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// Copyright(C) 2019 Lars Pontoppidan. All rights reserved.
// Use of this source code is governed by an MIT license file distributed with this software package
module particle
import particle.vec2
import sokol.sgl
const (
default_life_time = 1000
default_v_color = Color{93, 136, 193, 255}
)
// * Module public
pub fn new(location vec2.Vec2) &Particle {
p := &Particle{
location: location
velocity: vec2.Vec2{0, 0}
acceleration: vec2.Vec2{0, 0}
color: particle.default_v_color
life_time: particle.default_life_time
life_time_init: particle.default_life_time
}
return p
}
fn remap(v f64, min f64, max f64, new_min f64, new_max f64) f64 {
return (((v - min) * (new_max - new_min)) / (max - min)) + new_min
}
// Particle
pub struct Particle {
mut:
location vec2.Vec2
velocity vec2.Vec2
acceleration vec2.Vec2
color Color
life_time f64
life_time_init f64
}
pub fn (mut p Particle) update(dt f64) {
mut acc := p.acceleration
acc.multiply_f64(dt)
p.velocity = p.velocity.add(acc)
p.location = p.location.add(p.velocity)
lt := p.life_time - (1000 * dt)
if lt > 0 {
p.life_time = lt
p.color.r = p.color.r - 1 // byte(remap(p.life_time,0.0,p.life_time_init,0,p.color.r))
p.color.g = p.color.g - 1 // byte(remap(p.life_time,0.0,p.life_time_init,0,p.color.g))
p.color.b = p.color.b - 1 // byte(remap(p.life_time,0.0,p.life_time_init,0,p.color.b))
p.color.a = byte(int(remap(p.life_time, 0.0, p.life_time_init, 0, 255))) - 10
} else {
p.life_time = 0
}
}
pub fn (p Particle) is_dead() bool {
return p.life_time <= 0.0
}
pub fn (p Particle) draw() {
l := p.location
sgl.c4b(p.color.r, p.color.g, p.color.b, p.color.a)
lx := f32(l.x)
ly := f32(l.y)
sgl.v2f(lx, ly)
sgl.v2f(lx + 2, ly)
sgl.v2f(lx + 2, ly + 2)
sgl.v2f(lx, ly + 2)
}
pub fn (mut p Particle) reset() {
p.location.zero()
p.acceleration.zero()
p.velocity.zero()
// p.color = Color{93, 136, 193, 255}
p.color = particle.default_v_color
p.life_time = particle.default_life_time
p.life_time_init = p.life_time
}
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