Before this change, transformed images would take up as much atlas
texture space to fit them. However, we can easily run out of space for
large images or images with large scaling applied.
This change limits transformed images to their rendered bounds which is
the window size in the worst case.
Updates gio#219 (fixes the chat kitchen example)
Signed-off-by: Elias Naur <mail@eliasnaur.com>
A follow-up change will cause some transformed images to render outside
their allocated atlas bounds. This change uses the GPU viewport to clip
them so they won't overwrite other atlas content.
Updates gio#219
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This change allows atlas packer clients to start with large maximum
atlas dimensions, then shrink the maximum once the underlying atlas has
been allocated.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Previously, the packer optimized for the smalles space where the image
fits. Empirically, smaller atlases can be achieved by greedily picking the
smallest total area.
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>
There's no meaningful reason to have them separate. The intention was to
enable rendering concurrent with other processing, but that's gaining
framerate at the expense of input latency and complicating ImageOp
semantics.
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>
Changes to the gioui.org/shader module are generally breaking changes,
which means that a particular version of gioui.org must be build with a
particular version of gioui.org/shader. Until now, the gpu package
checked the module version against an expected version and would fail at
runtime if there's a mismatch.
This change replaces all that complexity with a simple procedural
change: bump the module major version of gioui.org/shader at each such
incompatible change. It doesn't matter that we'll eventually reach
gioui.org/v1234/shader; the module is internal and won't break clients.
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>
The default renderer tracks opaque rectangle draw operations and render
them front-to-back with a z-buffer to omit overdraw. However,
- Overlapping opaque rectangles are rare in a GUI, and the most common
instance, a solid window background, is already optimized to a glClear.
- A z-buffer is memory heavy.
- We conservatively assume a 16-bit depth buffer, which limits the
number of drawing operations to 64k (#127).
- Depth buffer support makes GPU ports more complex, especially for
upcoming ports (Metal, Vulkan).
- The compute renderer doesn't use z-buffers.
This change removes the optimization; a follow-up removes GPU backend
support.
Fixes gio#127
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The only reason for separate files is Objective-C callbacks into Go,
or when the Go side is common, yet the Objective-C side differs from
macOS to iOS.
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>
This change avoids the hard dependency on GPU support for sRGB encoded
textures in the compute renderer.
With this change and the previously added CPU fallback, Gio no longer
rely on any GPU functionality outside the OpenGL ES 2.0 level.
Fixes gio#49
Fixes gio#154
Fixes gio#97
Fixes gio#36
Fixes gio#172
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The SRGBFBO emulates a framebuffer in the sRGB colorspace. However, some
low-end devices may not have EXT_sRGB support to store framebuffer content in
sRGB.
This change handles missing EXT_sRGB support by falling back to the linear RGB colorspace.
Falling back loses color precision but is better than failing.
Updates gio#49
Updates gio#154
Updates gio#97
Updates gio#36
Updates gio#172
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This change adds a CPU fallback for devices that don't support the old
renderer nor have GPU support for compute programs.
Most of the hard work is implemented in the gioui.org/cpu module. It
uses the SwiftShader project with light modification to output
statically compiled CPU .o files for each compute program.
The CPU fallback only covers Linux and Android on arm, arm64, amd64
architectures. There is no fundamental reason support can't be extended
to other platforms:
- macOS and iOS are probably easy, but it's likely that virtually every
device has GPU support for compute shaders.
- Windows needs a Cgo-less port, or a build constraint to require a C
compiler (Gio core doesn't).
- FreeBSD and OpenBSD are probably also easy to do because they're so
similar to Linux.
- The 386 binaries didn't work properly in my tests, so fixes to
SwiftShader is probably needed. However, I expect virtually every
Intel device can run amd64 binaries.
Updates gio#49
Fixes gio#228
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The CPU fallback for the compute renderer is contained in a separate
module for space reasons, but the CPU binaries must exactly match the
compute programs. However, there is no way to express that constraint
in go.mod.
This change generates hashes of every compute program so that a
following change can verify the CPU binaries match the programs.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The hash of the clipping paths that affect drawing operations are computed
and used to quickly determine that two operations are not equal, the
most likely outcome of a comparison.
However, for paths that are constructed once and cached computing the
hash at every frame is wasteful. This is especially true for text, which
is both cached and also among the largest paths in a frame.
This change moves the hashing to op/clip.Path construction time, and
stores the hash in the ops list so it won't be re-computed at every use.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
To re-use previously cached layers, the compute renderer must know
whether two drawing operations are equal. In the case two operations are
not equal, a fast hash comparison will most likely fail. In the case two
equal operations with complicated clipping paths, the comparison of the
path data is expensive.
This change adds support for fast ops.Key comparisons, where two paths
are equal if their ops.Key are. This is an optimization that kicks in
for text rendering, where glyph clipping shapes are re-used across
frames.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur