From a91c6b5420cf99ad53dce42fe0bbaea5f58cd8e8 Mon Sep 17 00:00:00 2001 From: Patrice Mandin Date: Mon, 6 Dec 2004 15:01:00 +0000 Subject: [PATCH] Document new OpenGL feature --- README.MiNT | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/README.MiNT b/README.MiNT index 8eeb1fa7b..7b464b3f8 100644 --- a/README.MiNT +++ b/README.MiNT @@ -75,6 +75,9 @@ SDL_VIDEODRIVER: Set to 'xbios' to force xbios video driver Set to 'gem' to force gem video driver +SDL_VIDEO_GL_DRIVER: + Set to filename to load as OpenGL library, if you use SDL_GL_LoadLibrary() + SDL_AUDIODRIVER: Set to 'mint_gsxb' to force Atari GSXB audio driver Set to 'mint_mcsn' to force Atari MCSN audio driver @@ -126,6 +129,21 @@ SDL_JOYSTICK_ATARI: ============================================================================== VI. More informations about drivers: +OpenGL: + The default is to use the Mesa offscreen driver (osmesa.ldg). If you want + to use an older OpenGL implementation, like mesa_gl.ldg or tiny_gl.ldg, + your program must use SDL_GL_LoadLibrary() to do so, and retrieve the + needed function pointers with SDL_LoadFunction(). In all cases, the OpenGL + context is taken care of by SDL itself, you just have to use gl* functions. + + However, there is one OpenGL call that has a different prototype in the old + implementations: glOrtho(). In the old implementations, it has 6 float as + parameters, in the standard one, it has 6 double parameters. If you want + to compile testdyngl, or any other SDL program that loads its OpenGL + library, you must change the glOrtho() prototype used in this program. In + osmesa.ldg, you can retrieve a glOrtho() with double parameters, by searching + for the function "glOrtho6d". + Xbios video: Video chip is detected using the _VDO cookie. Screen enhancers are not supported, but could be if you know how to