Fry3DX 0.4: an easy 3D modeller

Shapes with live settings, shape editing, knife and hole tools, drawing
shapes onto other objects, combining objects (add / subtract / overlap),
copies, thickness, painting with stickers and layers, a Layout tab, a
Print tab with checks, packed .fry files with autosave, export to GLB,
glTF, FBX, OBJ, 3MF, STL and PLY, folders in Layers, its own crash
screen, and a website for GitHub Pages in docs/.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NMSrd5oe1GpUD7E6d825KP

engine/shaders/adapt.frag

@@ -0,0 +1,32 @@
+#version 460
+// Eye adaptation (1×1): the scene's average brightness (geometric mean of 16 taps of the
+// smallest bloom level), turned into an exposure that keeps a mid grey where it should be,
+// eased towards (0.6x to 1.8x, so nothing burns out) from last frame's at `speed` per second (faster into the dark is slower,
+// as eyes are). The tonemap multiplies its exposure by it.
+#define KEEL_POST // screen-space: render targets, sampled clamped
+#include "backend.glsl"
+PUSH_BLOCK {
+    uint src;      // the smallest bloom level
+    uint prev;     // last frame's (0 = start fresh)
+    float dt;
+    float speed;
+    float key;     // the brightness to aim for
+    float minE, maxE;
+    float pad;
+} pc;
+layout(location = 0) out vec4 o_exposure;
+
+void main() {
+    float sum = 0.0;
+    for (int y = 0; y < 4; ++y)
+        for (int x = 0; x < 4; ++x) {
+            vec3 c = sampleTexLod(pc.src, (vec2(x, y) + 0.5) / 4.0, 0.0).rgb;
+            sum += log(max(dot(c, vec3(0.2126, 0.7152, 0.0722)), 1e-4));
+        }
+    float average = exp(sum / 16.0);
+    float target = clamp(pc.key / average, pc.minE, pc.maxE);
+    if (pc.prev == 0u) { o_exposure = vec4(target); return; }
+    float last = sampleTexLod(pc.prev, vec2(0.5), 0.0).r;
+    float rate = target > last ? pc.speed * 0.6 : pc.speed; // brightening (into the dark) is slower
+    o_exposure = vec4(last + (target - last) * (1.0 - exp(-pc.dt * rate)));
+}