• 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
edb6377

DX7 VC++6 Slow Alpha Blending

5 posts in this topic

Limitations: VC++ 6 and DX7

FPS = 60 (Dither)
FPS drops significantly when rendering Alpha Blended Text

Any Ideas?


Code as below.

Called to draw surface with Alpha Blend
[CODE]
// Alpha mode

DXDraw::RGBMASK mask = DXDraw::GetInstance()->GetRGBmask();
DWORD r, g, b, color;

// Render a alpha blended
for( int y = rc.top; y < rc.bottom; y++ )
{
for( int x = 0; x < rc.right; x++ )
{
color = pDestStart[ x ];
MergeColor( pimpl->backgroundColor, color );
pDestStart[ x ] = color;
}
pDestStart += pitch;
}
[/CODE]

Merge Color Code
[CODE]
// Add the color 1 with the second and divide the result by 2
#define MergeColor( clr1, clr2 )\
r = ( ( clr1 & mask.rMask ) + ( clr2 & mask.rMask ) ) >> 1;\
g = ( ( clr1 & mask.gMask ) + ( clr2 & mask.gMask ) ) >> 1;\
b = ( ( clr1 & mask.bMask ) + ( clr2 & mask.bMask ) ) >> 1;\
color = ( r & mask.rMask ) | ( g & mask.gMask ) | ( b & mask.bMask );
[/CODE] Edited by edb6377
0

Share this post


Link to post
Share on other sites
[quote name='jbadams' timestamp='1344309865' post='4966895']
[i][b]why[/b] do you think you need to stick with VC++6 and DirectX7?[/i]
[/quote]

perhaps he is maintaining some VERY old code that will generate thousands of errors if put through a modern compiler and a 1 line fix in the original environment would be faster than fix 6 thousands errors and then still be confronted with the original error in a new ecosystem.

If that's the case I sympathise for him [img]http://public.gamedev.net//public/style_emoticons/default/rolleyes.gif[/img] but my directdraw is a bit rusty [img]http://public.gamedev.net//public/style_emoticons/default/biggrin.png[/img]

If that's not the case.. yahh, get a real compiler and api.
0

Share this post


Link to post
Share on other sites
Please note that I've split off an off-topic discussion of continued usage of Visual C++ 6 into a new topic: "[url="http://www.gamedev.net/topic/629235-using-visual-c-6/"]Using Visual C++ 6"[/url]. Please keep this discussion on topic from this point onwards.
0

Share this post


Link to post
Share on other sites
Looks like you're emulating alpha blending by doing doing it on your own directly on the back buffer. You should check if the Driver supports hardware alpha blending (blit) and use that instead (Look the API documentation on how to that, there were plenty of examples in the DX7 SDK).
You may need to attach an 8-bit alpha surface in order to get smooth alpha blending with a 16-bit image (I assume you're using 16-bit because you said you were using dithering).

Emulation will slowdown your application badly because you're reading from GPU memory and then sending it back.
If you're forced to emulation (that would be a very ancient card, like, a 1995 video card) may be requesting the back buffer to be stored in local memory rather than hardware memory could help. Can't remember if that was possible though (was it called system memory rather than local memory?).
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