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>
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>
To ease the integration with foreign OpenGL contexts, carefully save the
context state before rendering a frame and restore it afterwards. Gio
rendering can then be mixed with OpenGL code that expects exclusive
control over context state.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This changes moves the macOS specific setup for desktop OpenGL to the
portable opengl package. The opengl package already takes care of the
desktop OpenGL setup for sRGB framebuffers, and by moving the code we
avoid calling the wrong OpenGL functions in case both OpenGL.framework
and ANGLE libGLESv2.dylib is linked into the program.
Remove the interface casting expressions for gl.Functions; it wasn't
worth the trouble to keep updated.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Desktop OpenGL implements a GL_FRAMEBUFFER_SRGB setting; query that instead
of the frambuffer color encoding.
With this change it is no longer necessary to enable FRAMEBUFFER_SRGB
in the macOS setup; remove it.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
macOS is the only platform where desktop OpenGL is used. To support
foreign ANGLE contexts add a setting to override Gio's selection of
OpenGL implementation.
The bulk of this change is making all function pointers per-context
instead of global, and loading the OpenGL library dynamically. As a side
effect we're closer to Gio tolerating a platform without any OpenGL
implementation. For example, Apple has deprecated OpenGL and OpenGL ES
on its platforms and may remove them in the future.
Note that as a side-effect of this change, Gio needs Go 1.16 or newer to
run on iOS.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Programs such as gio-example/glfw rely on Gio drawing blending with
the framebuffer background. This change makes it so when sRGB emulation
is active.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The reflected uniform names are for the shader versions that don't use uniform
buffer objects. For UBO shaders, the names won't resolve.
This change adds a panic when shader uniforms are not found, and fixes
Fixes gio#216
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The CPU fallback of the compute renderer needs ReadPixels data in OpenGL
format (origin at bottom left). Unfortunately, the OpenGL driver
automatically mirrors images in the Y-axis to match the top left origin
image.RGBA.
Remove the mirroring from the driver and introduce a DownloadImage to
restore the old behaviour.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
It is no longer necessary for outside users of package gpu to explicitly
initialize a specific driver. The Direct3D driver is already internal,
this moves the OpenGL driver internally as well. The rename to opengl is
to avoid the name clash with the low-level "gioui.org/internal/glimpl"
package that we're about to rename.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur