I have a particle emitter which emits multiple duplicates of the same image, as usual. However I'd like some of the particles to be flipped, either completely at a random amount, or sort of in the middle, so that particles falling to the left would be flipped and particles falling to the right won't be.
However I couldn't find anything regarding flipping particles without flipping ALL of them. I'd only like some to be flipped. Is this possible in any way?
There are serveral way's, I think the "fastest" would be just to use the scaleX property of the emiter.
this code flips about 10% of the particles
( 0.9 > Math.random() ), through multiplying it with-1, when it should be flipped.
Example Code:
this.add.particles('sparkle').createEmitter({
x: 200,
y: 100,
scaleX: {
onEmit: function () {
return ( 0.9 > Math.random() ) ? -1 : 1;
}
},
speed: { min: -100, max: 100 },
quantity: 0.1,
frequency: 1,
});
But I assume from a earlier question, that you have emitter with a "random scale" property. I that case you woud have to do something like this:
Example Code, for random scaled particles:
gameState.splash = this.add.particles('droplet').createEmitter({
x: gameState.height/2,
y: gameState.width/2,
scale: {
onEmit: function () {
// create random new scale
let newRandowmScale = Phaser.Math.FloatBetween(0.05, 0.3);
return ( 0.9 > Math.random() ) ? -1 * newRandowmScale : newRandowmScale;
}
},
speed: { min: -100, max: 100 },
...
});
UPDATE(SlowerFix): Example Code, for random scaled particles:
What the update does: save the current scale of the
scaleXevent and use it in thescaleYevent. (it is hacky, but should work. I will see if there is a cleaner solution)
gameState.splash = this.add.particles('droplet').createEmitter({
x: gameState.height/2,
y: gameState.width/2,
scaleY:{
onEmit: function(particle){
// keep scale value positive
return Math.abs(particle.scaleX);
}
},
scaleX:{
onEmit: function(p){
let scale = Phaser.Math.FloatBetween(.2, .5);
return Math.random() > .9 ? scale * -1 : scale;
}
},
speed: { min: -100, max: 100 },
...
});