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gtk2/gtk/gtkglarea.c
Benjamin Otte 82a99a3643 texture: Expose subclasses as subclasses 
This is necessary so that bidnings work properly and don't make
gdk_gl_texture_release() a function on GdkTexture.
It also allows code to identify what type of texture they are dealing
with.

Finally, we can now decide to add getters later without screwing
anything up, if we want to allow people to access GL textures directly.
2018-03-18 05:57:07 +01:00

1330 lines
37 KiB
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/* GTK - The GIMP Toolkit
*
* gtkglarea.c: A GL drawing area
*
* Copyright © 2014 Emmanuele Bassi
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "config.h"
#include "gtkglarea.h"
#include "gtkintl.h"
#include "gtkstylecontext.h"
#include "gtkmarshalers.h"
#include "gtkprivate.h"
#include "gtkrender.h"
#include "gtksnapshot.h"
#include <epoxy/gl.h>
/**
* SECTION:gtkglarea
* @Title: GtkGLArea
* @Short_description: A widget for custom drawing with OpenGL
*
* #GtkGLArea is a widget that allows drawing with OpenGL.
*
* #GtkGLArea sets up its own #GdkGLContext 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 #GtkGLArea::render signal,
* or subclass #GtkGLArea and override the @GtkGLAreaClass.render() virtual
* function.
*
* The #GtkGLArea widget ensures that the #GdkGLContext 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 #GtkGLArea is to
* create a widget instance and connect to the #GtkGLArea::render signal:
*
* |[<!-- language="C" -->
* ]|
*
* The `render()` function will be called when the #GtkGLArea is ready
* for you to draw its content:
*
* |[<!-- language="C" -->
* 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;
* }
*
* void setup_glarea (void)
* {
* // 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);
* }
* ]|
*
* If you need to initialize OpenGL state, e.g. buffer objects or
* shaders, you should use the #GtkWidget::realize signal; you
* can use the #GtkWidget::unrealize signal to clean up. Since the
* #GdkGLContext creation and initialization may fail, you will
* need to check for errors, using gtk_gl_area_get_error(). An example
* of how to safely initialize the GL state is:
*
* |[<!-- language="C" -->
* 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 #GdkGLContext
* you should use the #GtkGLArea::create-context signal.
*/
typedef struct {
guint id;
int width;
int height;
GdkTexture *holder;
} Texture;
typedef struct {
GdkGLContext *context;
GError *error;
gboolean have_buffers;
int required_gl_version;
guint frame_buffer;
guint depth_stencil_buffer;
Texture *texture;
GList *textures;
gboolean has_depth_buffer;
gboolean has_stencil_buffer;
gboolean needs_resize;
gboolean needs_render;
gboolean auto_render;
gboolean use_es;
} GtkGLAreaPrivate;
enum {
PROP_0,
PROP_CONTEXT,
PROP_HAS_DEPTH_BUFFER,
PROP_HAS_STENCIL_BUFFER,
PROP_USE_ES,
PROP_AUTO_RENDER,
LAST_PROP
};
static GParamSpec *obj_props[LAST_PROP] = { NULL, };
enum {
RENDER,
RESIZE,
CREATE_CONTEXT,
LAST_SIGNAL
};
static void gtk_gl_area_allocate_buffers (GtkGLArea *area);
static void gtk_gl_area_allocate_texture (GtkGLArea *area);
static guint area_signals[LAST_SIGNAL] = { 0, };
G_DEFINE_TYPE_WITH_PRIVATE (GtkGLArea, gtk_gl_area, GTK_TYPE_WIDGET)
static void
gtk_gl_area_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkGLArea *self = GTK_GL_AREA (gobject);
switch (prop_id)
{
case PROP_AUTO_RENDER:
gtk_gl_area_set_auto_render (self, g_value_get_boolean (value));
break;
case PROP_HAS_DEPTH_BUFFER:
gtk_gl_area_set_has_depth_buffer (self, g_value_get_boolean (value));
break;
case PROP_HAS_STENCIL_BUFFER:
gtk_gl_area_set_has_stencil_buffer (self, g_value_get_boolean (value));
break;
case PROP_USE_ES:
gtk_gl_area_set_use_es (self, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
gtk_gl_area_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (GTK_GL_AREA (gobject));
switch (prop_id)
{
case PROP_AUTO_RENDER:
g_value_set_boolean (value, priv->auto_render);
break;
case PROP_HAS_DEPTH_BUFFER:
g_value_set_boolean (value, priv->has_depth_buffer);
break;
case PROP_HAS_STENCIL_BUFFER:
g_value_set_boolean (value, priv->has_stencil_buffer);
break;
case PROP_CONTEXT:
g_value_set_object (value, priv->context);
break;
case PROP_USE_ES:
g_value_set_boolean (value, priv->use_es);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
gtk_gl_area_realize (GtkWidget *widget)
{
GtkGLArea *area = GTK_GL_AREA (widget);
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
GTK_WIDGET_CLASS (gtk_gl_area_parent_class)->realize (widget);
g_clear_error (&priv->error);
priv->context = NULL;
g_signal_emit (area, area_signals[CREATE_CONTEXT], 0, &priv->context);
/* In case the signal failed, but did not set an error */
if (priv->context == NULL && priv->error == NULL)
g_set_error_literal (&priv->error, GDK_GL_ERROR,
GDK_GL_ERROR_NOT_AVAILABLE,
_("OpenGL context creation failed"));
priv->needs_resize = TRUE;
}
static void
gtk_gl_area_notify (GObject *object,
GParamSpec *pspec)
{
if (strcmp (pspec->name, "scale-factor") == 0)
{
GtkGLArea *area = GTK_GL_AREA (object);
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
priv->needs_resize = TRUE;
}
if (G_OBJECT_CLASS (gtk_gl_area_parent_class)->notify)
G_OBJECT_CLASS (gtk_gl_area_parent_class)->notify (object, pspec);
}
static GdkGLContext *
gtk_gl_area_real_create_context (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
GtkWidget *widget = GTK_WIDGET (area);
GError *error = NULL;
GdkGLContext *context;
context = gdk_window_create_gl_context (gtk_widget_get_window (widget), &error);
if (error != NULL)
{
gtk_gl_area_set_error (area, error);
g_clear_object (&context);
g_clear_error (&error);
return NULL;
}
gdk_gl_context_set_use_es (context, priv->use_es);
gdk_gl_context_set_required_version (context,
priv->required_gl_version / 10,
priv->required_gl_version % 10);
gdk_gl_context_realize (context, &error);
if (error != NULL)
{
gtk_gl_area_set_error (area, error);
g_clear_object (&context);
g_clear_error (&error);
return NULL;
}
return context;
}
static void
gtk_gl_area_resize (GtkGLArea *area, int width, int height)
{
glViewport (0, 0, width, height);
}
/*
* Creates all the buffer objects needed for rendering the scene
*/
static void
gtk_gl_area_ensure_buffers (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
GtkWidget *widget = GTK_WIDGET (area);
gtk_widget_realize (widget);
if (priv->context == NULL)
return;
if (priv->have_buffers)
return;
priv->have_buffers = TRUE;
glGenFramebuffersEXT (1, &priv->frame_buffer);
if ((priv->has_depth_buffer || priv->has_stencil_buffer))
{
if (priv->depth_stencil_buffer == 0)
glGenRenderbuffersEXT (1, &priv->depth_stencil_buffer);
}
else if (priv->depth_stencil_buffer != 0)
{
/* Delete old depth/stencil buffer */
glDeleteRenderbuffersEXT (1, &priv->depth_stencil_buffer);
priv->depth_stencil_buffer = 0;
}
gtk_gl_area_allocate_buffers (area);
}
static void
delete_one_texture (gpointer data)
{
Texture *texture = data;
if (texture->holder)
gdk_gl_texture_release (GDK_GL_TEXTURE (texture->holder));
if (texture->id != 0)
{
glDeleteTextures (1, &texture->id);
texture->id = 0;
}
g_free (texture);
}
static void
gtk_gl_area_ensure_texture (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
GtkWidget *widget = GTK_WIDGET (area);
gtk_widget_realize (widget);
if (priv->context == NULL)
return;
if (priv->texture == NULL)
{
GList *l, *link;
l = priv->textures;
while (l)
{
Texture *texture = l->data;
link = l;
l = l->next;
if (texture->holder)
continue;
priv->textures = g_list_delete_link (priv->textures, link);
if (priv->texture == NULL)
priv->texture = texture;
else
delete_one_texture (texture);
}
}
if (priv->texture == NULL)
{
priv->texture = g_new (Texture, 1);
priv->texture->width = 0;
priv->texture->height = 0;
priv->texture->holder = NULL;
glGenTextures (1, &priv->texture->id);
}
gtk_gl_area_allocate_texture (area);
}
/*
* Allocates space of the right type and size for all the buffers
*/
static void
gtk_gl_area_allocate_buffers (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
GtkWidget *widget = GTK_WIDGET (area);
int scale, width, height;
if (priv->context == NULL)
return;
scale = gtk_widget_get_scale_factor (widget);
width = gtk_widget_get_width (widget) * scale;
height = gtk_widget_get_height (widget) * scale;
if (priv->has_depth_buffer || priv->has_stencil_buffer)
{
glBindRenderbuffer (GL_RENDERBUFFER, priv->depth_stencil_buffer);
if (priv->has_stencil_buffer)
glRenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
else
glRenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);
}
priv->needs_render = TRUE;
}
static void
gtk_gl_area_allocate_texture (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
GtkWidget *widget = GTK_WIDGET (area);
int scale, width, height;
if (priv->context == NULL)
return;
if (priv->texture == NULL)
return;
g_assert (priv->texture->holder == NULL);
scale = gtk_widget_get_scale_factor (widget);
width = gtk_widget_get_width (widget) * scale;
height = gtk_widget_get_height (widget) * scale;
if (priv->texture->width != width ||
priv->texture->height != height)
{
glBindTexture (GL_TEXTURE_2D, priv->texture->id);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
if (gdk_gl_context_get_use_es (priv->context))
glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
else
glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_BGRA, GL_UNSIGNED_BYTE, NULL);
priv->texture->width = width;
priv->texture->height = height;
}
}
/**
* gtk_gl_area_attach_buffers:
* @area: a #GtkGLArea
*
* 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
* #GtkGLArea::render signal, and doesn't normally need to be called
* by application code.
*/
void
gtk_gl_area_attach_buffers (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
if (priv->context == NULL)
return;
gtk_gl_area_make_current (area);
if (priv->texture == NULL)
gtk_gl_area_ensure_texture (area);
else if (priv->needs_resize)
gtk_gl_area_allocate_texture (area);
if (!priv->have_buffers)
gtk_gl_area_ensure_buffers (area);
else if (priv->needs_resize)
gtk_gl_area_allocate_buffers (area);
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, priv->frame_buffer);
if (priv->texture != NULL)
glFramebufferTexture2D (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_TEXTURE_2D, priv->texture->id, 0);
if (priv->depth_stencil_buffer)
{
if (priv->has_depth_buffer)
glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
GL_RENDERBUFFER_EXT, priv->depth_stencil_buffer);
if (priv->has_stencil_buffer)
glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
GL_RENDERBUFFER_EXT, priv->depth_stencil_buffer);
}
}
static void
gtk_gl_area_delete_buffers (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
if (priv->context == NULL)
return;
priv->have_buffers = FALSE;
if (priv->depth_stencil_buffer != 0)
{
glDeleteRenderbuffersEXT (1, &priv->depth_stencil_buffer);
priv->depth_stencil_buffer = 0;
}
if (priv->frame_buffer != 0)
{
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0);
glDeleteFramebuffersEXT (1, &priv->frame_buffer);
priv->frame_buffer = 0;
}
}
static void
gtk_gl_area_delete_textures (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
if (priv->texture)
{
delete_one_texture (priv->texture);
priv->texture = NULL;
}
/* FIXME: we need to explicitly release all outstanding
* textures here, otherwise release_texture will get called
* later and access freed memory.
*/
g_list_free_full (priv->textures, delete_one_texture);
priv->textures = NULL;
}
static void
gtk_gl_area_unrealize (GtkWidget *widget)
{
GtkGLArea *area = GTK_GL_AREA (widget);
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
if (priv->context != NULL)
{
gtk_gl_area_make_current (area);
gtk_gl_area_delete_buffers (area);
gtk_gl_area_delete_textures (area);
/* Make sure to unset the context if current */
if (priv->context == gdk_gl_context_get_current ())
gdk_gl_context_clear_current ();
}
g_clear_object (&priv->context);
g_clear_error (&priv->error);
GTK_WIDGET_CLASS (gtk_gl_area_parent_class)->unrealize (widget);
}
static void
gtk_gl_area_size_allocate (GtkWidget *widget,
const GtkAllocation *allocation,
int baseline,
GtkAllocation *out_clip)
{
GtkGLArea *area = GTK_GL_AREA (widget);
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
GTK_WIDGET_CLASS (gtk_gl_area_parent_class)->size_allocate (widget, allocation, baseline, out_clip);
if (gtk_widget_get_realized (widget))
priv->needs_resize = TRUE;
}
static void
gtk_gl_area_draw_error_screen (GtkGLArea *area,
GtkSnapshot *snapshot,
gint width,
gint height)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
PangoLayout *layout;
int layout_height;
layout = gtk_widget_create_pango_layout (GTK_WIDGET (area),
priv->error->message);
pango_layout_set_width (layout, width * PANGO_SCALE);
pango_layout_set_alignment (layout, PANGO_ALIGN_CENTER);
pango_layout_get_pixel_size (layout, NULL, &layout_height);
gtk_snapshot_render_layout (snapshot,
gtk_widget_get_style_context (GTK_WIDGET (area)),
0, (height - layout_height) / 2,
layout);
g_object_unref (layout);
}
static void
release_texture (gpointer data)
{
Texture *texture = data;
texture->holder = NULL;
}
static void
gtk_gl_area_snapshot (GtkWidget *widget,
GtkSnapshot *snapshot)
{
GtkGLArea *area = GTK_GL_AREA (widget);
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
gboolean unused;
int w, h, scale;
GLenum status;
scale = gtk_widget_get_scale_factor (widget);
w = gtk_widget_get_width (widget) * scale;
h = gtk_widget_get_height (widget) * scale;
if (w == 0 || h == 0)
return;
if (priv->error != NULL)
{
gtk_gl_area_draw_error_screen (area,
snapshot,
gtk_widget_get_width (widget),
gtk_widget_get_height (widget));
return;
}
if (priv->context == NULL)
return;
gtk_gl_area_make_current (area);
gtk_gl_area_attach_buffers (area);
if (priv->has_depth_buffer)
glEnable (GL_DEPTH_TEST);
else
glDisable (GL_DEPTH_TEST);
status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
if (status == GL_FRAMEBUFFER_COMPLETE_EXT)
{
Texture *texture;
if (priv->needs_render || priv->auto_render)
{
if (priv->needs_resize)
{
g_signal_emit (area, area_signals[RESIZE], 0, w, h, NULL);
priv->needs_resize = FALSE;
}
g_signal_emit (area, area_signals[RENDER], 0, priv->context, &unused);
}
priv->needs_render = FALSE;
texture = priv->texture;
priv->texture = NULL;
priv->textures = g_list_prepend (priv->textures, texture);
texture->holder = gdk_gl_texture_new (priv->context,
texture->id,
texture->width,
texture->height,
release_texture, texture);
gtk_snapshot_append_texture (snapshot,
texture->holder,
&GRAPHENE_RECT_INIT (0, 0,
gtk_widget_get_width (widget),
gtk_widget_get_height (widget)),
"GL Area");
g_object_unref (texture->holder);
}
else
{
g_warning ("fb setup not supported (%x)", status);
}
}
static gboolean
create_context_accumulator (GSignalInvocationHint *ihint,
GValue *return_accu,
const GValue *handler_return,
gpointer data)
{
g_value_copy (handler_return, return_accu);
/* stop after the first handler returning a valid object */
return g_value_get_object (handler_return) == NULL;
}
static void
gtk_gl_area_class_init (GtkGLAreaClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
klass->resize = gtk_gl_area_resize;
klass->create_context = gtk_gl_area_real_create_context;
widget_class->realize = gtk_gl_area_realize;
widget_class->unrealize = gtk_gl_area_unrealize;
widget_class->size_allocate = gtk_gl_area_size_allocate;
widget_class->snapshot = gtk_gl_area_snapshot;
gtk_widget_class_set_accessible_role (widget_class, ATK_ROLE_DRAWING_AREA);
/**
* GtkGLArea:context:
*
* The #GdkGLContext used by the #GtkGLArea widget.
*
* The #GtkGLArea widget is responsible for creating the #GdkGLContext
* instance. If you need to render with other kinds of buffers (stencil,
* depth, etc), use render buffers.
*/
obj_props[PROP_CONTEXT] =
g_param_spec_object ("context",
P_("Context"),
P_("The GL context"),
GDK_TYPE_GL_CONTEXT,
G_PARAM_READABLE |
G_PARAM_STATIC_STRINGS);
/**
* GtkGLArea:auto-render:
*
* If set to %TRUE the #GtkGLArea::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 gtk_gl_area_queue_render() must be called.
* This mode is useful when the scene changes seldomly, but takes a long time
* to redraw.
*/
obj_props[PROP_AUTO_RENDER] =
g_param_spec_boolean ("auto-render",
P_("Auto render"),
P_("Whether the GtkGLArea renders on each redraw"),
TRUE,
GTK_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS |
G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkGLArea:has-depth-buffer:
*
* If set to %TRUE the widget will allocate and enable a depth buffer for the
* target framebuffer.
*/
obj_props[PROP_HAS_DEPTH_BUFFER] =
g_param_spec_boolean ("has-depth-buffer",
P_("Has depth buffer"),
P_("Whether a depth buffer is allocated"),
FALSE,
GTK_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS |
G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkGLArea:has-stencil-buffer:
*
* If set to %TRUE the widget will allocate and enable a stencil buffer for the
* target framebuffer.
*/
obj_props[PROP_HAS_STENCIL_BUFFER] =
g_param_spec_boolean ("has-stencil-buffer",
P_("Has stencil buffer"),
P_("Whether a stencil buffer is allocated"),
FALSE,
GTK_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS |
G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkGLArea:use-es:
*
* If set to %TRUE the widget will try to create a #GdkGLContext using
* OpenGL ES instead of OpenGL.
*
* See also: gdk_gl_context_set_use_es()
*/
obj_props[PROP_USE_ES] =
g_param_spec_boolean ("use-es",
P_("Use OpenGL ES"),
P_("Whether the context uses OpenGL or OpenGL ES"),
FALSE,
GTK_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS |
G_PARAM_EXPLICIT_NOTIFY);
gobject_class->set_property = gtk_gl_area_set_property;
gobject_class->get_property = gtk_gl_area_get_property;
gobject_class->notify = gtk_gl_area_notify;
g_object_class_install_properties (gobject_class, LAST_PROP, obj_props);
/**
* GtkGLArea::render:
* @area: the #GtkGLArea that emitted the signal
* @context: the #GdkGLContext used by @area
*
* The ::render signal is emitted every time the contents
* of the #GtkGLArea 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.
*
* Returns: %TRUE to stop other handlers from being invoked for the event.
* %FALSE to propagate the event further.
*/
area_signals[RENDER] =
g_signal_new (I_("render"),
G_TYPE_FROM_CLASS (gobject_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGLAreaClass, render),
_gtk_boolean_handled_accumulator, NULL,
NULL,
G_TYPE_BOOLEAN, 1,
GDK_TYPE_GL_CONTEXT);
/**
* GtkGLArea::resize:
* @area: the #GtkGLArea that emitted the signal
* @width: the width of the viewport
* @height: the height of the viewport
*
* 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.
*/
area_signals[RESIZE] =
g_signal_new (I_("resize"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGLAreaClass, resize),
NULL, NULL,
_gtk_marshal_VOID__INT_INT,
G_TYPE_NONE, 2, G_TYPE_INT, G_TYPE_INT);
/**
* GtkGLArea::create-context:
* @area: the #GtkGLArea that emitted the signal
* @error: (allow-none): location to store error information on failure
*
* 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
* gtk_gl_area_set_error() to register a more detailed error
* of how the construction failed.
*
* Returns: (transfer full): a newly created #GdkGLContext;
* the #GtkGLArea widget will take ownership of the returned value.
*/
area_signals[CREATE_CONTEXT] =
g_signal_new (I_("create-context"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGLAreaClass, create_context),
create_context_accumulator, NULL,
_gtk_marshal_OBJECT__VOID,
GDK_TYPE_GL_CONTEXT, 0);
}
static void
gtk_gl_area_init (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
gtk_widget_set_has_window (GTK_WIDGET (area), FALSE);
priv->auto_render = TRUE;
priv->needs_render = TRUE;
priv->required_gl_version = 0;
}
/**
* gtk_gl_area_new:
*
* Creates a new #GtkGLArea widget.
*
* Returns: (transfer full): the newly created #GtkGLArea
*/
GtkWidget *
gtk_gl_area_new (void)
{
return g_object_new (GTK_TYPE_GL_AREA, NULL);
}
/**
* gtk_gl_area_set_error:
* @area: a #GtkGLArea
* @error: (allow-none): a new #GError, or %NULL to unset the error
*
* Sets an error on the area which will be shown instead of the
* GL rendering. This is useful in the #GtkGLArea::create-context
* signal if GL context creation fails.
*/
void
gtk_gl_area_set_error (GtkGLArea *area,
const GError *error)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
g_clear_error (&priv->error);
if (error)
priv->error = g_error_copy (error);
}
/**
* gtk_gl_area_get_error:
* @area: a #GtkGLArea
*
* Gets the current error set on the @area.
*
* Returns: (nullable) (transfer none): the #GError or %NULL
*/
GError *
gtk_gl_area_get_error (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_val_if_fail (GTK_IS_GL_AREA (area), NULL);
return priv->error;
}
/**
* gtk_gl_area_set_use_es:
* @area: a #GtkGLArea
* @use_es: whether to use OpenGL or OpenGL ES
*
* Sets whether the @area should create an OpenGL or an OpenGL ES context.
*
* You should check the capabilities of the #GdkGLContext before drawing
* with either API.
*/
void
gtk_gl_area_set_use_es (GtkGLArea *area,
gboolean use_es)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
g_return_if_fail (!gtk_widget_get_realized (GTK_WIDGET (area)));
use_es = !!use_es;
if (priv->use_es != use_es)
{
priv->use_es = use_es;
g_object_notify_by_pspec (G_OBJECT (area), obj_props[PROP_USE_ES]);
}
}
/**
* gtk_gl_area_get_use_es:
* @area: a #GtkGLArea
*
* Retrieves the value set by gtk_gl_area_set_use_es().
*
* Returns: %TRUE if the #GtkGLArea should create an OpenGL ES context
* and %FALSE otherwise
*/
gboolean
gtk_gl_area_get_use_es (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_val_if_fail (GTK_IS_GL_AREA (area), FALSE);
return priv->use_es;
}
/**
* gtk_gl_area_set_required_version:
* @area: a #GtkGLArea
* @major: the major version
* @minor: the minor version
*
* 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.
*/
void
gtk_gl_area_set_required_version (GtkGLArea *area,
gint major,
gint minor)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
g_return_if_fail (!gtk_widget_get_realized (GTK_WIDGET (area)));
priv->required_gl_version = major * 10 + minor;
}
/**
* gtk_gl_area_get_required_version:
* @area: a #GtkGLArea
* @major: (out): return location for the required major version
* @minor: (out): return location for the required minor version
*
* Retrieves the required version of OpenGL set
* using gtk_gl_area_set_required_version().
*/
void
gtk_gl_area_get_required_version (GtkGLArea *area,
gint *major,
gint *minor)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
if (major != NULL)
*major = priv->required_gl_version / 10;
if (minor != NULL)
*minor = priv->required_gl_version % 10;
}
/**
* gtk_gl_area_get_has_depth_buffer:
* @area: a #GtkGLArea
*
* Returns whether the area has a depth buffer.
*
* Returns: %TRUE if the @area has a depth buffer, %FALSE otherwise
*/
gboolean
gtk_gl_area_get_has_depth_buffer (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_val_if_fail (GTK_IS_GL_AREA (area), FALSE);
return priv->has_depth_buffer;
}
/**
* gtk_gl_area_set_has_depth_buffer:
* @area: a #GtkGLArea
* @has_depth_buffer: %TRUE to add a depth buffer
*
* If @has_depth_buffer is %TRUE the widget will allocate and
* enable a depth buffer for the target framebuffer. Otherwise
* there will be none.
*/
void
gtk_gl_area_set_has_depth_buffer (GtkGLArea *area,
gboolean has_depth_buffer)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
has_depth_buffer = !!has_depth_buffer;
if (priv->has_depth_buffer != has_depth_buffer)
{
priv->has_depth_buffer = has_depth_buffer;
g_object_notify (G_OBJECT (area), "has-depth-buffer");
priv->have_buffers = FALSE;
}
}
/**
* gtk_gl_area_get_has_stencil_buffer:
* @area: a #GtkGLArea
*
* Returns whether the area has a stencil buffer.
*
* Returns: %TRUE if the @area has a stencil buffer, %FALSE otherwise
*/
gboolean
gtk_gl_area_get_has_stencil_buffer (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_val_if_fail (GTK_IS_GL_AREA (area), FALSE);
return priv->has_stencil_buffer;
}
/**
* gtk_gl_area_set_has_stencil_buffer:
* @area: a #GtkGLArea
* @has_stencil_buffer: %TRUE to add a stencil buffer
*
* If @has_stencil_buffer is %TRUE the widget will allocate and
* enable a stencil buffer for the target framebuffer. Otherwise
* there will be none.
*/
void
gtk_gl_area_set_has_stencil_buffer (GtkGLArea *area,
gboolean has_stencil_buffer)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
has_stencil_buffer = !!has_stencil_buffer;
if (priv->has_stencil_buffer != has_stencil_buffer)
{
priv->has_stencil_buffer = has_stencil_buffer;
g_object_notify (G_OBJECT (area), "has-stencil-buffer");
priv->have_buffers = FALSE;
}
}
/**
* gtk_gl_area_queue_render:
* @area: a #GtkGLArea
*
* Marks the currently rendered data (if any) as invalid, and queues
* a redraw of the widget, ensuring that the #GtkGLArea::render signal
* is emitted during the draw.
*
* This is only needed when the gtk_gl_area_set_auto_render() has
* been called with a %FALSE value. The default behaviour is to
* emit #GtkGLArea::render on each draw.
*/
void
gtk_gl_area_queue_render (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
priv->needs_render = TRUE;
gtk_widget_queue_draw (GTK_WIDGET (area));
}
/**
* gtk_gl_area_get_auto_render:
* @area: a #GtkGLArea
*
* Returns whether the area is in auto render mode or not.
*
* Returns: %TRUE if the @area is auto rendering, %FALSE otherwise
*/
gboolean
gtk_gl_area_get_auto_render (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_val_if_fail (GTK_IS_GL_AREA (area), FALSE);
return priv->auto_render;
}
/**
* gtk_gl_area_set_auto_render:
* @area: a #GtkGLArea
* @auto_render: a boolean
*
* If @auto_render is %TRUE the #GtkGLArea::render signal will be
* emitted every time the widget draws. This is the default and is
* useful if drawing the widget is faster.
*
* If @auto_render 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
* gtk_gl_area_queue_render() must be called. This mode is useful when
* the scene changes seldomly, but takes a long time to redraw.
*/
void
gtk_gl_area_set_auto_render (GtkGLArea *area,
gboolean auto_render)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
auto_render = !!auto_render;
if (priv->auto_render != auto_render)
{
priv->auto_render = auto_render;
g_object_notify (G_OBJECT (area), "auto-render");
if (auto_render)
gtk_widget_queue_draw (GTK_WIDGET (area));
}
}
/**
* gtk_gl_area_get_context:
* @area: a #GtkGLArea
*
* Retrieves the #GdkGLContext used by @area.
*
* Returns: (transfer none): the #GdkGLContext
*/
GdkGLContext *
gtk_gl_area_get_context (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_val_if_fail (GTK_IS_GL_AREA (area), NULL);
return priv->context;
}
/**
* gtk_gl_area_make_current:
* @area: a #GtkGLArea
*
* Ensures that the #GdkGLContext used by @area is associated with
* the #GtkGLArea.
*
* This function is automatically called before emitting the
* #GtkGLArea::render signal, and doesn't normally need to be called
* by application code.
*/
void
gtk_gl_area_make_current (GtkGLArea *area)
{
GtkGLAreaPrivate *priv = gtk_gl_area_get_instance_private (area);
g_return_if_fail (GTK_IS_GL_AREA (area));
g_return_if_fail (gtk_widget_get_realized (GTK_WIDGET (area)));
if (priv->context != NULL)
gdk_gl_context_make_current (priv->context);
}
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