Objects

Object

Like shown previously in the introduction to give our Heaps application visual (2D) content we need classes that are build upon h2d.Object.

An Object (represented by h2d.Object) is the base class of all 2D objects, so any thing that you can add to the screen (so to a h2d.Scene to be more precise, which mainly is s2d when inside hxd.App).

h2d.Object provides variables like a position (x,y), a scale (scaleX,scaleY), a rotation and methods to change them. However the class itself is only a container and has nothing to render by itself. For instance h2d.Flow, h2d.Layers and h2d.Mask are all "invisible", too, by that sense. Their job is to structure in which order their children objects are rendered.

A sub-class that does rendering however is h2d.Drawable(Drawable). These objects are the base for any actually visible objects in the world of the game like for instance the player, enemies, buildings, the landscape, but furthermore also buttons (h2d.Interactive) or a h2d.Text.

These are all h2d package classes (and sub-classes) that extend h2d.Object and can be used to create 2D content:

• Console
• Drawable
  • Anim, Bitmap, Particles, SpriteBatch
  • Graphics
    • Benchmark
  • Interactive
    • Slider
  • Text
    • HtmlText, TextInput
  • TileGroup
    • ScaleGrid
  • Video
• Flow
  • CheckBox, Dropdown
• Mask
  • KeyFrames
• Layers
  • CdbLevel, Scene, ZGroup
• ObjectFollower
• Loader

Sample

A collection of different objects that all inherit from h2d.Object:

class AllKindsOfObjects extends hxd.App {
    static function main() {new AllKindsOfObjects();}
    function new() {super();}
    override function init() {

        // a mere h2d.Object (no visual qualities => nothing to see here)
        var obj = new h2d.Object( s2d );
        // a mere h2d.Object has no visual qualities to it
        // it's just a container by itself... even though added to the scene there's nothing to see...
        
        // a h2d.Text (like from the Hello World! sample)
        var text = new h2d.Text( hxd.res.DefaultFont.get(), s2d );
        text.text = "A simple h2d.Text";
        text.textColor = 0xFBC707;

        // a h2d.Bitmap (from coded tile, no resource used)
        var bitmap = new h2d.Bitmap( h2d.Tile.fromColor( 0xFF0000, 32, 32 ), s2d );

        // a h2d.Graphics
        var graphics = new h2d.Graphics( s2d );
        graphics.lineStyle( 2, 0xFFFFFF );
        graphics.beginFill( 0x33cc33 );
        graphics.drawCircle( 0, 0, 16 );
        graphics.beginFill( 0xff6666 );
        graphics.drawRect( 4, 4, 12, 12 );

        // an h2d.Anim object
        var k = 32;
        var tfa = []; // tiles for animation "tfa"
        tfa.push( h2d.Tile.fromColor( 0xFF0000, k, k ) );
        tfa.push( h2d.Tile.fromColor( 0xFFFF00, k, k ) );
        tfa.push( h2d.Tile.fromColor( 0x00FFFF, k, k ) );
        tfa.push( h2d.Tile.fromColor( 0x0000FF, k, k ) );
        tfa.push( h2d.Tile.fromColor( 0xFF00FF, k, k ) );
        var anim = new h2d.Anim( tfa, 2, s2d );

        // a h2d.Interactive (button-like) object
        var interactive = new h2d.Interactive( 100, 50, s2d );
        var col_default = 0xFF3366ff;
        var col_over    = 0xFF809fff;
        var col_push    = 0xFF33cc33;
        interactive.backgroundColor = col_default;
        interactive.onOver  = (e)->{ interactive.backgroundColor = col_over; };
        interactive.onOut   = (e)->{ interactive.backgroundColor = col_default; };
        interactive.onPush  = (e)->{ interactive.backgroundColor = col_push; };
        interactive.onClick = (e)->{ trace("Clicking button."); };

        // info texts
        explanationLabel( text,        "h2d.Text:" );
        explanationLabel( bitmap,      "h2d.Bitmap:" );
        explanationLabel( graphics,    "h2d.Graphics:" );
        explanationLabel( anim,        "h2d.Anim:" );
        explanationLabel( interactive, "h2d.Interactive:\n(click me)" );

        // scatter positions
        text       .setPosition( 200, 100 );
        bitmap     .setPosition( 200, 200 );
        graphics   .setPosition( 200, 300 );
        anim       .setPosition( 200, 400 );
        interactive.setPosition( 200, 500 );
    }
    
    function explanationLabel( obj:h2d.Object, explanation:String ) : h2d.Text {
        var t = new h2d.Text( hxd.res.DefaultFont.get(), obj );
        t.text = explanation;
        t.setPosition( -150, 0 );
        return t;
    }
}

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Object trees

Objects can be added to a scene directly (a h2d.Scene, for instance s2d when inside hxd.App) or be added to another h2d.Object creating an object tree. Object trees are regarded in the next section about Object trees.