Moving Draw() code to a Class - c#

I'm creating a game in monogame, and I've loaded tiles in my game inside the Draw() function like so:
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin();
spriteBatch.Draw(danChar, charPosition, Color.White);
// loop below loads the 'grass' tiles only
// assuming gameworld size of 770x450
for (int i = 0; i < 770; i += 31) // adds 31 to i (per tile)
{
position = new Vector2(i, 392); // places incrementation into vector position
spriteBatch.Draw(gameTile, position, Color.White); // draws the tile each time
if (i == 744)
{
i = i + 26; // fills last space between 744 and 770
position = new Vector2(i, 392);
}
spriteBatch.Draw(gameTile, position, Color.White);
}
// loop below loads the brick tiles only (ones without grass)
spriteBatch.End(); // ends the spriteBatch call
base.Draw(gameTime);
}
However I would prefer that this was a separate class rather than being placed directly into the draw function, however I'm not too sure how to do this and would appreciate any help given.
Thanks in advance!

If you just want to move the code as is to another class, create your class (e.g. something like GameWorld seems to appropriate for your code)
public class GameWorld
{
// You may wish to move your gameTile definition into this class if it is the only
// class that uses it, and handle the content loading for it in here.
// e.g. if you're currently loading the texture in the LoadContent method in your game
// class, create a LoadContent method here and pass in ContentManger as a parameter.
// I've passed in the texture as a parameter to the Draw method in this example to
// simplify as I'm not sure how you're managing your textures.
public void Draw(SpriteBatch spriteBatch, GameTime gameTime, Texture2D gameTile)
{
// loop below loads the 'grass' tiles only
// assuming gameworld size of 770x450
for (int i = 0; i < 770; i += 31) // adds 31 to i (per tile)
{
Vector2 position = new Vector2(i, 392); // places incrementation into vector position
spriteBatch.Draw(gameTile, position, Color.White); // draws the tile each time
if (i == 744)
{
i = i + 26; // fills last space between 744 and 770
position = new Vector2(i, 392);
}
spriteBatch.Draw(gameTile, position, Color.White);
}
// loop below loads the brick tiles only (ones without grass)
}
}
Then the Draw method in your Game class would look like
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin();
spriteBatch.Draw(danChar, charPosition, Color.White);
// Assuming you've created/loaded an instance of the GameWorld class
// called gameWorld in Initialize/LoadContent
gameWorld.Draw(spriteBatch, gameTime, gameTile);
spriteBatch.End(); // ends the spriteBatch call
base.Draw(gameTime);
}
Just make sure you're calling the Draw methods in the correct order. e.g. you want your player to appear above any background tiles.
I believe the default SpriteSortMode is Deferred which draws in the order the calls are made (i.e. from the back to the front).
You can specify a different SpriteSortMode in your call to spriteBatch.Begin() if you need to but for a simple game just move the Draw calls around.
More info on SpriteSortMode at MSDN if needed.
Similarly you can chain your Update, LoadContent methods into these classes if you wish, making sure to pass in anything you need as arguments.
Update:
To define gameWorld as an instance of the GameWorld class, you define it near the top of your game class, then typically initialize it in the Initialize method.
So your game class will look something like
public class MyGameName : Microsoft.Xna.Framework.Game
{
private SpriteBatch spriteBatch;
// other variable declarations
// Add a declaration for gameWorld
private GameWorld gameWorld;
protected override Initialize()
{
// Add the following line to initialize your gameWorld instance
gameWorld = new GameWorld();
}
// other existing code - your LoadContent, Update, Draw methods etc.
}

Related

Why do games sometimes skip frames in monogame/xna?

This is a simple project created from MonoGame Cross-Platform Desktop template. I created a ball Texture2D and tried to make it move.So I added some code to the Update function.
position.X += 3;
And then in the Draw function
_spriteBatch.Begin();
_spriteBatch.Draw(ballTexture, position, Color.White);
_spriteBatch.End();
I can see the ball flashing sometimes.
Why is that and what can I do to make it not skip frames?
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
namespace SimpleTest
{
public class Game1 : Game
{
private GraphicsDeviceManager _graphics;
private SpriteBatch _spriteBatch;
private Texture2D dirtTexture;
private Vector2 position;
private int direction = 1;
public Game1()
{
_graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
IsMouseVisible = true;
}
protected override void Initialize()
{
// TODO: Add your initialization logic here
base.Initialize();
}
protected override void LoadContent()
{
_spriteBatch = new SpriteBatch(GraphicsDevice);
// TODO: use this.Content to load your game content here
dirtTexture = Content.Load<Texture2D>("dirt");
}
protected override void Update(GameTime gameTime)
{
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
Exit();
// TODO: Add your update logic here
base.Update(gameTime);
if (position.X > 600)
direction = -1;
else if (position.X < 100)
direction = 1;
position.X = position.X + direction * 3;
}
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
// TODO: Add your drawing code here
_spriteBatch.Begin();
_spriteBatch.Draw(dirtTexture, position, Color.White);
_spriteBatch.End();
base.Draw(gameTime);
}
}
}
I think base.Update(gameTime); should only be placed at the very end of the Update() Method, Just like base.Draw(gameTime);. That way it won't skip any lines.
I guess your PC might be running slowly which is the problem, and not your code. To test it, you can replace your Draw method as follows:
protected override void Draw(GameTime gameTime)
{
Color color=gameTime.IsRunningSlowly?Color.Red:Color.CornflowerBlue;
GraphicsDevice.Clear(color);
// TODO: Add your drawing code here
_spriteBatch.Begin();
_spriteBatch.Draw(dirtTexture, position, Color.White);
_spriteBatch.End();
base.Draw(gameTime);
}
Everything is the same, except now we are colouring the screen as Red instead of the usual blue only if the game is in fact running slow (Which is due to your PC). We can know this by the gameTime variable as shown in the first two lines of the method. Test it out and see if you can see the game background going red when the "frame-skipping" happens.
I did test your exact code in my PC and it was working fine. Needless to say, I did use some other png I had instead of the "dirt" Texture2D you used but I don't think that it should be necessary.
Perhaps it's due to GC. You could use my -almost- garbage free build to verify.
You can install the updated SDK from here or the nuget package.

Xna draw order not working right

I have an 2d array of Texture2D, it holds the different parts of the map in this array. I have a problem though, when I run the game, the map is drawn correctly but for some reason the array[0, 0] texture overlaps all my textures including my player texture and mouse texture. Every other texture works as my mouse and player texture correctly overlaps the map.
I'm really confused right now as the map textures are being drawn together using a nested for loop.
Here is my draw method for my map which I call in the Game's Draw method:
public void Draw()
{
// Draws the Map from a 2D Array
for (int row = 0; row < mapTexture.GetLength(0); row++)
{
for (int col = 0; col < mapTexture.GetLength(1); col++)
{
spriteBatch.Draw(mapTexture[row, col], mapPosition[row, col], Color.White);
}//end for
}//end for
}//end Draw()
My actual draw method:
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin(SpriteSortMode.BackToFront, BlendState.AlphaBlend);
spriteBatch.Draw(mouseIcon, mouseIconPosition, Color.White);
player.Draw();
map.Draw();
spriteBatch.End();
base.Draw(gameTime);
}//end Draw()
Try inverting the order that they're drawn, AND use SpriteSortMode.Deferred
You can try use overloaded SpriteBatch.Draw method with depth. As example:
SpriteBatch.Draw (Texture2D, Vector2, Nullable, Color, Single, Vector2, Single, SpriteEffects, Single) Adds a sprite to the batch of sprites to be rendered, specifying the texture, screen position, optional source rectangle, color tint, rotation, origin, scale, effects, and sort depth.
or can try change order for drawing:
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend);
map.Draw(); // first
player.Draw(); // second
spriteBatch.Draw(mouseIcon, mouseIconPosition, Color.White); // third
spriteBatch.End();
base.Draw(gameTime);
}//end Draw()
(its for SpriteSortMode.Deferred)
P.S. Sorry for google-translating
oops... I have not updated comments before responding

Draw() method in XNA stops working inside a for loop

So far, this is my first XNA game and I'm having real trouble trying to learn this.
I'm following a tutorial from Microsoft, found here: XNA Xbox Live Indie Games
Every now and again, the code breaks. Admittedly, I have taken a couple of bits out that I didn't think I'd need and I've created two enemy classes rather than just the one, but I don't think I hit any major faultlines with my adjustments.
In the Draw() method in the main Game1.cs file, I've had to include a for loop that will iterate through a list of available enemies and draw them upon update. However, the line of code flags up as incorrect, and I have absolutely no idea why. I followed the tutorial, and it looks like it should work, but it doesn't. Here's the entire Draw() method:
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.ForestGreen);
backRect.Width = 800;
backRect.Height = 480;
// TODO: Add your drawing code here
// Start drawing
spriteBatch.Begin();
spriteBatch.Draw(backgroundTexture, backRect, Color.White);
// Draw the Player
player.Draw(spriteBatch);
for (int i = 0; i < goblins.Count; i++)
{
goblins[i].Draw(spriteBatch);
}
// Stop drawing
spriteBatch.End();
base.Draw(gameTime);
}
It's the code inside the for loop that won't work. Any ideas how to fix it and/or any suggestions for a better tutorial?
I like this tutorial a lot:
http://xbox.create.msdn.com/en-US/education/tutorial/2dgame/getting_started
It got me started off pretty well.
You always need to call SpriteBatch.Begin() and SpriteBatch.End() on your sprite-batches. I am not sure about mixing them, but try to avoid it and use as few spritebatches as possible.
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.ForestGreen);
backRect.Width = 800;
backRect.Height = 480;
// TODO: Add your drawing code here
// Start drawing
spriteBatch.Begin();
spriteBatch.Draw(backgroundTexture, backRect, Color.White);
// Draw the Player
spriteBatch.Draw(playerTexture, playerRect, Color.White);
for (int i = 0; i < goblins.Count; i++)
{
spriteBatch.Draw(goblins[i].Texture, goblins[i].Rect, Color.White);
}
// Stop drawing
spriteBatch.End();
base.Draw(gameTime);
}
See here for the documentation.

Drawing a "floor" texture

Alright, let's say that I have a tile texture of some floor or something. And I'd like that my player will walk on that.
How can I set this tile to make it a as a floor?
I need this tile texture to be all over the screen width right?
How am I doing it?
Thanks
If you want a really easy way, here it is:
First you create a new Class and name it Tile:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework; // Don't forget those, they will let you
using Microsoft.Xna.Framework.Content; // access some class like:
using Microsoft.Xna.Framework.Graphics; // Texture2D or Vector2
namespace Your_Project _Name
{
class Tile
{
}
{
So far so good, now create the Texture and Position in your class just like this:
namespace Your_Project _Name
{
class Tile
{
Texture2D texture;
Vector2 position;
public void Initialize()
{
}
public void Draw()
{
}
}
{
As you can see I also created two Methods, Initialize and Draw, now we will Initialize our
texture and position for the tile texture in the public void Initialize(),
I don't know how you use your ContentManager but here is a easy way:
public void Initialize(ContentManager Content)
{
texture = Content.Load<Texture2D>("YourfloorTexture"); //it will load your texture.
position = new Vector2(); //the position will be (0,0)
}
Now we need to draw our texture a number of time how will we do that? The way thasc said, the code can be more complex but here is one that you will understand, I will add a SpriteBatch so I can Draw. All this is done in the public void Draw():
public void Draw(SpriteBatch spriteBatch)
{
for (int i=0; i<30;i++) //will do a loop 30 times. Each Time i will =
//a valor from 0 to 30.
{
spriteBatch.Draw(texture, position, Color.White);
//Will draw the texture once, at the position Vector2
//right now position = (0,0)
spriteBatch.Draw(texture, new Vector2((int)i,(int)i), Color.White);
//Will Draw the texture 30 times, the first time on the position (0,0)
//Second Time on (1,1) .. third (2,2) etc...
spriteBatch.Draw(texture, new Vector2((int)position.X + (i * texture.Width), (int)position.Y + (i * texture.Height), Color.White));
//Will Draw the Texture 30 times Spaced by the Width and height
//of the texture (this is the code you need)
}
}
I didn't tried it but it should work, now its just a sample, you can figure out the rest. There is a lot of other methods to do it but this one is really easy. Ok, now the final step is to implement this class so go in your principal class where you have all your code and before this:
public Game1()
Create a new instance of your tile class
Tile tile;
and Initialize it in the protected override void Initialize():
tile = new Tile();
tile.Initialize(Content);
Now you have to draw it on the screen go at the end of the class and find protected override void Draw(GameTime gameTime) and call the draw method of our class:
spriteBatch.Begin();
tile.Draw(spriteBatch);
spriteBatch.End();
This is all the steps to complete a plain simple tile system. As I said there is a lot of others methods you just have to read tutorials about them or create them on your own.
If you don't plan on doing anything extra with the tiled background, I'd recommend thasc's solution and tile the sprite in a single call.
To do that, you create a rectangle as large as your background, and pass SamplerState.LinearWrap to SpriteBatch.Begin, then call Draw on the background rectangle.
Rectangle backgroundRect = new Rectangle(0, 0, backWidth, backHeight);
spriteBatch.Begin(..., ..., SamplerState.LinearWrap, ..., ...);
spriteBatch.Draw(backgroundTexture, backgroundRect, Color.White);
spriteBatch.End();
In case you're curious, what this does is create a single polygon that covers the background area, which will grab coordinates off your texture from 0.0f to backWidth. Textures are usually mapped between (0.0f, 0.0f) and (1.0f, 1.0f), which represent the corners of the given texture. If you go beyond these boundaries, TextureAddressMode defines how these coordinates will be treated:
Clamp will cut down the coordinates back into the 0-1 range.
Wrap will wrap the coordinates back to 0, so 0.0 = 2.0 = 4.0 = etc. and 1.0 = 3.0 = 5.0 = etc.
Mirror will also wrap, but mirroring the texture every other pass, basically going left-to-right-to-left-etc. as the polygon is rendered.

XNA C# Code Question

Here is my class I made to draw a HUD:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework;
namespace Sleyser1
{
public class Hud
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
Texture2D tempHUD;
Rectangle viewportRect;
SpriteFont HUD;
Vector2 FontPos;
Vector2 FontPos2;
public void Hud()
{
HUD = Content.Load<SpriteFont>("HUD");
FontPos = new Vector2(40, 20);
FontPos2 = new Vector2(150, 20);
spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, null, null, null);
spriteBatch.Draw(tempHUD, viewportRect, Color.White);
string output = "Health:";
string output2 = "Magic:";
Vector2 FontOrigin = HUD.MeasureString(output) / 2;
spriteBatch.DrawString(HUD, output, FontPos, Color.Red, 0, FontOrigin, 1.0f, SpriteEffects.None, 0.5f);
spriteBatch.DrawString(HUD, output2, FontPos2, Color.Blue, 0, FontOrigin, 1.0f, SpriteEffects.None, 0.5f);
spriteBatch.End();
}
}
}
So how do I call it from here so that it draws.
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
base.Draw(gameTime);
}
The question I am asking is how do you call a class from a method?
public void Hud()
is actually the constructor of your class, it should not be responsible for drawing (especially since you draw the same class many times and the purpose of the constructor is to ...construct a class)
So, the first step is to remove this:
spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, null, null, null);
spriteBatch.Draw(tempHUD, viewportRect, Color.White);
string output = "Health:";
string output2 = "Magic:";
Vector2 FontOrigin = HUD.MeasureString(output) / 2;
spriteBatch.DrawString(HUD, output, FontPos, Color.Red, 0, FontOrigin, 1.0f, SpriteEffects.None, 0.5f);
spriteBatch.DrawString(HUD, output2, FontPos2, Color.Blue, 0, FontOrigin, 1.0f, SpriteEffects.None, 0.5f);
spriteBatch.End();
from the constructor and add it to a new class method, such as Draw().
UPDATE:
XNA provides a Game class which seems to be the main class of the application. It should contain a reference to an object of your class.
The spritebatch is also a member of the Game class so it should be passed to the Draw function of your HUD as a parameter. Then all you need to do is call the HUD's Draw method (of a HUD object which is a reachable from the Game object) from the Game's Draw method.
Agree with the other answers here, but I'd go one further.
Turn your Hud class into a component, specifically one that that implements DrawableGameComponent. This way, you can encapsulate all your Hud logic into one place, and as the name implies, the component is able to draw itself.
So, steps :-
In your LoadContent method, add the following code :-
Services.AddService(typeof(SpriteBatch), spriteBatch);
Create a new game component within Visual Studio 2010
Change the class your component inherits from. To start with, it'll be GameComponent. Change this into DrawableGameComponent
Override the LoadContent method. While you're not specifically loading any additional content in your example, you may wish to add Hud specific content at a later time.
Override the Update method. Any state changes to the Hud ( i.e. changing health or magic values ) should be made here.
Override the Draw method. Anything specific to drawing should go here. Note that you can get a handle to the main SpriteBatch service ( declared earlier on ) by including the following code in this overridden method :-
SpriteBatch spriteBatch =
Game.Services.GetService(typeof(SpriteBatch)) as SpriteBatch;
Finally, in the initialize method of your game class, add the following code:-
Components.Add(new HudComponent(this));
Your component will now be part of the main game loop.
Make an abstract class, for example GameElement, which contains methods Update and Draw.
Then create a (static) list of GameElement List<GameElement> Elements.
Make your class HUD inherit GameElement and implement methods Update (updates logic based on gametime) and Draw (draws the game element to the surface). When you create the HUD add it to to list Elements
In the main Draw method call foreach(var element in Elements) element.Draw().
That way you handle drawing and updating of the HUD and any other game element (Scene, Player, etc), and you never have to change the main drawing and updating loop .
You can even make GameElement an interface IGameElement so that you are not restricted to inheriting GameElement class.
You cant call a class you create an instance of it.
Classname class = new Classname();
class.method();

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