I'm a student studying Games Development. I want a sprite to speed up on it's second passing of the screen. How do I do this?
Code I wrote so far:
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
int displaywidth;
int displayheight;
int carwrap;
int carspeed;
//structure for 2D graphics
struct graphic2D
{
public Texture2D image;
public Rectangle rect;
}
//structure for moving 2D graphics
struct sprite2D
{
public Texture2D image; //texture to hold image
public Vector3 position; //position on screen
public Rectangle rect; //size and position
public Vector2 origin; //centre point
public float size; //size ratio
public Vector3 velocity; // sprite speed and direction
public BoundingSphere bsphere; //bounding sphere
}
sprite2D car;
sprite2D car2;
graphic2D background;
Boolean gameover;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
// set game resolution to current resolution
//this.graphics.PreferredBackBufferWidth = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Width;
//this.graphics.PreferredBackBufferHeight = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Height;
}
/// <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()
{
// TODO: Add your initialization logic here
//store height and width of screen
displaywidth = graphics.GraphicsDevice.Viewport.Width;
displayheight = graphics.GraphicsDevice.Viewport.Height;
base.Initialize();
}
/// <summary>
/// LoadContent will be called once per game and is the place to load
/// all of your content.
/// </summary>
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
//load background image
background.image = Content.Load<Texture2D>("challenge1");
//work out ratio for image depending on screen size
float ratio = ((float)displaywidth / background.image.Width);
background.rect.Width = displaywidth;
background.rect.Height = (int)(background.image.Height * ratio);
background.rect.X = 0;
background.rect.Y = (displayheight - background.rect.Height) / 2;
// Loads sprites to car
car.image = Content.Load<Texture2D>("sub1");
car2.image = Content.Load<Texture2D>("sub2");
reset();
// TODO: use this.Content to load your game content here
}
// use the reset to initialise at start of game and call again when game is restarted
void reset()
{
//set initial position car 1
car.position = new Vector3(displaywidth / 10, displayheight / 2, 0);
car.size = 0.5f; //set size of car
car.origin.X = car.image.Width / 2;
car.origin.Y = car.image.Height / 2;
car.rect.Width = (int)(car.image.Width * car.size);
car.rect.Height = (int)(car.image.Height * car.size);
car.velocity = new Vector3(4, 0, 0);
carspeed = 0;
//car 2
car2.position = new Vector3(displaywidth / 10, displayheight / 1.2f, 0);
car2.size = 0.5f; //set size of car
car2.origin.X = car2.image.Width / 2;
car2.origin.Y = car2.image.Height / 2;
car2.rect.Width = (int)(car2.image.Width * car.size);
car2.rect.Height = (int)(car2.image.Height * car.size);
car2.velocity = new Vector3(8, 0, 0); // Velocity of (X,Y,Z)
gameover = false;
}
/// <summary>
/// UnloadContent will be called once per game and is the place to unload
/// all content.
/// </summary>
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}
/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
KeyboardState keys = Keyboard.GetState(); //reads keyboard
if (!gameover)
{
// code for when game is running
car.position += car.velocity; //add current velocity to pos of thr
// check if car hits any of the four sides and bounce it off them
if ((car.position.X + car.rect.Width / 2) >= displaywidth) //RHS
car.position.X = 0;
carwrap++;
if (carwrap % 2 == 0)
carspeed++;
car.rect.X = (int)car.position.X;
car.rect.Y = (int)car.position.Y;
//set bounding sphere
car.bsphere = new BoundingSphere(car.position, car.rect.Width / 2);
// car 2
car2.position += car2.velocity; //add current velocity to pos of thr
// check if car hits any of the four sides and bounce it off them
if
((car2.position.X + car2.rect.Width / 4) >= displaywidth) //RHS
car2.position.X = 0;
//other way
//if ((car2.position.X - car2.rect.Width / 2) <= 0)//LHS
//car2.position.X = (car2.rect.Width / 2);
car2.rect.X = (int)car2.position.X;
car2.rect.Y = (int)car2.position.Y;
//set bounding sphere
car2.bsphere = new BoundingSphere(car2.position, car2.rect.Width / 2);
}
else
{
reset();
}
base.Update(gameTime);
}
/// <summary>
/// This is called when the game should draw itself.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
// TODO: Add your drawing code here
spriteBatch.Begin();
spriteBatch.Draw(background.image, background.rect, Color.White);
//draw car
spriteBatch.Draw(car.image, car.rect, null, Color.White, 0,car.origin, SpriteEffects.None, 0);
spriteBatch.Draw(car2.image, car2.rect, null, Color.White, 0, car2.origin, SpriteEffects.None, 0);
spriteBatch.End();
base.Draw(gameTime);
}
}
