The Big Programming Thread - Page 427

On January 15 2014 08:43 Zocat wrote:
It's called busy spin / spin lock afaik.
Overall you should avoid using it, since it just burns the CPU.

I think one thing were you can use it was when you only have to wait for very very short amount of times where implementing events would introduce a larger overhead. (No idea if that's true though, never used it)

On January 15 2014 09:29 sluggaslamoo wrote:


Its called a latch function, its used a lot more than you think.

On January 15 2014 09:35 darkness wrote:


Wikipedia seems to suggest "busy-waiting or spinning".

On January 15 2014 22:35 Pucca wrote:
I'm working on a C++ program, I'm a noob so I was wondering if anyone could give some tips on my logic.

StarCraft 1 like any program has independent data strings for each piece of information in the game. My goal is to read this data string and place it into a constantly updating .txt file.

There are two data strings I have, Total Score of Player A and Total Score of Player B. I want to combine the two. So like Player A is 15 Player B is 14 the output becomes 29 places into the text file.

So my logic is

Data stream of Player A is A
Data stream of Player B is B
ReadProcessData of A
ReadProcessData of B
combine? (I don't know C++ function to add) A and B to result in C
Fstream C to TeamA.txt **refresh every .2sec**

As long as the data streams are consider variables you can add them no? Any assistance is appreciate, if you'd like to help me please PM me. Thanks.

On January 15 2014 22:52 darkness wrote:
I can't help with C++ but variables cannot be added if there is no + operator implementation. Example in Java (generics, called template in C++):

T t;
K k;

System.out.println(t + k);

Let me know if I am mistaken, but I wasn't able to do this once.

cout << t + k << "\n";

On January 15 2014 22:35 Pucca wrote:
I'm working on a C++ program, I'm a noob so I was wondering if anyone could give some tips on my logic.

StarCraft 1 like any program has independent data strings for each piece of information in the game. My goal is to read this data string and place it into a constantly updating .txt file.

There are two data strings I have, Total Score of Player A and Total Score of Player B. I want to combine the two. So like Player A is 15 Player B is 14 the output becomes 29 places into the text file.

So my logic is

Data stream of Player A is A
Data stream of Player B is B
ReadProcessData of A
ReadProcessData of B
combine? (I don't know C++ function to add) A and B to result in C
Fstream C to TeamA.txt **refresh every .2sec**

As long as the data streams are consider variables you can add them no? Any assistance is appreciate, if you'd like to help me please PM me. Thanks.

	string text="42.0";
	float value=stof(text); //float value = 42.0f
	auto new_text=text+text; //new_text is a string with value = "42.042.0"

string t_0="32";
string t_1="10";
//convert t_0 and t_1 to ints, add them and pass the result to to_string
string t_2=to_string(stoi(t_0)+stoi(t_1)); //has value "42"

On January 15 2014 23:06 Tobberoth wrote:

Isn't this a very roundabout way of doing it? Isn't it better to parse the data from the processes into strings, then simply write these strings to the common file when they change?

On January 14 2014 11:39 sluggaslamoo wrote:


Yep basically what you said and not much more than that if at all. Those classes will basically serve as "models".

Controllers handle inputs. For example in a website it will handle the URL's, in your case its the game controller inputs. There should be minimal logic in the controller. Think about how much logic is in an actual game controller, it takes a signal, and converts it into an instruction to the game, that's all your controller should do as well. As a rule of thumb, light controllers, fat models.

Pretty much all the logic should be in your models. Anything code that has anything to do with a model, should be in the model itself. For example, "moving a Paddle", there should be a move method on the Paddle itself, don't write the logic in the controller or anywhere else. In the controller you would handle the mouse movement, and delegate all logic to the Paddle by passing in the mouse event or minimal information necessary.

You could also do it declaratively, by adding in a listener to the paddle in the beginning and firing it off with the controller.

When I was saying that your last example was MVC, I was more or less being tongue in cheek about MVC not being the issue there. When you do things properly your program will naturally become MVC of sorts. Even when you do implement what I said, it won't be MVC really.

MVC normally has an ORM associated with it, and you declare Models as an abstraction for saveable/stateful components in your application.

I only pointed it out because you specifically wanted your app to be MVC. I don't think its necessary to think of it like that though. MVC is much more useful for applications where you need to save state. This is more or less focused on doing Responsibility Driven Design.

On January 17 2014 10:33 WarSame wrote:

Thank you to you and Blisse. I redid the design a bit and made it more MVC-like. I moved the data logic into PongData and created my Paddle and Ball classes. It turned out fairly nicely, I think, but there's still a few parts where it doesn't look as great as it probably could. Also, for some reason every once in a while the ball simple doesn't collide with the paddle and clips right through, but I can't track down why.

For now, it's likely done. At some point in the future I may come back and add in Ball[] and Paddle[] in order to allow for extras to be added in on demand.

The code is here: https://github.com/WarSame/PongGraeme

On January 17 2014 11:16 WarSame wrote:
Well the way I handled the collision was:

if the ball is not in the paddle, and the ball will be in the paddle on the next cycle, make the ball bounce. Depending on where it hit the paddle it then bounces differently.

Also, it seems kinda odd that you can use a Double to store the ball location and then paint it onto the screen as an int. I suppose the graphics library for Java has some sort of rounding function. Is that wrong?

1 - 2 - 3 - 4 - 5 - 6
O       []

1 - 2 - 3 - 4 - 5 - 6
---------[]---O

On January 17 2014 11:27 WarSame wrote:
For checking if it will be in the paddle on the next cycle I used the current position and the speed. I first check whether the current position was outside the paddle. Then I checked if the next position was inside the paddle. If it was I bounced the ball off of the paddle.

On January 17 2014 11:27 WarSame wrote:
For checking if it will be in the paddle on the next cycle I used the current position and the speed. I first check whether the current position was outside the paddle. Then I checked if the next position was inside the paddle. If it was I bounced the ball off of the paddle.

EDIT: So it's close to what you said. In my case it interpolated between the 2 points of the paddle location and the paddle thickness plus location.

On January 17 2014 11:54 sluggaslamoo wrote:


This is the same as only checking once, but moving the ball after the check.



Are you sure its interpolation and not just checking two points?