RTFSS

::Inici >Formats utilitzats

Formats utilitzats

Els formats de fitxers usats son:

Support for JPG,TGA,DDS file for textures,cubemaps and logos.

This three formats has been selected with care for their special features.

JPG has been selected for being a good compression lossy codec and their support from image manipulation packages.

TGA has been selected for their ability to retain alpha chanels (util for translucent textures and logos in OpenGL)
and lossless capabilities and easy to implement a reader.

DDS is the standard of fact for DirectX textures and OpenGL. It abilities are a lot and include:

easy readying of it (see nvidia.developer.com)

ability to store compressed textures in the internal format that supports hardware cards (S3TC).
This avoids compressing the applications to send to the videocard and low memory footprint on the graphics card.

alpha channels

support for storing mipmaps in one file.

in one file you can have 6 faces of the cubemap stored with mipmaps and in a compressed format.

Wavefront OBJ (.OBJ) for 3d objects description. We have selected this format for being "simple" to implement and retaining a lot of features via material files (.MTL) like textures,bumpmaps,etc..
Material files it is also implemented

For sound data we have supported OGG Vorbis (.OGG). Ogg Vorbis sound format is enabled via libvorbis.
It has been selected for three reasons:

For having good compression (some people say better than mp3 at same bitrate specially for low bitrates)

Open source format

Easy to learn and use librares..

Support for .lzma format of lzma SDK for loading compressed scenes descriptions and OBJ's and fonts.
It is one of the more efficient lossless compression scheme with an "avaiable" SDK which is easy of use and small in C++
and C.
Decompresses on a Pentium 4C 3.0Ghz at +20Mbytes/s.

This reduces space of the demo on disk reducing OBJ files for initial sample scene from +20MBytes to 3-4Mbytes.

glf format of the font of glfont library.

scn Internal file format developed for storing most of the state of the demo.

Grid format. Internal file format developed for storing the grid to apply