This patch performs several changes.
* Alters the fourcc codes to types that ignore the alpha channel where
possible to allow the gpu to internally use 24-bit formats.
* Attempts to use DRM_FORMAT_RGB888 first as some GPUs may support this
* If DMABUF is not in use the data is now imported directly as RGB24
without the post-processing shader
According to Erik @ NVidia the open source NVidia driver will not
create a EGLImage from a DMABUF if the target is not
GL_TEXTURE_EXTERNAL_OES. This change set converts the dmabuf texture
from GL_TEXTURE_2D to GL_TEXTURE_EXTERNAL_OES and at runtime performs a
global search & replace on fragment shaders as needed to remain
compatible, replacing `sampler2D` with `samplerExternalOES`.
Ref: https://github.com/NVIDIA/open-gpu-kernel-modules/discussions/243#discussioncomment-3283415
This avoids race conditions in GL drivers when attempting to render and
call glEGLImageTargetTexture2DOES on the same texture.
Also, when using glEGLImageTargetTexture2DOES, we do not need to allocate
storage for textures.
The way things were handled in EGLTexture is not only very hard to
follow, but broken. This change set breaks up EGLTexture into a modular
design making it easier to implement the various versions.
Note that DMABUF is currently broken and needs to be re-implemented.
