Draw particles, match the client's fog, and measure frame delay

Particles (point sprites) are drawn as instanced camera-facing squares sized like Direct3D 9's. Fog is by depth buffer value, as Direct3D 9 does with IMVU's projections. At most one frame is queued for display, frames carry the adapter's timestamp so the renderer process logs the delay to presenting, and the log's lines from several processes no longer mix.

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

renderer/log.hpp

@@ -0,0 +1,18 @@
+#pragma once
+// The renderer processes' log: %TEMP%\t5de-renderer-process.log, shared by all of them (lines start with the pid).
+
+#include <format>
+#include <string_view>
+#include <utility>
+
+namespace t5de::log {
+
+void write(std::string_view line);
+
+template <class... Args>
+void info(std::format_string<Args...> format, Args&&... args)
+{
+    write(std::format(format, std::forward<Args>(args)...));
+}
+
+} // namespace t5de::log