public static bool TestPolygonVsPolygon(Polygon polygon1, Polygon polygon2, out ShapeCollision shapeCollision, bool flip = false)
{
if (!CheckPolygons(polygon1, polygon2, out ShapeCollision tmp1, flip) ||
!CheckPolygons(polygon2, polygon1, out ShapeCollision tmp2, flip))
{
shapeCollision = new ShapeCollision();
return(false);
}
ShapeCollision result;
ShapeCollision other;
if (System.Math.Abs(tmp1.Overlap) < System.Math.Abs(tmp2.Overlap))
{
result = tmp1;
other = tmp2;
}
else
{
result = tmp2;
other = tmp1;
}
result.OtherOverlap = other.Overlap;
result.Separation = other.Separation;
result.Normal = other.Normal;
shapeCollision = result;
return(true);
} //testPolygonVsPolygon
public override void Draw(SpriteBatch spriteBatch, GameTime gameTime)
{
if (SelectedGameObjects.Count > 0)
{
foreach (var selectedGameObject in SelectedGameObjects)
{
if (SimulationGame.VisibleArea.Contains(selectedGameObject.Position))
{
var worldDrawPosition = Rectangle.Empty;
if (selectedGameObject is AmbientObject)
{
var gameObject = (AmbientObject)selectedGameObject;
worldDrawPosition = new Rectangle((int)(gameObject.Position.X - gameObject.GetObjectType().SpriteOrigin.X), (int)(gameObject.Position.Y - gameObject.GetObjectType().SpriteOrigin.Y), gameObject.GetObjectType().SpriteBounds.X, gameObject.GetObjectType().SpriteBounds.Y);
}
else if (selectedGameObject is AmbientHitableObject)
{
var gameObject = (AmbientHitableObject)selectedGameObject;
worldDrawPosition = new Rectangle((int)(gameObject.Position.X - gameObject.GetObjectType().SpriteOrigin.X), (int)(gameObject.Position.Y - gameObject.GetObjectType().SpriteOrigin.Y), gameObject.GetObjectType().SpriteBounds.X, gameObject.GetObjectType().SpriteBounds.Y);
}
else if (selectedGameObject is LivingEntity)
{
var gameObject = (LivingEntity)selectedGameObject;
worldDrawPosition = new Rectangle((int)(gameObject.Position.X - gameObject.GetObjectType().SpriteOrigin.X), (int)(gameObject.Position.Y - gameObject.GetObjectType().SpriteOrigin.Y), gameObject.GetObjectType().SpriteBounds.X, gameObject.GetObjectType().SpriteBounds.Y);
}
var uiPosition = SimulationGame.ConvertWorldPositionToUIPosition(worldDrawPosition.X, worldDrawPosition.Y);
SimulationGame.PrimitiveDrawer.Rectangle(new Rectangle((int)uiPosition.X, (int)uiPosition.Y, worldDrawPosition.Width, worldDrawPosition.Height), Color.Yellow);
}
}
}
else if (SelectedBlockType != null)
{
var uiPosition = SimulationGame.ConvertWorldPositionToUIPosition(SelectedBlockPosition.X * WorldGrid.BlockSize.X, SelectedBlockPosition.Y * WorldGrid.BlockSize.Y);
SimulationGame.PrimitiveDrawer.Rectangle(new Rectangle((int)uiPosition.X, (int)uiPosition.Y, WorldGrid.BlockSize.X, WorldGrid.BlockSize.Y), Color.Blue);
}
else if (SelectedWorldLink != null)
{
var uiPosition = SimulationGame.ConvertWorldPositionToUIPosition(SelectedWorldLink.FromBlock.X * WorldGrid.BlockSize.X, SelectedWorldLink.FromBlock.Y * WorldGrid.BlockSize.Y);
SimulationGame.PrimitiveDrawer.Rectangle(new Rectangle((int)uiPosition.X, (int)uiPosition.Y, WorldGrid.BlockSize.X, WorldGrid.BlockSize.Y), Color.Orange);
}
if (startDragPosition != null)
{
var _startDragPosition = startDragPosition ?? Point.Zero;
var uiStartDragPosition = SimulationGame.ConvertWorldPositionToUIPosition(_startDragPosition.X, _startDragPosition.Y).ToPoint();
var selectionRect = ShapeCollision.ConvertLineToRect(uiStartDragPosition, SimulationGame.MouseState.Position);
if (selectionRect.Width > 20 || selectionRect.Height > 20)
{
SimulationGame.PrimitiveDrawer.Rectangle(selectionRect.ToXnaRectangle(), Color.White);
}
}
}
public ShapeCollision clone()
{
var clone = new ShapeCollision();
clone.copy_from(this);
return(clone);
}
private void handleOnMouseMove(MouseMoveEvent mouseMoveEvent)
{
if (mouseMoveEvent.LeftButtonDown && startDragPosition == null)
{
startDragPosition = SimulationGame.RealWorldMousePosition.ToPoint();
}
if (mouseMoveEvent.LeftButtonDown == false && startDragPosition != null)
{
selectGameObjects(ShapeCollision.ConvertLineToRect(startDragPosition ?? Point.Zero, SimulationGame.RealWorldMousePosition.ToPoint()));
startDragPosition = null;
}
}
public void copy_from(ShapeCollision other)
{
overlap = other.overlap;
separationX = other.separationX;
separationY = other.separationY;
unitVectorX = other.unitVectorX;
unitVectorY = other.unitVectorY;
otherOverlap = other.otherOverlap;
otherSeparationX = other.otherSeparationX;
otherSeparationY = other.otherSeparationY;
otherUnitVectorX = other.otherUnitVectorX;
otherUnitVectorY = other.otherUnitVectorY;
shape1 = other.shape1;
shape2 = other.shape2;
}
////////////////private static bool Intersect(Vector2[] polygon1, Vector2[] polygon2)
////////////////{
//////////////// var pointsA = polygon1;
//////////////// var edgesA = BuildEdges(pointsA);
//////////////// int edgeCountA = edgesA.Length;
//////////////// var pointsB = polygon2;
//////////////// var edgesB = BuildEdges(pointsB);
//////////////// int edgeCountB = edgesB.Length;
//////////////// Vector2 edge;
//////////////// // Loop through all the edges of both polygons
//////////////// for (int edgeIndex = 0; edgeIndex < edgeCountA + edgeCountB; edgeIndex++)
//////////////// {
//////////////// if (edgeIndex < edgeCountA)
//////////////// {
//////////////// edge = edgesA[edgeIndex];
//////////////// }
//////////////// else
//////////////// {
//////////////// edge = edgesB[edgeIndex - edgeCountA];
//////////////// }
//////////////// // ===== 1. Find if the polygons are currently intersecting =====
//////////////// // Find the axis perpendicular to the current edge
//////////////// Vector2 axis = new Vector2(-edge.y, edge.x);
//////////////// axis.Normalize();
//////////////// // Find the projection of the polygon on the current axis
//////////////// float minA = 0; float minB = 0; float maxA = 0; float maxB = 0;
//////////////// ProjectPolygon(axis, pointsA, ref minA, ref maxA);
//////////////// ProjectPolygon(axis, pointsB, ref minB, ref maxB);
//////////////// // Check if the polygon projections are currentlty intersecting
//////////////// //if (IntervalDistance(minA, maxA, minB, maxB) <= 0.000001) return true;
//////////////// if (Intersects(minA, maxA, minB, maxB, true))
//////////////// return true;
//////////////// }
//////////////// return false;
////////////////}
////////////////private static Vector2[] BuildEdges(Vector2[] points/*,Vector2 offset*/)
////////////////{
//////////////// Vector2 p1;
//////////////// Vector2 p2;
//////////////// List<Vector2> edges = new List<Vector2>(points.Length - 1);
//////////////// for (int i = 0; i < points.Length; i++)
//////////////// {
//////////////// p1 = points[i];
//////////////// if (i + 1 >= points.Length)
//////////////// {
//////////////// p2 = points[0];
//////////////// }
//////////////// else
//////////////// {
//////////////// p2 = points[i + 1];
//////////////// }
//////////////// //edges.Add(offset+p2 - p1);
//////////////// edges.Add(p2 - p1);
//////////////// }
//////////////// return edges.ToArray();
////////////////}
////////////////// Calculate the distance between [minA, maxA] and [minB, maxB]
////////////////// The distance will be negative if the intervals overlap
////////////////private static float IntervalDistance(float minA, float maxA, float minB, float maxB)
////////////////{
//////////////// if (minA < minB)
//////////////// {
//////////////// return minB - maxA;
//////////////// }
//////////////// else
//////////////// {
//////////////// return minA - maxB;
//////////////// }
////////////////}
////////////////public static bool Intersects(float min1, float max1, float min2, float max2, bool strict, bool correctMinMax = true)
////////////////{
//////////////// if (correctMinMax)
//////////////// {
//////////////// float tmp1 = min1, tmp2 = max1;
//////////////// min1 = Math.Min(tmp1, tmp2);
//////////////// max1 = Math.Max(tmp1, tmp2);
//////////////// tmp1 = min2;
//////////////// tmp2 = max2;
//////////////// min2 = Math.Min(tmp1, tmp2);
//////////////// max2 = Math.Max(tmp1, tmp2);
//////////////// }
//////////////// if (strict)
//////////////// return (min1 <= min2 && max1 > min2) || (min2 <= min1 && max2 > min1);
//////////////// else
//////////////// return (min1 <= min2 && max1 >= min2) || (min2 <= min1 && max2 >= min1);
////////////////}
////////////////// Calculate the projection of a polygon on an axis and returns it as a [min, max] interval
////////////////private static void ProjectPolygon(Vector2 axis, Vector2[] polygon, ref float min, ref float max)
////////////////{
//////////////// // To project a point on an axis use the dot product
//////////////// //float d = Vector2.Dot(axis, polygon[0]);
//////////////// float d = DotProduct(axis, polygon[0]);
//////////////// min = d;
//////////////// max = d;
//////////////// for (int i = 0; i < polygon.Length; i++)
//////////////// {
//////////////// d = DotProduct(polygon[i], axis);
//////////////// if (d < min)
//////////////// {
//////////////// min = d;
//////////////// }
//////////////// else
//////////////// {
//////////////// if (d > max)
//////////////// {
//////////////// max = d;
//////////////// }
//////////////// }
//////////////// }
////////////////}
////////////////public static float DotProduct(Vector2 vectorA, Vector2 vectorB)
////////////////{
//////////////// return vectorA.x * vectorB.x + vectorA.y * vectorB.y;
////////////////}
private static bool Intersect(Vector2[] polygon1, Vector2[] polygon2)
{
var into = new ShapeCollision();
var flip = false;
var tmp1 = checkPolygons(polygon1, polygon2, flip);
var tmp2 = checkPolygons(polygon2, polygon1, !flip);
if (tmp1 == null)
{
return(false);
}
if (tmp2 == null)
{
return(false);
}
ShapeCollision result = null;
ShapeCollision other = null;
if (System.Math.Abs(tmp1.overlap) < System.Math.Abs(tmp2.overlap))
{
result = tmp1;
other = tmp2;
}
else
{
result = tmp2;
other = tmp1;
}
result.otherOverlap = other.overlap;
result.otherSeparationX = other.separationX;
result.otherSeparationY = other.separationY;
result.otherUnitVectorX = other.unitVectorX;
result.otherUnitVectorY = other.unitVectorY;
into.copy_from(result);
result = other = null;
//return Math.Abs(into.otherOverlap) > 0.00001;
return(true);
}
/** Internal api - test a circle against a circle */
public static ShapeCollision testCircleVsCircle(Circle circleA, Circle circleB, bool flip = false)
{
var result = new ShapeCollision();
var circle1 = flip ? circleB : circleA;
var circle2 = flip ? circleA : circleB;
//add both radii together to get the colliding distance
var totalRadius = circle1.transformedRadius + circle2.transformedRadius;
//find the distance between the two circles using Pythagorean theorem. No square roots for optimization
var distancesq = Util.vec_lengthsq(circle1.x - circle2.x, circle1.y - circle2.y);
//if your distance is less than the totalRadius square(because distance is squared)
if (distancesq < totalRadius * totalRadius)
{
//find the difference. Square roots are needed here.
float difference = (float)(totalRadius - System.Math.Sqrt(distancesq));
result.shape1 = circle1;
result.shape2 = circle2;
var unitVecX = circle1.x - circle2.x;
var unitVecY = circle1.y - circle2.y;
var unitVecLen = Util.vec_length(unitVecX, unitVecY);
unitVecX = Util.vec_normalize(unitVecLen, unitVecX);
unitVecY = Util.vec_normalize(unitVecLen, unitVecY);
result.unitVectorX = unitVecX;
result.unitVectorY = unitVecY;
//find the movement needed to separate the circles
result.separationX = result.unitVectorX * difference;
result.separationY = result.unitVectorY * difference;
//the magnitude of the overlap
result.overlap = Util.vec_length(result.separationX, result.separationY);
return(result);
} //if distancesq < r^2
return(null);
}
public static ShapeCollision testPolygonVsPolygon(Polygon polygon1, Polygon polygon2, bool flip = false)
{
var output = new ShapeCollision();
if ((tmp1 = checkPolygons(polygon1, polygon2, flip)) == null)
{
return(null);
}
//i dont need collision data
/*
* if ( (tmp2 = checkPolygons(polygon2, polygon1, !flip)) == null) {
* return null;
* }
*
* ShapeCollision result = null;
* ShapeCollision other = null;
*
* if (System.Math.Abs(tmp1.overlap) < System.Math.Abs(tmp2.overlap)) {
* result = tmp1;
* other = tmp2;
* } else {
* result = tmp2;
* other = tmp1;
* }
*
* result.otherOverlap = other.overlap;
* result.otherSeparationX = other.separationX;
* result.otherSeparationY = other.separationY;
* result.otherUnitVectorX = other.unitVectorX;
* result.otherUnitVectorY = other.unitVectorY;
*
* output.copy_from(result);
* result = other = null;
*/
ShapeCollision result = tmp1;
return(result);
} //testPolygonVsPolygon
public static ShapeCollision testPolygonVsPolygon(Polygon polygon1, Polygon polygon2, bool flip = false)
{
var output = new ShapeCollision();
if ((tmp1 = checkPolygons(polygon1, polygon2, flip)) == null)
{
return(null);
}
if ((tmp2 = checkPolygons(polygon2, polygon1, !flip)) == null)
{
return(null);
}
ShapeCollision result = null;
ShapeCollision other = null;
if (System.Math.Abs(tmp1.overlap) < System.Math.Abs(tmp2.overlap))
{
result = tmp1;
other = tmp2;
}
else
{
result = tmp2;
other = tmp1;
}
result.otherOverlap = other.overlap;
result.otherSeparationX = other.separationX;
result.otherSeparationY = other.separationY;
result.otherUnitVectorX = other.unitVectorX;
result.otherUnitVectorY = other.unitVectorY;
output.copy_from(result);
result = other = null;
return(result);
} //testPolygonVsPolygon
/** Internal api - test a circle against a circle */
public static bool TestCircleVsCircle(Circle circleA, Circle circleB, out ShapeCollision shapeCollision, bool flip = false)
{
shapeCollision = new ShapeCollision();
Circle circle1 = flip ? circleB : circleA;
Circle circle2 = flip ? circleA : circleB;
//add both radii together to get the colliding distance
float totalRadius = circle1.TransformedRadius + circle2.TransformedRadius;
//find the distance between the two circles using Pythagorean theorem. No square roots for optimization
float distancesq = (circle1.Position - circle2.Position).LengthSquared();
//if your distance is less than the totalRadius square(because distance is squared)
if (distancesq < totalRadius * totalRadius)
{
//find the difference. Square roots are needed here.
float difference = (float)(totalRadius - System.Math.Sqrt(distancesq));
shapeCollision.Shape1 = circle1;
shapeCollision.Shape2 = circle2;
Vector2 normal = circle1.Position - circle2.Position;
normal.Normalize();
shapeCollision.Normal = normal;
//find the movement needed to separate the circles
shapeCollision.Separation *= difference;
//the magnitude of the overlap
shapeCollision.Overlap = shapeCollision.Separation.Length();
return(true);
} //if distancesq < r^2
return(false);
}
public override bool CollidesWithCircle(Circle circle, out ShapeCollision shapeCollision, bool flip = false) => Sat2D.TestCircleVsCircle(this, circle, out shapeCollision, flip);
/** Internal api - test a circle against a polygon */
public static bool TestCircleVsPolygon(Circle circle, Polygon polygon, out ShapeCollision shapeCollision, bool flip = false)
{
shapeCollision = new ShapeCollision();
var verts = polygon.TransformedVertices;
float testDistance = float.MaxValue;
Vector2 closest = Vector2.Zero;
for (int i = 0; i < verts.Count; i++)
{
float distance = (circle.Position - verts[i]).LengthSquared();
if (distance < testDistance)
{
testDistance = distance;
closest = verts[i];
}
}
Vector2 normalAxis = closest - circle.Position;
normalAxis.Normalize();
//project all its points, 0 outside the loop
float test = 0.0f;
float min1 = Vector2.Dot(normalAxis, verts[0]);
float max1 = min1;
for (int j = 1; j < verts.Count; j++)
{
test = Vector2.Dot(normalAxis, verts[j]);
if (test < min1)
{
min1 = test;
}
if (test > max1)
{
max1 = test;
}
}
// project the circle
float max2 = circle.TransformedRadius;
float min2 = -circle.TransformedRadius;
float offset = Vector2.Dot(normalAxis, -circle.Position);
min1 += offset;
max1 += offset;
float test1 = min1 - max2;
float test2 = min2 - max1;
//if either test is greater than 0, there is a gap, we can give up now.
if (test1 > 0 || test2 > 0)
{
return(false);
}
// circle distance check
float distMin = -(max2 - min1);
if (flip)
{
distMin *= -1;
}
shapeCollision.Overlap = distMin;
shapeCollision.Normal = normalAxis;
float closestDist = System.Math.Abs(distMin);
// find the normal axis for each point and project
for (int i = 0; i < verts.Count; i++)
{
normalAxis = FindNormalAxis(verts, i);
normalAxis.Normalize();
// project the polygon(again? yes, circles vs. polygon require more testing...)
min1 = Vector2.Dot(normalAxis, verts[0]);
max1 = min1; //set max and min
//project all the other points(see, cirlces v. polygons use lots of this...)
for (int j = 1; j < verts.Count; j++)
{
test = Vector2.Dot(normalAxis, verts[j]);
if (test < min1)
{
min1 = test;
}
if (test > max1)
{
max1 = test;
}
}
// project the circle(again)
max2 = circle.TransformedRadius; //max is radius
min2 = -circle.TransformedRadius; //min is negative radius
//offset points
offset = Vector2.Dot(normalAxis, -circle.Position);
min1 += offset;
max1 += offset;
// do the test, again
test1 = min1 - max2;
test2 = min2 - max1;
//failed.. quit now
if (test1 > 0 || test2 > 0)
{
return(false);
}
distMin = -(max2 - min1);
if (flip)
{
distMin *= -1;
}
if (System.Math.Abs(distMin) < closestDist)
{
shapeCollision.Normal = normalAxis;
shapeCollision.Overlap = distMin;
closestDist = System.Math.Abs(distMin);
}
} //for
//if you made it here, there is a collision!!!!!
if (flip)
{
shapeCollision.Shape1 = polygon;
shapeCollision.Shape2 = circle;
}
else
{
shapeCollision.Shape1 = circle;
shapeCollision.Shape2 = polygon;
}
shapeCollision.Separation *= shapeCollision.Overlap;
if (!flip)
{
shapeCollision.Normal = -shapeCollision.Normal;
}
return(true);
}
/** Internal api - implementation details for testPolygonVsPolygon */
public static ShapeCollision checkPolygons(Polygon polygon1, Polygon polygon2, bool flip = false)
{
var result = new ShapeCollision();
// TODO: This is unused, check original source
var test1 = 0.0f;
var test2 = 0.0f;
var testNum = 0.0f;
var min1 = 0.0f;
var max1 = 0.0f;
var min2 = 0.0f;
var max2 = 0.0f;
var closest = float.MaxValue;
var axisX = 0.0f;
var axisY = 0.0f;
var verts1 = polygon1.transformedVertices;
var verts2 = polygon2.transformedVertices;
var count1 = verts1.Length;
var count2 = verts2.Length;
// loop to begin projection
for (var i = 0; i < count1; i++)
{
axisX = findNormalAxisX(verts1, i);
axisY = findNormalAxisY(verts1, i);
var aLen = Util.vec_length(axisX, axisY);
axisX = Util.vec_normalize(aLen, axisX);
axisY = Util.vec_normalize(aLen, axisY);
// project polygon1
min1 = Util.vec_dot(axisX, axisY, verts1[0].x, verts1[0].y);
max1 = min1;
for (var j = 1; j < count1; j++)
{
testNum = Util.vec_dot(axisX, axisY, verts1[j].x, verts1[j].y);
if (testNum < min1)
{
min1 = testNum;
}
if (testNum > max1)
{
max1 = testNum;
}
}
// project polygon2
min2 = Util.vec_dot(axisX, axisY, verts2[0].x, verts2[0].y);
max2 = min2;
for (var j = 1; j < count2; j++)
{
testNum = Util.vec_dot(axisX, axisY, verts2[j].x, verts2[j].y);
if (testNum < min2)
{
min2 = testNum;
}
if (testNum > max2)
{
max2 = testNum;
}
}
test1 = min1 - max2;
test2 = min2 - max1;
if (test1 > 0 || test2 > 0)
{
return(null);
}
var distMin = -(max2 - min1);
if (flip)
{
distMin *= -1;
}
if (System.Math.Abs(distMin) < closest)
{
result.unitVectorX = axisX;
result.unitVectorY = axisY;
result.overlap = distMin;
closest = System.Math.Abs(distMin);
}
break;
}
result.shape1 = flip ? polygon2 : polygon1;
result.shape2 = flip ? polygon1 : polygon2;
result.separationX = -result.unitVectorX * result.overlap;
result.separationY = -result.unitVectorY * result.overlap;
if (flip)
{
result.unitVectorX = -result.unitVectorX;
result.unitVectorY = -result.unitVectorY;
}
return(result);
}
/** Internal api - test a circle against a polygon */
public static ShapeCollision testCircleVsPolygon(Circle circle, Polygon polygon, bool flip = false)
{
var result = new ShapeCollision();
var verts = polygon.transformedVertices;
var circleX = circle.x;
var circleY = circle.y;
float testDistance = float.MaxValue;
var distance = 0.0f;
var closestX = 0.0f;
var closestY = 0.0f;
for (var i = 0; i < verts.Length; i++)
{
distance = Util.vec_lengthsq(circleX - verts[i].x, circleY - verts[i].y);
if (distance < testDistance)
{
testDistance = distance;
closestX = verts[i].x;
closestY = verts[i].y;
}
}
var normalAxisX = closestX - circleX;
var normalAxisY = closestY - circleY;
var normAxisLen = Util.vec_length(normalAxisX, normalAxisY);
normalAxisX = Util.vec_normalize(normAxisLen, normalAxisX);
normalAxisY = Util.vec_normalize(normAxisLen, normalAxisY);
//project all its points, 0 outside the loop
var test = 0.0f;
var min1 = Util.vec_dot(normalAxisX, normalAxisY, verts[0].x, verts[0].y);
var max1 = min1;
for (var j = 1; j < verts.Length; j++)
{
test = Util.vec_dot(normalAxisX, normalAxisY, verts[j].x, verts[j].y);
if (test < min1)
{
min1 = test;
}
if (test > max1)
{
max1 = test;
}
}
// project the circle
var max2 = circle.transformedRadius;
var min2 = -circle.transformedRadius;
var offset = Util.vec_dot(normalAxisX, normalAxisY, -circleX, -circleY);
min1 += offset;
max1 += offset;
var test1 = min1 - max2;
var test2 = min2 - max1;
//if either test is greater than 0, there is a gap, we can give up now.
if (test1 > 0 || test2 > 0)
{
return(null);
}
// circle distance check
var distMin = -(max2 - min1);
if (flip)
{
distMin *= -1;
}
result.overlap = distMin;
result.unitVectorX = normalAxisX;
result.unitVectorY = normalAxisY;
var closest = System.Math.Abs(distMin);
// find the normal axis for each point and project
for (var i = 0; i < verts.Length; i++)
{
normalAxisX = findNormalAxisX(verts, i);
normalAxisY = findNormalAxisY(verts, i);
var aLen = Util.vec_length(normalAxisX, normalAxisY);
normalAxisX = Util.vec_normalize(aLen, normalAxisX);
normalAxisY = Util.vec_normalize(aLen, normalAxisY);
// project the polygon(again? yes, circles vs. polygon require more testing...)
min1 = Util.vec_dot(normalAxisX, normalAxisY, verts[0].x, verts[0].y);
max1 = min1; //set max and min
//project all the other points(see, cirlces v. polygons use lots of this...)
for (var j = 1; j < verts.Length; j++)
{
test = Util.vec_dot(normalAxisX, normalAxisY, verts[j].x, verts[j].y);
if (test < min1)
{
min1 = test;
}
if (test > max1)
{
max1 = test;
}
}
// project the circle(again)
max2 = circle.transformedRadius; //max is radius
min2 = -circle.transformedRadius; //min is negative radius
//offset points
offset = Util.vec_dot(normalAxisX, normalAxisY, -circleX, -circleY);
min1 += offset;
max1 += offset;
// do the test, again
test1 = min1 - max2;
test2 = min2 - max1;
//failed.. quit now
if (test1 > 0 || test2 > 0)
{
return(null);
}
distMin = -(max2 - min1);
if (flip)
{
distMin *= -1;
}
if (System.Math.Abs(distMin) < closest)
{
result.unitVectorX = normalAxisX;
result.unitVectorY = normalAxisY;
result.overlap = distMin;
closest = System.Math.Abs(distMin);
}
} //for
//if you made it here, there is a collision!!!!!
if (flip)
{
result.shape1 = polygon;
result.shape2 = circle;
}
else
{
result.shape1 = circle;
result.shape2 = polygon;
}
result.separationX = result.unitVectorX * result.overlap;
result.separationY = result.unitVectorY * result.overlap;
if (!flip)
{
result.unitVectorX = -result.unitVectorX;
result.unitVectorY = -result.unitVectorY;
}
return(result);
}
public override bool CollidesWithPolygon(Polygon polygon, out ShapeCollision shapeCollision, bool flip = false) => Sat2D.TestCircleVsPolygon(this, polygon, out shapeCollision, flip);
private static ShapeCollision checkPolygons(Vector2[] polygon1, Vector2[] polygon2, bool flip = false)
{
var result = new ShapeCollision();
// TODO: This is unused, check original source
var offset = 0.0f;
var test1 = 0.0f;
var test2 = 0.0f;
var testNum = 0.0f;
var min1 = 0.0f;
var max1 = 0.0f;
var min2 = 0.0f;
var max2 = 0.0f;
var closest = float.MaxValue;
var axisX = 0.0f;
var axisY = 0.0f;
var verts1 = polygon1;
var verts2 = polygon2;
var founded = false;
// loop to begin projection
for (var i = 0; i < verts1.Length; i++)
{
axisX = findNormalAxisX(verts1, i);
axisY = findNormalAxisY(verts1, i);
var aLen = vec_length(axisX, axisY);
axisX = vec_normalize(aLen, axisX);
axisY = vec_normalize(aLen, axisY);
// project polygon1
min1 = vec_dot(axisX, axisY, verts1[0].x, verts1[0].y);
max1 = min1;
for (var j = 1; i < verts1.Length; i++)
{
testNum = vec_dot(axisX, axisY, verts1[j].x, verts1[j].y);
if (testNum < min1)
{
min1 = testNum;
}
if (testNum > max1)
{
max1 = testNum;
}
}
// project polygon2
min2 = vec_dot(axisX, axisY, verts2[0].x, verts2[0].y);
max2 = min2;
for (var j = 1; i < verts2.Length; i++)
{
testNum = vec_dot(axisX, axisY, verts2[j].x, verts2[j].y);
if (testNum < min2)
{
min2 = testNum;
}
if (testNum > max2)
{
max2 = testNum;
}
}
test1 = min1 - max2;
test2 = min2 - max1;
if (test1 > 0 || test2 > 0)
{
return(null);
}
//if (test1 > 0 || test2 > 0) continue;
//founded = true;
var distMin = -(max2 - min1);
if (flip)
{
distMin *= -1;
}
if (System.Math.Abs(distMin) < closest)
{
result.unitVectorX = axisX;
result.unitVectorY = axisY;
result.overlap = distMin;
closest = System.Math.Abs(distMin);
}
}
//if (!founded)
// return null;
result.shape1 = flip ? polygon2 : polygon1;
result.shape2 = flip ? polygon1 : polygon2;
result.separationX = -result.unitVectorX * result.overlap;
result.separationY = -result.unitVectorY * result.overlap;
if (flip)
{
result.unitVectorX = -result.unitVectorX;
result.unitVectorY = -result.unitVectorY;
}
return(result);
}
public override bool CollidesWith(Shape shape, out ShapeCollision shapeCollision) => shape.CollidesWithCircle(this, out shapeCollision, true);
public override bool CollidesWithCircle(Circle circle, out ShapeCollision shapeCollision, bool flip = false) => Sat2D.TestCircleVsPolygon(circle, this, out shapeCollision, !flip);