Add compatibility with old OpenGL 2.1 drivers

If ARB_framebuffer_object is not supported, try to fall-back to
EXT_framebuffer_object if present.

In current version of godot, the way framebuffers are used is backward
compatible with the older EXT_framebuffer_object extension.

Fixes #6591
Done with SuperUserNameMan

(cherry picked from commit a27fafb273)
This commit is contained in:
Błażej Szczygieł 2016-09-25 12:57:56 +02:00 committed by Rémi Verschelde
parent a5fe7ffbcd
commit f4da1e9ed2

View file

@ -10785,8 +10785,46 @@ void RasterizerGLES2::init() {
print_line(String("GLES2: Using GLEW ") + (const char*) glewGetString(GLEW_VERSION));
}
// Godot makes use of functions from ARB_framebuffer_object extension which is not implemented by all drivers.
// On the other hand, these drivers might implement the older EXT_framebuffer_object extension
// with which current source code is backward compatible.
bool framebuffer_object_is_supported = glewIsSupported("GL_ARB_framebuffer_object");
if ( !framebuffer_object_is_supported ) {
WARN_PRINT("GL_ARB_framebuffer_object not supported by your graphics card.");
if ( glewIsSupported("GL_EXT_framebuffer_object") ) {
// falling-back to the older EXT function if present
WARN_PRINT("Falling-back to GL_EXT_framebuffer_object.");
glIsRenderbuffer = glIsRenderbufferEXT;
glBindRenderbuffer = glBindRenderbufferEXT;
glDeleteRenderbuffers = glDeleteRenderbuffersEXT;
glGenRenderbuffers = glGenRenderbuffersEXT;
glRenderbufferStorage = glRenderbufferStorageEXT;
glGetRenderbufferParameteriv = glGetRenderbufferParameterivEXT;
glIsFramebuffer = glIsFramebufferEXT;
glBindFramebuffer = glBindFramebufferEXT;
glDeleteFramebuffers = glDeleteFramebuffersEXT;
glGenFramebuffers = glGenFramebuffersEXT;
glCheckFramebufferStatus = glCheckFramebufferStatusEXT;
glFramebufferTexture1D = glFramebufferTexture1DEXT;
glFramebufferTexture2D = glFramebufferTexture2DEXT;
glFramebufferTexture3D = glFramebufferTexture3DEXT;
glFramebufferRenderbuffer = glFramebufferRenderbufferEXT;
glGetFramebufferAttachmentParameteriv = glGetFramebufferAttachmentParameterivEXT;
glGenerateMipmap = glGenerateMipmapEXT;
framebuffer_object_is_supported = true;
}
else {
ERR_PRINT("Framebuffer Object is not supported by your graphics card.");
}
}
// Check for GL 2.1 compatibility, if not bail out
if (!glewIsSupported("GL_VERSION_2_1")) {
if (!(glewIsSupported("GL_VERSION_2_1") && framebuffer_object_is_supported)) {
ERR_PRINT("Your system's graphic drivers seem not to support OpenGL 2.1 / GLES 2.0, sorry :(\n"
"Try a drivers update, buy a new GPU or try software rendering on Linux; Godot will now crash with a segmentation fault.");
OS::get_singleton()->alert("Your system's graphic drivers seem not to support OpenGL 2.1 / GLES 2.0, sorry :(\n"