zig-raylib/src/particles.zig
jonathan santis 76fde82477 sdf
2024-12-11 14:25:38 +01:00

203 lines
7.5 KiB
Zig

const pr = @import("primitives.zig");
const utils = @import("utils.zig");
const std = @import("std");
const rl = @import("raylib");
var prng = std.rand.DefaultPrng.init(124346234556);
const rand = prng.random();
pub const Particle = struct {
const Self = @This();
position: pr.Vec = .{ .a = .{ .x = 0, .y = 0, .z = 0 } },
velocity: pr.Vec = .{ .a = .{ .x = 0, .y = 0, .z = 0 } },
acceleration: pr.Vec = .{ .a = .{ .x = 0, .y = 0, .z = 0 } },
lifespan: u8 = 0,
show: u8 = 0,
size: f32 = 0,
max_x: i32 = 0,
max_y: i32 = 0,
pub fn new(self: *Self, max_x: i32, max_y: i32) void {
self.max_x = max_x;
self.max_y = max_y;
}
pub fn update(self: *Self) void {
self.velocity.add(self.acceleration);
self.position.add(self.velocity);
//this is ambigous
//must fix!!
if (self.position.a.y > @as(f32, @floatFromInt(self.max_y))) {
self.velocity.a.y *= -0.9;
// self.acceleration.a.y *= -0.5;
}
if (self.lifespan > 0) {
self.lifespan -= 1;
} else {
self.show = 0;
}
self.acceleration.a.x = 0;
self.acceleration.a.y = 0;
self.acceleration.a.z = 0;
}
pub fn spawn(self: *Self, xaccel: f32, yaccel: f32) void {
const xrnr = utils.randMinMaxFloat(-xaccel, xaccel);
const yrnr = utils.randMinMaxFloat(-yaccel, yaccel);
self.size = utils.randMinMaxFloat(-2, 2);
self.lifespan = rand.intRangeAtMost(u8, 75, 255);
self.acceleration.a.x = xrnr;
self.acceleration.a.y = yrnr;
self.position.a.x = @floatFromInt(rl.getMouseX() - @divTrunc(self.max_x, 2));
self.position.a.y = @floatFromInt(rl.getMouseY() - @divTrunc(self.max_y, 2));
self.velocity.a.x = 0;
self.velocity.a.y = 0;
self.position.a.color.r = rand.intRangeAtMost(u8, 0, 30);
self.position.a.color.g = rand.intRangeAtMost(u8, 0, 255);
self.position.a.color.b = rand.intRangeAtMost(u8, 0, 255);
self.show = 1;
}
pub fn applyGravity(self: *Self, val: f32) void {
self.velocity.a.y += val;
}
pub fn applyForce(self: *Self, vec: pr.Vec) void {
self.acceleration.a.x += vec.a.x * 0.8;
self.acceleration.a.y += vec.a.y * 0.8;
self.acceleration.a.z = vec.a.z;
self.velocity.a.x *= 0.995;
self.velocity.a.y *= 0.995;
}
};
pub const Emitter = struct {
particleCount: u32 = 0,
particles: []Particle = undefined,
max_x: i32 = 0,
max_y: i32 = 0,
pub fn init(self: *Emitter, allocator: std.mem.Allocator, max_x: i32, max_y: i32) !void {
var xrnr = utils.randMinMaxFloat(-1, 1);
var yrnr = utils.randMinMaxFloat(-0.5, 0.5);
self.max_x = max_x;
self.max_y = max_y;
self.particles = try allocator.alloc(Particle, 500000);
for (self.particles) |*p| {
xrnr = utils.randMinMaxFloat(-2, 2);
yrnr = utils.randMinMaxFloat(-2, 2);
p.* = Particle{ .velocity = .{ .a = .{ .x = 0, .y = 0 } }, .acceleration = .{ .a = .{ .x = xrnr, .y = yrnr } } };
p.*.new(self.max_x, self.max_y);
}
}
pub fn emit(self: *Emitter, count: u32, xaccel: f32, yaccel: f32) void {
var i: u32 = 0;
for (self.particles) |*p| {
if (p.show == 0) {
i += 1;
p.spawn(xaccel, yaccel);
}
if (i >= count) {
break;
}
}
}
pub fn update(self: *Emitter, att: []Attractor, texture: rl.Texture2D, color: rl.Color) void {
var posx: i32 = 0;
var posy: i32 = 0;
var vec2: rl.Vector2 = undefined;
if (rl.isMouseButtonPressed(rl.MouseButton.mouse_button_right)) {
for (att) |*at| {
if (at.init_done != 1) {
at.init(.{ .a = .{ .x = @floatFromInt(rl.getMouseX() - @divTrunc(self.max_x, 2)), .y = @floatFromInt(rl.getMouseY() - @divTrunc(self.max_y, 2)), .z = 0 } }, self.max_x, self.max_y);
at.mode = 1;
break;
}
}
}
if (rl.isMouseButtonPressed(rl.MouseButton.mouse_button_middle)) {
for (att) |*at| {
if (at.init_done != 1) {
at.init(.{ .a = .{ .x = @floatFromInt(rl.getMouseX() - @divTrunc(self.max_x, 2)), .y = @floatFromInt(rl.getMouseY() - @divTrunc(self.max_y, 2)), .z = 0 } }, self.max_x, self.max_y);
at.mode = 0;
break;
}
}
}
for (att) |at| {
at.draw();
}
for (self.particles) |*p| {
if (p.show == 1) {
//p.applyGravity(2);
for (att) |at| {
if (at.mode == 0) {
p.applyForce(at.attract(p.*));
} else {
p.applyForce(at.repel(p.*));
}
}
p.update();
if (p.position.a.x < 10000 and p.position.a.x > -10000) {
posx = @intFromFloat(@as(f32, @floatFromInt(self.max_x)) / 2 + p.position.a.x);
}
if (p.position.a.y < 10000 and p.position.a.y > -10000) {
posy = @intFromFloat(@as(f32, @floatFromInt(self.max_y)) / 2 + p.position.a.y);
}
//rl.drawRectangle(posx,posy,2,2,rl.Color{.r=p.position.a.color.r,.g=p.position.a.color.g,.b=p.position.a.color.b,.a=255});
vec2 = .{ .x = (@as(f32, @floatFromInt(self.max_x)) / 2 + p.position.a.x), .y = (@as(f32, @floatFromInt(self.max_y)) / 2 + p.position.a.y) };
rl.drawTextureEx(texture, vec2, 0.5, p.size, color);
}
}
}
};
pub const Attractor = struct {
vec: pr.Vec,
init_done: u8 = 0,
mode: u8 = 0,
max_x: i32 = 0,
max_y: i32 = 0,
pub fn init(self: *Attractor, vec: pr.Vec, max_x: i32, max_y: i32) void {
self.vec = vec;
self.init_done = 1;
self.max_x = max_x;
self.max_y = max_y;
}
pub fn attract(self: Attractor, particle: Particle) pr.Vec {
if (self.init_done == 1) {
const distance = self.vec.sub(particle.position);
var force: pr.Vec = undefined;
if (distance.a.x != 0 and distance.a.y != 0) {
force.a.x = distance.a.x / 10 * @abs(1 / distance.a.x);
force.a.y = distance.a.y / 10 * @abs(1 / distance.a.y);
force.a.z = 0;
}
return force;
} else {
return .{ .a = .{ .x = 0, .y = 0, .z = 0 } };
}
}
pub fn repel(self: Attractor, particle: Particle) pr.Vec {
if (self.init_done == 1) {
const distance = self.vec.sub(particle.position);
var force: pr.Vec = undefined;
if (distance.a.x != 0 and distance.a.y != 0) {
force.a.x = -distance.a.x / 10 * @abs(1 / distance.a.x);
force.a.y = -distance.a.y / 10 * @abs(1 / distance.a.y);
force.a.z = 0;
}
return force;
} else {
return .{ .a = .{ .x = 0, .y = 0, .z = 0 } };
}
}
pub fn draw(self: Attractor) void {
const posx: i32 = @intFromFloat(@as(f32, @floatFromInt(self.max_x)) / 2 + self.vec.a.x);
const posy: i32 = @intFromFloat(@as(f32, @floatFromInt(self.max_y)) / 2 + self.vec.a.y);
if (self.init_done == 1) {
rl.drawRectangle(posx, posy, 10, 10, rl.Color{ .r = 10, .g = 10, .b = 120, .a = 255 });
}
}
};