mutter/cogl/cogl-onscreen.h
Robert Bragg df51574116 onscreen: Adds support for resizable windows
This adds api to be able to request that the window system allows a
given onscreen framebuffer to be resizable, and api to add and remove
resize handlers to be called whenever the framebuffer does actually
change size.

The new functions are:
  cogl_onscreen_{get,set}_resizable()
  cogl_onscreen_{add,remove}_resize_handler()

The examples cogl-hello and cogl-x11-foreign have been updated to use
the new api. To smoke test how Cogl updates the viewport automatically
in response to window resizes the cogl-hello test doesn't explicitly
respond to resize events by setting the viewport and cogl-x11-foreign
responds by setting a viewport that is offset by a quarter of the
window's width/height and half the width and height of the window.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit a1a8cc00bfa2cecaf1007aec5f3dd95dc07b1786)
2012-08-06 18:51:32 +01:00

538 lines
19 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2011,2012 Intel Corporation.
*
* 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/>.
*
*
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
*/
#if !defined(__COGL_H_INSIDE__) && !defined(COGL_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_ONSCREEN_H
#define __COGL_ONSCREEN_H
#include <cogl/cogl-context.h>
#include <cogl/cogl-framebuffer.h>
#include <glib.h>
G_BEGIN_DECLS
typedef struct _CoglOnscreen CoglOnscreen;
#define COGL_ONSCREEN(X) ((CoglOnscreen *)(X))
/**
* cogl_onscreen_new:
* @context: A #CoglContext
* @width: The desired framebuffer width
* @height: The desired framebuffer height
*
* Instantiates an "unallocated" #CoglOnscreen framebuffer that may be
* configured before later being allocated, either implicitly when
* it is first used or explicitly via cogl_framebuffer_allocate().
*
* Return value: A newly instantiated #CoglOnscreen framebuffer
* Since: 1.8
* Stability: unstable
*/
CoglOnscreen *
cogl_onscreen_new (CoglContext *context, int width, int height);
#ifdef COGL_HAS_X11
typedef void (*CoglOnscreenX11MaskCallback) (CoglOnscreen *onscreen,
uint32_t event_mask,
void *user_data);
/**
* cogl_x11_onscreen_set_foreign_window_xid:
* @onscreen: The unallocated framebuffer to associated with an X
* window.
* @xid: The XID of an existing X window
* @update: A callback that notifies of updates to what Cogl requires
* to be in the core X protocol event mask.
*
* Ideally we would recommend that you let Cogl be responsible for
* creating any X window required to back an onscreen framebuffer but
* if you really need to target a window created manually this
* function can be called before @onscreen has been allocated to set a
* foreign XID for your existing X window.
*
* Since Cogl needs, for example, to track changes to the size of an X
* window it requires that certain events be selected for via the core
* X protocol. This requirement may also be changed asynchronously so
* you must pass in an @update callback to inform you of Cogl's
* required event mask.
*
* For example if you are using Xlib you could use this API roughly
* as follows:
* [{
* static void
* my_update_cogl_x11_event_mask (CoglOnscreen *onscreen,
* uint32_t event_mask,
* void *user_data)
* {
* XSetWindowAttributes attrs;
* MyData *data = user_data;
* attrs.event_mask = event_mask | data->my_event_mask;
* XChangeWindowAttributes (data->xdpy,
* data->xwin,
* CWEventMask,
* &attrs);
* }
*
* {
* *snip*
* cogl_x11_onscreen_set_foreign_window_xid (onscreen,
* data->xwin,
* my_update_cogl_x11_event_mask,
* data);
* *snip*
* }
* }]
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_x11_onscreen_set_foreign_window_xid (CoglOnscreen *onscreen,
uint32_t xid,
CoglOnscreenX11MaskCallback update,
void *user_data);
/**
* cogl_x11_onscreen_get_window_xid:
* @onscreen: A #CoglOnscreen framebuffer
*
* Assuming you know the given @onscreen framebuffer is based on an x11 window
* this queries the XID of that window. If
* cogl_x11_onscreen_set_foreign_window_xid() was previously called then it
* will return that same XID otherwise it will be the XID of a window Cogl
* created internally. If the window has not been allocated yet and a foreign
* xid has not been set then it's undefined what value will be returned.
*
* It's undefined what this function does if called when not using an x11 based
* renderer.
*
* Since: 1.10
* Stability: unstable
*/
uint32_t
cogl_x11_onscreen_get_window_xid (CoglOnscreen *onscreen);
/* XXX: we should maybe remove this, since nothing currently uses
* it and the current implementation looks dubious. */
uint32_t
cogl_x11_onscreen_get_visual_xid (CoglOnscreen *onscreen);
#endif /* COGL_HAS_X11 */
#ifdef COGL_HAS_WIN32_SUPPORT
/**
* cogl_win32_onscreen_set_foreign_window:
* @onscreen: A #CoglOnscreen framebuffer
* @hwnd: A win32 window handle
*
* Ideally we would recommend that you let Cogl be responsible for
* creating any window required to back an onscreen framebuffer but
* if you really need to target a window created manually this
* function can be called before @onscreen has been allocated to set a
* foreign XID for your existing X window.
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_win32_onscreen_set_foreign_window (CoglOnscreen *onscreen,
HWND hwnd);
/**
* cogl_win32_onscreen_get_window:
* @onscreen: A #CoglOnscreen framebuffer
*
* Queries the internally created window HWND backing the given @onscreen
* framebuffer. If cogl_win32_onscreen_set_foreign_window() has been used then
* it will return the same handle set with that API.
*
* Since: 1.10
* Stability: unstable
*/
HWND
cogl_win32_onscreen_get_window (CoglOnscreen *onscreen);
#endif /* COGL_HAS_WIN32_SUPPORT */
#if defined (COGL_HAS_EGL_PLATFORM_WAYLAND_SUPPORT)
struct wl_surface *
cogl_wayland_onscreen_get_surface (CoglOnscreen *onscreen);
struct wl_shell_surface *
cogl_wayland_onscreen_get_shell_surface (CoglOnscreen *onscreen);
/**
* cogl_wayland_onscreen_resize:
* @onscreen: A #CoglOnscreen framebuffer
* @width: The desired width of the framebuffer
* @height: The desired height of the framebuffer
* @offset_x: A relative x offset for the new framebuffer
* @offset_y: A relative x offset for the new framebuffer
*
* Queues a resize of the given @onscreen framebuffer which will be applied
* during the next swap buffers request. Since a buffer is usually conceptually
* scaled with a center point the @offset_x and @offset_y arguments allow the
* newly allocated buffer to be positioned relative to the old buffer size.
*
* For example a buffer that is being resized by moving the bottom right
* corner, and the top left corner is remaining static would use x and y
* offsets of (0, 0) since the top-left of the new buffer should have the same
* position as the old buffer. If the center of the old buffer is being zoomed
* into then all the corners of the new buffer move out from the center and the x
* and y offsets would be (-half_x_size_increase, -half_y_size_increase) where
* x/y_size_increase is how many pixels bigger the buffer is on the x and y
* axis.
*
* If cogl_wayland_onscreen_resize() is called multiple times before the next
* swap buffers request then the relative x and y offsets accumulate instead of
* being replaced. The @width and @height values superseed the old values.
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_wayland_onscreen_resize (CoglOnscreen *onscreen,
int width,
int height,
int offset_x,
int offset_y);
#endif /* COGL_HAS_EGL_PLATFORM_WAYLAND_SUPPORT */
/**
* cogl_onscreen_set_swap_throttled:
* @onscreen: A #CoglOncsreen framebuffer
* @throttled: Whether swap throttling is wanted or not.
*
* Requests that the given @onscreen framebuffer should have swap buffer
* requests (made using cogl_framebuffer_swap_buffers()) throttled either by a
* displays vblank period or perhaps some other mechanism in a composited
* environment.
*
* Since: 1.8
* Stability: unstable
*/
void
cogl_onscreen_set_swap_throttled (CoglOnscreen *onscreen,
CoglBool throttled);
/**
* cogl_onscreen_show:
* @onscreen: The onscreen framebuffer to make visible
*
* This requests to make @onscreen visible to the user.
*
* Actually the precise semantics of this function depend on the
* window system currently in use, and if you don't have a
* multi-windowining system this function may in-fact do nothing.
*
* This function will implicitly allocate the given @onscreen
* framebuffer before showing it if it hasn't already been allocated.
*
* <note>Since Cogl doesn't explicitly track the visibility status of
* onscreen framebuffers it wont try to avoid redundant window system
* requests e.g. to show an already visible window. This also means
* that it's acceptable to alternatively use native APIs to show and
* hide windows without confusing Cogl.</note>
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_onscreen_show (CoglOnscreen *onscreen);
/**
* cogl_onscreen_hide:
* @onscreen: The onscreen framebuffer to make invisible
*
* This requests to make @onscreen invisible to the user.
*
* Actually the precise semantics of this function depend on the
* window system currently in use, and if you don't have a
* multi-windowining system this function may in-fact do nothing.
*
* This function does not implicitly allocate the given @onscreen
* framebuffer before hiding it.
*
* <note>Since Cogl doesn't explicitly track the visibility status of
* onscreen framebuffers it wont try to avoid redundant window system
* requests e.g. to show an already visible window. This also means
* that it's acceptable to alternatively use native APIs to show and
* hide windows without confusing Cogl.</note>
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_onscreen_hide (CoglOnscreen *onscreen);
/**
* cogl_onscreen_swap_buffers:
* @onscreen: A #CoglOnscreen framebuffer
*
* Swaps the current back buffer being rendered too, to the front for display.
*
* This function also implicitly discards the contents of the color, depth and
* stencil buffers as if cogl_framebuffer_discard_buffers() were used. The
* significance of the discard is that you should not expect to be able to
* start a new frame that incrementally builds on the contents of the previous
* frame.
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_onscreen_swap_buffers (CoglOnscreen *onscreen);
/**
* cogl_onscreen_swap_region:
* @onscreen: A #CoglOnscreen framebuffer
* @rectangles: An array of integer 4-tuples representing rectangles as
* (x, y, width, height) tuples.
* @n_rectangles: The number of 4-tuples to be read from @rectangles
*
* Swaps a region of the back buffer being rendered too, to the front for
* display. @rectangles represents the region as array of @n_rectangles each
* defined by 4 sequential (x, y, width, height) integers.
*
* This function also implicitly discards the contents of the color, depth and
* stencil buffers as if cogl_onscreen_discard_buffers() were used. The
* significance of the discard is that you should not expect to be able to
* start a new frame that incrementally builds on the contents of the previous
* frame.
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_onscreen_swap_region (CoglOnscreen *onscreen,
const int *rectangles,
int n_rectangles);
typedef void (*CoglSwapBuffersNotify) (CoglFramebuffer *framebuffer,
void *user_data);
/**
* cogl_onscreen_add_swap_buffers_callback:
* @onscreen: A #CoglOnscreen framebuffer
* @callback: A callback function to call when a swap has completed
* @user_data: A private pointer to be passed to @callback
*
* Installs a @callback function that should be called whenever a swap buffers
* request (made using cogl_onscreen_swap_buffers()) for the given
* @onscreen completes.
*
* <note>Applications should check for the %COGL_FEATURE_ID_SWAP_BUFFERS_EVENT
* feature before using this API. It's currently undefined when and if
* registered callbacks will be called if this feature is not supported.</note>
*
* We recommend using this mechanism when available to manually throttle your
* applications (in conjunction with cogl_onscreen_set_swap_throttled()) so
* your application will be able to avoid long blocks in the driver caused by
* throttling when you request to swap buffers too quickly.
*
* Return value: a unique identifier that can be used to remove to remove
* the callback later.
* Since: 1.10
* Stability: unstable
*/
unsigned int
cogl_onscreen_add_swap_buffers_callback (CoglOnscreen *onscreen,
CoglSwapBuffersNotify callback,
void *user_data);
/**
* cogl_onscreen_remove_swap_buffers_callback:
* @onscreen: A #CoglOnscreen framebuffer
* @id: An identifier returned from cogl_onscreen_add_swap_buffers_callback()
*
* Removes a callback that was previously registered
* using cogl_onscreen_add_swap_buffers_callback().
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_onscreen_remove_swap_buffers_callback (CoglOnscreen *onscreen,
unsigned int id);
/**
* cogl_onscreen_set_resizable:
* @onscreen: A #CoglOnscreen framebuffer
*
* Lets you request Cogl to mark an @onscreen framebuffer as
* resizable or not.
*
* By default, if possible, a @onscreen will be created by Cogl
* as non resizable, but it is not guaranteed that this is always
* possible for all window systems.
*
* <note>Cogl does not know whether marking the @onscreen framebuffer
* is truly meaningful for your current window system (consider
* applications being run fullscreen on a phone or TV) so this
* function may not have any useful effect. If you are running on a
* multi windowing system such as X11 or Win32 or OSX then Cogl will
* request to the window system that users be allowed to resize the
* @onscreen, although it's still possible that some other window
* management policy will block this possibility.</note>
*
* <note>Whenever an @onscreen framebuffer is resized the viewport
* will be automatically updated to match the new size of the
* framebuffer with an origin of (0,0). If your application needs more
* specialized control of the viewport it will need to register a
* resize handler using cogl_onscreen_add_resize_handler() so that it
* can track when the viewport has been changed automatically.</note>
*
* Since: 2.0
*/
void
cogl_onscreen_set_resizable (CoglOnscreen *onscreen,
CoglBool resizable);
/**
* cogl_onscreen_get_resizable:
* @onscreen: A #CoglOnscreen framebuffer
*
* Lets you query whether @onscreen has been marked as resizable via
* the cogl_onscreen_set_resizable() api.
*
* By default, if possible, a @onscreen will be created by Cogl
* as non resizable, but it is not guaranteed that this is always
* possible for all window systems.
*
* <note>If cogl_onscreen_set_resizable(@onscreen, %TRUE) has been
* previously called then this function will return %TRUE, but it's
* possible that the current windowing system being used does not
* support window resizing (consider fullscreen windows on a phone or
* a TV). This function is not aware of whether resizing is truly
* meaningful with your window system, only whether the @onscreen has
* been marked as resizable.</note>
*
* Return value: Returns whether @onscreen has been marked as
* resizable or not.
* Since: 2.0
*/
CoglBool
cogl_onscreen_get_resizable (CoglOnscreen *onscreen);
/**
* CoglOnscreenResizeCallback:
* @onscreen: A #CoglOnscreen framebuffer that was resized
* @width: The new width of @onscreen
* @height: The new height of @onscreen
* @user_data: The private passed to
* cogl_onscreen_add_resize_handler()
*
* Is a callback type used with the
* cogl_onscreen_add_resize_handler() allowing applications to be
* notified whenever an @onscreen framebuffer is resized.
*
* <note>Cogl automatically updates the viewport of an @onscreen
* framebuffer that is resized so this callback is also an indication
* that the viewport has been modified too</note>
*
* <note>A resize callback will only ever be called while dispatching
* Cogl events from the system mainloop; so for example during
* cogl_poll_dispatch(). This is so that callbacks shouldn't occur
* while an application might have arbitrary locks held for
* example.</note>
*
* Since: 2.0
*/
typedef void (*CoglOnscreenResizeCallback) (CoglOnscreen *onscreen,
int width,
int height,
void *user_data);
/**
* cogl_onscreen_add_resize_handler:
* @onscreen: A #CoglOnscreen framebuffer
* @callback: A #CoglOnscreenResizeCallback to call when the @onscreen
* changes size.
* @user_data: Private data to be passed to @callback.
*
* Registers a @callback with @onscreen that will be called whenever
* the @onscreen framebuffer changes size.
*
* The @callback can be removed using
* cogl_onscreen_remove_resize_handler() passing the same @callback
* and @user_data pair.
*
* <note>Since Cogl automatically updates the viewport of an @onscreen
* framebuffer that is resized, a resize callback can also be used to
* track when the viewport has been changed automatically by Cogl in
* case your application needs more specialized control over the
* viewport.</note>
*
* <note>A resize callback will only ever be called while dispatching
* Cogl events from the system mainloop; so for example during
* cogl_poll_dispatch(). This is so that callbacks shouldn't occur
* while an application might have arbitrary locks held for
* example.</note>
*
* Return value: a unique identifier that can be used to remove to remove
* the callback later.
*
* Since: 2.0
*/
unsigned int
cogl_onscreen_add_resize_handler (CoglOnscreen *onscreen,
CoglOnscreenResizeCallback callback,
void *user_data);
/**
* cogl_onscreen_remove_resize_handler:
* @onscreen: A #CoglOnscreen framebuffer
* @id: An identifier returned from cogl_onscreen_add_resize_handler()
*
* Removes a resize @callback and @user_data pair that were previously
* associated with @onscreen via cogl_onscreen_add_resize_handler().
*
* Since: 2.0
*/
void
cogl_onscreen_remove_resize_handler (CoglOnscreen *onscreen,
unsigned int id);
/**
* cogl_is_onscreen:
* @object: A #CoglObject pointer
*
* Gets whether the given object references a #CoglOnscreen.
*
* Return value: %TRUE if the object references a #CoglOnscreen
* and %FALSE otherwise.
* Since: 1.10
* Stability: unstable
*/
CoglBool
cogl_is_onscreen (void *object);
G_END_DECLS
#endif /* __COGL_ONSCREEN_H */