// the game itself var game; // global object with all customizable options var gameOptions = { // radius of the big circle - the "planet" - in pixels bigCircleRadius: 250, // radius of the small circle, in pixels playerRadius: 25, // player speed, in degrees per frame playerSpeed: 1, // world gravity worldGravity: 0.8, // jump force. First element is the first jump, second element - if any - the double jump, third element - if any - the triple jump and so on jumpForce: [12, 9, 6], // spike size - width, height - in pixels spikeSize: [25, 50], // distance needed to consider the player close to a spike, in degrees closeToSpike: 10, // distance needed to consider the player far from a spike, in degrees farFromSpike: 35 } window.onload = function() { // game configuration object var gameConfig = { thpe: Phaser.CANVAS, width: 800, height: 800, scene: [playGame] } game = new Phaser.Game(gameConfig); window.focus() resize(); window.addEventListener("resize", resize, false); } class playGame extends Phaser.Scene{ constructor(){ super("PlayGame"); } preload(){ this.load.image("bigcircle", "bigcircle.png"); this.load.image("player", "player.png"); this.load.image("spike", "spike.png"); this.load.image("mask", "mask.png"); } create(){ // adding a group which will contain all spikes this.spikeGroup = this.add.group(); // adding the big circle, the "planet", placed in the middle of the canvas this.bigCircle = this.add.sprite(game.config.width / 2, game.config.height / 2, "bigcircle"); this.bigCircle.displayWidth = gameOptions.bigCircleRadius * 2; this.bigCircle.displayHeight = gameOptions.bigCircleRadius * 2; // placing the player, just above the top of the "planet" this.player = this.add.sprite(game.config.width / 2, game.config.height / 2 - gameOptions.bigCircleRadius - gameOptions.playerRadius, "player"); this.player.displayWidth = gameOptions.playerRadius * 2; this.player.displayHeight = gameOptions.playerRadius * 2; // a few custom properties: currentAngle is the angle of the player this.player.currentAngle = -90; // jumpOffset is the amount of pixels to be added to player position when it jumps this.player.jumpOffset = 0; // how many jumps is the player doing? this.player.jumps = 0; // current jump force this.player.jumpForce = 0; // when the player clicks/taps on the canvas... this.input.on("pointerdown", function(e){ // can the player jump? if(this.player.jumps < gameOptions.jumpForce.length){ // player is jumping once more this.player.jumps ++; // adding the proper jump force to player's jumpForce property this.player.jumpForce = gameOptions.jumpForce[this.player.jumps - 1]; } }, this); // we are going to place nine spikes for(var i = 0; i < 9; i ++){ // adding the spike on the canvas var spike = this.add.sprite(0, 0, "spike"); // set spike origin point to left and horizontal middle spike.setOrigin(0, 0.5); // adding the spike to spike group this.spikeGroup.add(spike); // place the spike. Arguments are the spike itself and the quadrant of the big circle this.placeSpike(spike, Math.floor(i / 3)); } // adding the mask image which will act like a "fog" to hide and show spikes this.maskImage = this.add.sprite(game.config.width / 2, game.config.height / 2, "mask"); } // method to randomly place a spike into a quadrant placeSpike(spike, quadrant){ // choosing a random angle var randomAngle = Phaser.Math.Angle.WrapDegrees(Phaser.Math.Between(quadrant * 90, (quadrant + 1) * 90)); // this is the same random angle converted in radians var randomAngleRadians = Phaser.Math.DegToRad(randomAngle); // determining spike position according to its angle var spikeX = this.bigCircle.x + (gameOptions.bigCircleRadius - Phaser.Math.Between(4, 25)) * Math.cos(randomAngleRadians); var spikeY = this.bigCircle.y + (gameOptions.bigCircleRadius - Phaser.Math.Between(4, 25)) * Math.sin(randomAngleRadians); spike.x = spikeX; spike.y = spikeY; // saving spike's quadrant in a custom property spike.quadrant = quadrant; // setting spike angke spike.angle = randomAngle; // saving the three spike vertices in custom properties spike.top = new Phaser.Math.Vector2(spikeX + gameOptions.spikeSize[1] * Math.cos(randomAngleRadians), spikeY + gameOptions.spikeSize[1] * Math.sin(randomAngleRadians)); spike.base1 = new Phaser.Math.Vector2(spikeX + gameOptions.spikeSize[0] / 2 * Math.cos(randomAngleRadians + Math.PI / 2), spikeY + gameOptions.spikeSize[0] / 2 * Math.sin(randomAngleRadians + Math.PI / 2)); spike.base2 = new Phaser.Math.Vector2(spikeX + gameOptions.spikeSize[0] / 2 * Math.cos(randomAngleRadians - Math.PI / 2), spikeY + gameOptions.spikeSize[0] / 2 * Math.sin(randomAngleRadians - Math.PI / 2)); // is the player approaching to the spike? spike.approaching = false; } // method to be executed at each frame update(){ // is the player jumping? if(this.player.jumps > 0){ // adjusting player jump offset this.player.jumpOffset += this.player.jumpForce; // decreasing jump force due to gravity this.player.jumpForce -= gameOptions.worldGravity; // if jumpOffset is less than zero, it means the player touched the ground if(this.player.jumpOffset < 0){ // setting jump offset to zero this.player.jumpOffset = 0; // player is not jumping anymore this.player.jumps = 0; // there is no jump force this.player.jumpForce = 0; } } // setting new player current angle according to current position and speed this.player.currentAngle = Phaser.Math.Angle.WrapDegrees(this.player.currentAngle + gameOptions.playerSpeed); // moving the mask image accordingly this.maskImage.angle = this.player.currentAngle + 90; // getting the same angle in radians var radians = Phaser.Math.DegToRad(this.player.currentAngle); // determining the distance from the center according to planet radius, player radius and jump offset var distanceFromCenter = (gameOptions.bigCircleRadius * 2 + gameOptions.playerRadius * 2) / 2 + this.player.jumpOffset; // position the player using trigonometry this.player.x = this.bigCircle.x + distanceFromCenter * Math.cos(radians); this.player.y = this.bigCircle.y + distanceFromCenter * Math.sin(radians); // determining the number of revolutions the player has to do move according to planet and player size var revolutions = (gameOptions.bigCircleRadius * 2) / (gameOptions.playerRadius * 2) + 1; // set player rotation according to current angle and the number of revolutions needed this.player.angle = this.player.currentAngle * revolutions; // looping through each spike, as child of spikeGroup this.spikeGroup.children.iterate(function(spike){ // getting angle difference between the spike and the player var angleDiff = this.getAngleDifference(spike.angle, this.player.currentAngle); // if the player is not approaching the spike and it's close enough... if(!spike.approaching && angleDiff < gameOptions.closeToSpike){ // player is approaching the spike spike.approaching = true; } // if the player is approaching the spike... if(spike.approaching){ // checking for collision between the player and the two triangle sizes if(this.distToSegmentSquared(new Phaser.Math.Vector2(this.player.x, this.player.y), gameOptions.playerRadius, spike.top, spike.base1) || this.distToSegmentSquared(new Phaser.Math.Vector2(this.player.x, this.player.y), gameOptions.playerRadius, spike.top, spike.base2)){ // restart the game if the collision occurs this.scene.start("PlayGame"); } // if we are getting too far from the spike... if(angleDiff > gameOptions.farFromSpike){ // recycle the spike and move it in a random position three quadrants further this.placeSpike(spike, (spike.quadrant + 3) % 4); } } }, this) } // function to get the minimum difference between two angles a1 and a2 getAngleDifference(a1, a2){ var angleDifference = a1 - a2 angleDifference += (angleDifference > 180) ? -360 : (angleDifference < -180) ? 360 : 0 return Math.abs(angleDifference); } // function to get the distance between two points p1 and p2 getDistance(p1, p2){ return (p1.x - p2.x) * (p1.x - p2.x) + (p1.y - p2.y) * (p1.y - p2.y); } // function to determine if a circle is touching a line segment given the circle center, the radius and the points defining the segment distToSegmentSquared(circleCenter, circleRadius, segmentStart, segmentEnd){ var l2 = this.getDistance(segmentStart, segmentEnd); var t = ((circleCenter.x - segmentStart.x) * (segmentEnd.x - segmentStart.x) + (circleCenter.y - segmentStart.y) * (segmentEnd.y - segmentStart.y)) / l2; t = Math.max(0, Math.min(1, t)); var tX = segmentStart.x + t * (segmentEnd.x - segmentStart.x); var tY = segmentStart.y + t * (segmentEnd.y - segmentStart.y); var tPoint = { x: tX, y: tY } return this.getDistance(circleCenter, tPoint) < circleRadius * circleRadius; } } // pure javascript to scale the game function resize() { var canvas = document.querySelector("canvas"); var windowWidth = window.innerWidth; var windowHeight = window.innerHeight; var windowRatio = windowWidth / windowHeight; var gameRatio = game.config.width / game.config.height; if(windowRatio < gameRatio){ canvas.style.width = windowWidth + "px"; canvas.style.height = (windowWidth / gameRatio) + "px"; } else{ canvas.style.width = (windowHeight * gameRatio) + "px"; canvas.style.height = windowHeight + "px"; } }Now it’s time to add some kind of score and increase somehow the difficulty as you progress in the game, will do it next week, meanwhile download the source code.
HTML5 prototype of a circular endless runner featuring double jump built with Phaser – double, triple, infinite jumps and commented source code
Read all posts about "Circular endless runner" game
Another long title for another update to the HTML5 circular endless runner prototype built with Phaser.
I wanted to build a physics game without using physics and I am doing it quite well. I already developed gravity, jump, double jump and collision detection using only mathematics and trigonometry, and today I have a couple of new features:
* You are not longer limited to jump and double jump, you can adjust the game to let the player make any number of consecutive jumps just by changing a variable.
* There is a fog effect – which is actually a circular gradient fading to black to totally transparent black color – which makes the spikes appear and disappear giving the idea of an endless environment. But they are just 9 sprites placed here and there according to player position.
Have a look at the prototype:
Click or tap to jump and double jump, or even to make a triple jump and see how spikes smoothly appear and disappear.
What about the source code? I commented it line by line. There is still some – or better a lot of – room for improvement but having a source code with all comments will allow you to better understand how I built this prototype and above all to port the game in other languages, since I did not use any physics engine, just mathematics.