Added HL2 jumping system back to Sandbox (now works in multiplayer as…

… well)

garrysmod/gamemodes/sandbox/gamemode/player_class/player_sandbox.lua

@@ -139,13 +139,57 @@ function PLAYER:CalcView( view )
 
 end
 
-function PLAYER:GetHandsModel()
-
-	-- return { model = "models/weapons/c_arms_cstrike.mdl", skin = 1, body = "0100000" }
+--
+-- Reproduces the jump boost from HL2 singleplayer
+--
+local JUMPING
 
-	local cl_playermodel = self.Player:GetInfo( "cl_playermodel" )
-	return player_manager.TranslatePlayerHands( cl_playermodel )
+function PLAYER:StartMove( move )
+
+	-- Only apply the jump boost in FinishMove if the player has jumped during this frame
+	-- Using a global variable is safe here because nothing else happens between SetupMove and FinishMove
+	if bit.band( move:GetButtons(), IN_JUMP ) ~= 0 and bit.band( move:GetOldButtons(), IN_JUMP ) == 0 and self.Player:OnGround() then
+		JUMPING = true
+	end
+
+end
 
+function PLAYER:FinishMove( move )
+
+	-- If the player has jumped this frame
+	if JUMPING then
+		-- Get their orientation
+		local forward = self.Player:EyeAngles()
+		forward.p = 0
+		forward = forward:Forward()
+
+		-- Compute the speed boost
+
+		-- HL2 normally provides a much weaker jump boost when sprinting
+		-- For some reason this never applied to GMod, so we won't perform
+		-- this check here to preserve the "authentic" feeling
+		local speedBoostPerc = ( ( not self.Player:Crouching() ) and 0.5 ) or 0.1
+
+		local speedAddition = math.abs( move:GetForwardSpeed() * speedBoostPerc )
+		local maxSpeed = move:GetMaxSpeed() * ( 1 + speedBoostPerc )
+		local newSpeed = speedAddition + move:GetVelocity():Length2D()
+
+		-- Clamp it to make sure they can't bunnyhop to ludicrous speed
+		if newSpeed > maxSpeed then
+			speedAddition = speedAddition - (newSpeed - maxSpeed)
+		end
+
+		-- Reverse it if the player is running backwards
+		if move:GetForwardSpeed() < 0 then
+			speedAddition = -speedAddition
+		end
+
+		-- Apply the speed boost
+		move:SetVelocity(forward * speedAddition + move:GetVelocity())
+	end
+
+	JUMPING = nil
+
 end
 
 player_manager.RegisterClass( "player_sandbox", PLAYER, "player_default" )