Modern graphics APIs have immutable objects, with mutable data. For example,
a texture's dimensions are immutable, while the texture contents is not.
Change the GPU API abstraction to match.
Clearing a Texture is convenient to do with a plain []byte. Generalize
Texture.Upload to take a plain byte slice and introduce a helper function for
uploading *image.RGBA data.
Add TextureFormatRGBA8, a format for the linear RGB colorspace.
Add OpenGL ES 3.1 functions for compute programs.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, the entire byte buffer would be passed to WebGL, even
though its size may be (much) larger than the source data.
Remakably, this hasn't resulted in any problems until the use of
glBufferSubData, which require the passed data fits the buffer size.
As a bonus, this fix should speed up the wasm port by virtue of passing
much less data across the wasm<->js barrier.
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>
Elias Naur