We use functions from GL_ARB_framebuffer_object extension and not from
GL_EXT_framebuffer_object where functions are suffixed by EXT.
This avoids crashes on implementations supporting only the EXT version.
This allows us to use various framebuffer settings easily. Now the GPU
accelerated CLUT8 surface implementation does not need to query former
framebuffer state anymore.
For GLES1+ there exists GL_OES_texture_npot, which indicates that there is
NPOT support.
GLES2 always had (limited) NPOT support, which is all we require, thus we
always enable it.
Formerly, we required that the OpenGL mode was fixed at compile time. Now we
allow the code to work with whatever it is given at runtime.
It is still possible to force a context type on compile time.
Formerly we relied on static linkage. However, in the presense of modern
OpenGL (ES) implementations it is not easily identifable which library to link
against. For example, on Linux amd64 with nVidia drivers and SDL2 setup to
create a GLES 1.1 context one would need to link against libGL.so. However,
traditionally GLES 1.1 required to link against libGLESv1_CM.so. To prevent a
huge mess we simply resolve the OpenGL functions on run-time now and stop
linking against a static library (in most cases).
GLES support needs to be enabled manually on configure time for now.
Tizen changes have NOT been tested.
2016-03-16 20:29:24 +01:00
Renamed from backends/graphics/opengl/extensions.cpp (Browse further)
