/** Constructor: Sets up this panel and loads the images. */
public Engine() {
addKeyListener(new Controller());
setBackground(Color.black);
setPreferredSize(new Dimension(WIDTH, HEIGHT));
setFocusable(true);
// init world
final int defWidth = 150;
final int defHeight = 15;
final Random gen = new Random();
// 50% random, 25% hills, 25% platform
if (gen.nextBoolean()) {
world = RandomLevel.genWorldRandom(defWidth, defHeight, tp);
} else {
if (gen.nextBoolean()) {
world = RandomLevel.genWorldHills(defWidth, defHeight, tp);
} else {
world = RandomLevel.genWorldPlatform(defWidth, defHeight, tp);
}
}
// world = new Level("house.txt", tp);
// init hero
hero = new Hero();
hero.setImage(tp.get(Texture.hero));
hero.setPos(world.getStart());
renderer.addDynProp(hero);
renderer.setWorld(world);
// init test light
Point[] bgLights = world.getAll(Texture.bgLightDead);
Light tempLight;
final int cso = 15; // Cell size offset.
final int rRange = 100;
final int rMin = 75;
for (Point light : bgLights) {
tempLight = new Light(light.x + cso, light.y + cso, world);
tempLight.setRadius((short) (Math.random() * rRange + rMin));
renderer.addStaticProp(tempLight);
triggers.add(tempLight);
}
// Don't start this loop until setup is complete!
if (thread == null) {
running = true;
thread = new Thread(this);
thread.start();
}
}
/**
* Draws everything onto the main panel.
*
* @param page Graphics component to draw on
*/
public void paintComponent(Graphics page) {
super.paintComponent(page);
setForeground(Color.cyan);
renderer.draw(page, this, offX, offY);
// hero.draw(this, page, offX, offY);
for (Entity effect : effects) {
effect.draw(this, page, offX, offY);
/*if (effect instanceof Burst) {
Burst pop = (Burst) effect;
pop.draw(this, page, offX, offY);
}*/
}
// Draw hero position information
Rectangle r = hero.getBounds();
page.drawString("Position: x = " + (r.x + (r.width >> 1)), SCORE_PLACE_X, SCORE_PLACE_Y);
final int tab = 100;
final int lineHeight = 20;
page.drawString("y = " + (r.y + (r.height >> 1)), SCORE_PLACE_X + tab, SCORE_PLACE_Y);
page.drawString("Frame: " + frame, SCORE_PLACE_X, SCORE_PLACE_Y + lineHeight);
if (!running) {
page.drawString("Game over :(", WIDTH / 2, HEIGHT / 2);
}
}
/** The main loop, that controls all the action. It repeats until game over. */
public void run() {
long start = System.nanoTime();
long elapsed;
long wait;
final int minTimeBetweenFrames = 5;
while (running) {
// Timing
// elapsed is the number of nanoseconds since last frame
elapsed = System.nanoTime() - start;
elapsed = Math.min(MAX_FRAME, elapsed);
start = System.nanoTime();
Point pos = hero.getPos();
frame++;
// Physics!
simulate(hero, elapsed);
// Move camera
updateCamPos();
// Test 'victory' conditions
if (pos.y < LOWER_BOUND) {
running = false;
}
// Test world events (like touching a light)
testTriggers(triggers);
// Delete (release) dead effects.
deleteDeadEntities();
// redraw everything
repaint();
// "elapsed" is reassigned to the number of nanoseconds
// since this frame began
elapsed = System.nanoTime() - start;
// wait is how much time is remaining
// before the next frame needs to be drawn.
wait = targetTime - elapsed / NS_PER_MS;
// wait at least 5 ms between frames.
if (wait < 0) {
wait = minTimeBetweenFrames;
}
try {
Thread.sleep(wait);
} catch (InterruptedException e) {
e.printStackTrace();
}
} // end while
} // end run
/**
* Tests if the hero triggers world events, like by touching a light.
*
* @param trigs A list of triggers to test.
*/
private void testTriggers(ArrayList<Trigger> trigs) {
for (Trigger trigger : trigs) {
if (trigger.isTriggered(hero.getBounds())) {
trigger.triggerAction();
Entity burst = new Burst(tp);
burst.setPos(((Light) trigger).getPos());
effects.add(burst);
if (trigger instanceof Drawable) {
renderer.invalidate(((Drawable) trigger).getBounds());
}
}
}
}
/** Move the camera so that our hero doesn't go off-screen. */
private void updateCamPos() {
final int marginX = (int) (getWidth() * 0.25);
final int marginTop = (int) (getHeight() * 0.2);
final int marginBottom = (int) (getHeight() * 0.2);
Point pos = hero.getPos();
Dimension dim = hero.getSize();
// update x motion
// If too far left
if (pos.x - marginX < offX) {
offX = pos.x - marginX;
// if too far right
} else if (pos.x + marginX > offX + getWidth() - dim.width) {
offX = pos.x + marginX - getWidth() + dim.width;
}
// update y motion
// If too low
if (pos.y - marginBottom < offY) {
offY = pos.y - marginBottom;
// If too high
} else if (pos.y + marginTop > offY + getHeight() - dim.height) {
offY = pos.y + marginTop - getHeight() + dim.height;
}
}
/**
* Calculate the physics in our world for the given object.
*
* @param obj The object to move
* @param timeStep The time since last evaluation in nanoseconds
*/
public void simulate(Dynamic obj, long timeStep) {
/* Actions:
* 1. apply drag
* 2. add forces to object
* - gravity (unless resting on block)
* - arrow keys
*
* 3. apply forces to object. (done by the object)
*
* 4. a) move in x axis
* 5. a) resolve collisions in x axis
*
* 4. b) move in y axis
* 5. b) resolve collisions in y axis
*/
double seconds = timeStep / (double) NS_PER_S;
// 1. apply drag
obj.applyDrag(seconds);
// 2. add forces
obj.addForce(new Vector2D(0, GRAVITY));
obj.addForce(keyForce);
// 3. apply forces
obj.applyForces(seconds);
// get velocity in preparation for step 4
Vector2D vel = obj.getVel();
hero.setImage(tp.get(Texture.hero));
// 4. a) move x
obj.move((int) (vel.x * seconds), 0);
// 5. a) resolve collisions in x
Point bad = getWorldCollision(obj, Texture.brick);
// bad = null;
if (bad != null) {
int resolution = world.escapeX(obj, vel.x * seconds, bad);
obj.move(resolution, 0);
obj.getVel().setX(0);
}
// 4. b) move y
obj.move(0, (int) (vel.y * seconds));
// 5. b) resolve collisions in y
bad = getWorldCollision(obj, Texture.brick);
// bad = null;
if (bad != null) {
int resolution = world.escapeY(obj, vel.y * seconds, bad);
if (vel.y < 0) {
hero.setOnGround(true);
hero.setImage(tp.get(Texture.heroGround));
}
obj.move(0, resolution);
obj.getVel().setY(0);
} else {
hero.setOnGround(false);
}
}
