OpenGL ES is not installed by default on linux distributions, which
can lead to a cryptic error. Add a comment after the #include
mentioning what packages contain OpenGL ES on Ubuntu, which is
helpfully printed in the error message. For example:
$ go build golang.org/x/mobile/example/basic
# golang.org/x/mobile/gl
In file included from ../../mobile/gl/work.go:21:0:
work.h:6:117: fatal error: GLES2/gl2.h: No such file or directory
#include <GLES2/gl2.h> // install on Ubuntu with: sudo apt-get install libegl1-mesa-dev libgles2-mesa-dev libx11-dev
Change-Id: Ia7ba583cee4dfdeed408f582b29da90de9a4fab3
Reviewed-on: https://go-review.googlesource.com/18058
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
ANGLE is an open source project that implements OpenGL ES on top of
DirectX. It is used by Chrome to implement WebGL:
https://github.com/google/angle
It can be compiled into libGLESv2.dll/libEGL.dll and used directly
from Go. This CL includes the changes necessary to the gl package
to use ANGLE.
For the EGL changes, I intend to get x/exp/shiny/driver/gldriver
working, and then make x/mobile/app use it when compiling for
GOOS=windows. (The dependency on shiny's screen package will only
hold when building for desktop OSs.)
For golang/go#9306
Change-Id: I01cb39bc8b56547584b7992eab437bd7ed0312b5
Reviewed-on: https://go-review.googlesource.com/17675
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
It is an error to use a gl.Context concurrently. (Each Context
contains a state machine, so there is no way this can work.)
Up until now only the GL driver could report such a misuse, and
it generally does a poor job of it. Our command buffer adds some
small oppertunity for the race detector to help, but it makes it
harder to debug other kinds of driver crashes, so it is worth
disabling in debug mode.
To make it easy, compiling with -tags gldebug now inserts an
explicit check that there are no other active GL calls outstanding.
Adding something like:
go func() {
for {
glctx.GetInteger(gl.ALPHA_BITS)
}
}()
to x/mobile/example/basic now reliably crashes when compiled
with -tags gldebug, providing a stack trace that includes both
misbehaving goroutines.
Change-Id: I3d85d94220bca2a15eaf2742f13b44db1f3428bf
Reviewed-on: https://go-review.googlesource.com/15180
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
This means that if the OpenGL driver crashes, the stack trace will
contain a goroutine blocked in the function that caused the panic.
Fixesgolang/go#12786
Change-Id: I039c74f9e24de777b925475a50e8c96129692f70
Reviewed-on: https://go-review.googlesource.com/15160
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
All OpenGL functions are now methods on a Context interface. The
gl.Context matches the one loaded into thread-local storage in C.
For mobile apps, the context is owned by an app.App. For now, it is
provided through the events channel on a lifecycle event. Long-term,
it should probably be available by a method on app.App, but this is
inherently racey with our current use of a channel to deliver events.
Shiny-based programs will have a gl.Context associated with a each
shiny.Window. The expectation is each Window will have different
contexts, allowing them to draw separately.
Change-Id: Ie09986fb74e493129f2ea542a151c95c6fa29812
Reviewed-on: https://go-review.googlesource.com/13431
Reviewed-by: Nigel Tao <nigeltao@golang.org>
This change will break Darwin. I have only built and tested this on
desktop linux and Android linux. A follow-up CL will fix Darwin.
Currently, OpenGL gets its own thread, and UI C code (e.g. the Android
event loop, or the X11 event loop) gets its own thread. This relies on
multiple system-provided UI-related C libraries working nicely together,
even when running on different threads. Keeping all the C code on the
one thread seems more sound.
As side-effects:
- In package app/debug, DrawFPS now takes an explicit Config.
- In package app, some callbacks now take an explicit Config.
- In package exp/sprite, Render now takes an explicit Config.
- In package event, there are new events (Config, Draw, Lifecycle),
and an event filter mechanism to replace multiple app Callbacks.
- In package geom, the deprecated Width, Height and PixelsPerPt global
variables were removed in favor of an event.Config that is
explicitly passed around (and does not require mutex-locking).
Converting a geom.Pt to pixels now requires passing a pixelsPerPt.
- In package gl, the Do, Start and Stop functions are removed, as well
as the need to call Start in its own goroutine. There is no longer a
separate GL thread. Instead, package app explicitly performs any GL
work (gl.DoWork) when some is available (gl.WorkAvailable).
- In package gl/glutil, Image.Draw now takes an explicit Config.
Callbacks are no longer executed on 'the UI thread'.
Changing the app programming model from callbacks to events (since a
channel of events works with select) will be a follow-up change.
Change-Id: Id9865cd9ee1c45a98c613e9021a63c17226a64b1
Reviewed-on: https://go-review.googlesource.com/11351
Reviewed-by: David Crawshaw <crawshaw@golang.org>
All GL function calls fill out a C.struct_fnargs and drop it on the
work queue. The Start function drains the work queue and hands
over a batch of calls to C.process which runs them. This allows
multiple GL calls to be executed in a single cgo call.
A GL call is marked as blocking if it returns a value, or if it
takes a Go pointer. In this case the call will not return until
C.process sends a value on the retvalue channel.
Change-Id: I4c76b2a8ad55f57b0c98d200d0fb708d4634e042
Reviewed-on: https://go-review.googlesource.com/10452
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Reorder DrawElements arguments to match OpenGL spec order:
DrawElements(mode, ty, offset, count) -> (mode, count, ty, offset)
GetActiveAttrib, GetActiveUniform are defined by spec to accept
corresponding integer _index_, not location type. Change their
signature to do that:
GetActiveAttrib(p Program, a Attrib) -> (p Program, index uint32)
GetActiveUniform(p Program, u Uniform) -> (p Program, index uint32)
Clarify and make documentation, parameter names more clear for Uniform
(uniform location), Attrib (attribute location) types,
EnableVertexAttribArray, DisableVertexAttribArray, GetAttribLocation,
GetUniformLocation funcs.
Resolvesgolang/go#10218 again.
Change-Id: I5b822235d9485701186a43dae0b9fd898cc6a3d8
Reviewed-on: https://go-review.googlesource.com/8166
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Change func names and parameter order to more closely follow OpenGL
ES/WebGL spec.
BufferData(target, usage, src) -> BufferData(target, src, usage)
GenBuffer -> CreateBuffer
GenFramebuffer -> CreateFramebuffer
GenRenderbuffer -> CreateRenderbuffer
GenTexture -> CreateTexture
Fix issue where glBoolean helper was returning inverted result.
Make Attrib.String() logic consistent with others (print value, not
struct).
Make internal code of GetUniformLocation the same as GetAttribLocation
and BindAttribLocation for consistency.
Resolvesgolang/go#10218.
Change-Id: Ib33dfff7c22c4d178b2e6b8d228f80f3c17308a8
Reviewed-on: https://go-review.googlesource.com/8000
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Only used in package tests that are only
supported on OS X / linux (for now).
Change-Id: I9708cd370ccf52c231d66dec9ccc1c06b45f4acd
Reviewed-on: https://go-review.googlesource.com/5490
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
C changes the types silently, so there's no need for the code to be
different (beyond the standard header ifdef boilerplate).
Change-Id: I0eddb5fa050c083cdac9db499634bf3d1bb9bb04
Reviewed-on: https://go-review.googlesource.com/1184
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
I have included the gl.LINEAR bugfix here as it changes the
images substantially.
Based on Nigel's excellent analysis in cl/160710043.
LGTM=nigeltao
R=nigeltao
CC=golang-codereviews
https://golang.org/cl/168820043
It's not a big deal in this case, but we'll probably want to do the same
for the sprite/gl package.
LGTM=crawshaw
R=crawshaw
CC=golang-codereviews
https://golang.org/cl/163990043
