1 files changed, 367 insertions, 0 deletions
diff --git a/src/gpu/effects/shaders.cc b/src/gpu/effects/shaders.cc
new file mode 100644
index 0000000..0e80230
--- /dev/null
+++ b/src/gpu/effects/shaders.cc
@@ -0,0 +1,367 @@
+// This file is part of the 64k demo project.
+// It defines WGSL shader code for various effects.
+
+#include "../demo_effects.h"
+
+const char* main_shader_wgsl = R"(
+struct Uniforms {
+    audio_peak: f32,
+    aspect_ratio: f32,
+    time: f32,
+};
+
+@group(0) @binding(0) var<uniform> uniforms: Uniforms;
+
+@vertex fn vs_main(@builtin(vertex_index) i: u32) -> @builtin(position) vec4<f32> {
+    let PI = 3.14159265;
+    let num_sides = 7.0;
+    let scale = 0.5 + 0.3 * uniforms.audio_peak;
+    let tri_idx = f32(i / 3u);
+    let sub_idx = i % 3u;
+    if (sub_idx == 0u) {
+        return vec4<f32>(0.0, 0.0, 0.0, 1.0);
+    }
+    let angle = (tri_idx + f32(sub_idx - 1u)) * 2.0 * PI / num_sides + uniforms.time * 0.5;
+    return vec4<f32>(scale * cos(angle) / uniforms.aspect_ratio, scale * sin(angle), 0.0, 1.0);
+}
+
+@fragment fn fs_main() -> @location(0) vec4<f32> {
+    let h = uniforms.time * 2.0 + uniforms.audio_peak * 3.0;
+    let r = sin(h) * 0.5 + 0.5;
+    let g = sin(h + 2.0) * 0.9 + 0.3;
+    let b = sin(h + 4.0) * 0.5 + 0.5;
+    let boost = uniforms.audio_peak * 0.5;
+    return vec4<f32>(r + boost, g + boost, b + boost, 1.0);
+})";
+
+const char* particle_compute_wgsl = R"(
+struct Particle {
+    pos: vec4<f32>,
+    vel: vec4<f32>,
+    rot: vec4<f32>,
+    color: vec4<f32>,
+};
+
+struct Uniforms {
+    audio_peak: f32,
+    aspect_ratio: f32,
+    time: f32,
+    beat: f32,
+};
+
+@group(0) @binding(0) var<storage, read_write> particles: array<Particle>;
+@group(0) @binding(1) var<uniform> uniforms: Uniforms;
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) id: vec3<u32>) {
+    let i = id.x;
+    if (i >= arrayLength(&particles)) {
+        return;
+    }
+    var p = particles[i];
+    let new_pos = p.pos.xyz + p.vel.xyz * 0.016;
+    p.pos = vec4<f32>(new_pos, p.pos.w);
+    p.vel.y = p.vel.y - 0.01 * (1.0 + uniforms.audio_peak * 5.0);
+    p.rot.x = p.rot.x + p.rot.y * 0.016;
+    if (p.pos.y < -1.5) {
+        p.pos.y = 1.5;
+        p.pos.x = (f32(i % 100u) / 50.0) - 1.0 + (uniforms.audio_peak * 0.5);
+        p.vel.y = 0.0;
+    }
+    particles[i] = p;
+})";
+
+const char* particle_render_wgsl = R"(
+struct Particle {
+    pos: vec4<f32>,
+    vel: vec4<f32>,
+    rot: vec4<f32>,
+    color: vec4<f32>,
+};
+
+struct Uniforms {
+    audio_peak: f32,
+    aspect_ratio: f32,
+    time: f32,
+    beat: f32,
+};
+
+@group(0) @binding(0) var<storage, read> particles: array<Particle>;
+@group(0) @binding(1) var<uniform> uniforms: Uniforms;
+
+struct VSOut {
+    @builtin(position) pos: vec4<f32>,
+    @location(0) color: vec4<f32>,
+};
+
+@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_peak * 0.02;
+    var offsets = array<vec2<f32>, 6>(
+        vec2<f32>(-1, -1),
+        vec2<f32>(1, -1),
+        vec2<f32>(-1, 1),
+        vec2<f32>(-1, 1),
+        vec2<f32>(1, -1),
+        vec2<f32>(1, 1)
+    );
+    let offset = offsets[vi];
+    let c = cos(p.rot.x);
+    let s = sin(p.rot.x);
+    let rotated_offset = vec2<f32>(offset.x * c - offset.y * s, offset.x * s + offset.y * c);
+    let pos = vec2<f32>(p.pos.x + rotated_offset.x * size / uniforms.aspect_ratio, p.pos.y + rotated_offset.y * size);
+    return VSOut(vec4<f32>(pos, 0.0, 1.0), p.color * (0.5 + 0.5 * uniforms.audio_peak));
+}
+
+@fragment fn fs_main(@location(0) color: vec4<f32>) -> @location(0) vec4<f32> {
+    return color;
+}
+)";
+
+const char* passthrough_shader_wgsl = R"(
+@group(0) @binding(0) var smplr: sampler;
+@group(0) @binding(1) var txt: texture_2d<f32>;
+
+@vertex fn vs_main(@builtin(vertex_index) i: u32) -> @builtin(position) vec4<f32> {
+    var pos = array<vec2<f32>, 3>(
+        vec2<f32>(-1, -1),
+        vec2<f32>(3, -1),
+        vec2<f32>(-1, 3)
+    );
+    return vec4<f32>(pos[i], 0.0, 1.0);
+}
+
+@fragment fn fs_main(@builtin(position) p: vec4<f32>) -> @location(0) vec4<f32> {
+    return textureSample(txt, smplr, p.xy / vec2<f32>(1280.0, 720.0));
+})";
+
+const char* ellipse_shader_wgsl = R"(
+struct Uniforms {
+    time: f32,
+    beat: f32,
+    intensity: f32,
+    aspect_ratio: f32,
+};
+
+@group(0) @binding(0) var<uniform> uniforms: Uniforms;
+
+@vertex fn vs_main(@builtin(vertex_index) i: u32) -> @builtin(position) vec4<f32> {
+    var pos = array<vec2<f32>, 3>(
+        vec2<f32>(-1.0, -1.0),
+        vec2<f32>(3.0, -1.0),
+        vec2<f32>(-1.0, 3.0)
+    );
+    return vec4<f32>(pos[i], 0.0, 1.0);
+}
+
+fn sdEllipse(p: vec2<f32>, ab: vec2<f32>) -> f32 {
+    var p_abs = abs(p);
+    if (p_abs.x > p_abs.y) {
+        p_abs = vec2<f32>(p_abs.y, p_abs.x);
+    }
+    let l = ab.y * ab.y - ab.x * ab.x;
+    let m = ab.x * p_abs.x / l;
+    let n = ab.y * p_abs.y / l;
+    let m2 = m * m;
+    let n2 = n * n;
+    let c = (m2 + n2 - 1.0) / 3.0;
+    let c3 = c * c * c;
+    let d = c3 + m2 * n2;
+    let g = m + m * n2;
+    var co: f32;
+    if (d < 0.0) {
+        let h = acos((c3 + m2 * n2 * 2.0) / c3) / 3.0;
+        let s = cos(h);
+        let t = sin(h) * sqrt(3.0);
+        co = (sqrt(-c * (s + t * 2.0) + m2) + sign(l) * sqrt(-c * (s - t * 2.0) + m2) + abs(g) / (sqrt(-c * (s + t * 2.0) + m2) * sqrt(-c * (s - t * 2.0) + m2)) - m) / 2.0;
+    } else {
+        let h = 2.0 * m * n * sqrt(d);
+        let s = sign(c3 + m2 * n2 + h) * pow(abs(c3 + m2 * n2 + h), 1.0 / 3.0);
+        let u = sign(c3 + m2 * n2 - h) * pow(abs(c3 + m2 * n2 - h), 1.0 / 3.0);
+        let rx = -s - u + m2 * 2.0;
+        let ry = (s - u) * sqrt(3.0);
+        co = (ry / sqrt(sqrt(rx * rx + ry * ry) - rx) + 2.0 * g / sqrt(rx * rx + ry * ry) - m) / 2.0;
+    }
+    let si = sqrt(max(0.0, 1.0 - co * co));
+    return length(p_abs - vec2<f32>(ab.x * co, ab.y * si)) * sign(p_abs.y * ab.x * co - p_abs.x * ab.y * si);
+}
+
+@fragment fn fs_main(@builtin(position) p: vec4<f32>) -> @location(0) vec4<f32> {
+    let uv = (p.xy / vec2<f32>(1280.0, 720.0) - 0.5) * 2.0;
+    let movement = vec2<f32>(sin(uniforms.time * 0.7), cos(uniforms.time * 0.5));
+    let d = sdEllipse((uv * vec2<f32>(uniforms.aspect_ratio, 1.0)) - movement, vec2<f32>(0.5, 0.3) * (1.0 + uniforms.beat * 0.2));
+    return mix(vec4<f32>(0.2, 0.8, 0.4, 1.0), vec4<f32>(0.0), smoothstep(0.0, 0.01, d));
+})";
+
+const char* particle_spray_compute_wgsl = R"(
+struct Particle {
+    pos: vec4<f32>,
+    vel: vec4<f32>,
+    rot: vec4<f32>,
+    color: vec4<f32>,
+};
+
+struct Uniforms {
+    intensity: f32,
+    aspect_ratio: f32,
+    time: f32,
+    beat: f32,
+};
+
+@group(0) @binding(0) var<storage, read_write> particles: array<Particle>;
+@group(0) @binding(1) var<uniform> uniforms: Uniforms;
+
+fn hash(p: f32) -> f32 {
+    return fract(sin(p) * 43758.5453);
+}
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) id: vec3<u32>) {
+    let i = id.x;
+    if (i >= arrayLength(&particles)) {
+        return;
+    }
+    var p = particles[i];
+    if (p.pos.w <= 0.0) {
+        let r = hash(f32(i) + uniforms.time);
+        let angle = r * 6.28318;
+        p.pos = vec4<f32>(0.0, 0.0, 0.0, 1.0);
+        p.vel = vec4<f32>(cos(angle), sin(angle), 0.0, 0.0) * (0.5 + hash(r) * 0.5) * (1.0 + uniforms.intensity * 2.0);
+        p.color = vec4<f32>(hash(r + 0.1), hash(r + 0.2), 1.0, 1.0);
+    }
+    let new_pos = p.pos.xyz + p.vel.xyz * 0.016;
+    p.pos = vec4<f32>(new_pos, p.pos.w - 0.01 * (1.0 + uniforms.beat));
+    p.vel.y = p.vel.y - 0.01;
+    particles[i] = p;
+})";
+
+const char* gaussian_blur_shader_wgsl = R"(
+@group(0) @binding(0) var smplr: sampler;
+@group(0) @binding(1) var txt: texture_2d<f32>;
+
+struct Uniforms {
+    time: f32,
+    beat: f32,
+    intensity: f32,
+    aspect_ratio: f32,
+};
+
+@group(0) @binding(2) var<uniform> uniforms: Uniforms;
+
+@vertex fn vs_main(@builtin(vertex_index) i: u32) -> @builtin(position) vec4<f32> {
+    var pos = array<vec2<f32>, 3>(
+        vec2<f32>(-1, -1),
+        vec2<f32>(3, -1),
+        vec2<f32>(-1, 3)
+    );
+    return vec4<f32>(pos[i], 0.0, 1.0);
+}
+
+@fragment fn fs_main(@builtin(position) p: vec4<f32>) -> @location(0) vec4<f32> {
+    let uv = p.xy / vec2<f32>(1280.0, 720.0);
+    var res = vec4<f32>(0.0);
+    let size = 5.0 * uniforms.intensity;
+    for (var x: f32 = -2.0; x <= 2.0; x += 1.0) {
+        for (var y: f32 = -2.0; y <= 2.0; y += 1.0) {
+            res += textureSample(txt, smplr, uv + vec2<f32>(x, y) * size / 1280.0);
+        }
+    }
+    return res / 25.0;
+})";
+
+const char* solarize_shader_wgsl = R"(
+@group(0) @binding(0) var smplr: sampler;
+@group(0) @binding(1) var txt: texture_2d<f32>;
+
+struct Uniforms {
+    time: f32,
+    beat: f32,
+    intensity: f32,
+    aspect_ratio: f32,
+};
+
+@group(0) @binding(2) var<uniform> uniforms: Uniforms;
+
+@vertex fn vs_main(@builtin(vertex_index) i: u32) -> @builtin(position) vec4<f32> {
+    var pos = array<vec2<f32>, 3>(
+        vec2<f32>(-1, -1),
+        vec2<f32>(3, -1),
+        vec2<f32>(-1, 3)
+    );
+    return vec4<f32>(pos[i], 0.0, 1.0);
+}
+
+@fragment fn fs_main(@builtin(position) p: vec4<f32>) -> @location(0) vec4<f32> {
+    let uv = p.xy / vec2<f32>(1280.0, 720.0);
+    var col = textureSample(txt, smplr, uv);
+    let thr = 0.5 + 0.3 * sin(uniforms.time);
+    if (col.r < thr) {
+        col.r = 1.0 - col.r;
+    }
+    if (col.g < thr) {
+        col.g = 1.0 - col.g;
+    }
+    if (col.b < thr) {
+        col.b = 1.0 - col.b;
+    }
+    return col;
+})";
+
+const char* distort_shader_wgsl = R"(
+@group(0) @binding(0) var smplr: sampler;
+@group(0) @binding(1) var txt: texture_2d<f32>;
+
+struct Uniforms {
+    time: f32,
+    beat: f32,
+    intensity: f32,
+    aspect_ratio: f32,
+};
+
+@group(0) @binding(2) var<uniform> uniforms: Uniforms;
+
+@vertex fn vs_main(@builtin(vertex_index) i: u32) -> @builtin(position) vec4<f32> {
+    var pos = array<vec2<f32>, 3>(
+        vec2<f32>(-1, -1),
+        vec2<f32>(3, -1),
+        vec2<f32>(-1, 3)
+    );
+    return vec4<f32>(pos[i], 0.0, 1.0);
+}
+
+@fragment fn fs_main(@builtin(position) p: vec4<f32>) -> @location(0) vec4<f32> {
+    let uv = p.xy / vec2<f32>(1280.0, 720.0);
+    let dist = 0.1 * uniforms.intensity * sin(uv.y * 20.0 + uniforms.time * 5.0);
+    return textureSample(txt, smplr, uv + vec2<f32>(dist, 0.0));
+})";
+
+const char* chroma_aberration_shader_wgsl = R"(
+@group(0) @binding(0) var smplr: sampler;
+@group(0) @binding(1) var txt: texture_2d<f32>;
+
+struct Uniforms {
+    time: f32,
+    beat: f32,
+    intensity: f32,
+    aspect_ratio: f32,
+};
+
+@group(0) @binding(2) var<uniform> uniforms: Uniforms;
+
+@vertex fn vs_main(@builtin(vertex_index) i: u32) -> @builtin(position) vec4<f32> {
+    var pos = array<vec2<f32>, 3>(
+        vec2<f32>(-1, -1),
+        vec2<f32>(3, -1),
+        vec2<f32>(-1, 3)
+    );
+    return vec4<f32>(pos[i], 0.0, 1.0);
+}
+
+@fragment fn fs_main(@builtin(position) p: vec4<f32>) -> @location(0) vec4<f32> {
+    let uv = p.xy / vec2<f32>(1280.0, 720.0);
+    let off = 0.02 * uniforms.intensity;
+    let r = textureSample(txt, smplr, uv + vec2<f32>(off, 0.0)).r;
+    let g = textureSample(txt, smplr, uv).g;
+    let b = textureSample(txt, smplr, uv - vec2<f32>(off, 0.0)).b;
+    return vec4<f32>(r, g, b, 1.0);
+})";