KIND OF ARBITRARY ZOOM (hangs at len 5 for some reason)

src/client/render/compute/shader.wgsl

@@ -0,0 +1,102 @@
+override CHUNK_POW: u32 = 10;
+const LEN: u32 = REPLACE_LENu;
+const ILEN: i32 = i32(LEN);
+const LEN2: u32 = LEN * 2;
+override WGX: u32 = 8;
+override WGY: u32 = 8;
+
+struct View {
+    reset: u32,
+    level: i32,
+    dims: vec2<u32>,
+    scale: FixedDec,
+    corner_x: FixedDec,
+    corner_y: FixedDec,
+}
+
+@group(0) @binding(0)
+var<storage> view: View;
+@group(0) @binding(1)
+var<storage, read_write> work: array<u32>;
+@group(0) @binding(2)
+var output: texture_storage_2d<rgba8unorm, write>;
+
+@compute @workgroup_size(WGX, WGY, 1)
+fn main(
+    @builtin(global_invocation_id) id: vec3<u32>
+) {
+    if id.x > view.dims.x - 1 || id.y > view.dims.y - 1 {
+        return;
+    }
+    // TODO: actually use width
+    let varwidth = LEN + 2;
+    let workwidth = varwidth * 2 + 1;
+    let worki = (id.x * view.dims.y + id.y) * workwidth;
+    let xidx = worki + 1;
+    let yidx = xidx + varwidth;
+
+    // let dec = view.corner_x.dec;
+    // var rel_x = FixedDec(POS, dec, array<u32, LEN>());
+    // rel_x.parts[0] = id.x;
+    // rel_x = shr(rel_x, view.level);
+    // var rel_y = FixedDec(POS, dec, array<u32, LEN>());
+    // rel_y.parts[0] = id.y;
+    // rel_y = shr(rel_y, view.level);
+    // let cx = add(view.corner_x, rel_x);
+    // let cy = add(view.corner_y, rel_y);
+    let fdims = vec2<f32>(view.dims);
+    var stretch: vec2<f32>;
+    if fdims.x < fdims.y {
+        stretch = vec2(fdims.x / fdims.y, 1.0);
+    } else {
+        stretch = vec2(1.0, fdims.y / fdims.x);
+    }
+    let fpos = (vec2<f32>(id.xy) / fdims - 0.5) * stretch;
+    let cx = add(mul(from_f32(fpos.x), view.scale), view.corner_x);
+    let cy = add(mul(from_f32(fpos.y), view.scale), view.corner_y);
+    var x: FixedDec;
+    var y: FixedDec;
+    var i = work[worki];
+    if bool(view.reset) {
+        x = zero();
+        y = zero();
+        i = 0;
+    } else {
+        x = FixedDec(work[xidx + 0], bitcast<i32>(work[xidx + 1]), array<u32, LEN>());
+        y = FixedDec(work[yidx + 0], bitcast<i32>(work[yidx + 1]), array<u32, LEN>());
+        for (var j = 0u; j < LEN; j += 1u) {
+            x.parts[j] = work[xidx + 2 + j];
+            y.parts[j] = work[yidx + 2 + j];
+        }
+    }
+    let max = i + 1;
+    let thresh = from_f32(2.0 * 2.0);
+    loop {
+        let x2 = mul(x, x);
+        let y2 = mul(y, y);
+        if gt(add(x2, y2), thresh) || i >= max {
+            break;
+        }
+        let xy = mul(x, y);
+        y = add(add(xy, xy), cy);
+        x = add(sub(x2, y2), cx);
+        i += 1u;
+    }
+    work[worki] = i;
+    work[xidx + 0] = x.sign; work[xidx + 1] = bitcast<u32>(x.dec);
+    work[yidx + 0] = y.sign; work[yidx + 1] = bitcast<u32>(y.dec);
+    for (var j = 0u; j < LEN; j += 1u) {
+        work[xidx + 2 + j] = x.parts[j];
+        work[yidx + 2 + j] = y.parts[j];
+    }
+    var color = vec3<f32>(0.0, 0.0, 0.0);
+    if i != max {
+        let pi = 3.1415;
+        let hue = f32(i) / 30.0;
+        color.r = cos(hue);
+        color.g = cos(hue - 2.0 * pi / 3.0);
+        color.b = cos(hue - 4.0 * pi / 3.0);
+    }
+    textureStore(output, id.xy, vec4(color, 1.0));
+}
+