var game = new Phaser.Game(800, 600, Phaser.CANVAS, 'phaser-example', { preload: preload, create: create, update: update });
function preload() {
game.load.image('ball', 'assets/sprites/shinyball.png');
}
var bmd;
var waveSize = 8;
var wavePixelChunk = 2;
var waveData;
var waveDataCounter;
function create() {
// Create our BitmapData object at a size of 32x64
bmd = game.add.bitmapData(32, 64);
// And apply it to 100 randomly positioned sprites
for (var i = 0; i < 100; i++)
{
game.add.sprite(game.world.randomX, game.world.randomY, bmd);
}
// Populate the wave with some data
waveData = game.math.sinCosGenerator(32, 8, 8, 2);
}
function update() {
// Clear the BitmapData
bmd.cls();
updateWobblyBall();
}
// This creates a simple sine-wave effect running through our BitmapData.
// This is then duplicated across all 100 sprites using it, meaning we only have to calculate it and upload it to the GPU once.
function updateWobblyBall() {
var s = 0;
var copyRect = { x: 0, y: 0, w: wavePixelChunk, h: 32 };
var copyPoint = { x: 0, y: 0 };
for (var x = 0; x < 32; x += wavePixelChunk)
{
copyPoint.x = x;
copyPoint.y = waveSize + (waveSize / 2) + waveData.sin[s];
bmd.context.drawImage(game.cache.getImage('ball'), copyRect.x, copyRect.y, copyRect.w, copyRect.h, copyPoint.x, copyPoint.y, copyRect.w, copyRect.h);
copyRect.x += wavePixelChunk;
s++;
}
// Now all the pixel data has been redrawn we render it to the BitmapData object.
// In CANVAS mode this doesn't do anything, but on WebGL it pushes the new texture to the GPU.
// If your game is exclusively running under Canvas you can safely ignore this step.
bmd.render();
// Cycle through the wave data - this is what causes the image to "undulate"
Phaser.ArrayUtils.rotate(waveData.sin);
waveDataCounter++;
if (waveDataCounter === waveData.length)
{
waveDataCounter = 0;
}
}