In a discussion with Raph Levien, the author of our compute renderer
implementation, it became clear to me that it's not at all certain that
complex strokes will ever be efficiently supported by a GPU renderer.
At the same time, the machinery for converting a complex stroke to a
GPU-friendly outline has a significant maintenance cost. Further, it is
surprising to users that complex strokes are significantly slower and
allocate memory.
This change removes support for complex strokes, leaving only
round-capped, round-joined strokes supported by the compute renderer.
The default renderer still converts all strokes to outline, but it also
caches the result.
This is an API change. The complex stroke conversion code has been moved
to the external gioui.org/x/stroke package, with a similar API.
Updats gio#282 (Inkeliz brought up the allocation issue)
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The op.Save and Load methods exist to support the need for
transformation, clip, pointer area state to behave as stacks. For
example, layout needs to apply an offset to its children but not
subsequent operations.
Before this change, op.Save and Load were used to save and restore the
state:
ops := new(op.Ops)
// Save state.
state := op.Save(ops)
// Apply offset.
op.Offset(...).Add(ops)
// Draw with offset applied.
draw(ops)
// Restore state.
state.Load()
A drawback with the op.Save mechanism is that there is no direct
connection between the state change and the saving and loading of state.
This causes confusion as to when a Save/Load is needed and who is
responsible for performing them, which leads to subtle bugs and over-use
of Save/Loads.
This change gets rid of the general state stack and replaces it with
per-state stacks. There is now a stack for transformation, clip, pointer
areas, and they can only be restored by the code pushing state to them.
The example above now becomes:
ops := new(op.Ops)
// Push offset to the transformation stack.
stack := op.Offset(...).Push(ops)
// Draw with offset applied.
draw(ops)
// Restore state.
stack.Pop()
For convenience, transformation also be Add'ed if the stack operation is
not required.
Simple state such as the current material no longer has a way to be
restored; it is assumed the client of a PaintOp adds their desired
material operation before it.
API change: replace op.Save/Load with explicit Push/Pop scopes for
op.TransformOps, pointer.AreaOps, clip.Ops.
To ease porting, this change retains a version of op.Save/Load that
saves and restores the transformation and clip stacks. It also retains
an Add method for clip.Op.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Most Gio programs have exlusive access to their OpenGL contexts, where
saving and restoring of the GL state is not required.
This change applies to all OpenGL platforms, but matters most for WASM
where syscalls are slow.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, the sRGB emulation target would always be the
current framebuffer. Now it's the render target passed to BeginFrame.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
glGetUniformLocation can return -1 (not found) for uniforms that have
been optimized out during linking of a GPU program. This happens because
the default renderer compile multiple program from the same generic
template.
Updates gio#280
Signed-off-by: Elias Naur <mail@eliasnaur.com>
CFTypeRefs may not always contain valid pointers, so they must not be
stored in pointer types lest the Go runtime treats them as such.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
There are too many driver issues with ES 3.1 compute shaders. Most
devices support Vulkan but some, such as the Samsung J2, will fall back
to the CPU renderer.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To use glCopyTexSubImage2D on the Samsung J2 it's not enough to
set GL_READ_FRAMEBUFFER. This change binds GL_FRAMEBUFFER, setting both
READ_FRAMEBUFFER and DRAW_FRAMEBUFFER, fixing the issue.
Setting only GL_READ_FRAMEBUFFER was also a genuine bug, because OpenGL
ES 2.0 doesn't support it.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This change implements a Vulkan port for the two renderers, old and
compute. Run with GIORENDERER=forcecompute to test the compute renderer.
To shake out bugs faster, it is also made the default on systems that
support it. To disable Vulkan and force the use of OpenGL, use the
`novulkan` tag:
$ go run -tags novulkan gioui.org/example/kitchen
Don't forget to file an issue describing the issue that prompted the use
of the tag.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
MemoryBarrier is meant to stand in for OpenGL ES 3.1's glMemoryBarrier.
However, it badly fits with the other backends: Metal and D3D11 have
automatic memory barriers, and Vulkan needs barriers for graphics as
well.
This change removes MemoryBarrier, and puts the burden on the backends.
The OpenGL backend simply adds a barrier between every compute dispatch.
This change only adds a single memory barrier compared to the manual
barriers before this change, which is unlikely to affect performance
much.. We can revisit the automatic barriers if they ever become a
performance problem.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
driver.Device.NewFramebuffer doesn't provide additional information over
driver.Device.NewTexture, so Texture can hold its (optional) framebuffer
on behalf of the renderers. Metal don't even need a separate framebuffer
object.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Vulkan textures (VkImage) are always in a particular layout, where each
layout is optimized for a particular use (transfer, sampling, compute
storage). Vulkan allows layout transitions everywhere except inside
render passes. This change adds driver.Device.PrepareTexture for
instructing the driver to switch a texture to a layout for sampling
in preparation for using it in a render pass.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Vulkan doesn't support changing uniforms during a render pass. However,
push constants *can* be changed. The gio-shader repository was changed
to use push constants instead of uniforms, this change implements the
corresponding driver and renderer change.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
With the use of uniform buffers gone, we don't need the glsl 3.00 es
variant any longer.
We only support desktop OpenGL on macOS which is guaranteed to be
at least version 3.2, so we don't need the glsl 1.30 variant either.
Remove a test that depended on gl_VertexID which is not support in glsl
1.00 es.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Modern GPU API such as Metal and Vulkan use explicit render passes
and command buffers for recording rendering commands. They don't have
global state; each render pass starts with a clean set of bound
textures, pipeline etc.
Change our GPU abstraction to better match newer API and modify our two
renderers to explicitly describe their render passes.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
GPU contexts can hold on to a significant amount of resources. Clean
them up immediately instead of at test cleanup.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Don't copy the padding when stride is larger than the width. Applies to
Texture.Upload and Framebuffer.ReadPixels.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
A previous change[0] moved all OpenGL function calls to the internal
opengl package, so that Gio can use desktop OpenGL and OpenGL ES (ANGLE)
in the same program without confusing the function pointers.
However the change also moved the glFlush that constitutes a buffer
swap, or present, on macOS. Other platforms don't need the flush, so
this change moves it back to macOS-specific code, in glContext.Present
where it belongs. It also uses dlopen and dlsym to avoid symbol
confusion between Apple's OpenGL framework and ANGLE's libGLESv2.dylib.
The motivation is that we're getting rid of the desktop OpenGL backend
on macOS in favor of Metal, and so should reduce the number of global
special-cases catering to that platform.
[0] https://gioui.org/commit/476d2269a
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This change implements support for compute programs in the Direct3D 11
driver. The compute renderer doesn't work for me yet; my NVIDIA GTX 970
and Intel GPUs both display corrupted output and hangs.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
On my Fedora Intel GPU, issuing a glBufferSubData immediately after a
glBufferData with no data may leave the buffer cleared.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
One staging buffer is enough because BeginFrame waits for the completion
of the staging operatoins from the previous frame.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
OpenGL ES 2.0 doesn't support glBlitFramebuffer, but does support
glCopyTexSubImage2D. Fortunately, we don't need the extra features of
glBlitFramebuffer anyway.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The OpenGL (ES) implementations on Apple platforms are deprecated and
don't support GPU compute programs. This change adds support for the
replacement, the Metal GPU API.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The Metal (and presumably the D3D11) backend doesn't support transformed
framebuffer blits. The only caller doesn't need it either, so drop that
capability from the driver abstraction.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Modern API such as Metal and Vulkan want clients to compile expensive
state changes into pipeline objects. Change our GPU driver abstraction
to match, thereby paving the way for future drivers.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The opengl example has a screenshot functionality that renders to a
non-sRGB texture, whereas window rendering is to a sRGB capable EGL
surface. The opengl driver detects the switch from an sRGB capable
output to a non-sRGB capable output, but not the switch back. This
change releases the emulation framebuffer on the switch back.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Both the OpenGL and the Direct3D API are stateful and gpu.GPU renders to
the render target current when Frame is called.
Modern GPU API such as Metal don't have a concept of a current render
target, and the target even changes each frame.
Add RenderTarget and add an explicit target argument to GPU.Frame as
well as the underlying driver.Device.BeginFrame.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur