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Date: Sun, 22 Mar 2009 12:52:29 +0000 From: Luke Benstead Subject: OpenGL 3.0 Context Creation I've attached a patch which implements OpenGL 3.x context creation on the latest SVN. I've added two options to SDL_GL_SetAttribute, these are SDL_GL_CONTEXT_MAJOR_VERSION and SDL_GL_CONTEXT_MINOR_VERSION. These default to 2 and 1 respectively. If the major version is less than 3 then the current context creation method is used, otherwise the appropriate new context creation function is called (depending on the platform). Sample code: if (SDL_Init(SDL_INIT_VIDEO) != 0) { printf("Unable to initialize SDL: %s\n", SDL_GetError()); return 1; } SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3); //Without these 2 lines, SDL will create a GL 2.x context SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0); SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); SDL_Surface* screen = SDL_SetVideoMode( 640, 480, 16, SDL_OPENGL | SDL_FULLSCREEN ); I've implemented context creation on both Win32 and X and run basic tests on both. This patch doesn't provide access to all the options allowed by the new context creation (e.g. shared contexts, forward compatible contexts) but they can be added pretty easily.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 24 Mar 2009 10:43:53 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Initializing SDL</TITLE
><META
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"><LINK
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>SDL Library Documentation</TH
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>Chapter 1. The Basics</TD
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><DIV
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><H1
CLASS="SECT1"
><A
NAME="GUIDEBASICSINIT"
></A
>Initializing SDL</H1
><P
>SDL is composed of eight subsystems - Audio, CDROM, Event Handling, File I/O, Joystick Handling, Threading, Timers and Video. Before you can use any of these subsystems they must be initialized by calling <A
HREF="sdlinit.html"
><TT
CLASS="FUNCTION"
>SDL_Init</TT
></A
> (or <A
HREF="sdlinitsubsystem.html"
><TT
CLASS="FUNCTION"
>SDL_InitSubSystem</TT
></A
>). <TT
CLASS="FUNCTION"
>SDL_Init</TT
> must be called before any other SDL function. It automatically initializes the Event Handling, File I/O and Threading subsystems and it takes a parameter specifying which other subsystems to initialize. So, to initialize the default subsystems and the Video subsystems you would call:
<PRE
CLASS="PROGRAMLISTING"
>    SDL_Init ( SDL_INIT_VIDEO );</PRE
>
To initialize the default subsystems, the Video subsystem and the Timers subsystem you would call:
<PRE
CLASS="PROGRAMLISTING"
>    SDL_Init ( SDL_INIT_VIDEO | SDL_INIT_TIMER );</PRE
></P
><P
><TT
CLASS="FUNCTION"
>SDL_Init</TT
> is complemented by <A
HREF="sdlquit.html"
><TT
CLASS="FUNCTION"
>SDL_Quit</TT
></A
> (and <A
HREF="sdlquitsubsystem.html"
><TT
CLASS="FUNCTION"
>SDL_QuitSubSystem</TT
></A
>). <TT
CLASS="FUNCTION"
>SDL_Quit</TT
> shuts down all subsystems, including the default ones. It should always be called before a SDL application exits.</P
><P
>With <TT
CLASS="FUNCTION"
>SDL_Init</TT
> and <TT
CLASS="FUNCTION"
>SDL_Quit</TT
> firmly embedded in your programmers toolkit you can write your first and most basic SDL application. However, we must be prepare to handle errors. Many SDL functions return a value and indicates whether the function has succeeded or failed, <TT
CLASS="FUNCTION"
>SDL_Init</TT
>, for instance, returns -1 if it could not initialize a subsystem. SDL provides a useful facility that allows you to determine exactly what the problem was, every time an error occurs within SDL an error message is stored which can be retrieved using <TT
CLASS="FUNCTION"
>SDL_GetError</TT
>. Use this often, you can never know too much about an error.</P
><DIV
CLASS="EXAMPLE"
><A
NAME="AEN60"
></A
><P
><B
>Example 1-1. Initializing SDL</B
></P
><PRE
CLASS="PROGRAMLISTING"
>#include "SDL.h"   /* All SDL App's need this */
#include &#60;stdio.h&#62;

int main(int argc, char *argv[]) {
    
    printf("Initializing SDL.\n");
    
    /* Initialize defaults, Video and Audio */
    if((SDL_Init(SDL_INIT_VIDEO|SDL_INIT_AUDIO)==-1)) { 
        printf("Could not initialize SDL: %s.\n", SDL_GetError());
        exit(-1);
    }

    printf("SDL initialized.\n");

    printf("Quiting SDL.\n");
    
    /* Shutdown all subsystems */
    SDL_Quit();
    
    printf("Quiting....\n");

    exit(0);
}&#13;</PRE
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