Fix particle sizes, and add tools for comparing renderers

Particles: Direct3D 9's size limit evidently isn't the documented 64 pixels; unclamped (up to 2048) they match the client's renderer. A compare view shows the left half's scene over the right half, both renderers side by side; %TEMP%\t5de-renderer-view.txt switches views and %TEMP%\t5de-renderer-shaders\fixed_function.hlsl replaces the shaders while the client runs. The renderer process runs from a copy, so the program can be replaced meanwhile. The adapter recognizes only the textures and buffers it made (others reach the client renderer unchanged) and logs the others and render targets.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

adapter/plugin.cpp

@@ -33,13 +33,17 @@ imvu::SharedPtr<imvu::PiRenderEngine> create_imvu_engine(imvu::SharedPtr<imvu::I
     return create(std::move(window), imvu::RendererType::Direct3D);
 }
 
-// What the renderer process draws: T5DE_RENDERER_VIEW=off, split (the default: the right half) or full.
+// What the renderer process draws: T5DE_RENDERER_VIEW=off, split (the default: the right half), full or compare.
+// (The renderer process can also be switched while it runs: renderer/main.cpp.)
 protocol::View view()
 {
     wchar_t value[16] = {};
     GetEnvironmentVariableW(L"T5DE_RENDERER_VIEW", value, 16);
     const std::wstring_view setting = value;
-    return setting == L"off" ? protocol::View::Off : setting == L"full" ? protocol::View::Full : protocol::View::Split;
+    return setting == L"off"       ? protocol::View::Off
+           : setting == L"full"    ? protocol::View::Full
+           : setting == L"compare" ? protocol::View::Compare
+                                   : protocol::View::Split;
 }
 
 } // namespace