• 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
zerorepent

Filling opencl buffer/image with zeros

2 posts in this topic

Hi!

What is the way to fill a opencl buffer (or texture) with zeros? 

 

cl_int errorCode;
float arg = 0; //or a larger datastructure/type
errorCode = m_Queue->enqueueFillBuffer<float>(destinationBuffer,arg,0,size,NULL,0);

This operation seems really wasteful, but maybe I'm wrong? Is it perhaps better to use map/unmap and memset with zeros?  

 

For example I want to create a buffer of size x, fill it with z amounts of data (z<x) and fill the rest of the buffer with zeros. Is the only option then to first write z data, and then do a fill-function call like the one above with an offset? Is it possible to intialize a buffer filled with zeros. Googling only seem to result in information about zero-copy memory (which is interesting in itself, but not what I'm looking for). 

0

Share this post


Link to post
Share on other sites

What do you mean by wasteful? the enqueueFillBuffer functions are really self-documenting, they are meant to be used to fill buffers. Mapping and unmapping is another option, but the problem is that your memory usage spikes up if your buffer is large, unless you do it in small increments in which case you end up calling the API a lot which can also hurt (and isn't very elegant).

 

Of course, it's only available under OpenCL 1.2, so if that's the only 1.2 feature you're using it might make more sense to use a less modern approach and just implement the fill function yourself (it's actually not too hard, just enqueueWriteBuffer the given pattern over the entire buffer, just remember to use CL_FALSE for non-blocking writes, for the love of god).

 

Another option is to write a kernel designed to set buffers to zero, which might actually win out to every other approach bar zero-copy memory for large buffers on hardware devices (like GPU's) but this is very inelegant and tedious in terms of implementation. Though I'm not exactly sure how the enqueueFillBuffer is implemented, perhaps it uses that under the hood when appropriate.

 

Also, don't make the mistake I did. Don't foolishly memset an array of floats to zero. When I did that, it set them all to NaN in the OpenCL kernel for some reason sad.png

Edited by Bacterius
0

Share this post


Link to post
Share on other sites

wasteful might have been a poor choice of words, but what I mean is that since I'm not using complex pattern, i.e. just filling with zero using fill seems a bit overkill.

The Buffer sizes is in ranges between ~64KB and ~128MB. Using a small pattern a float seems to be rather inefficient because even if it zero:ed it still need to do size/4 memcopies. Thats why I thought maybe using unmap/map and memset might be faster, I guess my best option is to time it and compare. (or something similar to that)

Edited by zerorepent
0

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