public void OperatorOverloadPlus()
{
Vec2D point = new Vec2D( 1f, 2f ) + new Vec2D( 3f, 4f );
Assert.That( point.x, Is.InRange<float>( 4f - EPSILON, 4f + EPSILON ) );
Assert.That( point.y, Is.InRange<float>( 6f - EPSILON, 6f + EPSILON ) );
}
public void ConstructorXZ()
{
Vec2D point = new Vec2D( 1f, 2f );
Assert.That( point.x, Is.EqualTo( 1f ) );
Assert.That( point.y, Is.EqualTo( 2f ) );
}
public void OperatorOverloadMinus()
{
Vec2D point = new Vec2D( 4f, 3f ) - new Vec2D( 1f, 2f );
Assert.That( point.x, Is.InRange<float>( 3f - EPSILON, 3f + EPSILON ) );
Assert.That( point.y, Is.InRange<float>( 1f - EPSILON, 1f + EPSILON ) );
}
public void ConstructorParameterless()
{
Vec2D point = new Vec2D();
Assert.That( point.x, Is.EqualTo( 0f ) );
Assert.That( point.y, Is.EqualTo( 0f ) );
}
public void Length()
{
Vec2D point = new Vec2D( 2, 2 );
float length = point.Length();
float expected = (float)( 2 * Math.Sqrt( 2 ) );
Assert.That( length, Is.InRange<float>( expected - EPSILON, expected + EPSILON ) );
}
public void Distance()
{
Vec2D point1 = new Vec2D( 1, 1 );
Vec2D point2 = new Vec2D( 3, 3 );
float length = point1.Distance( point2 );
float expected = (float)( 2 * Math.Sqrt( 2 ) );
Assert.That( length, Is.InRange<float>( expected - EPSILON, expected + EPSILON ) );
}
/// <summary>
/// Returns a TriangleEnum representing the triangle (within the current slice, either
/// top or bottom, that the point belongs to).
/// </summary>
/// <param name="withinSlice">A point on the x-z cartesian plane, relative to the top-left
/// of the current slice.</param>
/// <param name="parity">The "parity" of the slice, indicating wither the border seaparting
/// the two triangles within the slice goes from top-left to bottom-right (ODD) or
/// bottom-left to top-right (EVEN).</param>
/// <returns>A TriangleEnum representing the triangle (within the current slice, either
/// top or bottom, that the point belongs to).</returns>
private TriangleEnum WhichTriangle(Vec2D withinSlice, ParityEnum parity)
{
float xFraction = withinSlice.x / Slice.x;
float yBorder = 0f;
if (parity == ParityEnum.Even)
{
// When parity is even, the border is bottom-left to top-right.
yBorder = Slice.y * xFraction;
}
else
{
// When parity is odd, the border is top-left to bottom-right.
yBorder = Slice.y * (1f - xFraction);
}
return((withinSlice.y < yBorder) ? TriangleEnum.Top : TriangleEnum.Bottom);
}
PointToCubic(Vec2D point)
{
// This function exhibited one of the nastiest bugs I've ever come across in my career
// thanks to a subtle order or bracketing error resulting in bad order of operations.
//
// The offending line of code:
// float q = ( point.x * ( SQRT_3 - point.y ) * ONE_THIRD ) / HexRadius;
//
// evaluates to:
// float q = ( point.x * ONE_THIRD * SQRT_3 - point.x * point.y * ONE_THIRD ) / HexRadius;
//
// Resulting is a weird distortion on the coordinate space because the x and y
// coordinates of the input point were getting multiplied together in the 2nd term!
//
// The correct version of the code is now implemented below -- after 2 solid days of
// meticulous and demoralizing debugging!!!
float q = (point.x * ONE_THIRD * SQRT_3 - point.y * ONE_THIRD) / HexRadius;
float r = (point.y * TWO_THIRDS) / HexRadius;
return(new FloatAxial(q, r).ToFloatCubic().Round());
}
PointToDirectionInHex(Vec2D point)
{
AxialHexCoord axial = PointToCubic(point).ToAxial();
//AxialHexCoord axial = PointToAxial( point );
Vec2D center = AxialToPoint(axial);
Vec2D topLeft = center - new Vec2D(0.5f * SQRT_3 * HexRadius, HexRadius);
Vec2D fromTopLeft = point - topLeft;
int hSlice = (int)Math.Floor(fromTopLeft.x / Slice.x);
int vSlice = (int)Math.Floor(fromTopLeft.y / Slice.y);
Vec2D withinSlice = new Vec2D(
fromTopLeft.x % Slice.x,
fromTopLeft.y % Slice.y
);
ParityEnum parity = ParityEnum.Even;
if (((hSlice & 1) + (vSlice & 1)) == 1)
{
// One of the two dimensions is odd, otherwise parity is even by default.
parity = ParityEnum.Odd;
}
//
// Debugging output associated with a horrible bug in PointToCubic()
//
//Console.WriteLine( "Point: x: " + point.x + ", y: " + point.y );
//Console.WriteLine( "Axial: q: " + axial.q + ", r: " + axial.r );
//Console.WriteLine( "Center: x: " + center.x + ", y: " + center.y );
//Console.WriteLine( "Top Left: x: " + topLeft.x + ", y: " + topLeft.y );
//Console.WriteLine( "From Top Left: x: " + fromTopLeft.x + ", y: " + fromTopLeft.y );
//Console.WriteLine( "Slice: x: " + Slice.x + ", y: " + Slice.y );
//Console.WriteLine( "Slice Index: x: " + hSlice + ", y: " + vSlice );
//Console.WriteLine( "Within Slice: x: " + withinSlice.x + ", y: " + withinSlice.y );
//Console.WriteLine( "Parity: " + parity );
// Compute and return the triangle by which the point is contained.
bool isInvalid = false;
DirectionEnum direction = DirectionEnum.E;
TriangleEnum triangle = WhichTriangle(withinSlice, parity);
if (hSlice == 0)
{
switch (vSlice)
{
case 0:
if (triangle == TriangleEnum.Bottom)
{
direction = DirectionEnum.NW;
}
else
{
isInvalid = true;
}
break;
case 1:
direction = (triangle == TriangleEnum.Top) ? DirectionEnum.NW : DirectionEnum.W;
break;
case 2:
direction = (triangle == TriangleEnum.Top) ? DirectionEnum.W : DirectionEnum.SW;
break;
case 3:
if (triangle == TriangleEnum.Top)
{
direction = DirectionEnum.SW;
}
else
{
isInvalid = true;
}
break;
default:
isInvalid = true;
break;
}
}
else // hSlice == 1
{
switch (vSlice)
{
case 0:
if (triangle == TriangleEnum.Bottom)
{
direction = DirectionEnum.NE;
}
else
{
isInvalid = true;
}
break;
case 1:
direction = (triangle == TriangleEnum.Top) ? DirectionEnum.NE : DirectionEnum.E;
break;
case 2:
direction = (triangle == TriangleEnum.Top) ? DirectionEnum.E : DirectionEnum.SE;
break;
case 3:
if (triangle == TriangleEnum.Top)
{
direction = DirectionEnum.SE;
}
else
{
isInvalid = true;
}
break;
default:
isInvalid = true;
break;
}
}
//
// Debugging output associated with a horrible bug in PointToCubic()
//
//Console.WriteLine( "Triangle: " + triangle );
//Console.WriteLine( "Direction: " + direction );
//Console.WriteLine( "" );
//Console.WriteLine( "" );
if (isInvalid)
{
throw new InvalidOperationException("This should never happen!");
}
else
{
return(direction);
}
}
/// <summary>
/// Returns the distance from this Vec2D to the given other.
/// </summary>
/// <param name="other">Any other Vec2D.</param>
/// <returns>A float representing the distance from this Vec2D to the given other.
/// </returns>
public float Distance(Vec2D other)
{
return((other - this).Length());
}
/// <summary>
/// Get the hex that contains the given point on the x-z cartesian plane.
/// </summary>
/// <param name="point">A point on the x-y cartesian plane.</param>
/// <returns>A CubicHexCoord representation of the grid position of the hex that the point
/// is contained by.</returns>
public CubicHexCoord PointToCubic( Vec2D point )
{
// This function exhibited one of the nastiest bugs I've ever come across in my career
// thanks to a subtle order or bracketing error resulting in bad order of operations.
//
// The offending line of code:
// float q = ( point.x * ( SQRT_3 - point.y ) * ONE_THIRD ) / HexRadius;
//
// evaluates to:
// float q = ( point.x * ONE_THIRD * SQRT_3 - point.x * point.y * ONE_THIRD ) / HexRadius;
//
// Resulting is a weird distortion on the coordinate space because the x and y
// coordinates of the input point were getting multiplied together in the 2nd term!
//
// The correct version of the code is now implemented below -- after 2 solid days of
// meticulous and demoralizing debugging!!!
float q = ( point.x * ONE_THIRD * SQRT_3 - point.y * ONE_THIRD ) / HexRadius;
float r = ( point.y * TWO_THIRDS ) / HexRadius;
return new FloatAxial( q, r ).ToFloatCubic().Round();
}
public void PointToDirectionInHex()
{
HexGrid grid = new HexGrid( 2f );
Vec2D hexPos = grid.AxialToPoint( new AxialHexCoord( 10, 10 ) );
float offset = 0.5f * grid.HexRadius;
Vec2D[] points = new Vec2D[ 12 ] {
new Vec2D( hexPos.x + offset, hexPos.y + 0f * offset - 0.01f ), // 0a
new Vec2D( hexPos.x + offset, hexPos.y + 0f * offset + 0.01f ), // 0b
new Vec2D( hexPos.x + offset, hexPos.y + 1f * offset - 0.01f ), // 1a
new Vec2D( hexPos.x + offset, hexPos.y + 1f * offset + 0.01f ), // 1b
new Vec2D( hexPos.x - offset, hexPos.y + 1f * offset + 0.01f ), // 2a
new Vec2D( hexPos.x - offset, hexPos.y + 1f * offset - 0.01f ), // 2b
new Vec2D( hexPos.x - offset, hexPos.y + 0f * offset + 0.01f ), // 3a
new Vec2D( hexPos.x - offset, hexPos.y + 0f * offset - 0.01f ), // 3b
new Vec2D( hexPos.x - offset, hexPos.y - 1f * offset + 0.01f ), // 4a
new Vec2D( hexPos.x - offset, hexPos.y - 1f * offset - 0.01f ), // 4b
new Vec2D( hexPos.x + offset, hexPos.y - 1f * offset - 0.01f ), // 5a
new Vec2D( hexPos.x + offset, hexPos.y -1f * offset + 0.01f ) // 5b
};
DirectionEnum[] results = new DirectionEnum[ 12 ];
for ( int i = 0; i < points.Length; i++ )
{
results[ i ] = grid.PointToDirectionInHex( points[ i ] );
}
Assert.That( results, Is.EquivalentTo( new DirectionEnum[ 12 ] {
DirectionEnum.E, // 0a
DirectionEnum.E, // 0b
DirectionEnum.SE, // 1a
DirectionEnum.SE, // 1b
DirectionEnum.SW, // 2a
DirectionEnum.SW, // 2b
DirectionEnum.W, // 3a
DirectionEnum.W, // 3b
DirectionEnum.NW, // 4a
DirectionEnum.NW, // 4b
DirectionEnum.NE, // 5a
DirectionEnum.NE // 5b
} ) );
}
/// <summary>
/// Create a new HexGrid given the radius of all hexes within the grid.
/// </summary>
/// <param name="hexRadius">The distance from the center of any given hex to one of its
/// vertices.</param>
public HexGrid( float hexRadius )
{
__hexRadius = hexRadius;
__slice = new Vec2D( 0.5f * SQRT_3 * HexRadius, 0.5f * HexRadius );
}
/// <summary>
/// Returns a TriangleEnum representing the triangle (within the current slice, either
/// top or bottom, that the point belongs to).
/// </summary>
/// <param name="withinSlice">A point on the x-z cartesian plane, relative to the top-left
/// of the current slice.</param>
/// <param name="parity">The "parity" of the slice, indicating wither the border seaparting
/// the two triangles within the slice goes from top-left to bottom-right (ODD) or
/// bottom-left to top-right (EVEN).</param>
/// <returns>A TriangleEnum representing the triangle (within the current slice, either
/// top or bottom, that the point belongs to).</returns>
private TriangleEnum WhichTriangle( Vec2D withinSlice, ParityEnum parity )
{
float xFraction = withinSlice.x / Slice.x;
float yBorder = 0f;
if ( parity == ParityEnum.Even )
{
// When parity is even, the border is bottom-left to top-right.
yBorder = Slice.y * xFraction;
}
else
{
// When parity is odd, the border is top-left to bottom-right.
yBorder = Slice.y * ( 1f - xFraction );
}
return ( withinSlice.y < yBorder ) ? TriangleEnum.Top : TriangleEnum.Bottom;
}
/// <summary>
/// Returns a DirectionEnum identifying the triangle by which the given point is contained.
/// </summary>
/// <param name="point">A point on the x-y cartesian plane.</param>
/// <returns>A DirectionEnum representing the direction of the triangle that the point is
/// contained by within the hex (relative to the center of the hex).</returns>
public DirectionEnum PointToDirectionInHex( Vec2D point )
{
AxialHexCoord axial = PointToCubic( point ).ToAxial();
//AxialHexCoord axial = PointToAxial( point );
Vec2D center = AxialToPoint( axial );
Vec2D topLeft = center - new Vec2D( 0.5f * SQRT_3 * HexRadius, HexRadius );
Vec2D fromTopLeft = point - topLeft;
int hSlice = (int)Math.Floor( fromTopLeft.x / Slice.x );
int vSlice = (int)Math.Floor( fromTopLeft.y / Slice.y );
Vec2D withinSlice = new Vec2D(
fromTopLeft.x % Slice.x,
fromTopLeft.y % Slice.y
);
ParityEnum parity = ParityEnum.Even;
if ( ( ( hSlice & 1 ) + ( vSlice & 1 ) ) == 1 )
{
// One of the two dimensions is odd, otherwise parity is even by default.
parity = ParityEnum.Odd;
}
//
// Debugging output associated with a horrible bug in PointToCubic()
//
//Console.WriteLine( "Point: x: " + point.x + ", y: " + point.y );
//Console.WriteLine( "Axial: q: " + axial.q + ", r: " + axial.r );
//Console.WriteLine( "Center: x: " + center.x + ", y: " + center.y );
//Console.WriteLine( "Top Left: x: " + topLeft.x + ", y: " + topLeft.y );
//Console.WriteLine( "From Top Left: x: " + fromTopLeft.x + ", y: " + fromTopLeft.y );
//Console.WriteLine( "Slice: x: " + Slice.x + ", y: " + Slice.y );
//Console.WriteLine( "Slice Index: x: " + hSlice + ", y: " + vSlice );
//Console.WriteLine( "Within Slice: x: " + withinSlice.x + ", y: " + withinSlice.y );
//Console.WriteLine( "Parity: " + parity );
// Compute and return the triangle by which the point is contained.
bool isInvalid = false;
DirectionEnum direction = DirectionEnum.E;
TriangleEnum triangle = WhichTriangle( withinSlice, parity );
if ( hSlice == 0 )
{
switch ( vSlice )
{
case 0:
if ( triangle == TriangleEnum.Bottom )
{
direction = DirectionEnum.NW;
}
else
{
isInvalid = true;
}
break;
case 1:
direction = ( triangle == TriangleEnum.Top ) ? DirectionEnum.NW : DirectionEnum.W;
break;
case 2:
direction = ( triangle == TriangleEnum.Top ) ? DirectionEnum.W : DirectionEnum.SW;
break;
case 3:
if ( triangle == TriangleEnum.Top )
{
direction = DirectionEnum.SW;
}
else
{
isInvalid = true;
}
break;
default:
isInvalid = true;
break;
}
}
else // hSlice == 1
{
switch ( vSlice )
{
case 0:
if ( triangle == TriangleEnum.Bottom )
{
direction = DirectionEnum.NE;
}
else
{
isInvalid = true;
}
break;
case 1:
direction = ( triangle == TriangleEnum.Top ) ? DirectionEnum.NE : DirectionEnum.E;
break;
case 2:
direction = ( triangle == TriangleEnum.Top ) ? DirectionEnum.E : DirectionEnum.SE;
break;
case 3:
if ( triangle == TriangleEnum.Top )
{
direction = DirectionEnum.SE;
}
else
{
isInvalid = true;
}
break;
default:
isInvalid = true;
break;
}
}
//
// Debugging output associated with a horrible bug in PointToCubic()
//
//Console.WriteLine( "Triangle: " + triangle );
//Console.WriteLine( "Direction: " + direction );
//Console.WriteLine( "" );
//Console.WriteLine( "" );
if ( isInvalid )
{
throw new InvalidOperationException( "This should never happen!" );
}
else
{
return direction;
}
}
HexGrid(float hexRadius)
{
__hexRadius = hexRadius;
__slice = new Vec2D(0.5f * SQRT_3 * HexRadius, 0.5f * HexRadius);
}
/// <summary>
/// Returns the distance from this Vec2D to the given other.
/// </summary>
/// <param name="other">Any other Vec2D.</param>
/// <returns>A float representing the distance from this Vec2D to the given other.
/// </returns>
public float Distance( Vec2D other )
{
return ( other - this ).Length();
}