• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
lride

How to measure the time it takes to evalueate an expression

8 posts in this topic

say I have a boolean expression

a<b

How can I measure the time it takes for my computer to evaluate a single expression? Edited by lride
0

Share this post


Link to post
Share on other sites
uhm...

I guess you could make a timestamp before and after the expression and look at the difference.

It will barely differ though, unless you have a [i]really [/i]complex expression.
0

Share this post


Link to post
Share on other sites
Would the result be inaccurate because it is such a small difference?
And how can I obtain the true time it takes to evaluate just the expression, not other things such as assigning the value to a variable

Normally when I just code [font=courier new,courier,monospace]1==2;[/font] compilers see the code as not effective and discards it. Edited by lride
0

Share this post


Link to post
Share on other sites
[quote name='lride' timestamp='1349398907' post='4986974']
Would the result be inaccurate because it is such a small difference?
[/quote]

There are high precision timers (on windows they are called "Multimedia Timers") that can give you i believe at the microsecond level (might even be nanosecond though at that level it probably would be inaccurate). Why do you need such a precise timing for only a single operation? If you are trying to figure out the clock speed of the user's processor there are better ways.
1

Share this post


Link to post
Share on other sites
I'm doing an experiment.

[quote name='metsfan' timestamp='1349399394' post='4986975']
[quote name='lride' timestamp='1349398907' post='4986974']
Would the result be inaccurate because it is such a small difference?
[/quote]

There are high precision timers (on windows they are called "Multimedia Timers") that can give you i believe at the microsecond level (might even be nanosecond though at that level it probably would be inaccurate). Why do you need such a precise timing for only a single operation? If you are trying to figure out the clock speed of the user's processor there are better ways.
[/quote]

Are you saying it would still be inaccurate at nanosecond level?
0

Share this post


Link to post
Share on other sites
Thank you. I understand.
[quote name='alvaro' timestamp='1349403018' post='4986988']

and the question you are asking is no longer meaningful.

[/quote]
0

Share this post


Link to post
Share on other sites
[quote name='lride' timestamp='1349403106' post='4986989']
Are you saying it would still be inaccurate at nanosecond level?
[/quote]
Note that on the nanosecond level, even calling your timing functions will show noise. Just calling QueryPerformanceCounter, storing it in a variable/register, and then calling it again will take some time. So you have to remember that the time you get back includes your operation and your call to QueryPerformanceCounter.

To help minimize this inaccuracy, you'll want to repeat your operation until it takes a significant amount of time compared to the noise introduced by your timing calls. But like alvaro said, modern CPUs are incredibly complicated, and the timings you get back in your testing setup may not match the average results in a real application.

To be more accurate, you'd read the generated assembly, look up your specs on your CPU and calculate by hand how much time an average expression to evaluate. But even then there are all sorts of things that the CPU can do that will make your calculated time just a guideline and not a fixed absolute.

So I guess it all depends on how accurate you want to be.
1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0