First and foremost, I'm not sure where this should have gone, so I placed it in the
General Chit Chat section. It's basically an optimization tutorial, but also a question, so I wasn't sure...
There is an FPS cap over the entire client-side MS engine, in the GameLoop Sub. Why the whole GameLoop?
Code:
' Lock fps
Do While GetTickCount < Tick + 60 ' <-- The 60 is the limiting number.
DoEvents
Loop
The 60 limits the FPS to 16 on every computer that plays it; the framerate cannot go above 16. However, if you change the number limiting it, the FPS increasing depending on the player's computer.
Why limit it to 16..? It makes the game look more choppy because the human eye requires at least 24 frames per second to see a smooth animation, and a higher frame rate makes it even more so.
The reason this happens is there is a main sub called the GameLoop that calls the functions of moving, blitting, and basically DOING everything over and over, making the game constantly run.
Inside the gameloop sub, there is a certain spot that blits players. If you actually lock that spot instead of the entire sub, then the game can run at a higher FPS, and the players move at the same rate (the 16 FPS rate, but at a higher FPS).
A simple way to do this is this:1) Add a variable called "TickMove" or something of the sort, and add it as a Long variable inside the GameLoop sub.
2) Lock the spot that checks to see if the player is moving, and limit it to a certain timeframe (Such as 16 times per second, 16 FPS, like earlier, before we did anything.) to disable the player shooting across the screen in a rather unruly manner.
To do this, go to the GameLoop Sub, and find where it checks to see if the player is trying to move. ("Call CheckMovement")
Put the lock around the Call procedure:
Code:
' Check if player (index) is trying to move
If GetTickCount > TickMove + 60 Then
Call CheckMovement
TickMove = GetTickCount
End If
This makes it so your player now moves at the same rate that it did when the FPS was locked.
In order to make it so NPCs and other players move at the same rate as everyone else, make a variable for the action and put the lock around the it as well:
Code:
If GetTickCount > TickNPCMove + 60 Then
For i = LBound(MapNpc) To UBound(MapNpc)
If MapNpc(i).Moving = True Then
TickNPCMove = GetTickCount
Exit For
End If
If MapNpc(i).Num > 0 Then Call ProcessNpcMovement(i)
Next i
TickNPCMove = GetTickCount
End If
Now finish it off by adding it to anything else that needs limiting to the base FPS (16 FPS).
So far all you've done is make it so the framerate increases, and nothing is smooth... would you like your players' movement smooth? Check the question below. (They are still a part of the post, not just a debug section or something of the sort)
Questions:My players are still really jumpy, and they do not walk smoothly, why? This tutorial doesn't fix the amount of times that the players appear while walking or running in their animation.
A player presses.. let's say... left once to go left one tile. While a player is walking, the character gets blitted however many times the gameloop sub is called (The same number of times as your FPS), but the player isn't actually shown on each pixel as it moves. It jerks from right to left when walking right by a certain number of pre-determined pixels, WALK_SPEED.
The base MS WALK_SPEED is 4, which means that the player gets shown every four pixels; eight times per tile walk (32 / 4 = 8). Also, every time that a player walks one tile, it takes exactly 480 ticks, or milliseconds.
The base RUN_SPEED is 8, which means that the player gets shown every eight pixels; 4 times per tile run (32 / 8 = 4). Also, every time that a player walks one tile, it takes exactly 240 ticks, or milliseconds.
In order to make the players get shown more times per tile move (instead of jerking over 4 tiles, you can make it jerk over 2, making it look smoother), change the WALK_SPEED and RUN_SPEED to lower numbers. (ie: 2 and 4)
!!BE SURE TO KEEP THE NUMBERS AT LEAST 1 AND AT MOST 32!! The two numbers HAVE to be divisible by 2 (unless the WALK_SPEED is 1 and the RUN_SPEED is 2), and a factor of 32. (1, 2, 4, 8, 16, and 32) This way, XOffset and YOffset don't get thrown off into some weird number, and render your player motionless.
If you change WALK_SPEED to 2, the player will walk half the speed as before because the player is allowed to move by the FPS cap that you set upon him or her. In the GameLoop sub, you'll notice that it is actually limiting the times that "Call ProcessMovement(i)" is called. That's because this is what actually MOVES the player. Code:
Sub ProcessMovement(ByVal Index As Long)
' Check if player is walking, and if so process moving them over
If Player(Index).Moving = MOVING_WALKING Then
Select Case GetPlayerDir(Index)
Case DIR_UP
Player(Index).YOffset = Player(Index).YOffset - WALK_SPEED
Case DIR_DOWN
Player(Index).YOffset = Player(Index).YOffset + WALK_SPEED
Case DIR_LEFT
Player(Index).XOffset = Player(Index).XOffset - WALK_SPEED
Case DIR_RIGHT
Player(Index).XOffset = Player(Index).XOffset + WALK_SPEED
End Select
' Check if completed walking over to the next tile
If (Player(Index).XOffset = 0) And (Player(Index).YOffset = 0) Then
Player(Index).Moving = 0
End If
End If
' Check if player is running, and if so process moving them over
If Player(Index).Moving = MOVING_RUNNING Then
Select Case GetPlayerDir(Index)
Case DIR_UP
Player(Index).YOffset = Player(Index).YOffset - RUN_SPEED
Case DIR_DOWN
Player(Index).YOffset = Player(Index).YOffset + RUN_SPEED
Case DIR_LEFT
Player(Index).XOffset = Player(Index).XOffset - RUN_SPEED
Case DIR_RIGHT
Player(Index).XOffset = Player(Index).XOffset + RUN_SPEED
End Select
' Check if completed walking over to the next tile
If (Player(Index).XOffset = 0) And (Player(Index).YOffset = 0) Then
Player(Index).Moving = 0
End If
End If
End Sub
When this "Sub ProcessMovement" is called, it moves the player by the number you set as WALK_SPEED or RUN_SPEED. So, if you set WALK_SPEED as 2, the player will walk 2 pixels every 60 ticks (.060 seconds, right?) (This is only if you set the FPS cap as "+ 60" earlier in step 2. -- VERY slow compared to before. When WALK_SPEED was 4, it moved the player 4 pixels every 60 milliseconds / ticks; double the speed than it is now!
To fix the speed that you just changed, change the FPS cap from "+ 60" to "+ 30", resulting in it being called twice as much. The player now moves just as fast as before, but is showed twice as much.
Mathematically this method works, but I'm still having trouble perfecting it.. it's just not perfect yet and I don't know why. Does anyone else?
It sure does makes sense though!
I hope that you all can make heads or tails out of what I've written, and I also hope that this has helped some people. It would be wonderful if someone finds a way to make it better. This may be the best, or worst method to accomplish this task, but it's the only way that I could think of, so comments / questions are welcome and needed.
:: Erik
PS: I really have trouble explaining stuff to people; I'm not a very good teacher. If you see any words that should be changed or rewritten, then just tell me if you're a regular user, or change it for me if you're a mod. Thanks again! Comments are welcome!
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