cairo/src/cairo-gl.h
Bryce Harrington 8ff3019f51 gl: Add support for OpenGL ES 3.0
This improves the OpenGL ES support to extend it to version 3.0.
A number of new features are available in glesv3 including creation of
multi-sampled renderbuffers.  These renderbuffers can be blitted to
single sample textures (but not the other way around).  Other features
such as PBO for image uploading, are left as followon work.

For this preliminary implementation, glesv3 backends always create
renderbuffers, which can be set as single sample or multisample.  The
renderbuffer's content is blitted to the texture only when used as a
source or a mask.

Images uploaded to a texture stay there until the surface is used as a
rendering target, at which point its painted to the renderbuffer.

This patch is heavily based off of Henry Song's initial GLESv3 patch
6f7f3795 from his cairogles fork of Cairo, and incorporates subsequent
fixes and pertinent refactorings from his trunk and review feedback from
Uli.

This implements the *functional* support for glesv3, excluding the
various optimization work to utilize its features.  Rendering and
performance should not be expected to improve notably from pure glesv2.
As the GL backend for Cairo remains "experimental", these changes should
likewise be considered as such.

Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
2017-09-13 15:18:04 -07:00

155 lines
5 KiB
C

/* Cairo - a vector graphics library with display and print output
*
* Copyright © 2009 Eric Anholt
* Copyright © 2009 Chris Wilson
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is Eric Anholt.
*/
/*
* cairo-gl.h:
*
* The cairo-gl backend provides an implementation of possibly
* hardware-accelerated cairo rendering by targeting the OpenGL API.
* The goal of the cairo-gl backend is to provide better performance
* with equal functionality to cairo-image where possible. It does
* not directly provide for applying additional OpenGL effects to
* cairo surfaces.
*
* Cairo-gl allows interoperability with other GL rendering through GL
* context sharing. Cairo-gl surfaces are created in reference to a
* #cairo_device_t, which represents a GL context created by the user.
* When that GL context is created with its sharePtr set to another
* context (or vice versa), its objects (textures backing cairo-gl
* surfaces) can be accessed in the other OpenGL context. This allows
* cairo-gl to maintain its drawing state in one context while the
* user's 3D rendering occurs in the user's other context.
*
* However, as only one context can be current to a thread at a time,
* cairo-gl may make its context current to the thread on any cairo
* call which interacts with a cairo-gl surface or the cairo-gl
* device. As a result, the user must make their own context current
* between any cairo calls and their own OpenGL rendering.
**/
#ifndef CAIRO_GL_H
#define CAIRO_GL_H
#include "cairo.h"
#if CAIRO_HAS_GL_SURFACE || CAIRO_HAS_GLESV2_SURFACE || CAIRO_HAS_GLESV3_SURFACE
CAIRO_BEGIN_DECLS
cairo_public cairo_surface_t *
cairo_gl_surface_create (cairo_device_t *device,
cairo_content_t content,
int width, int height);
cairo_public cairo_surface_t *
cairo_gl_surface_create_for_texture (cairo_device_t *abstract_device,
cairo_content_t content,
unsigned int tex,
int width, int height);
cairo_public void
cairo_gl_surface_set_size (cairo_surface_t *surface, int width, int height);
cairo_public int
cairo_gl_surface_get_width (cairo_surface_t *abstract_surface);
cairo_public int
cairo_gl_surface_get_height (cairo_surface_t *abstract_surface);
cairo_public void
cairo_gl_surface_swapbuffers (cairo_surface_t *surface);
cairo_public void
cairo_gl_device_set_thread_aware (cairo_device_t *device,
cairo_bool_t thread_aware);
#if CAIRO_HAS_GLX_FUNCTIONS
#include <GL/glx.h>
cairo_public cairo_device_t *
cairo_glx_device_create (Display *dpy, GLXContext gl_ctx);
cairo_public Display *
cairo_glx_device_get_display (cairo_device_t *device);
cairo_public GLXContext
cairo_glx_device_get_context (cairo_device_t *device);
cairo_public cairo_surface_t *
cairo_gl_surface_create_for_window (cairo_device_t *device,
Window win,
int width, int height);
#endif
#if CAIRO_HAS_WGL_FUNCTIONS
#include <windows.h>
cairo_public cairo_device_t *
cairo_wgl_device_create (HGLRC rc);
cairo_public HGLRC
cairo_wgl_device_get_context (cairo_device_t *device);
cairo_public cairo_surface_t *
cairo_gl_surface_create_for_dc (cairo_device_t *device,
HDC dc,
int width,
int height);
#endif
#if CAIRO_HAS_EGL_FUNCTIONS
#include <EGL/egl.h>
cairo_public cairo_device_t *
cairo_egl_device_create (EGLDisplay dpy, EGLContext egl);
cairo_public cairo_surface_t *
cairo_gl_surface_create_for_egl (cairo_device_t *device,
EGLSurface egl,
int width,
int height);
cairo_public EGLDisplay
cairo_egl_device_get_display (cairo_device_t *device);
cairo_public EGLSurface
cairo_egl_device_get_context (cairo_device_t *device);
#endif
CAIRO_END_DECLS
#else /* CAIRO_HAS_GL_SURFACE */
# error Cairo was not compiled with support for the GL backend
#endif /* CAIRO_HAS_GL_SURFACE */
#endif /* CAIRO_GL_H */