Copyright	Will Thompson Iñaki García Etxebarria and Jonas Platte
License	LGPL-2.1
Maintainer	Iñaki García Etxebarria (garetxe@gmail.com)
Safe Haskell	None
Language	Haskell2010

GI.Gtk.Objects.GLArea

Contents

Exported types
Methods
Properties
Signals

Description

GLArea is a widget that allows drawing with OpenGL.

GLArea sets up its own GLContext for the window it creates, and creates a custom GL framebuffer that the widget will do GL rendering onto. It also ensures that this framebuffer is the default GL rendering target when rendering.

In order to draw, you have to connect to the GLArea::render signal, or subclass GLArea and override the gtkGLAreaClass.render() virtual function.

The GLArea widget ensures that the GLContext is associated with the widget's drawing area, and it is kept updated when the size and position of the drawing area changes.

Drawing with GtkGLArea

The simplest way to draw using OpenGL commands in a GLArea is to create a widget instance and connect to the GLArea::render signal:

C code

 // create a GtkGLArea instance
 GtkWidget *gl_area = gtk_gl_area_new ();

 // connect to the "render" signal
 g_signal_connect (gl_area, "render", G_CALLBACK (render), NULL);

The render() function will be called when the GLArea is ready for you to draw its content:

C code

 static gboolean
 render (GtkGLArea *area, GdkGLContext *context)
 {
   // inside this function it's safe to use GL; the given
   // #GdkGLContext has been made current to the drawable
   // surface used by the #GtkGLArea and the viewport has
   // already been set to be the size of the allocation

   // we can start by clearing the buffer
   glClearColor (0, 0, 0, 0);
   glClear (GL_COLOR_BUFFER_BIT);

   // draw your object
   draw_an_object ();

   // we completed our drawing; the draw commands will be
   // flushed at the end of the signal emission chain, and
   // the buffers will be drawn on the window
   return TRUE;
 }

If you need to initialize OpenGL state, e.g. buffer objects or shaders, you should use the Widget::realize signal; you can use the Widget::unrealize signal to clean up. Since the GLContext creation and initialization may fail, you will need to check for errors, using gLAreaGetError. An example of how to safely initialize the GL state is:

C code

 static void
 on_realize (GtkGLarea *area)
 {
   // We need to make the context current if we want to
   // call GL API
   gtk_gl_area_make_current (area);

   // If there were errors during the initialization or
   // when trying to make the context current, this
   // function will return a #GError for you to catch
   if (gtk_gl_area_get_error (area) != NULL)
     return;

   // You can also use gtk_gl_area_set_error() in order
   // to show eventual initialization errors on the
   // GtkGLArea widget itself
   GError *internal_error = NULL;
   init_buffer_objects (&error);
   if (error != NULL)
     {
       gtk_gl_area_set_error (area, error);
       g_error_free (error);
       return;
     }

   init_shaders (&error);
   if (error != NULL)
     {
       gtk_gl_area_set_error (area, error);
       g_error_free (error);
       return;
     }
 }

If you need to change the options for creating the GLContext you should use the GLArea::create-context signal.

Since: 3.16

Synopsis

newtype GLArea = GLArea (ManagedPtr GLArea)
class GObject o => IsGLArea o
toGLArea :: (MonadIO m, IsGLArea o) => o -> m GLArea
noGLArea :: Maybe GLArea
gLAreaAttachBuffers :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m ()
gLAreaGetAutoRender :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m Bool
gLAreaGetContext :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m GLContext
gLAreaGetError :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m (Maybe GError)
gLAreaGetHasAlpha :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m Bool
gLAreaGetHasDepthBuffer :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m Bool
gLAreaGetHasStencilBuffer :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m Bool
gLAreaGetRequiredVersion :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m (Int32, Int32)
gLAreaGetUseEs :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m Bool
gLAreaMakeCurrent :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m ()
gLAreaNew :: (HasCallStack, MonadIO m) => m GLArea
gLAreaQueueRender :: (HasCallStack, MonadIO m, IsGLArea a) => a -> m ()
gLAreaSetAutoRender :: (HasCallStack, MonadIO m, IsGLArea a) => a -> Bool -> m ()
gLAreaSetError :: (HasCallStack, MonadIO m, IsGLArea a) => a -> Maybe GError -> m ()
gLAreaSetHasAlpha :: (HasCallStack, MonadIO m, IsGLArea a) => a -> Bool -> m ()
gLAreaSetHasDepthBuffer :: (HasCallStack, MonadIO m, IsGLArea a) => a -> Bool -> m ()
gLAreaSetHasStencilBuffer :: (HasCallStack, MonadIO m, IsGLArea a) => a -> Bool -> m ()
gLAreaSetRequiredVersion :: (HasCallStack, MonadIO m, IsGLArea a) => a -> Int32 -> Int32 -> m ()
gLAreaSetUseEs :: (HasCallStack, MonadIO m, IsGLArea a) => a -> Bool -> m ()
constructGLAreaAutoRender :: IsGLArea o => Bool -> IO (GValueConstruct o)
getGLAreaAutoRender :: (MonadIO m, IsGLArea o) => o -> m Bool
setGLAreaAutoRender :: (MonadIO m, IsGLArea o) => o -> Bool -> m ()
getGLAreaContext :: (MonadIO m, IsGLArea o) => o -> m GLContext
constructGLAreaHasAlpha :: IsGLArea o => Bool -> IO (GValueConstruct o)
getGLAreaHasAlpha :: (MonadIO m, IsGLArea o) => o -> m Bool
setGLAreaHasAlpha :: (MonadIO m, IsGLArea o) => o -> Bool -> m ()
constructGLAreaHasDepthBuffer :: IsGLArea o => Bool -> IO (GValueConstruct o)
getGLAreaHasDepthBuffer :: (MonadIO m, IsGLArea o) => o -> m Bool
setGLAreaHasDepthBuffer :: (MonadIO m, IsGLArea o) => o -> Bool -> m ()
constructGLAreaHasStencilBuffer :: IsGLArea o => Bool -> IO (GValueConstruct o)
getGLAreaHasStencilBuffer :: (MonadIO m, IsGLArea o) => o -> m Bool
setGLAreaHasStencilBuffer :: (MonadIO m, IsGLArea o) => o -> Bool -> m ()
constructGLAreaUseEs :: IsGLArea o => Bool -> IO (GValueConstruct o)
getGLAreaUseEs :: (MonadIO m, IsGLArea o) => o -> m Bool
setGLAreaUseEs :: (MonadIO m, IsGLArea o) => o -> Bool -> m ()
type C_GLAreaCreateContextCallback = Ptr () -> Ptr () -> IO (Ptr GLContext)
type GLAreaCreateContextCallback = IO GLContext
afterGLAreaCreateContext :: (IsGLArea a, MonadIO m) => a -> GLAreaCreateContextCallback -> m SignalHandlerId
genClosure_GLAreaCreateContext :: GLAreaCreateContextCallback -> IO Closure
mk_GLAreaCreateContextCallback :: C_GLAreaCreateContextCallback -> IO (FunPtr C_GLAreaCreateContextCallback)
noGLAreaCreateContextCallback :: Maybe GLAreaCreateContextCallback
onGLAreaCreateContext :: (IsGLArea a, MonadIO m) => a -> GLAreaCreateContextCallback -> m SignalHandlerId
wrap_GLAreaCreateContextCallback :: GLAreaCreateContextCallback -> C_GLAreaCreateContextCallback
type C_GLAreaRenderCallback = Ptr () -> Ptr GLContext -> Ptr () -> IO CInt
type GLAreaRenderCallback = GLContext -> IO Bool
afterGLAreaRender :: (IsGLArea a, MonadIO m) => a -> GLAreaRenderCallback -> m SignalHandlerId
genClosure_GLAreaRender :: GLAreaRenderCallback -> IO Closure
mk_GLAreaRenderCallback :: C_GLAreaRenderCallback -> IO (FunPtr C_GLAreaRenderCallback)
noGLAreaRenderCallback :: Maybe GLAreaRenderCallback
onGLAreaRender :: (IsGLArea a, MonadIO m) => a -> GLAreaRenderCallback -> m SignalHandlerId
wrap_GLAreaRenderCallback :: GLAreaRenderCallback -> C_GLAreaRenderCallback
type C_GLAreaResizeCallback = Ptr () -> Int32 -> Int32 -> Ptr () -> IO ()
type GLAreaResizeCallback = Int32 -> Int32 -> IO ()
afterGLAreaResize :: (IsGLArea a, MonadIO m) => a -> GLAreaResizeCallback -> m SignalHandlerId
genClosure_GLAreaResize :: GLAreaResizeCallback -> IO Closure
mk_GLAreaResizeCallback :: C_GLAreaResizeCallback -> IO (FunPtr C_GLAreaResizeCallback)
noGLAreaResizeCallback :: Maybe GLAreaResizeCallback
onGLAreaResize :: (IsGLArea a, MonadIO m) => a -> GLAreaResizeCallback -> m SignalHandlerId
wrap_GLAreaResizeCallback :: GLAreaResizeCallback -> C_GLAreaResizeCallback

Exported types

newtype GLArea Source #

Memory-managed wrapper type.

Constructors

GLArea (ManagedPtr GLArea)

Instances

GObject GLArea Source #
Instance details Defined in GI.Gtk.Objects.GLArea Methods gobjectType :: GLArea -> IO GType #
IsImplementorIface GLArea Source #
Instance details Defined in GI.Gtk.Objects.GLArea
IsObject GLArea Source #
Instance details Defined in GI.Gtk.Objects.GLArea
IsBuildable GLArea Source #
Instance details Defined in GI.Gtk.Objects.GLArea
IsWidget GLArea Source #
Instance details Defined in GI.Gtk.Objects.GLArea
IsGLArea GLArea Source #
Instance details Defined in GI.Gtk.Objects.GLArea

class GObject o => IsGLArea o Source #

Type class for types which can be safely cast to GLArea, for instance with toGLArea.

Instances

(GObject a, (UnknownAncestorError GLArea a :: Constraint)) => IsGLArea a Source #
Instance details Defined in GI.Gtk.Objects.GLArea
IsGLArea GLArea Source #
Instance details Defined in GI.Gtk.Objects.GLArea

toGLArea :: (MonadIO m, IsGLArea o) => o -> m GLArea Source #

Cast to GLArea, for types for which this is known to be safe. For general casts, use castTo.

noGLArea :: Maybe GLArea Source #

A convenience alias for Nothing :: Maybe GLArea.

Methods

attachBuffers

gLAreaAttachBuffers Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m ()

Ensures that the area framebuffer object is made the current draw and read target, and that all the required buffers for the area are created and bound to the frambuffer.

This function is automatically called before emitting the GLArea::render signal, and doesn't normally need to be called by application code.

Since: 3.16

getAutoRender

gLAreaGetAutoRender Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m Bool	Returns: `True` if the `area` is auto rendering, `False` otherwise

Returns whether the area is in auto render mode or not.

Since: 3.16

getContext

gLAreaGetContext Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m GLContext	Returns: the `GLContext`

Retrieves the GLContext used by area.

Since: 3.16

getError

gLAreaGetError Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m (Maybe GError)	Returns: the `GError` or `Nothing`

Gets the current error set on the area.

Since: 3.16

getHasAlpha

gLAreaGetHasAlpha Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m Bool	Returns: `True` if the `area` has an alpha component, `False` otherwise

Returns whether the area has an alpha component.

Since: 3.16

getHasDepthBuffer

gLAreaGetHasDepthBuffer Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m Bool	Returns: `True` if the `area` has a depth buffer, `False` otherwise

Returns whether the area has a depth buffer.

Since: 3.16

getHasStencilBuffer

gLAreaGetHasStencilBuffer Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m Bool	Returns: `True` if the `area` has a stencil buffer, `False` otherwise

Returns whether the area has a stencil buffer.

Since: 3.16

getRequiredVersion

gLAreaGetRequiredVersion Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m (Int32, Int32)

Retrieves the required version of OpenGL set using gLAreaSetRequiredVersion.

Since: 3.16

getUseEs

gLAreaGetUseEs Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m Bool	Returns: `True` if the `GLArea` should create an OpenGL ES context and `False` otherwise

Retrieves the value set by gLAreaSetUseEs.

Since: 3.22

makeCurrent

gLAreaMakeCurrent Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m ()

Ensures that the GLContext used by area is associated with the GLArea.

This function is automatically called before emitting the GLArea::render signal, and doesn't normally need to be called by application code.

Since: 3.16

new

gLAreaNew Source #

Arguments

:: (HasCallStack, MonadIO m)
=> m GLArea	Returns: a new `GLArea`

Creates a new GLArea widget.

Since: 3.16

queueRender

gLAreaQueueRender Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> m ()

Marks the currently rendered data (if any) as invalid, and queues a redraw of the widget, ensuring that the GLArea::render signal is emitted during the draw.

This is only needed when the gLAreaSetAutoRender has been called with a False value. The default behaviour is to emit GLArea::render on each draw.

Since: 3.16

setAutoRender

gLAreaSetAutoRender Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> Bool	`autoRender`: a boolean
-> m ()

If autoRender is True the GLArea::render signal will be emitted every time the widget draws. This is the default and is useful if drawing the widget is faster.

If autoRender is False the data from previous rendering is kept around and will be used for drawing the widget the next time, unless the window is resized. In order to force a rendering gLAreaQueueRender must be called. This mode is useful when the scene changes seldomly, but takes a long time to redraw.

Since: 3.16

setError

gLAreaSetError Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> Maybe GError	`error`: a new `GError`, or `Nothing` to unset the error
-> m ()

Sets an error on the area which will be shown instead of the GL rendering. This is useful in the GLArea::create-context signal if GL context creation fails.

Since: 3.16

setHasAlpha

gLAreaSetHasAlpha Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> Bool	`hasAlpha`: `True` to add an alpha component
-> m ()

If hasAlpha is True the buffer allocated by the widget will have an alpha channel component, and when rendering to the window the result will be composited over whatever is below the widget.

If hasAlpha is False there will be no alpha channel, and the buffer will fully replace anything below the widget.

Since: 3.16

setHasDepthBuffer

gLAreaSetHasDepthBuffer Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> Bool	`hasDepthBuffer`: `True` to add a depth buffer
-> m ()

If hasDepthBuffer is True the widget will allocate and enable a depth buffer for the target framebuffer. Otherwise there will be none.

Since: 3.16

setHasStencilBuffer

gLAreaSetHasStencilBuffer Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> Bool	`hasStencilBuffer`: `True` to add a stencil buffer
-> m ()

If hasStencilBuffer is True the widget will allocate and enable a stencil buffer for the target framebuffer. Otherwise there will be none.

Since: 3.16

setRequiredVersion

gLAreaSetRequiredVersion Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> Int32	`major`: the major version
-> Int32	`minor`: the minor version
-> m ()

Sets the required version of OpenGL to be used when creating the context for the widget.

This function must be called before the area has been realized.

Since: 3.16

setUseEs

gLAreaSetUseEs Source #

Arguments

:: (HasCallStack, MonadIO m, IsGLArea a)
=> a	`area`: a `GLArea`
-> Bool	`useEs`: whether to use OpenGL or OpenGL ES
-> m ()

Sets whether the area should create an OpenGL or an OpenGL ES context.

You should check the capabilities of the GLContext before drawing with either API.

Since: 3.22

Properties

autoRender

If set to True the GLArea::render signal will be emitted every time the widget draws. This is the default and is useful if drawing the widget is faster.

If set to False the data from previous rendering is kept around and will be used for drawing the widget the next time, unless the window is resized. In order to force a rendering gLAreaQueueRender must be called. This mode is useful when the scene changes seldomly, but takes a long time to redraw.

Since: 3.16

constructGLAreaAutoRender :: IsGLArea o => Bool -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “auto-render” property. This is rarely needed directly, but it is used by new.

getGLAreaAutoRender :: (MonadIO m, IsGLArea o) => o -> m Bool Source #

Get the value of the “auto-render” property. When overloading is enabled, this is equivalent to

get gLArea #autoRender

setGLAreaAutoRender :: (MonadIO m, IsGLArea o) => o -> Bool -> m () Source #

Set the value of the “auto-render” property. When overloading is enabled, this is equivalent to

set gLArea [ #autoRender := value ]

context

The GLContext used by the GLArea widget.

The GLArea widget is responsible for creating the GLContext instance. If you need to render with other kinds of buffers (stencil, depth, etc), use render buffers.

Since: 3.16

getGLAreaContext :: (MonadIO m, IsGLArea o) => o -> m GLContext Source #

Get the value of the “context” property. When overloading is enabled, this is equivalent to

get gLArea #context

hasAlpha

If set to True the buffer allocated by the widget will have an alpha channel component, and when rendering to the window the result will be composited over whatever is below the widget.

If set to False there will be no alpha channel, and the buffer will fully replace anything below the widget.

Since: 3.16

constructGLAreaHasAlpha :: IsGLArea o => Bool -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “has-alpha” property. This is rarely needed directly, but it is used by new.

getGLAreaHasAlpha :: (MonadIO m, IsGLArea o) => o -> m Bool Source #

Get the value of the “has-alpha” property. When overloading is enabled, this is equivalent to

get gLArea #hasAlpha

setGLAreaHasAlpha :: (MonadIO m, IsGLArea o) => o -> Bool -> m () Source #

Set the value of the “has-alpha” property. When overloading is enabled, this is equivalent to

set gLArea [ #hasAlpha := value ]

hasDepthBuffer

If set to True the widget will allocate and enable a depth buffer for the target framebuffer.

Since: 3.16

constructGLAreaHasDepthBuffer :: IsGLArea o => Bool -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “has-depth-buffer” property. This is rarely needed directly, but it is used by new.

getGLAreaHasDepthBuffer :: (MonadIO m, IsGLArea o) => o -> m Bool Source #

Get the value of the “has-depth-buffer” property. When overloading is enabled, this is equivalent to

get gLArea #hasDepthBuffer

setGLAreaHasDepthBuffer :: (MonadIO m, IsGLArea o) => o -> Bool -> m () Source #

Set the value of the “has-depth-buffer” property. When overloading is enabled, this is equivalent to

set gLArea [ #hasDepthBuffer := value ]

hasStencilBuffer

If set to True the widget will allocate and enable a stencil buffer for the target framebuffer.

Since: 3.16

constructGLAreaHasStencilBuffer :: IsGLArea o => Bool -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “has-stencil-buffer” property. This is rarely needed directly, but it is used by new.

getGLAreaHasStencilBuffer :: (MonadIO m, IsGLArea o) => o -> m Bool Source #

Get the value of the “has-stencil-buffer” property. When overloading is enabled, this is equivalent to

get gLArea #hasStencilBuffer

setGLAreaHasStencilBuffer :: (MonadIO m, IsGLArea o) => o -> Bool -> m () Source #

Set the value of the “has-stencil-buffer” property. When overloading is enabled, this is equivalent to

set gLArea [ #hasStencilBuffer := value ]

useEs

If set to True the widget will try to create a GLContext using OpenGL ES instead of OpenGL.

Signals

createContext

type C_GLAreaCreateContextCallback = Ptr () -> Ptr () -> IO (Ptr GLContext) Source #

Type for the callback on the (unwrapped) C side.

type GLAreaCreateContextCallback Source #

Arguments

= IO GLContext

Returns: a newly created GLContext; the GLArea widget will take ownership of the returned value.

The ::create-context signal is emitted when the widget is being realized, and allows you to override how the GL context is created. This is useful when you want to reuse an existing GL context, or if you want to try creating different kinds of GL options.

If context creation fails then the signal handler can use gLAreaSetError to register a more detailed error of how the construction failed.

Since: 3.16

afterGLAreaCreateContext :: (IsGLArea a, MonadIO m) => a -> GLAreaCreateContextCallback -> m SignalHandlerId Source #

Connect a signal handler for the “create-context” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gLArea #createContext callback

genClosure_GLAreaCreateContext :: GLAreaCreateContextCallback -> IO Closure Source #

Wrap the callback into a Closure.

mk_GLAreaCreateContextCallback :: C_GLAreaCreateContextCallback -> IO (FunPtr C_GLAreaCreateContextCallback) Source #

Generate a function pointer callable from C code, from a C_GLAreaCreateContextCallback.

noGLAreaCreateContextCallback :: Maybe GLAreaCreateContextCallback Source #

A convenience synonym for Nothing :: Maybe GLAreaCreateContextCallback.

onGLAreaCreateContext :: (IsGLArea a, MonadIO m) => a -> GLAreaCreateContextCallback -> m SignalHandlerId Source #

Connect a signal handler for the “create-context” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gLArea #createContext callback

wrap_GLAreaCreateContextCallback :: GLAreaCreateContextCallback -> C_GLAreaCreateContextCallback Source #

Wrap a GLAreaCreateContextCallback into a C_GLAreaCreateContextCallback.

render

type C_GLAreaRenderCallback = Ptr () -> Ptr GLContext -> Ptr () -> IO CInt Source #

Type for the callback on the (unwrapped) C side.

type GLAreaRenderCallback Source #

Arguments

= GLContext	`context`: the `GLContext` used by `area`
-> IO Bool	Returns: `True` to stop other handlers from being invoked for the event. `False` to propagate the event further.

The ::render signal is emitted every time the contents of the GLArea should be redrawn.

The context is bound to the area prior to emitting this function, and the buffers are painted to the window once the emission terminates.

Since: 3.16

afterGLAreaRender :: (IsGLArea a, MonadIO m) => a -> GLAreaRenderCallback -> m SignalHandlerId Source #

Connect a signal handler for the “render” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gLArea #render callback

genClosure_GLAreaRender :: GLAreaRenderCallback -> IO Closure Source #

Wrap the callback into a Closure.

mk_GLAreaRenderCallback :: C_GLAreaRenderCallback -> IO (FunPtr C_GLAreaRenderCallback) Source #

Generate a function pointer callable from C code, from a C_GLAreaRenderCallback.

noGLAreaRenderCallback :: Maybe GLAreaRenderCallback Source #

A convenience synonym for Nothing :: Maybe GLAreaRenderCallback.

onGLAreaRender :: (IsGLArea a, MonadIO m) => a -> GLAreaRenderCallback -> m SignalHandlerId Source #

Connect a signal handler for the “render” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gLArea #render callback

wrap_GLAreaRenderCallback :: GLAreaRenderCallback -> C_GLAreaRenderCallback Source #

Wrap a GLAreaRenderCallback into a C_GLAreaRenderCallback.

resize

type C_GLAreaResizeCallback = Ptr () -> Int32 -> Int32 -> Ptr () -> IO () Source #

Type for the callback on the (unwrapped) C side.

type GLAreaResizeCallback Source #

Arguments

= Int32	`width`: the width of the viewport
-> Int32	`height`: the height of the viewport
-> IO ()

The ::resize signal is emitted once when the widget is realized, and then each time the widget is changed while realized. This is useful in order to keep GL state up to date with the widget size, like for instance camera properties which may depend on the width/height ratio.

The GL context for the area is guaranteed to be current when this signal is emitted.

The default handler sets up the GL viewport.

Since: 3.16

afterGLAreaResize :: (IsGLArea a, MonadIO m) => a -> GLAreaResizeCallback -> m SignalHandlerId Source #

Connect a signal handler for the “resize” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gLArea #resize callback

genClosure_GLAreaResize :: GLAreaResizeCallback -> IO Closure Source #

Wrap the callback into a Closure.

mk_GLAreaResizeCallback :: C_GLAreaResizeCallback -> IO (FunPtr C_GLAreaResizeCallback) Source #

Generate a function pointer callable from C code, from a C_GLAreaResizeCallback.

noGLAreaResizeCallback :: Maybe GLAreaResizeCallback Source #

A convenience synonym for Nothing :: Maybe GLAreaResizeCallback.

onGLAreaResize :: (IsGLArea a, MonadIO m) => a -> GLAreaResizeCallback -> m SignalHandlerId Source #

Connect a signal handler for the “resize” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gLArea #resize callback

wrap_GLAreaResizeCallback :: GLAreaResizeCallback -> C_GLAreaResizeCallback Source #

Wrap a GLAreaResizeCallback into a C_GLAreaResizeCallback.