NewDevice creates a Device given an API, which is the necessary GPU
resources for a backend.
Convert gpu.New to take an API instead of a backend.Device directly.
In turn, this frees us to later unexport the backend package along with
the backend implementations (for now just gioui.org/gpu/gl for OpenGL).
It also allows programs that embed Gio (such as gioui.org/example/glfw)
to freely choose a backend, not just OpenGL.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
As a consequence, most API is gone from gpu/gl, and embedding Gio in
foreign frameworks don't need to provide an OpenGL implementation.
The next change simplifies the GLFW embedding example accordingly.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The new Framebuffer.ReadPixels method is enough to implement
Window.Screenshot. Use that instead of the OpenGL-specific
implementation.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To prepare package headless for multiple backends, refactor the common headless
driver to no longer assume an OpenGL context. Instead, introduce a headless
backend type and the OpenGL implementation, glBackend.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This is a refactoring change to prepare for another gpu.Backend
implementations.
Notably, app/loop.go no longer imports gpu/gl.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The rendering implementation is needed for using Gio UI with external
window libraries such as GLFW. Expose it in the new package gpu.
Updates #26
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We'd like to support Gio using a different renderer binding than
the builtin. A first step is to define the Functions interface
in package gl, and extract the concrete implementations to a
separate package.
Updates #26
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur