

This action will test to see if this BoundingBox2D totally contains a given BoundingBox. If any part of the given BoundingBox2D is outside this one, it will return false.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

    BoundingBox2D addition
    Vector2 minimum2
    Vector2 maximum2
    minimum:Set(2, 2)
    maximum:Set(1.5, 1.5)
    addition:Set(minimum, maximum)

    if not boundingBox:Contains(addition)
        boundingBox:Extend(addition)
    end
     
    output "The box, with the addition, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

This action will test to see if the point indicated by the given Vector2 is contained inside this BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

    Vector2 outlier
    outlier:Set(5,2)

    if not boundingBox:Contains(outlier)
        boundingBox:Extend(outlier)
    end
     
    output "The box, with the outlier, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

The Copy action will return a new BoundingBox2D with the same bounds as this BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    BoundingBox2D copy 
    copy:Set(boundingBox:Copy())

This action determines if two objects are equal based on their hash code values.

Example Code

use Libraries.Language.Object
        use Libraries.Language.Types.Text
        Object o
        Text t
        boolean result = o:Equals(t)

This action will extend the BoundingBox2D to contain the point at the given X and Y coordinates.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum

    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()
    
    number outlierX = 5
    number outlierY = 2
    boundingBox:Extend(outlierX, outlierY)

    output "The box, including the outlier, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

This action will extend the BoundingBox2D to contain a circle denoted by a center point and a radius.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

    Vector2 circleCenter
    circleCenter:Set(1, 1)
    number radius = 1.5

    boundingBox:Extend(circleCenter, radius)
     
    output "The box, now also containing the circle, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

This action will extend the BoundingBox2D to contain the provided bounds.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

    Vector2 maximum2
    Vector2 minimum2
    maximum2:Set(2, 2)
    minimum2:Set(1.5, 1.5)
    BoundingBox2D addition
    addition:Set(minimum2, maximum2)

    boundingBox:Extend(addition)
     
    output "The box, with the additional bounds, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

This action will extend the BoundingBox2D to include the given point.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    Vector2 outlier
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()
    
    outlier:Set(5, 2)
    boundingBox:Extend(outlier)

    output "The box, including the outlier, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

GetCenter will return a Vector2 object containing the point at the center of the BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)
    Vector2 center = boundingBox:GetCenter()

    output "The center of the bounding box is (" + center:GetX() 
            + ", " + center:GetY() + ") "

GetCenterX will return the X coordinate of the center of the BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    output "The center of the bounding box is (" + boundingBox:GetCenterX() 
            + ", " + boundingBox:GetCenterY() + ") "

GetCenterY will return the Y coordinate of the center of the BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    output "The center of the bounding box is (" + boundingBox:GetCenterX() 
            + ", " + boundingBox:GetCenterY() + ") "

GetDimensions will return the width and height of the BoundingBox2D stored within a Vector2 object.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)
    Vector2 dimensions = boundingBox:GetDimensions()

    output "The bounding box is " + dimensions:GetX() 
            + " wide by " + dimensions:GetY() + " tall. "

This action gets the hash code for an object.

Example Code

Object o
        integer hash = o:GetHashCode()

GetHeight will return the height of the BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    output "The bounding box is " + boundingBox:GetWidth() 
            + " wide by " + boundingBox:GetHeight() + " tall. "

GetMaximum will return the "maximum" point of the BoundingBox2D. This is specifically the point of the BoundingBox2D with the highest X and Y values. The point will be returned as a Vector2.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    output "The maximum of the bounding box is (" + boundingBox:GetMaximum():GetX() 
            + ", " + boundingBox:GetMaximum():GetY() + ")"

GetMinimum will return the "minimum" point of the BoundingBox2D. This is specifically the point of the BoundingBox2D with the lowest X and Y values. The point will be returned as a Vector2.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    output "The minimum of the bounding box is (" + boundingBox:GetMinimum():GetX() 
            + ", " + boundingBox:GetMinimum():GetY() + ")"

This action returns the perimeter of the BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box has perimeter " + boundingBox:GetPerimeter()

GetWidth will return the width of the BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    output "The bounding box is " + boundingBox:GetWidth() 
            + " wide by " + boundingBox:GetHeight() + " tall. "

This action will test to see if this BoundingBox2D intersects with the given BoundingBox2D.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

    BoundingBox2D addition
    Vector2 minimum2
    Vector2 maximum2
    minimum:Set(2, 2)
    maximum:Set(0.9, 0.9)
    addition:Set(minimum, maximum)

    if boundingBox:Intersects(addition)
        boundingBox:Extend(addition)
    end
     
    output "The box, with the addition, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

This action will invalidate the BoundingBox2D, setting its minimum values to positive infinity and setting its maximum values to negative infinity.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    Vector2 newMaximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()
    
    newMaximum:Set(5, 2)
    
    boundingBox:Invalidate()
    boundingBox:Extend(minimum)
    boundingBox:Extend(newMaximum)
    

    output "The box, with the new maximum, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

This action will return whether or not the BoundingBox2D defines a real, 2-dimensional area. This requires all of the values of the "minimum" point to be less than the values of the "maximum" point.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum

    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    if boundingBox:IsValid()
        output "The box is valid"
    else 
        output "The box is invalid"
    end

    output "Invalidating..."
    boundingBox:Invalidate()
    
    if boundingBox:IsValid()
        output "The box is valid"
    else 
        output "The box is invalid"
    end

The Set action can be provided with a pair of vectors to set the bounds of this BoundingBox2D. The first vector should represent the "minimum" point of the bounds, or the point with the lowest X and Y values. The second vector should represent the "maximum" point of the bounds, or the point with the highest X and Y values. This action will also calculate the center and dimensions of the BoundingBox2D given the maximum and minimum points.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

When provided with a BoundingBox2D as a parameter, the Set action will set the BoundingBox2D to match the bounds of the parameter.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)

    boundingBox:Set(minimum, maximum)

    BoundingBox2D copy 
    copy:Set(boundingBox:Copy())

This action will set the BoundingBox2D to the minimum possible size that contains all of the points in the given array.

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 point1   //the minimum point of the boundingBox
    Vector2 point2   //the maximum point of the boundingBox
    Vector2 outlier  //the outlier in addition to the original boundingBox
    point1:Set(-1, -1)
    point2:Set(1, 1)
    outlier:Set(5, 2)

    Array<Vector2> points
    //you would want to include the minimum and the maximum points of the 
    //original bounding box if you want to add an extra outlier 
    //(another way to do this is to use the Extend(Vector2 point) action)

    //but if you just want to bound a series of points, you just have to insert 
    //the points that you want the box to bound 
    
    points:Add(point1)
    points:Add(point2)
    points:Add(outlier)

    boundingBox:Set(points)

    output "The box, including the outlier, is centered at (" + boundingBox:GetCenterX() 
            + ", " + boundingBox:GetCenterY() + ") with a width of " 
            +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()

This action tests for overlap between the given BoundingBox2D and this BoundingBox2D

Example Code

use Libraries.Game.Collision.BoundingBox2D
    use Libraries.Compute.Vector2
    use Libraries.Containers.Array

    BoundingBox2D boundingBox
    Vector2 minimum
    Vector2 maximum
    minimum:Set(-1, -1)
    maximum:Set(1, 1)
    boundingBox:Set(minimum, maximum)

    output "The box is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and an height of " + boundingBox:GetHeight()

    BoundingBox2D addition
    Vector2 minimum2
    Vector2 maximum2
    minimum:Set(2, 2)
    maximum:Set(0.9, 0.9)
    addition:Set(minimum, maximum)

    if boundingBox:TestOverlap(addition)
        boundingBox:Extend(addition)
    end
     
    output "The box, with the addition, is centered at (" + boundingBox:GetCenterX() 
        + ", " + boundingBox:GetCenterY() + ") with a width of " 
        +  boundingBox:GetWidth() + " and a height of " + boundingBox:GetHeight()