README-SDL.txt
author Sam Lantinga <slouken@libsdl.org>
Wed, 18 Oct 2017 08:52:04 -0700
changeset 11630 ad4b5d85edee
parent 10892 996c14d41c46
permissions -rw-r--r--
Fixed bug 3821 - Allow SDL_CreateWindow and SDL_CreateRenderer with OpenGL ES 3.0 (GLES3) for Angle (Windows)

Carlos

Angle supports GLES3 but when using these functions (SDL_CreateWindow and SDL_CreateRenderer), defaults again to GLES2.0.

A current workaround (hack) to retrieve a GLES3.0 context with Angle is:

1) set

SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);

after InitSDL AND after calling SDL_CreateWindow (before SDL_CreateRenderer)

2) Comment lines 2032-2044 in SDL_render_gles2.c, funtion GLES2_CreateRenderer

window_flags = SDL_GetWindowFlags(window);
if (!(window_flags & SDL_WINDOW_OPENGL) ||
profile_mask != SDL_GL_CONTEXT_PROFILE_ES || major != RENDERER_CONTEXT_MAJOR || minor != RENDERER_CONTEXT_MINOR) {

changed_window = SDL_TRUE;
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, RENDERER_CONTEXT_MAJOR);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, RENDERER_CONTEXT_MINOR);

if (SDL_RecreateWindow(window, window_flags | SDL_WINDOW_OPENGL) < 0) {
goto error;
}
}

This retrives a GLES3 context as confirmed using glGetString(GL_VERSION). This should be fixed by modifying a few if's.
     1 
     2 Please distribute this file with the SDL runtime environment:
     3 
     4 The Simple DirectMedia Layer (SDL for short) is a cross-platform library
     5 designed to make it easy to write multi-media software, such as games
     6 and emulators.
     7 
     8 The Simple DirectMedia Layer library source code is available from:
     9 https://www.libsdl.org/
    10 
    11 This library is distributed under the terms of the zlib license:
    12 http://www.zlib.net/zlib_license.html
    13