feat(perf): direct STL parsing for near-instant large-file load (v0.7.1)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01XgHf5MW39U3Xo8y2uA229K
2026-07-14 14:20:36 +08:00
parent 45b27d51cb
commit 060ca4ecd0
7 changed files with 445 additions and 258 deletions
@@ -0,0 +1,41 @@
+using System.IO;
+
+namespace SmokeTest;
+
+/// <summary>產生測試用 binary STL：一片 gridN×gridN 的網格，每格 2 個三角形（波浪起伏，避免全共面）。</summary>
+internal static class MakeStl
+{
+    public static void Run(string path, int triCount)
+    {
+        // 每格 2 三角，格數 = triCount/2；邊長 grid = ceil(sqrt(cells))
+        int cells = System.Math.Max(1, triCount / 2);
+        int grid = (int)System.Math.Ceiling(System.Math.Sqrt(cells));
+        int tris = grid * grid * 2;
+
+        using var fs = File.Create(path);
+        using var bw = new BinaryWriter(fs);
+        bw.Write(new byte[80]);          // header
+        bw.Write((uint)tris);            // triangle count
+
+        static void WriteTri(BinaryWriter w, float ax, float ay, float az,
+            float bx, float by, float bz, float cx, float cy, float cz)
+        {
+            for (int i = 0; i < 3; i++) w.Write(0f);   // normal (0,0,0)
+            w.Write(ax); w.Write(ay); w.Write(az);
+            w.Write(bx); w.Write(by); w.Write(bz);
+            w.Write(cx); w.Write(cy); w.Write(cz);
+            w.Write((ushort)0);                        // attribute byte count
+        }
+
+        float Z(int x, int y) => (float)(System.Math.Sin(x * 0.1) * System.Math.Cos(y * 0.1) * 5.0);
+        for (int y = 0; y < grid; y++)
+            for (int x = 0; x < grid; x++)
+            {
+                float x0 = x, x1 = x + 1, y0 = y, y1 = y + 1;
+                WriteTri(bw, x0, y0, Z(x, y), x1, y0, Z(x + 1, y), x1, y1, Z(x + 1, y + 1));
+                WriteTri(bw, x0, y0, Z(x, y), x1, y1, Z(x + 1, y + 1), x0, y1, Z(x, y + 1));
+            }
+
+        Console.WriteLine($"寫出 {tris:N0} 三角形 → {path} ({new FileInfo(path).Length:N0} bytes)");
+    }
+}