public void Vector2f_InvertY_Converts()
{
var input = new Vector2f(1, 2);
var expected = new Vector2f(1, -2);
var result = input.InvertY();
Assert.AreEqual(expected, result);
}
/// <summary>
/// Creates and returns a track piece shape.
/// </summary>
/// <param name="position"></param>
/// <param name="rotation"></param>
/// <returns></returns>
private static RectangleShape CreateShape(Vector2f position, float rotation)
{
return(new RectangleShape
{
FillColor = FillColor,
OutlineColor = OutlineColor,
OutlineThickness = OutlineSize,
Size = PieceSize,
// invert the position and rotation for SFML
Position = position.InvertY(),
Rotation = rotation * -1f
});
}
/// <summary>
/// Creates the graphics and physics objects for the body of the car.
/// </summary>
private void CreateBody()
{
m_bodyShape = new ConvexShape((uint)Definition.NumBodyPoints)
{
OutlineColor = OutlineColor,
OutlineThickness = OutlineThickness,
Position = Car.StartPosition.ToVector2f().InvertY()
};
// build the vertex list for the polygon
var vertices = new Vertices(Definition.NumBodyPoints);
var angleStep = 360f / Definition.NumBodyPoints;
var angle = 0f;
for (int i = 0; i < Definition.NumBodyPoints; i++)
{
// the distance this point is from the center
var distance = m_definition.CalcBodyPoint(i);
// turn the distance into a point centered around (0,0)
var point = new Vector2f
{
X = distance * (float)Math.Cos(MathExtensions.DegToRad(angle)),
Y = distance * (float)Math.Sin(MathExtensions.DegToRad(angle))
};
m_bodyShape.SetPoint((uint)i, point.InvertY());
vertices.Add(point.ToVector2());
angle += angleStep;
}
// build the physics shape
m_bodyBody = BodyFactory.CreatePolygon(
m_physicsManager.World, vertices, m_definition.CalcBodyDensity(),
Car.StartPosition
);
m_bodyBody.BodyType = BodyType.Dynamic;
m_bodyBody.Friction = 1;
m_bodyBody.CollidesWith = ~CollisionCategory;
m_bodyBody.CollisionCategories = CollisionCategory;
}
/// <summary>
/// Randomly generates a new track, replacing an existing track.
/// </summary>
public void Generate()
{
Debug.Assert(Random != null);
Clear();
var stopwatch = new Stopwatch();
stopwatch.Start();
float maxX = 0;
float minX = 0;
float maxY = 0;
float minY = 0;
// first an invisible physics piece to block cars from running off the
// track to the left
var start = new Vector2f(-10, 0);
minX = start.X;
var body = BodyFactory.CreateEdge(
m_world, start.ToVector2(), start.ToVector2() + new Vector2(0, 10));
body.CollidesWith = Category.All;
body.CollisionCategories = CollisionCategory;
m_trackBodies.Add(body);
// the first visible piece is the starting pad and is positioned so that
// the random track starts at (0,0)
var rot = 0f;
var shape = new RectangleShape
{
FillColor = FillColor,
OutlineColor = OutlineColor,
OutlineThickness = OutlineSize,
Position = start.InvertY(),
Size = new Vector2f(10, PieceSize.Y),
Rotation = rot
};
var end = CalcEndPoint(start, shape.Size, rot);
m_trackShapes.Add(shape);
body = CreateBody(start, end);
m_trackBodies.Add(body);
m_startingLine = (start / 2f).X;
m_trackOutline.Append(new Vertex(start.InvertY(), FillColor));
m_trackOutline.Append(new Vertex(end.InvertY(), FillColor));
// place the rest of the pieces
for (int i = 0; i < NumPieces; i++)
{
start = end;
// the angle of the piece is randomized
var maxAngle = CalcMaxAngle(i);
var minAngle = CalcMinAngle(i);
var rotSign = rot < 0 ? -1f : 1f;
rot = (float)Random.NextDouble() * (maxAngle - minAngle) + minAngle;
// with a 40% chance to flip the sign from the last piece
if (Random.NextDouble() < 0.4)
{
rot *= -rotSign;
}
else
{
rot *= rotSign;
}
shape = CreateShape(start, rot);
end = CalcEndPoint(start, shape.Size, rot);
body = CreateBody(start, end);
m_trackOutline.Append(new Vertex(end.InvertY(), FillColor));
m_trackShapes.Add(shape);
m_trackBodies.Add(body);
maxY = Math.Max(maxY, end.Y);
minY = Math.Min(minY, end.Y);
}
// the finish line sensor is halfway down the finish line piece
var sensor = BodyFactory.CreateEdge(m_world,
(end + new Vector2f(5, 0)).ToVector2(),
(end + new Vector2f(5, 10)).ToVector2()
);
sensor.IsSensor = true;
sensor.CollisionCategories = FinishLineCategory;
sensor.CollidesWith = Car.Entity.CollisionCategory;
sensor.OnCollision += FinishLineOnCollision;
m_trackBodies.Add(sensor);
// create a landing pad at the end of the track
start = end;
shape = new RectangleShape
{
FillColor = FillColor,
OutlineColor = OutlineColor,
OutlineThickness = OutlineSize,
Position = start.InvertY(),
Size = new Vector2f(10, PieceSize.Y),
Rotation = 0f
};
end = start + new Vector2f(shape.Size.X, 0);
body = CreateBody(start, end);
m_trackShapes.Add(shape);
m_trackBodies.Add(body);
m_trackOutline.Append(new Vertex(end.InvertY(), FillColor));
maxX = end.X;
// create a holder so cars don't go off the end of the track
start = end;
end = start + new Vector2f(0, 10);
body = CreateBody(start, end);
m_trackBodies.Add(body);
Dimensions = new Vector2(maxX - minX, maxY - minY + 10);
Center = new Vector2(
minX + (Dimensions.X / 2f), minY + (Dimensions.Y / 2f));
m_generated = true;
// Log.DebugFormat("Generated {0} track pieces in {1} ms",
// m_trackShapes.Count, stopwatch.ElapsedMilliseconds);
}
