summaryrefslogtreecommitdiff
path: root/src/effects/particle_render.wgsl
blob: ef0db420963e750aa66a8a14364a185e0d76a506 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
// Particle rendering (vertex + fragment) - V2
struct Particle {
    pos: vec4f,
    vel: vec4f,
    rot: vec4f,
    color: vec4f,
};

#include "sequence_uniforms"

@group(0) @binding(0) var<storage, read> particles: array<Particle>;
@group(0) @binding(1) var<uniform> uniforms: UniformsSequenceParams;

struct VSOut {
    @builtin(position) pos: vec4f,
    @location(0) color: vec4f,
    @location(1) uv: vec2f,
};

@vertex fn vs_main(@builtin(vertex_index) vi: u32, @builtin(instance_index) ii: u32) -> VSOut {
    let p = particles[ii];
    let size = 0.02 + p.pos.z * 0.01 + uniforms.audio_intensity * 0.02;
    var offsets = array<vec2f, 6>(
        vec2f(-1, -1),
        vec2f(1, -1),
        vec2f(-1, 1),
        vec2f(-1, 1),
        vec2f(1, -1),
        vec2f(1, 1)
    );
    let offset = offsets[vi];
    let c = cos(p.rot.x);
    let s = sin(p.rot.x);
    let rotated_offset = vec2f(offset.x * c - offset.y * s, offset.x * s + offset.y * c);
    let pos = vec2f(p.pos.x + rotated_offset.x * size / uniforms.aspect_ratio, p.pos.y + rotated_offset.y * size);

    // Fade based on lifetime (p.pos.w goes from 1.0 to 0.0)
    let lifetime_fade = p.pos.w;
    let color_with_fade = vec4f(p.color.rgb * (0.5 + 0.5 * uniforms.audio_intensity), p.color.a * lifetime_fade);

    return VSOut(vec4f(pos, 0.0, 1.0), color_with_fade, offset);
}

@fragment fn fs_main(@location(0) color: vec4f, @location(1) uv: vec2f) -> @location(0) vec4f {
    // Calculate distance from center for circular shape
    let dist = length(uv);

    // Smooth circular falloff (1.0 at center, 0.0 at edge)
    let circle_alpha = smoothstep(1.0, 0.5, dist);

    // Apply circular fade to alpha channel
    return vec4f(color.rgb, color.a * circle_alpha);
}