package space.engine.test;

import org.newdawn.slick.AppGameContainer;
import org.newdawn.slick.BasicGame;
import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.Image;
import org.newdawn.slick.Input;
import org.newdawn.slick.SlickException;

import space.engine.ShaderProgram;

public class SimpleShaderTest extends BasicGame {

    public static void main(String[] args) throws SlickException {
        new AppGameContainer(new SimpleShaderTest(), 800, 600, false).start();
    }

    public SimpleShaderTest() {
        super("shader test");
    }

    Image clouds;
    ShaderProgram program;

    private boolean shaderWorks, useShader=true;

    @Override
    public void init(GameContainer container) throws SlickException {
        clouds = new Image("res/clouds.jpg");

        // We can disable 'strict' mode which means that trying to change a
        // non-active uniform won't throw a runtime exception
        //ShaderProgram.setStrictMode(false);

        //often its wise to hard-code the shader... but for now we'll use a file
        program = ShaderProgram.loadProgram("res/hellovert.shader", "res/hellofrag.shader");
        shaderWorks = program.valid();
        if (shaderWorks) {
            //set up our uniforms...
            program.bind();
            program.setUniform1i("tex", 0); //texture 0
            program.unbind();
        } else {
            System.out.println("Error loading shader... "+program.getLog());
        }
    }

    //@Override
    public void render(GameContainer container, Graphics g) throws SlickException {
        if (shaderWorks && useShader)
            program.bind();

        g.drawImage(clouds, 100, 100);

        if (shaderWorks && useShader)
            program.unbind();

        if (shaderWorks)
            g.drawString("Space to toggle shader", 10, 20);
        else
            g.drawString("Shader didn't load: "+program.getLog(), 10, 20);
    }

    @Override
    public void update(GameContainer container, int delta) throws SlickException {
        if (container.getInput().isKeyPressed(Input.KEY_SPACE))
            useShader = !useShader;
    }

}