HealthRenderSystem.java

package net.mostlyoriginal.ns2d.system.render;

import com.artemis.Aspect;
import com.artemis.ComponentMapper;
import com.artemis.Entity;
import com.artemis.annotations.Wire;
import com.artemis.systems.EntityProcessingSystem;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import net.mostlyoriginal.ns2d.component.*;
import net.mostlyoriginal.ns2d.system.passive.AssetSystem;
import net.mostlyoriginal.ns2d.system.passive.CameraSystem;

/**
 * @author Daan van Yperen
 */
@Wire
public class HealthRenderSystem extends EntityProcessingSystem {

    private ComponentMapper<Pos> pm;
    private ComponentMapper<Bounds> om;
    private ComponentMapper<Health> hm;

    private static final Color HOLO_COLOR = Color.valueOf("73BCC9");

    private CameraSystem cameraSystem;
    private AssetSystem assetSystem;

    private SpriteBatch batch = new SpriteBatch();
    public TextureRegion tick;
    public int tickWidth;

    public HealthRenderSystem() {
        super(Aspect.getAspectForAll(Pos.class, Bounds.class, Health.class, HealthIndicator.class));
    }

    @Override
    protected void initialize() {
        super.initialize();
        tick = assetSystem.get("health-tick").getKeyFrame(0);
        tickWidth = tick.getRegionWidth()-1;
    }

    @Override
    protected void begin() {
        batch.setProjectionMatrix(cameraSystem.camera.combined);
        batch.begin();
        batch.setColor(1f, 1f, 1f, 1f);
    }

    @Override
    protected void end() {
        batch.end();
    }

    @Override
    protected void process(Entity e) {



        final Bounds bounds = om.get(e);
        final Pos pos = pm.get(e);
        final Health health = hm.get(e);

        final int width = bounds.x2 - bounds.x1;

        float factor = 1f - (health.damage / (float)health.health);

        int ticks = (int)((width * factor) / tickWidth);

        //ticks = width / tickWidth;

        for ( int i=0; i< ticks; i++ )
        {
            batch.draw(tick, pos.x + i * tickWidth, pos.y + bounds.y2 + 10 );
        }
    }
}