collision

package com.badlogic.androidgames.gamedev2d;

import com.badlogic.androidgames.gamedev2d.framework.DynamicGameObject;
import com.badlogic.androidgames.gamedev2d.framework.Game;
import com.badlogic.androidgames.gamedev2d.framework.GameObject;
import com.badlogic.androidgames.gamedev2d.framework.Input.*;
import com.badlogic.androidgames.gamedev2d.framework.Screen;
import com.badlogic.androidgames.gamedev2d.framework.gl.Vertices;
import com.badlogic.androidgames.gamedev2d.framework.impl.GLGame;
import com.badlogic.androidgames.gamedev2d.framework.impl.GLGraphics;
import com.badlogic.androidgames.gamedev2d.framework.math.OverlapTester;
import com.badlogic.androidgames.gamedev2d.framework.math.Vector2;

import java.util.List;

import javax.microedition.khronos.opengles.GL10;

/**
 * Created by Kebir on 16.03.2018.
 */
public class CollisionTest extends GLGame {

    @Override
    public Screen getStartScreen() {
        return new CollisionScreen(this);
    }

    class CollisionScreen extends Screen {

        final int NUM_TARGETS = 20;
        final float WORLD_WIDTH = 9.6f;
        final float WORLD_HEIGHT = 6.4f;

        GLGraphics glGraphics;
        Cannon cannon;
        DynamicGameObject cannonBall;
        GameObject[] targets;


        Vertices cannonVertices;
        Vertices cannonBallVertices;
        Vertices targetVertices;

        float cannonAngle = 0.0f;
        Vector2 touchPoint = new Vector2();
        Vector2 gravity = new Vector2(0, -7);


        public CollisionScreen(Game game) {
            super(game);

            glGraphics = ((GLGame)game).getGLGraphics();
            cannon = new Cannon(0, 0, 1, 1);
            cannonBall = new DynamicGameObject(0, 0, 0.1f, 0.1f);
            targets = new GameObject[NUM_TARGETS];
            for(int i=0; i < targets.length; ++i) {
                targets[i] = new GameObject(
                        (float)Math.random() * WORLD_WIDTH,
                        (float)Math.random() * WORLD_HEIGHT,
                        0.2f,
                        0.2f);
            }

            // the cannon
            float[] vertices = new float[] {
                    -0.5f, -0.5f,
                     0.5f,  0.0f,
                    -0.5f,  0.5f
            };
            cannonVertices = new Vertices(glGraphics, 3, 0, false, false);
            cannonVertices.setVertices(vertices, 0, vertices.length);

            // the cannon ball
            vertices = new float[] {
                    0.0f, 0.0f,
                    0.1f, 0.0f,
                    0.1f, 0.1f,
                    0.0f, 0.1f,
            };
            short[] indices = new short[] {
                    0, 1, 2,
                    2, 3, 0
            };
            cannonBallVertices = new Vertices(glGraphics, 4, 6, false, false);
            cannonBallVertices.setVertices(vertices, 0, vertices.length);
            cannonBallVertices.setIndices(indices, 0, indices.length);

            // the target
            vertices = new float[] {
                    0.0f, 0.0f,
                    0.2f, 0.0f,
                    0.2f, 0.2f,
                    0.0f, 0.2f
            };
            indices = new short[] {
                    0, 1, 2,
                    2, 3, 0
            };
            targetVertices = new Vertices(glGraphics, 4, 6, false, false);
            targetVertices.setVertices(vertices, 0, vertices.length);
            targetVertices.setIndices(indices, 0, indices.length);
        }

        @Override
        public void update(float deltaTime) {
            List<TouchEvent> touchEvents = game.getInput().getTouchEvents();
            game.getInput().getKeyEvents();

            for(int i=0; i < touchEvents.size(); ++i) {
                TouchEvent event = touchEvents.get(i);

                touchPoint.x = (event.x / (float)glGraphics.getWidth()) * WORLD_WIDTH;
                touchPoint.y = (1 - (event.y / (float)glGraphics.getHeight())) * WORLD_HEIGHT;

                cannonAngle = touchPoint.sub(cannon.position).angle();

                if(event.type == TouchEvent.TOUCH_UP) {
                    float radians = cannonAngle * Vector2.TO_RADIANS;
                    float ballSpeed = touchPoint.dist(cannon.position);

                    cannonBall.position.set(cannon.position);
                    cannonBall.velocity.x = (float)Math.cos(radians) * ballSpeed;
                    cannonBall.velocity.y = (float)Math.sin(radians) * ballSpeed;
                }
            }

            for(int j=0; j < targets.length; ++j) {
                if(OverlapTester.overlapRectangles(cannonBall.bounds, targets[j].bounds)) {
                    targets[j].position.add(0.5f, 0.1f);
                    targets[j].bounds.lowerLeft.add(0.5f, 0.1f);
                }
            }

            cannonBall.velocity.add(gravity.x * deltaTime, gravity.y * deltaTime);
            cannonBall.position.add(cannonBall.velocity.x * deltaTime, cannonBall.velocity.y * deltaTime);
            cannonBall.bounds.lowerLeft.set(cannonBall.position.x - cannonBall.bounds.width/2, cannonBall.position.y - cannonBall.bounds.height/2);
        }

        @Override
        public void present(float deltaTime) {
            GL10 gl = glGraphics.getGL();

            // clear the screen with black
            gl.glClearColor(0, 0, 0, 1);
            gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
            // set the viewport to span the whole framebuffer
            gl.glViewport(0, 0, glGraphics.getWidth(), glGraphics.getHeight());
            // set up the projection matrix
            gl.glMatrixMode(GL10.GL_PROJECTION);
            gl.glLoadIdentity();
            gl.glOrthof(0.0f, WORLD_WIDTH, 0.0f, WORLD_HEIGHT, 1.0f, -1.0f);

            // the cannon
            gl.glMatrixMode(GL10.GL_MODELVIEW);
            gl.glLoadIdentity();
            gl.glTranslatef(cannon.position.x, cannon.position.y, 0);
            gl.glRotatef(cannonAngle, 0, 0, 1);
                // color white for the cannon
                gl.glColor4f(1, 1, 1, 1);
            cannonVertices.bind();
            cannonVertices.draw(GL10.GL_TRIANGLES, 0, 3);
            cannonVertices.unbind();

            // the cannonBall
            gl.glLoadIdentity();
            gl.glTranslatef(cannonBall.position.x, cannonBall.position.y, 0);
                // color red for the cannonBall
                gl.glColor4f(1, 0, 0, 1);
            cannonBallVertices.bind();
            cannonBallVertices.draw(GL10.GL_TRIANGLES, 0, 6);
            cannonBallVertices.unbind();

            // the target(s)

            targetVertices.bind();
            for(int i=0; i < targets.length; ++i) {
                gl.glLoadIdentity();
                gl.glTranslatef(targets[i].position.x, targets[i].position.y, 0);
                    // color blue for the targets
                    gl.glColor4f(0, 0, 1, 1);

                targetVertices.draw(GL10.GL_TRIANGLES, 0, 6);
            }
            targetVertices.unbind();

        }

        @Override
        public void pause() {

        }

        @Override
        public void resume() {

        }

        @Override
        public void dispose() {

        }
    }
}