I already explained you can randomly generate an endless terrain with a series of point and a simple Cosine interpolation in my horizontal endless runner tutorial series which eventually led to the creation of RRRisky Hills game, which is inspired by Risky Road game, which I deconstruced in another tutorial series.
And this is what I built:
There is no interactivity: a terrain is generated, then 30 random rectangles fall down, then a new terrain is generated, and so on.
Thanks to Simplify.js we can render the terrian with about 4% of the original amount of points.
And here is the source code:
let game;
let gameOptions = {
startTerrainHeight: 0.5,
amplitude: 300,
slopeLength: [100, 350],
worldScale: 30
}
window.onload = function() {
let gameConfig = {
type: Phaser.AUTO,
scale: {
mode: Phaser.Scale.FIT,
autoCenter: Phaser.Scale.CENTER_BOTH,
parent: "thegame",
width: 1334,
height: 750
},
scene: playGame
}
game = new Phaser.Game(gameConfig);
window.focus();
}
class playGame extends Phaser.Scene {
constructor() {
super("PlayGame");
}
create() {
let gravity = planck.Vec2(0, 3);
this.world = planck.World(gravity);
this.debugDraw = this.add.graphics();
this.debugDraw = this.add.graphics();
this.sliceStart = new Phaser.Math.Vector2(0, Math.random());
this.drawTerrain(this.slopeGraphics, this.sliceStart);
}
drawTerrain(graphics, sliceStart) {
let ground = this.world.createBody();
let slopePoints = [];
let slopes = 0;
let slopeStart = 0;
let slopeStartHeight = sliceStart.y;
let currentSlopeLength = Phaser.Math.Between(gameOptions.slopeLength[0], gameOptions.slopeLength[1]);
let slopeEnd = slopeStart + currentSlopeLength;
let slopeEndHeight = Math.random();
let currentPoint = 0;
while (currentPoint < game.config.width) {
if (currentPoint == slopeEnd) {
slopes ++;
slopeStartHeight = slopeEndHeight;
slopeEndHeight = Math.random();
var y = game.config.height * gameOptions.startTerrainHeight + slopeStartHeight * gameOptions.amplitude;
slopeStart = currentPoint;
currentSlopeLength = Phaser.Math.Between(gameOptions.slopeLength[0], gameOptions.slopeLength[1]);
slopeEnd += currentSlopeLength;
}
else {
var y = (game.config.height * gameOptions.startTerrainHeight) + this.interpolate(slopeStartHeight, slopeEndHeight, (currentPoint - slopeStart) / (slopeEnd - slopeStart)) * gameOptions.amplitude;
}
slopePoints.push(new Phaser.Math.Vector2(currentPoint, y))
currentPoint ++ ;
}
let simpleSlope = simplify(slopePoints, 1, true);
for (let i = 1; i < simpleSlope.length; i ++) {
ground.createFixture(planck.Edge(planck.Vec2(simpleSlope[i - 1].x / gameOptions.worldScale, simpleSlope[i - 1].y / gameOptions.worldScale), planck.Vec2(simpleSlope[i].x / gameOptions.worldScale, simpleSlope[i].y / gameOptions.worldScale)), {
density: 0,
friction : 1
});
}
this.add.text(0, game.config.height - 60, "Edges to generate terrain: " + simpleSlope.length, {
fontFamily: "Arial",
fontSize: 48,
color: "#00ff00"
});
this.polygons = 0;
this.time.addEvent({
delay: 500,
callbackScope: this,
callback: function() {
this.createBox(Phaser.Math.Between(0, game.config.width), -50, Phaser.Math.Between(20, 60), Phaser.Math.Between(20, 60))
this.polygons ++;
if(this.polygons > 30){
this.scene.start("PlayGame");
}
},
loop: true
});
}
createBox(posX, posY, width, height) {
let box = this.world.createBody();
box.setDynamic();
box.createFixture(planck.Box(width / 2 / gameOptions.worldScale, height / 2 / gameOptions.worldScale));
box.setPosition(planck.Vec2(posX / gameOptions.worldScale, posY / gameOptions.worldScale));
box.setMassData({
mass: 1,
center: planck.Vec2(),
I: 1
});
return box;
}
update(t, dt) {
this.world.step(dt / 1000 * 2);
this.world.clearForces();
this.debugDraw.clear();
for (let body = this.world.getBodyList(); body; body = body.getNext()) {
this.debugDraw.beginPath();
for (let fixture = body.getFixtureList(); fixture; fixture = fixture.getNext()) {
let shape = fixture.getShape();
switch (fixture.getType()) {
case "edge": {
this.debugDraw.lineStyle(4, 0xff0000);
let v1 = shape.m_vertex1;
let v2 = shape.m_vertex2;
this.debugDraw.moveTo(v1.x * gameOptions.worldScale, v1.y * gameOptions.worldScale);
this.debugDraw.lineTo(v2.x * gameOptions.worldScale, v2.y * gameOptions.worldScale);
this.debugDraw.strokePath();
break;
}
default: {
this.debugDraw.lineStyle(2, 0x00ff00);
this.debugDraw.fillStyle(0x00ff00, 0.2);
let vertices = shape.m_vertices.length;
for (let i = 0; i < vertices; i ++) {
let vertex = shape.getVertex(i);
let worldPosition = body.getWorldPoint(vertex);
if (i == 0) {
this.debugDraw.moveTo(worldPosition.x * gameOptions.worldScale, worldPosition.y * gameOptions.worldScale);
}
else {
this.debugDraw.lineTo(worldPosition.x * gameOptions.worldScale, worldPosition.y * gameOptions.worldScale);
}
}
this.debugDraw.closePath();
this.debugDraw.strokePath();
this.debugDraw.fillPath();
break;
}
}
}
}
}
interpolate(vFrom, vTo, delta) {
let interpolation = (1 - Math.cos(delta * Math.PI)) * 0.5;
return vFrom * (1 - interpolation) + vTo * interpolation;
}
}
Next time, I’ll add a car powered by Box2D, joints and motors, meanwhile download the source code.
