Develop Reference

MonoGame Problem with renderize Texture2D on camera movement

First, sorry for my bad English, English is not my native language.
I have a problem when I draw a Texture2D in screen. When I move a Texture in screen,
colors in border of the texture flickers. This is my code:
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using SharpDX.Direct2D1.Effects;
using System;
using System.Collections.Generic;
namespace PixelTest
{
public class Drawable
{
public Texture2D Image;
public Point Position;
public Point Size;
public Rectangle Source;
}
public class MainGame : Game
{
//PRIVATE READ-ONLY VARIABLES
private readonly GraphicsDeviceManager _graphics;
private readonly List<Drawable> _sprites;
//VARIABLES
private Texture2D _screen;
private Texture2D _tiles;
private SpriteBatch _spriteBatch;
private Point _camera;
private Point _scale;
private bool _byRect;
private KeyboardState _previousKeyState;
private BlendState _state;
private RasterizerState _rState;
//CONSTRUCTOR
public MainGame()
{
_graphics = new GraphicsDeviceManager(this);
_sprites = new List<Drawable>();
_tiles = null;
_spriteBatch = null;
_camera = Point.Zero;
_scale = new Point(1, 1);
Content.RootDirectory = "Content";
IsMouseVisible = true;
IsFixedTimeStep = true;
//_graphics.PreferHalfPixelOffset = true;
_graphics.PreferMultiSampling= true;
//_graphics.SynchronizeWithVerticalRetrace = false;
_state = new BlendState()
{
AlphaBlendFunction = BlendFunction.Add,
AlphaSourceBlend = Microsoft.Xna.Framework.Graphics.Blend.Zero,
AlphaDestinationBlend = Microsoft.Xna.Framework.Graphics.Blend.Zero,
ColorBlendFunction= BlendFunction.Add,
ColorDestinationBlend = Microsoft.Xna.Framework.Graphics.Blend.Zero,
ColorSourceBlend = Microsoft.Xna.Framework.Graphics.Blend.One,
};
_rState = new RasterizerState()
{
MultiSampleAntiAlias = false
};
}
protected override void Initialize()
{
base.Initialize();
_sprites.Add(new Drawable
{
Image = _tiles,
Position = new Point(32, 64),
Size = new Point(8, 8),
Source = new Rectangle(0, 0, 8, 8)
});
}
protected override void LoadContent()
{
_spriteBatch = new SpriteBatch(GraphicsDevice);
_tiles = Content.Load<Texture2D>("i001_tiles");
_screen = new Texture2D(GraphicsDevice, _graphics.PreferredBackBufferWidth, _graphics.PreferredBackBufferHeight);
var colors = new Color[_graphics.PreferredBackBufferWidth * _graphics.PreferredBackBufferHeight];
for (var i = 0; i < _graphics.PreferredBackBufferWidth * _graphics.PreferredBackBufferHeight; i++)
colors[i] = Color.Black;
_screen.SetData(colors);
}
protected override void UnloadContent()
{
base.UnloadContent();
_tiles.Dispose();
_screen.Dispose();
}
protected override void Update(GameTime gameTime)
{
base.Update(gameTime);
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
Exit();
var sKey = Keyboard.GetState();
var translateUnit = Point.Zero;
var scaleUnit = 0;
if (sKey.IsKeyDown(Keys.A))
translateUnit.X = -1;
else if (sKey.IsKeyDown(Keys.D))
translateUnit.X = 1;
else
translateUnit.X = 0;
if (sKey.IsKeyDown(Keys.W))
translateUnit.Y = -1;
else if (sKey.IsKeyDown(Keys.S))
translateUnit.Y = 1;
else
translateUnit.Y = 0;
if (sKey.IsKeyDown(Keys.F))
scaleUnit = -1;
else if (sKey.IsKeyDown(Keys.G))
scaleUnit = 1;
else
scaleUnit = 0;
if (sKey.IsKeyDown(Keys.U) && _previousKeyState.IsKeyUp(Keys.U))
_byRect = !_byRect;
var speed = translateUnit;// * 1;
_camera += speed;// RoundVec(speed);
_scale = new Point(4, 4);
_previousKeyState = sKey;
}
protected override void Draw(GameTime gameTime)
{
base.Draw(gameTime);
GraphicsDevice.Clear(Color.Blue);
_spriteBatch.Begin(SpriteSortMode.Deferred, _state, SamplerState.PointClamp, null, _rState, null, null);
//_spriteBatch.Draw(_screen, Vector2.Zero, Color.White);
foreach (var item in _sprites)
{
if (true)
{
var pos = item.Position;
var size = item.Size;
pos += _camera;
pos *= _scale;
size *= _scale;
var rect = new Rectangle(
(int)pos.X,
(int)pos.Y,
(int)size.X,
(int)size.Y);
_spriteBatch.Draw(
item.Image,
rect,
item.Source,
Color.White,
0F,
Vector2.Zero,
SpriteEffects.None,
0F);
}
else
{
var pos = item.Position;
//pos = RoundVec(pos * _scale) / _scale;
pos += _camera;
pos *= _scale;
_spriteBatch.Draw(
item.Image,
pos.ToVector2(),
item.Source,
Color.White,
0F,
Vector2.Zero,
_scale.ToVector2(),
SpriteEffects.None,
0F);
}
}
_spriteBatch.End();
}
}
}
I dont use floats values for camera position in this test and the flickers continue to happens. I dont know what is happen.
I tried various things, but nothing work.
Resources:
i001_tiles.png (no alpha values)
PrintScreens:
Maybe is just a ottical illusion, or a monitor problem, but the green part of texture merge with the blue background on camera movement, i dont know why.
In Movement Up:
This only occour with the colors different of white, when i movement camera to right, only the one pixel in green in the right merge with blue background.

How to debug where an unexpected null is coming from in my class?

In my Boss class, it says that my List "bulletlist" is null and give me a run time error but I see no errors can someone tell me what I am doing wrong? The games runs fine if I don't update my boss class. I put in my main class, player class, and bullet class, in as well.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace Space_Shooter
{
public class Boss
{
public Texture2D texture, bulletTexture , healthBarTexture;
public Vector2 position;
public float randomPositionX, randomPositionY , bulletDamage, shipDamage , health , MaxBullets;
public int speed, bulletSpeed , bulletDelayTime, bulletDelayTimeReset;
public bool isVisible;
public Rectangle boundingBox , bossHealthBar;
public List<Bullet> bulletList;
Random random = new Random();
Player p = new Player();
public Boss(Texture2D newTexture, Vector2 newPosition, Texture2D newBulletTexture)
{
texture = newTexture;
position = newPosition;
bulletTexture = newBulletTexture;
bulletList = new List<Bullet>();
bulletSpeed = 25;
bulletDamage = 25;
shipDamage = p.health / 2;
health = 2000;
bulletDelayTime = 30;
bulletDelayTimeReset = 30;
MaxBullets = 30;
isVisible = true;
}
public Boss()
{
}
public void Draw(SpriteBatch spriteBatch)
{
spriteBatch.Draw(texture, position, Color.White);
spriteBatch.Draw(healthBarTexture, bossHealthBar, Color.White);
foreach (Bullet b in bulletList)
{
b.Draw(spriteBatch);
}
}
public void loadContent(ContentManager content)
{
texture = content.Load<Texture2D>("Ship4");
bulletTexture = content.Load<Texture2D>("EnemyBullet");
healthBarTexture = content.Load <Texture2D> ("healthbar");
}
public void update(GameTime gameTime)
{
updateBullets();
Shoot();
checkBossCollison();
// Making bosses health bar
bossHealthBar = new Rectangle((int)position.X, (int)position.Y + 30, (int)health, 25);
// Creating collision box for boss
boundingBox = new Rectangle((int)position.X, (int)position.Y, (int)texture.Width, (int)texture.Height);
randomPositionX = random.Next(50, 750);
randomPositionY = random.Next(50, 400);
// setting boss movement
if (position.Y > randomPositionY)
position.Y -= speed;
if (position.Y < randomPositionY)
position.Y += speed;
if (position.X > randomPositionX)
position.X -= speed;
if (position.X < randomPositionX)
position.X += speed;
}
public void updateBullets()
{
// for each bullet in the bulletList: update the movement and if the bullet hits the bottom of the screen, remove it from the list
foreach (Bullet b in bulletList)
{
//make a Bounding box for every bullet in the bulletList
b.boundingBox = new Rectangle((int)b.position.X, (int)b.position.Y, b.texture.Width, b.texture.Height);
// set movement for the bullets
// if a bullet hits the bottom of the screen, then make visable false
if (b.position.Y >= 850)
b.isVisible = false;
// go through the bulletList and see if any of the bullets are not visible, if they are not then remove that bullet from the bulletList
for (int i = 0; i < bulletList.Count; i++)
{
if (!bulletList[i].isVisible)
{
bulletList.RemoveAt(i);
i--;
}
}
}
}
public void checkBossCollison()
{
// if boss ship comes in bcontact with player ship player is damaged
if (boundingBox.Intersects(p.boundingBox))
p.health -= shipDamage;
// if player bullets hit boss then boss is damaged and player bullets go invisible
for(int i = 0; i < p.bulletList.Count; i++)
{
if (boundingBox.Intersects(p.bulletList[i].boundingBox))
{
health -= p.bulletDamage;
p.bulletList[i].isVisible = false;
if (health == 0)
isVisible = false;
}
}
// if boss shoots player player is damaged and boss bullets go invisible
for(int i = 0; i < bulletList.Count; i++)
{
if (p.boundingBox.Intersects(bulletList[i].boundingBox))
{
p.health -= bulletDamage;
bulletList[i].isVisible = false;
}
}
}
public void Shoot()
{
// shoot only if our bullet delay resets
if (bulletDelayTime >= 0)
bulletDelayTime--;
// If bulletDelay is at 0, create a new bullet at enemy position, make it visible on the screen, then add that bullet to bulletList
if (bulletDelayTime <= 0)
{
// create new bullet and center it front and center of enemy ship
Bullet newBullet = new Bullet(bulletTexture);
newBullet.position = new Vector2(position.X + texture.Width / 2 - newBullet.texture.Width / 2, position.Y + 30);
newBullet.isVisible = true;
if (bulletList.Count() < MaxBullets)
bulletList.Add(newBullet);
}
// Reset bullet delay
if (bulletDelayTime == 0)
bulletDelayTime = bulletDelayTimeReset;
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace Space_Shooter
{
// Main
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
// variabls
SpriteBatch spriteBatch;
Random random = new Random();
Random randomNumberOfAsteroids = new Random();
int maxNumberOfAsteroids;
int numbersOfInvisibleEnemies;
// Lists
List<Asteroid> asteroidList = new List<Asteroid>();
List<Enemy> enemyList = new List<Enemy>();
// making player and starfield objects
Player P = new Player();
StarField starfield = new StarField();
Enemy E = new Enemy();
Boss boss = new Boss();
// Construtor
public Game1()
{
graphics = new GraphicsDeviceManager(this);
// setting full scren to off and setting screen measurments
graphics.IsFullScreen = false;
graphics.PreferredBackBufferWidth = 800;
graphics.PreferredBackBufferHeight = 850;
maxNumberOfAsteroids = 5; // Set the max number of asteroids that will be on the screen at one time ( randomly 0 to Max number)
numbersOfInvisibleEnemies = 0;
// Setting Title of screen
this.Window.Title = "Star Voyage";
Content.RootDirectory = "Content";
}
// Initialize
protected override void Initialize()
{
base.Initialize();
}
// Load content
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
// Call Load content function from Player.cs
P.LoadContent(Content);
starfield.LoadContent(Content);
boss.loadContent(Content);
}
// unload content
protected override void UnloadContent()
{
}
// update game screen
protected override void Update(GameTime gameTime)
{
// updating enemies and checking collision of thier ships to player ship
foreach (Enemy e in enemyList)
{
if (e.boundingBox.Intersects(P.boundingBox))
{
P.health -= e.enemyShipDamage;
e.isVisible = false;
}
// check enemy bullet collision with player ship
for (int i = 0; i < e.bulletList.Count; i++)
{
if (P.boundingBox.Intersects(e.bulletList[i].boundingBox))
{
P.health -= e.enemyBulletDamage;
e.bulletList[i].isVisible = false;
}
}
// check player bullet collision with enemy ships
for (int i = 0; i < P.bulletList.Count; i++)
{
if (e.boundingBox.Intersects(P.bulletList[i].boundingBox))
{
// when bullet hits enemy ship they disapear
P.bulletList[i].isVisible = false;
e.health -= P.bulletDamage;
if (e.health == 0)
e.isVisible = false;
}
}
e.Update(gameTime);
}
// for each asteroid in the asteroid list call the update function from Asteroid.cs
foreach (Asteroid a in asteroidList)
{
//Check to see if any of the arteroids are colliding with player ship
if (a.boundingBox.Intersects(P.boundingBox))
{
P.health -= a.asteroidDamage; // taking 20 off of player health bar each time the play shit is hit by an asteroid
a.isVisible = false;
}
// going through bullet list to see if any bullets come in contact with asteroids if they do set both the bullet and the asteroid to not visible
for (int i = 0; i < P.bulletList.Count; i++)
{
if (a.boundingBox.Intersects(P.bulletList[i].boundingBox))
{
a.isVisible = false;
P.bulletList.ElementAt(i).isVisible = false;
}
}
a.Update(gameTime);
}
loadAsteroids();
loadEnemyShips();
// Call fucntion Update from Player,cs
P.Update(gameTime);
// Call function update from StarField.cs
starfield.Update(gameTime);
boss.update(gameTime);
// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
base.Update(gameTime);
}
// Draw to game screen
protected override void Draw(GameTime gameTime)
{
spriteBatch.Begin();
starfield.Draw(spriteBatch);
foreach (Asteroid a in asteroidList)
{
a.Draw(spriteBatch);
}
foreach (Enemy e in enemyList)
{
e.Draw(spriteBatch);
}
// Backgound color
GraphicsDevice.Clear(Color.CornflowerBlue);
// Call Draw fuction from Player.cs
P.Draw(spriteBatch);
// boss.Draw(spriteBatch);
spriteBatch.End();
base.Draw(gameTime);
}
// Load Asteroids function
public void loadAsteroids()
{
// creating random variabls for X and Y positions of asteroids
int random_x = random.Next(0, 750), random_y = random.Next(-600, -50);
// if the number of Asteroids on the screen is less than the variable (numberOfAsteroids), create more untill it is not
if (asteroidList.Count() < randomNumberOfAsteroids.Next(0, maxNumberOfAsteroids))
{
asteroidList.Add(new Asteroid(Content.Load<Texture2D>("asteroid"), new Vector2(random_x, random_y)));
}
// if any of the asteroids from the list are destroyed (not visible) then remove them from the list
for (int i = 0; i < asteroidList.Count; i++)
{
if (!asteroidList[i].isVisible)
{
asteroidList.RemoveAt(i);
i--;
}
}
}
public void loadEnemyShips()
{
// creating random variabls for X and Y positions of asteroids
int random_x = random.Next(0, 750), random_y = random.Next(-600, -50);
// if the number of enemies on the screen is less than the variable (numberOfEnemies), create more untill it is not
if (enemyList.Count() < 3 && numbersOfInvisibleEnemies <= 9)
{
enemyList.Add(new Enemy(Content.Load<Texture2D>("enemyship"), new Vector2(random_x, random_y), Content.Load<Texture2D>("EnemyBullet")));
}
// keeping count of the number of destroied enemies
for (int i = 0; i < enemyList.Count; i++)
{
if (!enemyList[i].isVisible)
numbersOfInvisibleEnemies += 1;
// if any of the enemies from the list are destroyed (not visible) or if they go passed the bottom of the screen, then remove them from the list
if (!enemyList[i].isVisible || enemyList[i].position.Y >= 840)
{
enemyList.RemoveAt(i);
--i;
}
}
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace Space_Shooter
{
// main
public class Player
{
// Variables
public Texture2D texture , bulletTexture , healthTexture;
public Vector2 position , healthBarPosition;
public int speed;
public float health , bulletDamage , bulletDelay , bulletDelayReset;
double bulletCount;
// Lists
public List<Bullet> bulletList;
// Collision variables
public bool isColliding;
public Rectangle boundingBox , healthRectangle;
// Constructor
public Player()
{
bulletList = new List<Bullet>();
bulletDelay = 1; // for faster fire rate reduce number
bulletDelayReset = 5; // bullet delay reset has to be the same number as bullet delay
bulletCount = 1000; // amount of bullets alowed on the screen at a time
texture = null;
health = 200;
bulletDamage = 3;
healthBarPosition = new Vector2(50, 50);
position = new Vector2 (300, 300) ;
speed = 10;
isColliding = false;
}
// Load content
public void LoadContent(ContentManager Content)
{
texture = Content.Load<Texture2D>("player01");
bulletTexture = Content.Load<Texture2D>("playerbullet");
healthTexture = Content.Load<Texture2D>("healthbar");
}
// Draw
public void Draw(SpriteBatch spritebatch)
{
spritebatch.Draw(texture, position, Color.White);
spritebatch.Draw(healthTexture, healthRectangle, Color.White);
// For each Bullet b (bullet) in our bullet list, draw the bullet
foreach (Bullet b in bulletList)
{
b.Draw(spritebatch);
}
}
// Update
public void Update(GameTime gametime)
{
// Checking for keyboard input every frame
KeyboardState keystate = Keyboard.GetState();
// setting collision box for player ship
boundingBox = new Rectangle((int)position.X, (int)position.Y, texture.Width, texture.Height);
//set rectangle for healthbar (where to print on the screen and the height and width (25) is height (health is width
healthRectangle = new Rectangle((int) healthBarPosition.X, (int) healthBarPosition.Y, (int)health, 25);
if (keystate.IsKeyDown(Keys.Space))
{
shoot();
}
updateBullets();
// ship controls
if (keystate.IsKeyDown(Keys.W))
position.Y = position.Y - speed;
if (keystate.IsKeyDown(Keys.S))
position.Y = position.Y + speed;
if (keystate.IsKeyDown(Keys.A))
position.X = position.X - speed;
if (keystate.IsKeyDown(Keys.D))
position.X = position.X + speed;
// Keep ship in screen bounds
if (position.X <= 0)
position.X = 0;
if (position.X >= 800 - texture.Width)
position.X = 800 - texture.Width;
if (position.Y <= 0)
position.Y = 0;
if (position.Y >= 850 - texture.Height)
position.Y = 850 - texture.Height;
}
// Shoot Function, used to set the starting position of the players bullet
public void shoot()
{
// Shoot only if the bullet delay resets
if (bulletDelay >= 0)
bulletDelay--;
// If bulletDelay is at 0, create a new bullet at player position, make it visible on the scrren, then add that bullet to bulletList
if (bulletDelay <= 0)
{
Bullet newBullet1 = new Bullet(bulletTexture);
newBullet1.position = new Vector2(position.X - newBullet1.texture.Width / 2, position.Y + 30);
newBullet1.isVisible = true;
Bullet newBullet2 = new Bullet(bulletTexture);
newBullet2.position = new Vector2(position.X + 64 - newBullet2.texture.Width / 2, position.Y + 30);
newBullet2.isVisible = true;
// control the amount of bullets on the screen by increasing number
if (bulletList.Count() < bulletCount)
bulletList.Add(newBullet1);
bulletList.Add(newBullet2);
}
// Reset bullet dleay
if (bulletDelay == 0)
bulletDelay = bulletDelayReset;
}
public void updateBullets()
{
// for each bullet in the bulletList: update the movement and if the bullet hits the top of the screen, remove it from the list
foreach (Bullet b in bulletList)
{
// set movement for the bullets
b.position.Y = b.position.Y - b.speed;
//make a Bounding box for every bullet in the bullet list
b.boundingBox = new Rectangle((int)b.position.X, (int)b.position.Y, b.texture.Width, b.texture.Height);
// if a bullet hits the top of the screen, then make visable false
if (b.position.Y <= 0)
b.isVisible = false;
}
// go through the bulletList and see if any of the bullets are not visible, if they are not then remove that bullet from the bulletList
for (int i = 0; i < bulletList.Count; i++)
{
if (!bulletList[i].isVisible)
{
bulletList.RemoveAt(i);
i--;
}
}
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace Space_Shooter
{
public class Bullet
{
public Rectangle boundingBox;
public Texture2D texture;
public Vector2 position , origin;
public float speed;
public bool isVisible;
public Bullet(Texture2D newTexture)
{
speed = 25;
texture = newTexture;
isVisible = false;
}
public void Draw(SpriteBatch spritebatch)
{
spritebatch.Draw(texture, position, Color.White);
}
}
}

You initialize the list in the constructor:
public Boss(Texture2D newTexture, Vector2 newPosition, Texture2D newBulletTexture)
But, you don't call this constructor. You call Boss boss = new Boss();
Thus the constructor which initializes the list is not called.
You should initialize the list in all constructors:
public Boss()
{
bulletList = new List<Bullet>();
}
Better is too make the default constructor set all the default values, and if you need to set other values in another constructor, is to call the default constructor from the "second" constructor using : this():
public Boss()
{
bulletList = new List<Bullet>();
bulletSpeed = 25;
bulletDamage = 25;
shipDamage = p.health / 2;
health = 2000;
bulletDelayTime = 30;
bulletDelayTimeReset = 30;
MaxBullets = 30;
isVisible = true;
}
public Boss(Texture2D newTexture, Vector2 newPosition, Texture2D newBulletTexture)
: this() //Call default constructor
{
texture = newTexture;
position = newPosition;
bulletTexture = newBulletTexture;
}

XNA c# Sprite remain after mouseclick

I have a question.
Is there a way to make sprite remain after mouseclick on it without making a List of sprites? I mean, my code generates sprite randomly at the screen and if I hit red sprite it dissappear. How to make red sprites stay on the screen after click?
Here is my code:
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace Ghost
{
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
Texture2D ghostPic;
Texture2D background;
Random rand;
int ghostColour;
Rectangle ghostLocation;
float timeRemaining;
float showTime;
int score;
MouseState mouseState, mouseStatePrevious;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
}
protected override void Initialize()
{
graphics.PreferredBackBufferHeight = 550;
graphics.PreferredBackBufferWidth = 750;
this.IsMouseVisible = true;
this.Window.Title = "Ghost Hunt | Score: 0";
this.Window.AllowUserResizing = true;
showTime = 0.5f;
rand = new Random();
base.Initialize();
}
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
ghostPic = Content.Load<Texture2D>("GhostPic");
background = Content.Load<Texture2D>("Background");
// TODO: use this.Content to load your game content here
}
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}
protected override void Update(GameTime gameTime)
{
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
if (Keyboard.GetState(PlayerIndex.One).IsKeyDown(Keys.Escape))
this.Exit();
mouseState = Mouse.GetState();
if (mouseState.LeftButton == ButtonState.Pressed && mouseStatePrevious.LeftButton == ButtonState.Released && ghostLocation.Contains(mouseState.X, mouseState.Y))
{
if (ghostColour == 0) score++;
if (ghostColour == 1)
{
score--;
}
this.Window.Title = "Ghost Hunt | Score: " + score.ToString();
timeRemaining = 0.0f;
}
else
{
timeRemaining = MathHelper.Max(0, timeRemaining - (float)gameTime.ElapsedGameTime.TotalSeconds);
}
mouseStatePrevious = mouseState;
if (timeRemaining == 0.0f)
{
ghostColour = rand.Next(2);
ghostLocation = new Rectangle(rand.Next(GraphicsDevice.Viewport.Bounds.Width - ghostPic.Width), rand.Next(GraphicsDevice.Viewport.Bounds.Height - ghostPic.Height), ghostPic.Width / 2, ghostPic.Height / 2);
timeRemaining = showTime;
}
base.Update(gameTime);
}
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin();
spriteBatch.Draw(background, new Rectangle(0,0,GraphicsDevice.Viewport.Bounds.Width,GraphicsDevice.Viewport.Bounds.Height), Color.White);
switch (ghostColour)
{
case 0:
spriteBatch.Draw(ghostPic, ghostLocation, Color.White * 0.7f);
break;
case 1:
spriteBatch.Draw(ghostPic, ghostLocation, new Color(255,0,0,50));
break;
}
spriteBatch.End();
base.Draw(gameTime);
}
}
}

I suppose you could make an array like Sprite[] instead of a List but the redraw will still clear your screen and redraw it entirely, clearing any non-stored drawables.
What could be fun is making a LinkedList instead where you keep the last 10 sprites saved, throw away the first when 10 is reached. This would allow you to draw a trail of sprites that follows the position of your current sprite drawing.

How to generate infinitly enemies in XNA? [closed]

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I was developing a game using XNA frame work and here is my code
I just want to generate infinite number of enemies
here is my code please help
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace fight_in_the_sky
{
/// <summary>
/// This is the main type for your game
/// </summary>
///
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spritebatch;
Texture2D anim, background1, background2, enemy;
Rectangle rect0, rect2, rectdst, srcrect, rect3, rect4, srcrect2, enemy_rect;
float elapsed;
float delay = 40f;
int frames = 0;
Random random = new Random();
public Vector2 velocity;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
graphics.PreferredBackBufferWidth = 800;
graphics.PreferredBackBufferHeight = 600;
IsMouseVisible = true;
}
protected override void Initialize()
{
// TODO: Add your initialization logic here
rectdst = new Rectangle(0, 250, 115, 69);
rect3 = new Rectangle(0,0,1280,720);
rect4 = new Rectangle(1280, 0, 1280, 720);
enemy_rect = new Rectangle(random.Next(800-94,800-47),random.Next(600-122,600-61),376/8,61);
velocity.X = 3f;
velocity.Y = 3f;
base.Initialize();
}
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spritebatch = new SpriteBatch(GraphicsDevice);
background1= Content.Load<Texture2D>("starfield006");
background2= Content.Load<Texture2D>("starfield005");
anim=Content.Load<Texture2D>("shipAnimation");
enemy =Content.Load<Texture2D>("mineAnimation");
rect0 = new Rectangle(0, 0, 800, 600);
rect2 = new Rectangle(0, 250,200, 100);
// TODO: use this.Content to load your game content here
}
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}
protected override void Update(GameTime gameTime)
{
// Allows the game to exit
// if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
// this.Exit();
// TODO: Add your update logic here
elapsed += (float)gameTime.ElapsedGameTime.Milliseconds;
if (Keyboard.GetState().IsKeyDown(Keys.Left))
{
rectdst.X -= 12;
if (rectdst.X < 0) { rectdst.X = 0; }
}
if (Keyboard.GetState().IsKeyDown(Keys.Right))
{
rectdst.X += 12;
if (rectdst.X > 700) { rectdst.X = 700; }
}
if (Keyboard.GetState().IsKeyDown(Keys.Up))
{
rectdst.Y -= 12;
if (rectdst.Y < 0) { rectdst.Y = 0; }
}
if (Keyboard.GetState().IsKeyDown(Keys.Down))
{ rectdst.Y += 10; if (rectdst.Y > 550) { rectdst.Y = 550; } }
base.Update(gameTime);
if (elapsed >= delay)
{
if (frames >= 7)
{ frames = 0; }
else { frames++; }
elapsed = 0;
}
srcrect = new Rectangle(115 * frames, 0, 115, 69);
srcrect2 = new Rectangle(47*frames,0,47,61);
if (rect3.X + background1.Width <= 0)
rect3.X = rect4.X + background2.Width;
if (rect4.X + background2.Width <= 0)
rect4.X = rect3.X + background1.Width;
rect3.X -= 5;
rect4.X -= 5;
enemy_rect.X +=(int) velocity.X;
enemy_rect.Y += (int)velocity.Y;
if (enemy_rect.Y >= 600 - 61 || enemy_rect.Y <= 0) velocity.Y = -velocity.Y;
if (enemy_rect.X >= 800 - 47) velocity.X = -velocity.X;
}
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
// TODO: Add your drawing code here
spritebatch.Begin();
spritebatch.Draw(background1,rect3, Color.Azure);
spritebatch.Draw(background2,rect4, Color.Azure);
spritebatch.Draw(anim, rectdst, srcrect, Color.White);
spritebatch.Draw(enemy, enemy_rect, srcrect2, Color.White);
spritebatch.End();
base.Draw(gameTime);
}
}
}
and here is a shot of my current output
http://imgur.com/7y43S7O

Infinite is unpractical to build into a game, because sooner or later you would either run out of RAM or your screen would be too full to call it a game. Anyway, I can give you a basic idea to work with.
If you want your enemy count to keep increasing you can use a list and add an enemy every time you want one to appear
List<Enemy> enemies = new List<Enemy>;
In Update:
if(spawnTimer > spawnInterval && enemies.Count()<enemyLimit){
enemies.add(new Enemy([rectangle of spawn location and image size]);
spawnTimer = 0;
}
for(int i=0; i<enemies.Count();i++){
if(enemies[i].defeated){
enemies.Remove(enemies[i]);
}
spawnTimer+=gameTime.ElapsedGameTime.TotalSeconds;
in Draw:
for(int i=0; i<enemies.Count();i++){
spritebatch.Draw(enemy, enemies[i].Rect, srcrect2, Color.White);
}
class Enemy{
public Rectangle Rect{get;set;}
public bool defeated{get;set;}
public int Health{get;set;}
public Enemy(Rectangle rect){
Rect = rect;
Health = 100;
defeated = false;
}
}

Player collision on a singe image map

The problem that I am having is wrapping my brain around how I could use a single png called Test Map.png:
This has a black border around the screen and smaller stepping blocks for the player to test the collision. I have the gravity working by using a player class and the main class Game1.cs to draw and update the game. I use this ball:
This is my sprite that I move around the screen.
Here is the player.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
namespace Gravity_Test_V2
{
class Player
{
public Texture2D Texture;
public Vector2 Velocity;
public Vector2 Position;
public float ground;
private float Speed;
private Rectangle screenBound;
public bool isJumping; //are we jumping or not
public bool goingUp; //if going up or not
public float initialVelocity; //initial velocity
private float jumpU; //How high the player can jump
private float g; //gravity
public float t; //time
private KeyboardState prevKB;
public Player(Texture2D Texture, Vector2 Position, float Speed, Rectangle screenBound)
{
this.Texture = Texture;
this.Position = Position;
ground = Position.Y;
this.Speed = Speed;
this.screenBound = screenBound;
Velocity = Vector2.Zero;
isJumping = goingUp = true;
jumpU = 2.5f;
g = -9.8f;
t = 0;
}
public void Update(GameTime gameTime)
{
Position.X += (Velocity.X * Speed);
//Set the Y position to be subtracted so that the upward movement would be done by decreasing the Y value
Position.Y -= (Velocity.Y * Speed);
goingUp = (Velocity.Y > 0);
// TODO: Add your update logic here
if (isJumping == true)
{
//motion equation using velocity: v = u + at
Velocity.Y = (float)(initialVelocity + (g * t));
//Increase the timer
t += (float)gameTime.ElapsedGameTime.TotalSeconds;
}
if (isJumping == true && Position.Y > screenBound.Height - Texture.Height)
{
Position.Y = ground = screenBound.Height - Texture.Height;
Velocity.Y = 0;
isJumping = false;
t = 0;
}
if (Position.X < 0)
{
//if Texture touches left side of the screen, set the position to zero and the velocity to zero.
Position.X = 0;
Velocity.X = 0;
}
else if (Position.X + Texture.Width > screenBound.Width)
{
//if Texture touches left side of the screen, set the position to zero and the velocity to zero.
Position.X = screenBound.Width - Texture.Width;
Velocity.X = 0;
}
if (Position.Y < 0)
{
//if the Texture touches the top of the screen, reset the timer and set the initial velocity to zero.
Position.Y = 0;
t = 0;
initialVelocity = 0;
}
}
public void Input(KeyboardState keyState)
{
if (keyState.IsKeyDown(Keys.Space) && (isJumping == false || Position.Y == ground))
{
isJumping = true;
initialVelocity = jumpU;
}
if (keyState.IsKeyDown(Keys.Left) && !keyState.IsKeyDown(Keys.Right))
{
if (Velocity.X > -1.0f)
{
Velocity.X -= (1.0f / 10);
}
else
{
Velocity.X = -1.0f;
}
}
else if (!keyState.IsKeyDown(Keys.Left) && keyState.IsKeyDown(Keys.Right))
{
if (Velocity.X < 1.0f)
{
Velocity.X += (1.0f / 10);
}
else
{
Velocity.X = 1.0f;
}
}
else
{
if (Velocity.X > 0.05 || Velocity.X < -0.05)
Velocity.X *= 0.70f;
else
Velocity.X = 0;
}
prevKB = keyState;
}
public void Fall()
{
t = 0;
initialVelocity = 0;
}
public void Draw(SpriteBatch spriteBatch)
{
spriteBatch.Draw(Texture, new Rectangle((int)Position.X, (int)Position.Y, Texture.Width, Texture.Height), Color.White);
}
}
}
Is there some simple way to make it so the player can collide with the Test Map.png while its inside the Test Map's texture?
EDIT: 1/21/2014 9 AM 'ish'
Level One:
EDIT: 1/21/2014 10:27
I have used a pixle based system to test to see if the player colides with an object but I try to sepreate the object from the play into classes and it will stop working. I mixed both my movment and collision projects together to try and make it work. I took player.cs (witch I have not changed) and added the pixel based collision into the Game1.cs I need to know how to make the player, witch is being controlled by the player.cs class, be seen by the Game1.cs class and used while being called upon by the player.cs class.
Note* I have also changed it so that the game would be using the falling triangles supplied by the pixel based system. I will add the test image when I am able to make this work.
At the moment The player can move and jump but is not reconsidered as colliding.
EDIT: 1/21/2014 10:34
I use 2 projects:
Collision:
http://xbox.create.msdn.com/en-US/education/catalog/tutorial/collision_2d_perpixel
Movment System:
http://gamepopper.co.uk/academic-projects/2012-2/jumping-platformer-example/
I have mixed them up and used pices of them to try and make my own platform.
Game1.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace Collision_Test
{
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
KeyboardState prevKB;
Player player;
SpriteFont font;
Texture2D personTexture;
Texture2D blockTexture;
// The color data for the images; used for per pixel collision
Color[] personTextureData;
Color[] blockTextureData;
Vector2 personPosition;
const int PersonMoveSpeed = 5;
public static int screenWidth = 800;
public static int screenHeight = 500;
// Blocks
List<Vector2> blockPositions = new List<Vector2>();
float BlockSpawnProbability = 0.01f;
const int BlockFallSpeed = 1;
Random random = new Random();
// For when a collision is detected
bool personHit = false;
// The sub-rectangle of the drawable area which should be visible on all TVs
Rectangle safeBounds;
// Percentage of the screen on every side is the safe area
const float SafeAreaPortion = 0.05f;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
this.graphics.PreferredBackBufferWidth = screenWidth;
this.graphics.PreferredBackBufferHeight = screenHeight;
this.graphics.ApplyChanges();
}
protected override void Initialize()
{
base.Initialize();
// Calculate safe bounds based on current resolution
Viewport viewport = graphics.GraphicsDevice.Viewport;
safeBounds = new Rectangle(
(int)(viewport.Width * SafeAreaPortion),
(int)(viewport.Height * SafeAreaPortion),
(int)(viewport.Width * (1 - 2 * SafeAreaPortion)),
(int)(viewport.Height * (1 - 2 * SafeAreaPortion)));
// Start the player in the center along the bottom of the screen
personPosition.X = (safeBounds.Width - personTexture.Width) / 2;
personPosition.Y = safeBounds.Height - personTexture.Height;
}
/// <summary>
/// Load your graphics content.
/// </summary>
protected override void LoadContent()
{
blockTexture = Content.Load<Texture2D>("Block");
personTexture = Content.Load<Texture2D>("Person");
font = Content.Load<SpriteFont>("Font");
player = new Player(personTexture, Vector2.Zero, 6.0f, new Rectangle(0, 0,
this.graphics.PreferredBackBufferWidth,
this.graphics.PreferredBackBufferHeight));
// Extract collision data
blockTextureData =
new Color[blockTexture.Width * blockTexture.Height];
blockTexture.GetData(blockTextureData);
personTextureData =
new Color[personTexture.Width * personTexture.Height];
personTexture.GetData(personTextureData);
// Create a sprite batch to draw those textures
spriteBatch = new SpriteBatch(graphics.GraphicsDevice);
}
void HandleInput(KeyboardState keyState)
{
player.Input(keyState);
if (prevKB.IsKeyUp(Keys.F) && keyState.IsKeyDown(Keys.F))
{
this.graphics.ToggleFullScreen();
this.graphics.ApplyChanges();
}
}
protected override void Update(GameTime gameTime)
{
// Get input
KeyboardState keyboard = Keyboard.GetState();
GamePadState gamePad = GamePad.GetState(PlayerIndex.One);
HandleInput(Keyboard.GetState());
player.Update(gameTime);
prevKB = Keyboard.GetState();
// Allows the game to exit
if (gamePad.Buttons.Back == ButtonState.Pressed ||
keyboard.IsKeyDown(Keys.Escape))
{
this.Exit();
}
// Spawn new falling blocks
if (random.NextDouble() < BlockSpawnProbability)
{
float x = (float)random.NextDouble() *
(Window.ClientBounds.Width - blockTexture.Width);
blockPositions.Add(new Vector2(x, -blockTexture.Height));
}
// Get the bounding rectangle of the person
Rectangle personRectangle =
new Rectangle((int)personPosition.X, (int)personPosition.Y,
personTexture.Width, personTexture.Height);
// Update each block
personHit = false;
for (int i = 0; i < blockPositions.Count; i++)
{
// Animate this block falling
blockPositions[i] =
new Vector2(blockPositions[i].X,
blockPositions[i].Y + BlockFallSpeed);
// Get the bounding rectangle of this block
Rectangle blockRectangle =
new Rectangle((int)blockPositions[i].X, (int)blockPositions[i].Y,
blockTexture.Width, blockTexture.Height);
// Check collision with person
if (IntersectPixels(personRectangle, personTextureData,
blockRectangle, blockTextureData))
{
personHit = true;
}
// Remove this block if it have fallen off the screen
if (blockPositions[i].Y > Window.ClientBounds.Height)
{
blockPositions.RemoveAt(i);
// When removing a block, the next block will have the same index
// as the current block. Decrement i to prevent skipping a block.
i--;
}
}
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 device = graphics.GraphicsDevice;
// Change the background to red when the person was hit by a block
if (personHit)
{
device.Clear(Color.Red);
}
else
{
device.Clear(Color.CornflowerBlue);
}
spriteBatch.Begin();
player.Draw(spriteBatch);
// Draw blocks
foreach (Vector2 blockPosition in blockPositions)
spriteBatch.Draw(blockTexture, blockPosition, Color.White);
spriteBatch.End();
base.Draw(gameTime);
}
/// <summary>
/// Determines if there is overlap of the non-transparent pixels
/// between two sprites.
/// </summary>
/// <param name="rectangleA">Bounding rectangle of the first sprite</param>
/// <param name="dataA">Pixel data of the first sprite</param>
/// <param name="rectangleB">Bouding rectangle of the second sprite</param>
/// <param name="dataB">Pixel data of the second sprite</param>
/// <returns>True if non-transparent pixels overlap; false otherwise</returns>
static bool IntersectPixels(Rectangle rectangleA, Color[] dataA,
Rectangle rectangleB, Color[] dataB)
{
// Find the bounds of the rectangle intersection
int top = Math.Max(rectangleA.Top, rectangleB.Top);
int bottom = Math.Min(rectangleA.Bottom, rectangleB.Bottom);
int left = Math.Max(rectangleA.Left, rectangleB.Left);
int right = Math.Min(rectangleA.Right, rectangleB.Right);
// Check every point within the intersection bounds
for (int y = top; y < bottom; y++)
{
for (int x = left; x < right; x++)
{
// Get the color of both pixels at this point
Color colorA = dataA[(x - rectangleA.Left) +
(y - rectangleA.Top) * rectangleA.Width];
Color colorB = dataB[(x - rectangleB.Left) +
(y - rectangleB.Top) * rectangleB.Width];
// If both pixels are not completely transparent,
if (colorA.A != 0 && colorB.A != 0)
{
// then an intersection has been found
return true;
}
}
}
// No intersection found
return false;
}
}
}

Provided the background of the texture is transparent, you could use Per-Pixel Collision detection.
Essentially it checks the pixels rather than a rectangular box to determine if a collision has occurred. Given your "player" is a ball, it's probably a good idea to use this anyway.

Considering that your map is only black & White, you could process it before starting the game and obtain coords of every Rectangle of black areas, and then use it to use simple collision detection by just checking intersection between the ball bounding box and rectangles.
For example, in pseudocode:
You have a list:
List<Rectangle> rects = new List<Rectangle>();
void LoadMap()
{
Texture2D map = Content.Load<Texture2D>(#"TexturePath");
//Get a 1D array with image's pixels
Color[] map_pixels = new Color[map.Width * map.Height];
map.GetData(map_pixels);
//Convert it in a 2D array
Color[,] map_pixels_2D = new Color[map.Width, map.Height];
for (int x = 0; x < map.Width; x++)
for (int y = 0; y < map.Height; y++)
map_pixels_2D[x, y] = map_pixels[x + y * map.Width];
//**NOTE THAT**: From here it is just an example, probably not working good,
//I wrote it just to share the idea
//Here goes the code to trace rectangles in the map
Rectangle r = Rectangle.Empty;
bool NWvertex_done = false, NEvertex_done = false, SWvertex_done = false;
for (int x = 0; x < map.Width; x++)
{
if (!SWvertex_done)
{
if (map_pixels_2D[x, y+1] == Color.White); //last bottom vertex
{
r.Height = r.Y + y;
SWvertex_done = true;
rects.Add(r);
NWvertex_done = false;
NEvertex_done = false;
r = Rectangle.Empty;
}
}
for (int y = 0; y < map.Height; y++)
{
if (map_pixels_2D[x, y] != Color.White
{
if (!NWvertex_done)
{
SWvertex_done = false;
r.X = x;
r.Y = y;
NWvertex_done = true;
}
else if(!NEvertex_done)
{
if (map_pixels_2D[x, y+1] == Color.White); //last right vertex
{
r.Width = r.X + x;
NEvertex_done = true;
}
}
}
}
}
}
public override void Update(GameTime gametime)
{
//maybe other things
//
foreach (Rectangle rect in rects)
{
//Better with Distance of ball-center and rect
if (ballRect.Intersect(rect))
{
//there is a collision!
//Do something
}
break;
}
//maybe other things
//
}