Struct gdk::GLContext [−][src]
pub struct GLContext(_);
Expand description
GLContext
is an object representing the platform-specific
OpenGL drawing context.
GdkGLContexts
are created for a Window
using
Window::create_gl_context()
, and the context will match
the Visual
of the window.
A GLContext
is not tied to any particular normal framebuffer.
For instance, it cannot draw to the Window
back buffer. The GDK
repaint system is in full control of the painting to that. Instead,
you can create render buffers or textures and use gdk_cairo_draw_from_gl()
in the draw function of your widget to draw them. Then GDK will handle
the integration of your rendering with that of other widgets.
Support for GLContext
is platform-specific, context creation
can fail, returning None
context.
A GLContext
has to be made “current” in order to start using
it, otherwise any OpenGL call will be ignored.
Creating a new OpenGL context
In order to create a new GLContext
instance you need a
Window
, which you typically get during the realize call
of a widget.
A GLContext
is not realized until either make_current()
,
or until it is realized using realize()
. It is possible to
specify details of the GL context like the OpenGL version to be used, or
whether the GL context should have extra state validation enabled after
calling Window::create_gl_context()
by calling realize()
.
If the realization fails you have the option to change the settings of the
GLContext
and try again.
Using a GdkGLContext
You will need to make the GLContext
the current context
before issuing OpenGL calls; the system sends OpenGL commands to
whichever context is current. It is possible to have multiple
contexts, so you always need to ensure that the one which you
want to draw with is the current one before issuing commands:
⚠️ The following code is in C ⚠️
gdk_gl_context_make_current (context);
You can now perform your drawing using OpenGL commands.
You can check which GLContext
is the current one by using
current()
; you can also unset any GLContext
that is currently set by calling clear_current()
.
This is an Abstract Base Class, you cannot instantiate it.
Implementations
Retrieves the value set using set_forward_compatible()
.
Returns
true
if the context should be forward compatible
Retrieves the major and minor version requested by calling
set_required_version()
.
Returns
major
return location for the major version to request
minor
return location for the minor version to request
This is supported on crate feature v3_22
only.
v3_22
only.This is supported on crate feature v3_20
only.
v3_20
only.Whether the GLContext
is in legacy mode or not.
The GLContext
must be realized before calling this function.
When realizing a GL context, GDK will try to use the OpenGL 3.2 core
profile; this profile removes all the OpenGL API that was deprecated
prior to the 3.2 version of the specification. If the realization is
successful, this function will return false
.
If the underlying OpenGL implementation does not support core profiles,
GDK will fall back to a pre-3.2 compatibility profile, and this function
will return true
.
You can use the value returned by this function to decide which kind of OpenGL API to use, or whether to do extension discovery, or what kind of shader programs to load.
Returns
true
if the GL context is in legacy mode
Makes the self
the current one.
Sets whether the GLContext
should be forward compatible.
Forward compatibile contexts must not support OpenGL functionality that has been marked as deprecated in the requested version; non-forward compatible contexts, on the other hand, must support both deprecated and non deprecated functionality.
The GLContext
must not be realized or made current prior to calling
this function.
compatible
whether the context should be forward compatible
This is supported on crate feature v3_22
only.
v3_22
only.Requests that GDK create a OpenGL ES context instead of an OpenGL one, if the platform and windowing system allows it.
The self
must not have been realized.
By default, GDK will attempt to automatically detect whether the
underlying GL implementation is OpenGL or OpenGL ES once the self
is realized.
You should check the return value of uses_es()
after
calling realize()
to decide whether to use the OpenGL or
OpenGL ES API, extensions, or shaders.
use_es
whether the context should use OpenGL ES instead of OpenGL, or -1 to allow auto-detection
Clears the current GLContext
.
Any OpenGL call after this function returns will be ignored
until make_current()
is called.
Trait Implementations
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Returns the type identifier of Self
.
Auto Trait Implementations
impl RefUnwindSafe for GLContext
impl UnwindSafe for GLContext
Blanket Implementations
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T
. Read more
Upcasts an object to a reference of its superclass or interface T
. Read more
Tries to downcast to a subclass or interface implementor T
. Read more
Tries to downcast to a reference of its subclass or interface implementor T
. Read more
Tries to cast to an object of type T
. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast
and upcast
will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T
. This handles upcasting, downcasting
and casting between interface and interface implementors. All checks are performed at
runtime, while downcast
and upcast
will do many checks at compile-time already. Read more
Casts to T
unconditionally. Read more
Casts to &T
unconditionally. Read more
Returns true
if the object is an instance of (can be cast to) T
.
pub fn set_properties_from_value(
&self,
property_values: &[(&str, Value)]
) -> Result<(), BoolError>
pub fn set_property<'a, N, V>(
&self,
property_name: N,
value: V
) -> Result<(), BoolError> where
N: Into<&'a str>,
V: ToValue,
pub fn set_property_from_value<'a, N>(
&self,
property_name: N,
value: &Value
) -> Result<(), BoolError> where
N: Into<&'a str>,
Safety Read more
Safety Read more
Safety Read more
Safety Read more
pub fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec) + Send + Sync,
pub fn connect_notify_local<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: 'static + Fn(&T, &ParamSpec),
pub unsafe fn connect_notify_unsafe<F>(
&self,
name: Option<&str>,
f: F
) -> SignalHandlerId where
F: Fn(&T, &ParamSpec),
pub fn has_property<'a, N>(&self, property_name: N, type_: Option<Type>) -> bool where
N: Into<&'a str>,
pub fn find_property<'a, N>(&self, property_name: N) -> Option<ParamSpec> where
N: Into<&'a str>,
pub fn connect<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value> + Send + Sync + 'static,
N: Into<&'a str>,
Same as connect
but takes a SignalId
instead of a signal name.
pub fn connect_local<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value> + 'static,
N: Into<&'a str>,
Same as connect_local
but takes a SignalId
instead of a signal name.
pub unsafe fn connect_unsafe<'a, N, F>(
&self,
signal_name: N,
after: bool,
callback: F
) -> Result<SignalHandlerId, BoolError> where
F: Fn(&[Value]) -> Option<Value>,
N: Into<&'a str>,
Same as connect_unsafe
but takes a SignalId
instead of a signal name.
Emit signal by signal id.
Emit signal with details by signal id.
Emit signal by it’s name.
pub fn bind_property<'a, O, N, M>(
&'a self,
source_property: N,
target: &'a O,
target_property: M
) -> BindingBuilder<'a> where
O: ObjectType,
M: Into<&'a str>,
N: Into<&'a str>,
Same as emit
but takes Value
for the arguments.
Same as emit_by_name
but takes Value
for the arguments.
Returns a SendValue
clone of self
.
impl<'a, T, C> FromValueOptional<'a> for T where
C: ValueTypeChecker<Error = ValueTypeMismatchOrNoneError>,
T: FromValue<'a, Checker = C>,