• 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
Sagaceil

Using compressed and non compressed mipmaps

8 posts in this topic

Is it posible to use both compressed and uncompressed texture data when uploading mipmaps for texture ? I'm working on better streaming system for textures with seamless transition beetwen mipmap lvl's. 

So far so good. Everything working fine untill I'm uploading non compressed data using glTexImage. I'm setting GL_TEXTURE_MAX_LEVEL to the last (1x1) mipmap index but it seems that texture gets uncompletness when that happen. I'm forced to set GL_TEXTURE_MAX_LEVEL as the last compressed mipmap and then it works.

My question : bcoz glTexImage doesnt return any GL Error, is it possible to use non compressed data with compressed in another mipmaps ( compressed data works great when te resolution is >= 16, i need <16 texture mipmaps to avoid aliasing ).

 

Thanks for any help ! :)

0

Share this post


Link to post
Share on other sites

So actually theres no way to use compressed textures and use lower size than 4px. I supposue that compression require 4x4 px blocks to be compressed.

0

Share this post


Link to post
Share on other sites

There's no problem using compression for non-multiples of 4x4 blocks. Many, if not all, compression formats works just fine with any texture size.

0

Share this post


Link to post
Share on other sites


Many, if not all, compression formats works just fine with any texture size.

That would be nice, but is it so? I've found contradictory statements about the ability to compress NPOT textures.

 

My last own tests regarding this issue were done with OpenGL 2.1 on Mac OS 10.6, and at that time using GL_RGB as external format and GL_COMPRESSED_RGB as internal format to glTexImage2D has led to internal format GL_RGB8 for a rectangular texture, regardless whether its size was a multiple of 4 in both dimensions or not. The same image but padded to square POT size then led to GL_COMPRESSED_RGB_S3TC_DXT1 internal format.

 

The ARB_texture_rectangle stated that glTexImage is allowed to do what is shown by mentioned tests. It further stated that glCompressedTexImage is not supported for rectangular textures, although there is room for enhanced formats: "This is because several existing hardware implementations of texture compression formats such as S3TC are not designed for compressing rectangular textures. This does not preclude future texture compression extensions from supporting compressed internal formats that do work with rectangular extensions ..."

 

And the specification for OpenGL 4.4 core profile states in section 8.7: "... except that compressed rectangle texture formats are not supported."

 

On the other hand I've read somewhere that it is actually found that some implementations actually do accept pre-compressed rectangular textures, although even it may be that they do not compress such textures themselves.

 

Very confusing ...

0

Share this post


Link to post
Share on other sites

I have no problems with odd-sized texture compression, they load just fine. I get compressed internal formats for odd-sized textures with uncompressed and compressed source data and with a generic and a specific compressed internal format.

 

You keep talking about texture rectangles though, they have some general limitations as far as I remember. I have never used them so don't know how they interact with texture compression and if there are some additional requirements.

Edited by Brother Bob
0

Share this post


Link to post
Share on other sites

Ok, solved.

 

I'm uploading compressed mipmaps using glCompressedTex* ( mipmaps with size >= 4px ) and using glTexImage* with GL_COMPRESSED_RGB(A) for lower mipmaps.

0

Share this post


Link to post
Share on other sites

Just curious, why aren't you using the same for methods for mipmaps less than 4 pixels? I don't know the internal format is supposed to be chosen for a generic format, but chances are that the explicit format you use for images larger than 4 pixels just happens to be the same as the generic format for images smaller than 4 pixels. If the driver cannot use the same format for the generic one, your approach till fail.

0

Share this post


Link to post
Share on other sites

When Im importing textures to engine, Im doing offline compression using close fit range compression. So I have to ananlize whole 4x4 blocks as an input. When loading textures , they are in compressed format arleady, and the last mipmaps are stored as a raw RGB(A) data.

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