Some GPU APIs such as Direct3D can return an error after drawing
a frame indicating a transient device error. Recreate device and
retry if it happens.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
OpenGL supports casting from int to float during vertex array
reading. Direct3D doesn't. Since we're transpiling from GLSL, we can't
directly use the Direct3D builtin "asint". So that leaves using
"ivec2" instead of vec2.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Add a series of low level gpu.Backend tests to assure the correct behaviour of
Backends. The immediate use is debugging of the Direct3D port, in the future
for developing new backends.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Uniform buffers are byte slice backed by Go structs. However, if a uniform
buffer value is embedded in a larger structure with pointers, the Cgo
pointer checker will complain. Avoid the error by moving the uniform
values into separate structures.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
DefaultFramebuffer was set up at Backend creation time, which is
difficult to predict. Instead, let GPU query and cache the current
FBO when created.
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>
Along with ReadPixels in the next change, a Framebuffer with depth is enough to
implement screenshot functionality on top of any Backend.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
"handling" means panicing, but at least the panicing is moved up
a layer, leaving future changes to do it properly in GPU.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
OpenGL doesn't care if the texture to a framebuffer changes, but
Direct3D does. Change Backend to better match both APIs.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Direct3D needs to know the texture bind usage up front, in particular
whether the texture is going to be used as a render target.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
It serves no purpose other than paranoia. Perhaps buggy drivers exists that
require unused texture slots cleared before drawing to a texture, but if so the
workaround belongs in the GL backend.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The offset argument to DrawElements is in 16-bit shorts, while the
underlying DrawElements use byte offsets.
No users of DrawElements use a non-zero offset, so nothing changed.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Emulate them for the OpenGL ES backend because 2.0 doesn't support uniform
buffers. The future d3d backend only supports uniform (constant) buffers.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
InputLayout is the abstraction for the mapping between vertex data and
shader inputs. The mapping is implicit in OpenGL but explicit in
Direct3D.
Infer the attribute name location index using shader reflection data,
and get rid of a parameter to NewProgram.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We're about to add Direct3D support, where shaders are written in
HLSL. Rather than write shaders twice (or more), convert them to
a GLSL variant understood by the glslcc cross-compiler and generate
the OpenGL ES 2.0 and HLSL variants. The HLSL is used by a future
change.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The error message is not appropriate where there are multiple backends,
and there's a much better chance Gio will run with the direct3d backend
where no external DLLs are required.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The srgb package was recently created to contain just the sRGB
emulation, but the names weren't shortened accordingly.
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 GPU implementation only uses immutable buffers so far, so let's
make it easy and performant for the backends.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, the index buffer would start empty and grow up to the
maximum size (128kb). It would never shrink. We're about to tighten the GPU
buffer API to be immutable for performance and to better match Direct3D, so
allocate the index buffer once at startup, and limit it to a reasonable size.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
It was left over from a previous approach to enable the program
to decide the ordering between calls to Layout vs Clicked.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Now that pkg.go.dev supports the UNLICENSE, the COPYING file confuses
the automatic license detection. Move the license text back to README.md.
This is merely a cosmetic change, there are no licensing changes to
the project.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur