Use dynamic budget for progressive load timeout

The progressive load timeout was hardcoded to 10ms, causing the CPU
to be mostly idle during map loading. This commit replaces the fixed
value with a dynamic budget derived from the display refresh rate
when VSync is enabled, or from the configured adaptivefps.menu limit
otherwise.

Fixes: #8774

binaries/data/mods/public/gui/credits/texts/programming.json

@@ -317,6 +317,7 @@
 				{ "nick": "voroskoi" },
 				{ "nick": "vts", "name": "Jeroen DR" },
 				{ "nick": "vv221", "name": "Antoine Le Gonidec" },
+				{ "nick": "vyordan", "name": "Yordan Vasquez" },
 				{ "nick": "wacko", "name": "Andrew Spiering" },
 				{ "nick": "WhiteTreePaladin", "name": "Brian Ashley" },
 				{ "nick": "wowgetoffyourcellphone", "name": "Justus Avramenko" },

source/main.cpp

@@ -93,6 +93,7 @@ that of Atlas depending on commandline parameters.
 #include <SDL_stdinc.h>
 #include <SDL_timer.h>
 #include <SDL_video.h>
+#include <algorithm>
 #include <chrono>
 #include <cstdlib>
 #include <ctime>
@@ -327,11 +328,17 @@ static int ProgressiveLoad()
 {
 	PROFILE3("progressive load");
 
+	const double budget = 1.0 / std::clamp(
+		g_VideoMode.IsVSyncEnabled() ?
+			static_cast<double>(g_VideoMode.GetDesktopFreq()) :
+			g_ConfigDB.Get("adaptivefps.menu", 60.0),
+		10.0, 360.0);
+
 	std::wstring description;
 	int progressPercent{0};
 	try
 	{
-		const PS::Loader::ProgressiveLoadResult result{PS::Loader::ProgressiveLoad(10e-3)};
+		const PS::Loader::ProgressiveLoadResult result{PS::Loader::ProgressiveLoad(budget)};
 		description = result.nextDescription;
 		progressPercent = result.progressPercent;
 		switch(result.status)