Hash :
b4cd43eb
Author :
Date :
2001-11-05T21:01:13
FTGL 1.1 October 31 2001 DESCRIPTION: FTGL library is a cross platform tool to allow OpenGL (www.opengl.org) to render characters from arbitrary fonts. Unlike other OpenGL font libraries FTGL uses standard font file formats so doesn't need a preprocessing step to convert the high quality font data into a lesser quality, proprietary format. FTGL uses the Freetype (www.freetype.org) font library to open and 'decode' the fonts. It then takes that output and stores it in a format most efficient for OpenGL rendering. Rendering modes supported are - Bit maps - Pix maps - Texture maps - Outlines - Polygon meshes FTGL is designed to be used in commercial quality software. It has been written with performance, robustness and simplicity in mind. USAGE: FTGLPixmapFont font; font.Open( "Fonts:Arial"); font.FaceSize( 72); font.render( "Hello World!"); This library was inspired by gltt, Copyright (C) 1998-1999 Stephane Rehel ( gltt.sourceforge.net) Bezier curve code contributed by Jed Soane. Demo, Linux port and gltt maintainance by Gerard Lanois Linux port by Matthias Kretz Windows port by Max Rheiner Please contact me if you have any suggestions, feature requests, or problems. Henry Maddocks henryj@paradise.net.nz http://homepages.paradise.net.nz/henryj/ //======================================================================== Things to think about... The whole char size thing is major headache. At the moment if you call font.CharSize( x) the glyph list is destroyed and rebuilt, which will be really, really, really inefficient if you change sizes often. Will the freetype cache stuff help? What about the new (FT 2.0.5) FTSize public api. When is the best time to construct the glyphList? After the call to Size(x) is the earliest but what happens if the client doesn't set the char size? Define a default size, check if glyphlist is valid in render function, if not call size with default size. Might have to move the init code out of the glyph constructors into an init function so that they can return errors. good site...http://cgm.cs.mcgill.ca/~luc/ PROFILING test 1 100,000 frames. No openGL context. The results of the first profile are in and as expected using freetype to return the char index for a glyph is costing us. A staggering 10% of the rendering time in fact!!! Kerning has a similar impact. test 2 100,000 frames. No openGL context. Performance results for the new FTCharmap class are quite satisfying:) The overall render time went from 12.009 seconds down to 4.595. The charIndex call went from 9.066 to 1.754. My concerns about the performance of std::map seemed to be unfounded in this case. Kerning is still an issue as can be seen in the proportional difference in these figures. I don't think this can be resolved easily. Check that I do this properly.. ============================ Dave Williss a �crit : Question: If I do this... TT_New_Glyph(face, &glyph); for (i = 0 ; i < n ; ++i) { TT_Load_Glyph(instance, glyph, index[i], flags); ... use glyph... } TT_Done_Glyph(glyph) Will I be leaking memory on each call to Load Glyph or should I create and destroy the glyph handle for each call? Seems terribily inefficient but to do that, but doing it as above I seem to be leaking memory. No, this is the correct behaviour. Each call to TT_Load_Glyph overwrites the previous content.. and this was designed on purpose because the real content of a TT_Glyph object is _really_ complex with TrueType, and you don't want to create them on each glyph load..