particlesystem
A particle system: an emitter that spawns short-lived particles, moves them,
fades them between a start and end size and color, and draws them in one
batch. Configure it with the setters, call update each frame and draw to
show it. With no texture the particles are colored squares; with a texture
they are textured quads.
type ParticleSystem = ref object
An emitter that spawns short-lived particles and animates them. Without
a texture the particles are colored squares; with one they are textured quads.
Fields
-
textureTexture
newParticleSystem ¶
proc newParticleSystem(texture: Texture = nil; maxParticles = 2000): ParticleSystem
A particle system, optionally drawing a texture per particle. Configure it
with the setters, update it every frame and draw it to show it.
Parameters
-
texture(Texture) -
maxParticles(auto)
Returns
ParticleSystem
setPosition ¶
proc setPosition(ps: ParticleSystem; x, y: float)
Move the emitter; new particles spawn here.
Parameters
-
ps(ParticleSystem) -
x(float) -
y(float)
setEmissionRate ¶
proc setEmissionRate(ps: ParticleSystem; rate: float)
How many particles spawn per second.
Parameters
-
ps(ParticleSystem) -
rate(float)
setParticleLifetime ¶
proc setParticleLifetime(ps: ParticleSystem; min, max: float)
How long each particle lives, in seconds, picked from this range.
Parameters
-
ps(ParticleSystem) -
min(float) -
max(float)
setSpeed ¶
proc setSpeed(ps: ParticleSystem; min, max: float)
The initial speed of each particle, picked from this range.
Parameters
-
ps(ParticleSystem) -
min(float) -
max(float)
setDirection ¶
proc setDirection(ps: ParticleSystem; radians: float)
The direction particles fly out in.
Parameters
-
ps(ParticleSystem) -
radians(float)
setSpread ¶
proc setSpread(ps: ParticleSystem; radians: float)
The angle of the cone around the direction that particles scatter into.
Parameters
-
ps(ParticleSystem) -
radians(float)
setLinearAcceleration ¶
proc setLinearAcceleration(ps: ParticleSystem; ax, ay: float)
A constant acceleration on every particle, like gravity or wind.
Parameters
-
ps(ParticleSystem) -
ax(float) -
ay(float)
setSizes ¶
proc setSizes(ps: ParticleSystem; startSize, endSize: float)
Each particle's size fades from start to end over its life.
Parameters
-
ps(ParticleSystem) -
startSize(float) -
endSize(float)
setColors ¶
proc setColors(ps: ParticleSystem; startColor, endColor: Color)
Each particle's color fades from start to end over its life. Fading the
end alpha to 0 makes particles dissolve.
Parameters
-
ps(ParticleSystem) -
startColor(Color) -
endColor(Color)
setSpin ¶
proc setSpin(ps: ParticleSystem; min, max: float)
How fast each particle rotates, in radians per second, from this range.
Parameters
-
ps(ParticleSystem) -
min(float) -
max(float)
start ¶
proc start(ps: ParticleSystem)
stop ¶
proc stop(ps: ParticleSystem)
Stop emitting. Particles already alive keep moving until they expire.
Parameters
-
ps(ParticleSystem)
isActive ¶
proc isActive(ps: ParticleSystem): bool
Whether the emitter is emitting.
Parameters
-
ps(ParticleSystem)
Returns
bool
count ¶
proc count(ps: ParticleSystem): int
How many particles are alive right now.
Parameters
-
ps(ParticleSystem)
Returns
int
emit ¶
proc emit(ps: ParticleSystem; count: int)
Spawn count particles right now, regardless of the emission rate.
Parameters
-
ps(ParticleSystem) -
count(int)
update ¶
proc update(ps: ParticleSystem; dt: float)
Advance the system by dt seconds: spawn, move, age and retire particles.
Call every frame from the update callback.
Parameters
-
ps(ParticleSystem) -
dt(float)
draw ¶
proc draw(ps: ParticleSystem; nim2d: Nim2d; x = 0.0; y = 0.0)
Draw every live particle in one batch, optionally offset by (x, y).
Parameters
-
ps(ParticleSystem) -
nim2d(Nim2d) -
x(auto) -
y(auto)