• 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.

Archived

This topic is now archived and is closed to further replies.

Guest Anonymous Poster

Physical to video memory blit/HW accel

7 posts in this topic

Some cards can accelerate that function, but not all.

It's always best to use as much DirectX in your DirectX programs as possible as new cards add new features all the time. By doing so, you get at least a limited degree of support without recompiling.

0

Share this post


Link to post
Share on other sites
You should be able to check if your card supports sys to vram acceleration by using the DirectX properties program (for DX5.0 anyway. I'm sure DX6.0 has some form of this as well).

Also, you may want to check to see if your memcpy() copies DWORDs, WORDs, or BYTEs at a time. Most compilers use DWORDs for 32 bit apps, but I think some don't. The only other thing I can think of is if you're copying unaligned data, DirectX MAY do some dynamic ordering to at least TRY to setup aligned copying, which if it did would beat out your unaligned memcpy. Always try to keep mem movement aligned if possible.

Rock

0

Share this post


Link to post
Share on other sites
if you want to use memcpy() like fn to do the blt, use mmx. it'll allow you to move qwords and *might* be a bit faster than dd's bltfast.
0

Share this post


Link to post
Share on other sites
I say just stick with the directx bltfast or blt statment. Alot of hardware ive seen accelerates it and your not likly to beat that. Plus its genraly going to work on any system with a directx compatable driver unlike some of the other routines i have seen.
0

Share this post


Link to post
Share on other sites
Thanks for all the replies guys. I wasn't considering not using DirectX for the blit, since it's so much faster, I was just wondering why this was happening. Also I am considering allowing the user to select either DirectX blitting or regular memcpy (I hear memcpy is noticeably faster than the HEL implementation of BltFast sys->vid). Anyway I will have to give it a go on an older video card and see what difference it makes.

As Rock suggested I checked out the DX Device Viewer tool, which tells me that Sys->Vid memory Blt's are accelerated. I was also wondering (technically) how this would be accelerated, since the bus is limited to a certain speed anyway. If anyone has any thoughts there I'd be interested to hear about it as I don't know a lot about video hardware acceleration/capabilities.

Also thanks for the suggestion on using MMX Queasy, I'm going to look into that.

Phoenix

0

Share this post


Link to post
Share on other sites
I'm just pondering some unusual results I got when testing a project. When blitting from a 480x480 physical memory buffer into the back buffer (in video memory), I get better results using BltFast than memcpy'ing it line by line, contrary to what I have been told. Can the video card accelerate this operation (I didn't think it could, but this makes me think it must be). Using memcpy the speed is around half as slow... any ideas? Thanks!

Phoenix

0

Share this post


Link to post
Share on other sites
Few references from DirectX SDK Help:

"The IDirectDraw4::GetCaps method fills in the capabilities of the device driver for the hardware and the hardware-emulation layer (HEL)."

From the filled DDCAPS structure check if dwCaps has DDCAPS_CANBLTSYSMEM 'flag checked' or something

"DDCAPS_CANBLTSYSMEM
Indicates that display hardware is capable of blitting to or from system memory."

You could check that and then use preferred blitting method, am I right?

------------------
"Tank, I need an exit. Fast!"

0

Share this post


Link to post
Share on other sites