Develop Reference

How to make a simple progress bar

var barDisplay : float = 0;
var pos : Vector2 = new Vector2(20,40);
var size : Vector2 = new Vector2(60,20);
var progressBarEmpty : Texture2D;
var progressBarFull : Texture2D;
function OnGUI()
{
// draw the background:
GUI.BeginGroup (new Rect (pos.x, pos.y, size.x, size.y));
GUI.Box (Rect (0,0, size.x, size.y),progressBarEmpty);
// draw the filled-in part:
GUI.BeginGroup (new Rect (0, 0, size.x * barDisplay, size.y));
GUI.Box (Rect (0,0, size.x, size.y),progressBarFull);
GUI.EndGroup ();
GUI.EndGroup ();
}
function Update()
{
// for this example, the bar display is linked to the current time,
// however you would set this value based on your desired display
// eg, the loading progress, the player's health, or whatever.
barDisplay = Time.time * 0.05;
}
How do I make a geometry dash type progress bar in unity using OnGUI? I tried looking it up online, couldn't find it really. I am building a runner game something like Temple run and I want to show the player how much of the map is left to go.

For a progress bar
You can use the Unity scrollbar object to make what you're looking for. There's a good tutorial on it here. Essentially, you add a scrollbar object to your canvas, and then change the slider value from code.
For scrolling textures
If you want a scrolling texture on your progress bar, then you can animate an image placed on the slider. If you don't want to animate it by hand, then it's a little more complicated. Ideally you could set the texture offset of the image in code to get it to scroll, but after looking it up I don't think that Unity allows you to do that on non-3D objects.
If you still want it to scroll and don't want to make a hand-drawn animation for it, you might want to look into combining the UI mask component (tutorial here), and the built-in 2D animation tools (tutorial here).

C# XNA - Start draw from bottom-center

Normally XNA start drawing sprite from top-left, but I would like to start draw object from bottom-center, how this could be done?

You want to specify a different origin in your SpriteBatch.Draw calls. The default is 0,0 (top-left). Note that the origin is relative to the sprite, not the screen.
So if your sprite is 64x64, you want to use an origin of 32x64 for bottom center.
e.g. using this override (MSDN)
spriteBatch.Draw (
texture,
position,
sourceRectangle,
color,
rotation,
new Vector2(32, 64), // origin
scale,
effects,
layerDepth
)
You can calculate these on the fly if you wish. e.g if you're using the full texture you could specify it as new Vector2(texture.Center.X, texture.Height). Or alternatively you could base it on the sourceRectangle if you're using a sprite sheet.
You need to specify a bunch of other arguments to use these Draw overrides but you can just pass in the defaults. The defaults are:
sourceRectangle: null = full texture
color: Color.White = default color (sprite colors will be used)
rotation: 0f = no rotation
scale: 1f = default scale
efects: SpriteEffects.None = no flipping
layerDepth: 0 = default layer

Lets say you are drawing an image WidthxHeight on position XxY.
spriteBatch.Draw(texture, position, Color.White);
First let's set the bottom of the image to those coordinates by subtracting images height from position's Y coordinate (subtracting because in XNA the Y-axis is inverted, not like in your math class)
spriteBatch.Draw(texture, position + new Vector2(0, -texture.Height), Color.White);
Second, let's set the image to the left by subtracting half of the image's width from position's X coordinate.
spriteBatch.Draw(texture, position + new Vector2(-texture.Width/2, -texture.Height), Color.White);
And there you have it.
Edit: Another thought: you can create new variable called DrawPosition and use that variable when needed, instead of always substracting. That would look something like this:
private Texture2D texture;
public Vector2 position;
public Vector2 DrawPosition
{ get { return position + new Vector2(-texture.Width/2, -texture.Height); } }
public void Draw(SpriteBatch spriteBatch)
{ spriteBatch.Draw(texture, DrawPosition, Color.White); }
Or, if this new variable doesn't make sense to you, create a function that will return the DrawPosition()
public Vector2 DrawPosition()
{ return position + new Vector2(-texture.Width/2, -texture.Height); }

Why does part of the color gets removed in a draw function with a vector2 and a rectangle

When I draw a sprite like: spriteBatch.Draw(textureMap0, mapPos0, rectMap0, Color.White); the rectMap0 sprite loses the color, and only one type of color stays. This is how the rectangle is set up:
if (mapPos0.X == 350)
rectMap0 = new Rectangle((int)mapPos0.X, (int)mapPos0.Y, textureMap0.Width, textureMap0.Height);
else
rectMap0 = new Rectangle((int)mapPos0.X, (int)mapPos0.Y, textureMap0.Width / 2, textureMap0.Height / 2);
This:
Instead of:

You are using a source rectangle in your draw, so that is probably too small or not displaying the right part.
Try Adding:
Console.WriteLine(rectMap0.ToString());
The Line before the .Draw() Call so you can check the specifications of your rectangle.
If you want to draw the entire image remember you can use null as the arguement is nullable.

Wobbling texture using source rectangle

I'm having a little trouble with a texture2d I'm trying to draw in XNA. Basically, I have a power-up "cooldown fill-effect" going on. I have a texture that I'm trying to draw partially as the cooldown decreases. So, for example, at 10% cooldown done I'm drawing only 10% cooldown of of the texture (the bottom), 20% done only 20% of the bottom of the texture, and so on.
The problem I'm having is, when drawing the texture, it keeps wobbling as it fills up.
Note that below, ActiveSkillTexture is my preloaded fill texture. It's size is the size of the fully filled graphic.
InterfaceDrawer.Draw is a method that calls SpriteBatch.Draw, but does some extra stuff beforehand. For all intents and purposes, it's the same as SpriteBatch.Draw.
Scale is my scale factor, it's just a float between 0 and 1.
MyDest is a pre-calculated position for where this texture should draw (from the top-left, as usual).
Here's a snippet of code:
Rectangle NewBounds = ActiveSkillTexture.Bounds;
float cooldown = GetCooldown(ActiveSkillId);
if (cooldown > 0) //cooldown timer
{
//Code that calculated cooldown percent which I'm leaving out
if (percentdone != 1) //the percentage the cooldown is done
{
//code for fill-from bottom --
float SubHeight = ActiveSkillTexture.Height * percentremaining;
float NewHeight = ActiveSkillTexture.Height * percentdone;
NewBounds.Y += (int) SubHeight;
NewBounds.Height = (int) NewHeight;
MyDest.Y += SubHeight * Scale;
}
}
if (ActiveSkillTexture != null)
InterfaceDrawer.Draw(SpriteBatch, ActiveSkillTexture, MyDest, NewBounds, Color, 0.0f, Vector2.Zero, Scale, SpriteEffects.None, 0.0f);
I know you can't see it, but it's basically wobbling up and done as it fills. I tried printing out the values for the destination, the newbounds rectangle, etc. and they all seemed to consistently increase and not "sway", so I'm not sure what's going on. Interestingly enough, if I fill it from the top, it doesn't happen. But that's probably because I don't have to do math to alter the destination position each time I draw it (because it should draw from the top-left corner each time).
Any help would be greatly appreciated. Thanks!

I think this would be easier if you set the Vector2.Origin parameter of your spriteBatch.Draw as the bottom-left of your texture.
In this way you simply increase your sourceRectangle.Height, with something like this:
sourceRectangle.Height = ActiveSkillTexture.Height * percentdone;
without doing that useless math to find the destination position.

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.