//
// Is a cell intersecting with a rectangle
//
public static bool IsCellIntersectingWithRectangle(Vector3 cellPos, float cellSize, Rectangle obstacle)
{
bool isColliding = false;
float halfCellSize = cellSize * 0.5f;
Vector3 FL = new Vector3(cellPos.x - halfCellSize, cellPos.y, cellPos.z + halfCellSize);
Vector3 FR = new Vector3(cellPos.x + halfCellSize, cellPos.y, cellPos.z + halfCellSize);
Vector3 BL = new Vector3(cellPos.x - halfCellSize, cellPos.y, cellPos.z - halfCellSize);
Vector3 BR = new Vector3(cellPos.x + halfCellSize, cellPos.y, cellPos.z - halfCellSize);
Rectangle cell = new Rectangle(FL, FR, BL, BR);
//Step 1. AABB
if (Intersections.AreIntersectingAABB(obstacle, cell))
{
//Step 2. Triangle-triangle intersections
if (Intersections.AreRectangleRectangleIntersecting(obstacle, cell))
{
isColliding = true;
}
}
return(isColliding);
}
//
// Use the car's corners and then rectangle-rectangle-intersection with the obstacles to check if the car is intersecting with an obstacle
//
private static bool IsCarIntersectingWithObstacles(Rectangle carRectangle, IntVector2 carCenterCellPos, Map map)
{
bool hasInvalidPosition = false;
////Alternative 1. Find if one of the cells the car is intersecting is an obstacle
////This is slower because it requires a lot of triangle-triangle intersections to identify the cells
////which is the same as intersecting with the obstacles in the first place
//bool isCellIntersectedByCarObstacle = FindIfCellBlockedByRectangleIsObstacle(carRectangle, carCenterCellPos, map);
//if (isCellIntersectedByCarObstacle)
//{
// hasInvalidPosition = true;
// return hasInvalidPosition;
//}
//return false;
//But if we want more accurate collision detection we have to take into account that the obstacle
//may not block the entire cell, so the can can maybe move into this position without colliding with an obstacle
//Find all obstacles that are close to the car, so we dont have to check all obstacles
//List<Obstacle> obstaclesThatAreClose = FindCloseObstaclesCell(carPos);
//List<Obstacle> obstaclesThatAreClose = FindCloseObstaclesAABB(carCorners, map);
//Maybe more efficient to instead of finding obstacles that are close, go through all obstacles
//because the obstacle detection algorithm is using AABB anyway
List <Obstacle> obstaclesThatAreClose = map.allObstacles;
for (int i = 0; i < obstaclesThatAreClose.Count; i++)
{
Rectangle obstacleCorners = obstaclesThatAreClose[i].cornerPos;
//Rectangle-rectangle intersection, which is here multiple triangle-triangle intersection tests
if (Intersections.AreRectangleRectangleIntersecting(carRectangle, obstacleCorners))
{
hasInvalidPosition = true;
return(hasInvalidPosition);
}
}
return(hasInvalidPosition);
}
//Instantiate one cube and add its position to the array
void AddObstacle(Map map, Rectangle avoidRect)
{
//Generate random coordinates in the map
float posX = Random.Range(1f, map.MapWidth - 1f);
float posZ = Random.Range(1f, map.MapWidth - 1f);
//Rotation
float rotY = Random.Range(0f, 360f);
//Size
float sizeX = Random.Range(Parameters.minObstacleSize, Parameters.maxObstacleSize);
float sizeZ = Random.Range(Parameters.minObstacleSize, Parameters.maxObstacleSize);
Vector3 pos = new Vector3(posX, 0.5f, posZ);
Quaternion rot = Quaternion.Euler(0f, rotY, 0f);
Vector3 scale = new Vector3(sizeX, 1f, sizeZ);
//Update the prefab with the new data
obstaclePrefabObj.transform.position = pos;
obstaclePrefabObj.transform.rotation = rot;
obstaclePrefabObj.transform.localScale = scale;
Obstacle newObstacle = new Obstacle(obstaclePrefabObj.transform);
//The obstacle shouldnt intersect with the start area
if (Intersections.AreRectangleRectangleIntersecting(avoidRect, newObstacle.cornerPos))
{
return;
}
//Add a new obstacle object at this position
Instantiate(obstaclePrefabObj, obstaclesParent);
map.allObstacles.Add(newObstacle);
}
//
// Check if the trailer is colliding with the drag vehicle
//
public static bool IsTrailerCollidingWithDragVehicle(
Vector3 semiRearWheelPos, float semiHeading, CarData semiData,
Vector3 trailerRearWheelPos, float trailerHeading, CarData trailerData)
{
bool isColliding = false;
//Use triangle-traingle intersection so we need the rectangles
Vector3 trailerCenter = trailerData.GetCenterPos(trailerRearWheelPos, trailerHeading);
Rectangle trailerRect = CarData.GetCornerPositions(trailerCenter, trailerHeading, trailerData.carWidth * 0.9f, trailerData.CarLength);
//The semi's cabin rectangle
Vector3 cabinCenter = semiData.GetSemiCabinCenter(semiRearWheelPos, semiHeading);
//Make it slightly shorter or too many false collisions
Rectangle semiRect = CarData.GetCornerPositions(cabinCenter, semiHeading, semiData.carWidth, semiData.cabinLength * 0.95f);
if (Intersections.AreRectangleRectangleIntersecting(trailerRect, semiRect))
{
return(true);
}
return(isColliding);
}