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