Loadingscreen: Cleanup (TTT-2#1601)

As requested on Discord I added a minimum render time, by default it is
4 seconds. For now you can't change it via convar, you have to call
`loadingscreen.SetDuration` to edit that.

Moreover I cleaned up the rendering of the loadingscreen, mostly by
improving the blurry-ness

lua/ttt2/libraries/gameloop.lua

@@ -162,6 +162,10 @@ if SERVER then
             gameloop.SetLevelStartTime(CurTime())
         end
 
+        -- make sure that the duration of the loading screen is added to the
+        -- duration of the prep time
+        timePrepPhase = timePrepPhase + loadingscreen.GetDuration()
+
         gameloop.mapWinType = WIN_NONE
 
         -- reset the role of all players on the server and client

lua/ttt2/libraries/loadingscreen.lua

@@ -24,6 +24,10 @@ function loadingscreen.Begin()
     -- add manual syncing so that the loading screen starts as soon as the
     -- cleanup map is started
     if SERVER then
+        loadingscreen.timeBegin = SysTime()
+
+        timer.Remove("TTT2LoadingscreenEndTime")
+
         net.Start("TTT2LoadingScreenActive")
         net.WriteBool(true)
         net.Broadcast()
@@ -47,16 +51,26 @@ end
 -- @internal
 -- @realm shared
 function loadingscreen.End()
-    loadingscreen.isShown = false
+    if CLIENT then
+        loadingscreen.isShown = false
+    end
 
     if SERVER then
-        net.Start("TTT2LoadingScreenActive")
-        net.WriteBool(false)
-        net.Broadcast()
+        local duration = loadingscreen.timeBegin - SysTime() + loadingscreen.GetDuration()
+
+        -- this timer makes sure the loading screen is displayed for at least the
+        -- time that is set as the minimum time
+        timer.Create("TTT2LoadingscreenEndTime", duration, 1, function()
+            loadingscreen.isShown = false
 
-        -- disables sounds a while longer so it stays muted
-        timer.Simple(1.5, function()
-            loadingscreen.disableSounds = false
+            net.Start("TTT2LoadingScreenActive")
+            net.WriteBool(false)
+            net.Broadcast()
+
+            -- disables sounds a while longer so it stays muted
+            timer.Simple(1.5, function()
+                loadingscreen.disableSounds = false
+            end)
         end)
     end
 end
@@ -69,6 +83,22 @@ if SERVER then
             return false
         end
     end)
+
+    ---
+    -- Reads the minimum time that a loadingscreen should have.
+    -- @return number The minimum time
+    -- @realm server
+    function loadingscreen.GetDuration()
+        return loadingscreen.duration or 4
+    end
+
+    ---
+    -- Sets the minimum time that a loadingscreen should have.
+    -- @param number duration The minimum time in seconds
+    -- @realm server
+    function loadingscreen.SetDuration(duration)
+        loadingscreen.duration = duration
+    end
 end
 
 if CLIENT then
@@ -158,13 +188,20 @@ if CLIENT then
                 - math.min((SysTime() - loadingscreen.timeStateChange) / durationStateChange, 1.0)
         end
 
-        local c = vskin.GetBackgroundColor()
+        -- stop rendering the loadingscreen if the progress is close to 0, this removes
+        -- an ugly step when transitioning from blurry to sharp
+        if progress < 0.01 then
+            return
+        end
+
+        local c = util.ColorDarken(vskin.GetDarkAccentColor(), 90)
 
-        local colorLoadingScreen = Color(c.r, c.g, c.b, 220 * progress)
+        local colorLoadingScreen = Color(c.r, c.g, c.b, 235 * progress)
         local colorTip = table.Copy(util.GetDefaultColor(colorLoadingScreen))
         colorTip.a = 255 * progress
 
-        draw.BlurredBox(0, 0, ScrW(), ScrH(), progress * 5)
+        draw.BlurredBox(0, 0, ScrW(), ScrH(), progress * 10)
+        draw.BlurredBox(0, 0, ScrW(), ScrH(), progress * 3)
         draw.Box(0, 0, ScrW(), ScrH(), colorLoadingScreen)
 
         draw.AdvancedText(