wvlvik/sprites

Scripts that allow you to render Sprites in PlayCanvas

Rendering Sprites in PlayCanvas

Download sprite.js and upload it to your project or copy paste the code in a new script.

Add the script to an Entity with a Script Component. You will see the following script attributes:

• textureAsset: This is the sprite that you want to render. If you want transparency for your sprite make sure that this is a .png file.
• pos: This is the Vec2 (x,y) screen coordinate for your sprite.
• size: This is the width and height as Vec2 of your sprite in pixels. For best results use the actual width of the uploaded image. Powers of 2 have better quality.
• depth: This is the z-index of your sprite. If you want it to appear behind other sprites increase this value.
• uPercentage: A value between [0,1] that specifies the maximum u value of the texture.
• vPercentage: A value between [0,1] that specifies the maximum v value of the texture.
• anchor: Determines where to anchor the sprite on the screen, for example top, center, bottom right etc.
• pivot: Determines the alignment (or pivot point) of the sprite.
• tint: A color to multiply the current color of the sprite with.
• maxResHeight: Set this to the target resolution height of your app. The final scale of your sprite will be calculated as canvasHeight / maxResHeight.

Creating a UI with Sprites

Using the sprite.js script you can create a user interface for your application.

• Create images using your favorite tool. For best quality sprites should be png files with power of 2 width and height.
• Upload them to PlayCanvas.

For each one of your sprites:

• Create an Entity
• Add a script component to the Entity
• Add sprite to script component
• Click on textureAsset and pick the desired image
• Set the rest of the fields to your liking
• Launch the application

Buttons

You can attach an event handler for each sprite for the 'click' event. For example add this script on the same Entity as the sprite:

var MyScript = pc.createScript('myScript');

MyScript.prototype.initialize = function() {
    this.entity.script.sprite.on('click', this.onClick, this);
};

MyScript.prototype.onClick = function() {
    console.log('click');
};

That way you can have buttons that do something when you click on them.

Progress Bars

Check out this scene for an example on how to make progress bars using sprites and different anchors:

https://playcanvas.com/editor/scene/443447

Rendering Text

Check out this repository for scripts and details on how to render bitmap fonts: https://github.com/playcanvas/fonts