ElectricityRenderer.java

package stray.util.render;

import stray.Main;
import stray.util.MathHelper;

import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.math.Vector2;

/**
 * 
 * used code from http://www.java-gaming.org/?action=pastebin&id=1025
 *
 */
public class ElectricityRenderer {

	// do a default of thickness = 3f
	// default number of bolts = 3

	private static Vector2 tempSphereVector = new Vector2(0, 0);

	public static void drawLine(SpriteBatch batch, float _x1, float _y1, float _x2, float _y2,
			float thickness) {
		float length = (float) MathHelper.calcDistance(_x1, _y1, _x2, _y2);
		float dx = _x1;
		float dy = _y1;
		dx = dx - _x2;
		dy = dy - _y2;
		float angle = MathUtils.radiansToDegrees * MathUtils.atan2(dy, dx);
		angle = angle - 180;
		batch.draw(Main.filltex, _x1, _y1, 0f, thickness * 0.5f, length, thickness, 1f, 1f, angle,
				0, 0, 1, 1, false, false);
	}

	public static void drawLine(SpriteBatch batch, float _x1, float _y1, float _x2, float _y2,
			float thickness, Texture tex) {
		float length = (float) MathHelper.calcDistance(_x1, _y1, _x2, _y2);
		float dx = _x1;
		float dy = _y1;
		dx = dx - _x2;
		dy = dy - _y2;
		float angle = MathUtils.radiansToDegrees * MathUtils.atan2(dy, dx);
		angle = angle - 180;
		batch.draw(tex, _x1, _y1, 0f, thickness * 0.5f, length, thickness, 1f, 1f, angle, 0, 0,
				tex.getWidth(), tex.getHeight(), false, false);
	}

	public static void drawChainLightning(SpriteBatch batch, Vector2[] points, float thickness,
			int numberOfBolts, float floatbits) {
		for (int i = 0; i < points.length - 1; i++) {
			drawP2PLightning(batch, points[i].x, points[i].y, points[i + 1].x, points[i + 1].y,
					MathUtils.random(60f, 140f), MathUtils.random(0.8f, 3.8f), thickness, numberOfBolts, floatbits);
		}
	}

	/**
	 * 
	 * @param batch
	 * @param x1
	 * @param y1
	 * @param x2
	 * @param y2
	 * @param displace how far away between each bolt in pixels
	 * @param detail default 2, the greater the number, the less "detailed" the bolts are
	 * @param thickness default 3, in pixels
	 * @param numberOfBolts 
	 * @param colour floatbits colour
	 */
	public static void drawP2PLightning(SpriteBatch batch, float x1, float y1, float x2, float y2,
			float displace, float detail, float thickness, int numberOfBolts, float colour) {
		batch.setBlendFunction(GL20.GL_SRC_ALPHA, GL20.GL_ONE);
		for (int i = 0; i < numberOfBolts; i++) {
			batch.setColor(colour);
			drawSingleP2PLightning(batch, x1, y1, x2, y2, displace, detail, thickness);
		}
		batch.setBlendFunction(GL20.GL_SRC_ALPHA, GL20.GL_ONE_MINUS_SRC_ALPHA);
		batch.setColor(Color.WHITE);
	}
	
	public static float getDefaultColor(float alpha){
		return Color.toFloatBits(MathUtils.random(14f, 54f) / 255f, MathUtils.random(100f, 210f) / 255f,
				MathUtils.random(200f, 239f) / 255f, alpha);
	}

	/**
	 * same as drawP2PLightning but only draws one set of bolts
	 * 
	 * @see drawP2PLightning
	 */
	public static void drawSingleP2PLightning(SpriteBatch batch, float x1, float y1, float x2,
			float y2, float displace, float detail, float thickness) {
		if (displace < detail) {
			drawLine(batch, x1, y1, x2, y2, thickness, Main.filltex);
		} else {
			float mid_x = (x2 + x1) * 0.5f;
			float mid_y = (y2 + y1) * 0.5f;
			mid_x += (Main.getRandom().nextDouble() - 0.5f) * displace;
			mid_y += (Main.getRandom().nextDouble() - 0.5f) * displace;
			drawSingleP2PLightning(batch, x1, y1, mid_x, mid_y, displace * 0.5f, detail, thickness);
			drawSingleP2PLightning(batch, x2, y2, mid_x, mid_y, displace * 0.5f, detail, thickness);
		}
	}

}