// Breaks an asteroid apart when it is hit by a blast
private void breakApart(Asteroid asteroid, Blast blast)
{
//crash sound
breakEffect.Play(.5f, .5f, 1f);
Vector3 explosionVector;
if (asteroid.scale < .75)
{
score += 150;
asteroids.Remove(asteroid);
currentAsteroidCount--;
}
else
{
if (asteroid.scale == 2)
{
score += 50;
}
if (asteroid.scale == 1)
{
score += 100;
}
asteroid.scale /= 2;
Asteroid copy1 = new Asteroid();
copy1.scale = asteroid.scale;
copy1.position = asteroid.position;
Asteroid copy2 = new Asteroid();
copy2.scale = asteroid.scale;
copy2.position = asteroid.position;
//find vector perpendicular to asteroid velocity and blaster velocity
//using the cross product, then normalized
explosionVector = Vector3.Normalize(Vector3.Cross(asteroid.velocity, blast.velocity));
//updates positions along the explosion vector
copy1.position += asteroid.scale * explosionVector;
copy2.position -= asteroid.scale * explosionVector;
//updates velocities
copy1.velocity += (40f / asteroid.scale) * explosionVector;
copy2.velocity -= (40f / asteroid.scale) * explosionVector;
asteroids.Remove(asteroid);
asteroids.Add(copy1);
asteroids.Add(copy2);
currentAsteroidCount++;
}
}
//Creates a new blast at location of ship and figures out velocity for it, then adds it to the list
private void shoot()
{
blast = new Blast();
blast.scale = 10f;
blast.velocity = world.Up * 500f;
blast.position = blast.velocity * .05f;
blast.texture = blastTexture;
blastList.Add(blast);
laser.Play(.5f, .7f, 1f);
}
// Checks if a blast has hit an asteroid
private bool hitCheck(Model model1, Matrix world1, Blast blast)
{
for (int meshIndex1 = 0; meshIndex1 < model1.Meshes.Count; meshIndex1++)
{
BoundingSphere sphere1 = model1.Meshes[meshIndex1].BoundingSphere;
sphere1 = sphere1.Transform(world1);
if (Vector3.Distance(sphere1.Center, blast.position) < sphere1.Radius)
{
blastList.Remove(blast);
return(true);
}
}
return(false);
}
//draws a blast to the screen as a billboard
private void DrawBlast(Blast blast, BasicEffect effect)
{
//mostly Dr. Wittman's Particle code
Matrix billboard = Matrix.CreateBillboard(blast.position, new Vector3(0, 0, 150), Vector3.UnitY, null);
GraphicsDevice.DepthStencilState = DepthStencilState.DepthRead;
GraphicsDevice.BlendState = BlendState.Additive;
GraphicsDevice.RasterizerState = RasterizerState.CullNone;
GraphicsDevice.SetVertexBuffer(vertexBuffer);
effect.World = Matrix.CreateScale(blast.scale) * billboard;
effect.View = view;
effect.Projection = projection;
effect.Texture = blast.texture;
effect.TextureEnabled = true;
effect.LightingEnabled = false;
effect.PreferPerPixelLighting = false;
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
{
pass.Apply();
GraphicsDevice.DrawPrimitives(PrimitiveType.TriangleList, 0, 2);
}
}
/// <summary>
/// Allows the game to perform any initialization it needs to before starting to run.
/// This is where it can query for any required services and load any non-graphic
/// related content. Calling base.Initialize will enumerate through any components
/// and initialize them as well.
/// </summary>
protected override void Initialize()
{
asteroidModel = Content.Load <Model>("Models/rock1");
asteroidTexture = Content.Load <Texture2D>("Textures/rock1");
asteroids = new List <Asteroid>();
for (int i = 0; i < startingAsteroidCount; ++i) //generating all initial asteroids
{
asteroid = new Asteroid();
asteroid.position = Vector3.Zero;
while (Math.Abs(asteroid.position.X) < 75 || Math.Abs(asteroid.position.Y) < 75 || Math.Abs(asteroid.position.Z) < 75)
{
asteroid.position = choosePosition(-positionRange, positionRange);
}
asteroid.velocity = chooseVelocity();
asteroid.scale = 2;
asteroids.Add(asteroid);
}
//Creates thruster
thruster = new Blast();
thruster.scale = 0f;
thruster.velocity = Vector3.Zero;
//Creates new list of blasts
blastList = new List <Blast>();
basicEffect = new BasicEffect(GraphicsDevice);
//sets up vertexBuffer for a square that is later used for blasts
VertexPositionColorTexture[] vertices = new VertexPositionColorTexture[6];
Vector2 upperLeft = new Vector2(0, 0);
Vector2 lowerLeft = new Vector2(0, 1);
Vector2 upperRight = new Vector2(1, 0);
Vector2 lowerRight = new Vector2(1, 1);
vertices[0] = new VertexPositionColorTexture(new Vector3(1, 1, 0), Color.White, upperRight);
vertices[1] = new VertexPositionColorTexture(new Vector3(1, -1, 0), Color.White, lowerRight);
vertices[2] = new VertexPositionColorTexture(new Vector3(-1, -1, 0), Color.White, lowerLeft);
vertices[3] = new VertexPositionColorTexture(new Vector3(1, 1, 0), Color.White, upperRight);
vertices[4] = new VertexPositionColorTexture(new Vector3(-1, -1, 0), Color.White, lowerLeft);
vertices[5] = new VertexPositionColorTexture(new Vector3(-1, 1, 0), Color.White, upperLeft);
vertexBuffer = new VertexBuffer(basicEffect.GraphicsDevice, typeof(VertexPositionColorTexture), vertices.Length, BufferUsage.WriteOnly);
vertexBuffer.SetData <VertexPositionColorTexture>(vertices);
//gameplay variables
lives = 3;
score = 0;
level = 1;
nextLevelScore = 500;
gameover = false;
isSpacePressed = false;
base.Initialize();
}