PostProcessing.java

package stray.util.render;

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

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.glutils.FrameBuffer;
import com.badlogic.gdx.graphics.glutils.ShaderProgram;

/**
 * 
 * helper class for applying post-processing and rendering it
 *
 */
public class PostProcessing {

	/**
	 * gaussian blur on the entire screen
	 * 
	 * @param batch
	 * @param buffer
	 * @param blurshader
	 * @param radius
	 *            amount in pixels to blur
	 */
	public static void twoPassBlur(Batch batch, FrameBuffer buffer, ShaderProgram blurshader,
			float radius, float x, float y, float drawWidth, float drawHeight, int u, int v,
			int width, int height) {
		buffer.begin();
		batch.setShader(blurshader);
		blurshader.setUniformf("radius", (float) radius);
		blurshader.setUniformf("dir", 1f, 0f);
		batch.draw(buffer.getColorBufferTexture(), x, y, drawWidth, drawHeight, u, v, width,
				height, false, true);
		batch.flush();
		buffer.end();

		buffer.begin();
		blurshader.setUniformf("dir", 0f, 1f);
		batch.draw(buffer.getColorBufferTexture(), x, y, drawWidth, drawHeight, u, v, width,
				height, false, true);
		batch.setShader(null);
		buffer.end();

		batch.draw(buffer.getColorBufferTexture(), 0, Gdx.graphics.getHeight(), buffer.getWidth(),
				-buffer.getHeight());
		batch.flush();
	}

	/**
	 * makes the screen rainbowy and move
	 * 
	 * @param batch
	 * @param buffer
	 * @param saturation
	 *            default 0.4f
	 * @param displace
	 *            default 6
	 */
	public static void euphoria(Batch batch, FrameBuffer buffer, float saturation, float displace) {
		batch.setColor(Main.getRainbow(0.5f, saturation).r, Main.getRainbow(0.5f, saturation).g,
				Main.getRainbow(0.5f, saturation).b, saturation);
		batch.draw(buffer.getColorBufferTexture(), (displace * 2 * MathHelper.clampNumberFromTime(1f)),
				Gdx.graphics.getHeight(), buffer.getWidth(), -buffer.getHeight());
		batch.draw(buffer.getColorBufferTexture(), 0, Gdx.graphics.getHeight()
				+ (displace * 2 * MathHelper.clampNumberFromTime(1f)), buffer.getWidth(), -buffer.getHeight());
		batch.draw(buffer.getColorBufferTexture(), (-displace * 2 * MathHelper.clampNumberFromTime(1f)),
				Gdx.graphics.getHeight(), buffer.getWidth(), -buffer.getHeight());
		batch.draw(buffer.getColorBufferTexture(), 0, Gdx.graphics.getHeight()
				- (displace * 2 * MathHelper.clampNumberFromTime(1f)), buffer.getWidth(), -buffer.getHeight());
		batch.flush();
		batch.setColor(1, 1, 1, 1);
	}

	/**
	 * synthetic method that has defaults
	 * 
	 * @param batch
	 * @param buffer
	 */
	public static void euphoria(Batch batch, FrameBuffer buffer) {
		euphoria(batch, buffer, 0.4f, 6);
	}

	public static void heat(Batch batch, FrameBuffer buffer, Main main, float x, float y,
			float drawWidth, float drawHeight, int u, int v, int width, int height) {
		buffer.begin();
		main.warpshader.begin();
		main.warpshader.setUniformf(main.warpshader.getUniformLocation("amplitude"), 0.25f, 0.1f);
		main.warpshader.setUniformf(main.warpshader.getUniformLocation("frequency"), 10f, 5f);
		main.warpshader.setUniformf(main.warpshader.getUniformLocation("speed"), 2.5f);
		main.warpshader.end();
		warp(batch, buffer, main, x, y, drawWidth, drawHeight, u, v, width, height);
		buffer.end();
		twoPassBlur(batch, buffer, main.blurshader, 0.5f, x, y, drawWidth, drawHeight, u, v, width,
				height);
	}

	public static void warp(Batch batch, FrameBuffer buffer, Main main, float x, float y,
			float drawWidth, float drawHeight, int u, int v, int width, int height) {
		batch.setShader(main.warpshader);
		batch.draw(buffer.getColorBufferTexture(), x, y, drawWidth, drawHeight, u, v, width,
				(height), false, true);
		batch.flush();
		batch.setShader(null);
	}
}