These formats require EXT_texture_norm16, which in turn needs OpenGL
ES 3.1. The EXT_texture_norm16 extension does not support passing
gl_internalformat = GL_RGBA to glTexImage2D, as can be done for
formats available in OpenGL ES 2.0, so this commit adds a field to
wlr_gles2_pixel_format to provide a more specific internalformat
parameter to glTexImage2D.
commit 44e8451cd9 ("render/gles2: hide shm formats without GL
support") added the is_gles2_pixel_format_supported() function to
render/gles2/pixel_format.c, whose stated purpose is to "check whether
the renderer has the needed GL extensions to read a given pixel format."
It then used that function to filter the pixel formats returned by
get_gles2_shm_formats().
The result of this change is that RGB formats are no longer reported for
GL drivers that don't implement EXT_read_format_bgra, even when those
formats are supported for rendering (which they have to be for
wlr_gles2_renderer_create() to succeed). This is a pretty clear
regression, since wlr_renderer_init_wl_shm() fails when either of
WL_SHM_FORMAT_ARGB8888 or WL_SHM_FORMAT_XRGB8888 are missing.
To fix the regression, change is_gles2_pixel_format_supported() to
accept all pixel formats that support rendering, regardless of whether
we can read them or not, and move the check for EXT_read_format_bgra
back into gles2_read_pixels(). (There's already a check for this
extension in gles2_preferred_read_format(), so we're not breaking any
abstraction that wasn't already broken.)
Tested on the NVIDIA 495.46 proprietary driver, which doesn't support
EXT_read_format_bgra.
Fixes: 44e8451cd9 ("render/gles2: hide shm formats without GL support")
The half-float formats depend on GL_OES_texture_half_float_linear,
not just the GL_OES_texture_half_float extension, because the latter
does not include support for linear magni/minification filters.
The new 2101010 and 16161616F formats are only available on little-
endian builds, since their gl_types are larger than a byte and thus
endianness dependent.
We were assuming GL_BGRA_EXT was always supported.
We now check that it's supported for rendering. We fail if it isn't because
this format is specified as "always supported" by the Wayland protocol.
We also check if it's supported for reading pixels. A new preferred_read_format
function returns the preferred format that can be used to read pixels. This is
used by the screencopy protocol.
This backports some changes to #319 to fix the screenshooter data
format. This also adds wlr_backend_get_renderer which will be
useful to support multiple renderers.
