Introduce EGL backend support for the OpenGL canvas

wxWidgets 3.1.5+ on Linux will compile with the Wayland EGL
canvas as the backend instead of the X11 backend. This requires a
version of GLEW compiled with the proper EGL defines and a different
header/code for certain parts that are X11 GLEW specific.

This introduces an in-tree version of GLEW that will be built with the
GLEW_EGL flag then statically linked into the KiCad executables when
EGL support is needed.

3d-viewer/3d_canvas/eda_3d_canvas.cpp

@@ -27,7 +27,7 @@
  * @brief Implementation of a 3d canvas
  */
 
-#include <GL/glew.h>    // Must be included first
+#include <gal/opengl/kiglew.h>    // Must be included first
 #include <gl_utils.h>
 #include <wx/tokenzr.h>
 

3d-viewer/3d_rendering/3d_render_ogl_legacy/c3d_render_ogl_legacy.cpp

@@ -27,11 +27,7 @@
  * @brief
  */
 
-// Apple, in their infinite wisdom, has decided to mark OpenGL as deprecated.
+#include <gal/opengl/kiglew.h>    // Must be included first
-// Luckily we can silence warnings about its deprecation. This is needed on the GLEW
-// includes since they seem to transitively include the OpenGL headers.
-#define GL_SILENCE_DEPRECATION 1
-#include <GL/glew.h>
 
 #include "c3d_render_ogl_legacy.h"
 #include "ogl_legacy_utils.h"

3d-viewer/3d_rendering/3d_render_ogl_legacy/c_ogl_3dmodel.cpp

@@ -28,7 +28,8 @@
  * @brief
  */
 
-#include <GL/glew.h>
+#include <gal/opengl/kiglew.h>    // Must be included first
+
 #include "c_ogl_3dmodel.h"
 #include "ogl_legacy_utils.h"
 #include "../common_ogl/ogl_utils.h"

3d-viewer/3d_rendering/3d_render_raytracing/c3d_render_raytracing.cpp

@@ -27,7 +27,8 @@
  * @brief
  */
 
-#include <GL/glew.h>
+#include <gal/opengl/kiglew.h>    // Must be included first
+
 #include <algorithm>
 #include <atomic>
 #include <chrono>

3d-viewer/common_ogl/ogl_utils.cpp

@@ -27,7 +27,7 @@
  * @brief implements generic openGL functions that are common to any openGL target
  */
 
-#include <GL/glew.h>
+#include <gal/opengl/kiglew.h>    // Must be included first
 
 #include "openGL_includes.h"
 #include "ogl_utils.h"

CMakeLists.txt

@@ -34,6 +34,7 @@ endif()
 project( kicad )
 
 include( GNUInstallDirs )
+include( CMakeDependentOption )
 
 # Path to local CMake modules.
 set( CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/CMakeModules )
@@ -126,6 +127,15 @@ option( KICAD_WIN32_DPI_AWARE
     "Turn on DPI awareness for Windows builds only"
     OFF )
 
+option( KICAD_USE_EGL
+    "Build KiCad with EGL backend support for Wayland."
+    OFF )
+
+cmake_dependent_option( KICAD_USE_BUNDLED_GLEW
+    "Use the bundled version of GLEW - only available when KICAD_USE_EGL is set"
+    ON "KICAD_USE_EGL"
+    OFF )
+
 # when option KICAD_SCRIPTING OR KICAD_SCRIPTING_MODULES is enabled:
 # PYTHON_EXECUTABLE can be defined when invoking cmake
 # ( use -DPYTHON_EXECUTABLE=<python path>/python.exe or python2 )
@@ -447,6 +457,12 @@ if( KICAD_USE_OCC )
     unset( KICAD_USE_OCE CACHE )
 endif()
 
+if( KICAD_USE_EGL AND UNIX AND NOT APPLE )
+    message( STATUS "Configuring KiCad for the wxGLCanvas EGL backend" )
+    add_definitions( -DKICAD_USE_EGL )
+elseif( KICAD_USE_EGL )
+    message( STATUS "Ignoring KICAD_USE_EGL since not on Linux" )
+endif()
 
 # KIFACE_SUFFIX is the file extension used for top level program modules which
 # implement the KIFACE interface.  A valid suffix starts with a period '.'.
@@ -599,7 +615,25 @@ find_package( OpenGL REQUIRED )
 #
 # Find GLEW library, required
 #
-if( NOT GLEW_FOUND )
+# The EGL canvas on GTK requires the use of a GLEW version compiled with an EGL flag.
+# The one built in the thirdparty directory has the flag for EGL set, so we use it unless told
+# otherwise. Then we search for the system GLEW version and use that instead.
+#
+if( KICAD_USE_EGL AND KICAD_USE_BUNDLED_GLEW AND UNIX AND NOT APPLE )
+    if( OpenGL_EGL_FOUND )
+        message( STATUS "Found OpenGL EGL library: ${OPENGL_egl_LIBRARY}" )
+    else()
+        message( FATAL_ERROR "OpenGL EGL library not found" )
+    endif()
+
+    # Add the custom GLEW target
+    add_subdirectory( thirdparty/glew )
+
+    # Set the standard package variables to point to our custom target to mimic the system version.
+    set( GLEW_LIBRARIES glew )
+    set( GLEW_FOUND TRUE )
+    include_directories( SYSTEM $<TARGET_PROPERTY:glew,PRIVATE_INCLUDE_DIRECTORIES> )
+else()
     find_package( GLEW REQUIRED )
     check_find_package_result( GLEW_FOUND "GLEW" )
     include_directories( SYSTEM ${GLEW_INCLUDE_DIR} )

Documentation/development/compiling.md

@@ -198,6 +198,17 @@ passed via the OCE_DIR flag.  This option is enabled by default.
 Alternatively KICAD_USE_OCC can be used instead of OCE. Both options are not supposed to be enabled
 at the same time.
 
+## Wayland EGL support ## {#egl_opt}
+
+The KICAD_USE_EGL option switches the OpenGL backend from using X11 bindings to Wayland EGL bindings.
+This option is only relevant on Linux when running wxWidgets 3.1.5+ with the EGL backend of
+the wxGLCanvas (which is the default option, but can be disabled in the wxWidgets build).
+
+By default, setting KICAD_USE_EGL will use a in-tree version of the GLEW library (that is compiled with
+the additional flags needed to run on an EGL canvas) staticly linked into KiCad. If the system
+version of GLEW supports EGL (it must be compiled with the GLEW_EGL flag), then it can be used instead
+by setting KICAD_USE_BUNDLED_GLEW to OFF.
+
 ## Development Analysis Tools ## {#dev_tools}
 
 KiCad can be compiled with support for several features to aid in the catching and debugging of

common/build_version.cpp

@@ -239,6 +239,10 @@ wxString GetVersionInfoData( const wxString& aTitle, bool aHtml, bool aBrief )
     aMsg << indent4 << "KICAD_USE_OCC=" << ON;
 #endif
 
+#ifdef KICAD_USE_EGL
+    aMsg << indent4 << "KICAD_USE_EGL=" << ON;
+#endif
+
     aMsg << indent4 << "KICAD_SPICE=";
 #ifdef KICAD_SPICE
     aMsg << ON;

common/gal/opengl/utils.cpp

@@ -24,7 +24,8 @@
 
 #include <confirm.h>    // DisplayError
 
-#include <GL/glew.h>
+#include <gal/opengl/kiglew.h>    // Must be included first
+
 #include <stdexcept>
 #include <wx/log.h>     // wxLogDebug
 

include/gal/opengl/kiglew.h

@@ -0,0 +1,68 @@
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2020 KiCad Developers, see AUTHORS.txt for contributors.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+/**
+ * This file is used for including the proper GLEW header for the platform.
+ */
+
+#ifndef KIGLEW_H_
+#define KIGLEW_H_
+
+// Pull in the configuration options for wxWidgets
+#include <wx/setup.h>
+
+// Apple, in their infinite wisdom, has decided to mark OpenGL as deprecated.
+// Luckily we can silence warnings about its deprecation. This is needed on the GLEW
+// includes since they transitively include the OpenGL headers.
+#define GL_SILENCE_DEPRECATION 1
+
+#ifdef __WXGTK__
+
+    #ifdef KICAD_USE_EGL
+
+        #ifdef wxUSE_GLCANVAS_EGL
+            // wxWidgets was compiled with the EGL canvas, so use the EGL header for GLEW
+            #include <GL/eglew.h>
+        #else
+            #error "KICAD_USE_EGL can only be used when wxWidgets is compiled with the EGL canvas"
+        #endif
+
+    #else   // KICAD_USE_EGL
+
+        #ifdef wxUSE_GLCANVAS_EGL
+            #error "KICAD_USE_EGL must be defined since wxWidgets has been compiled with the EGL canvas"
+        #else
+            // wxWidgets wasn't compiled with the EGL canvas, so use the X11 GLEW
+            #include <GL/glxew.h>
+        #endif
+
+    #endif  // KICAD_USE_EGL
+
+#else   // __WXGTK__
+
+    // Non-GTK platforms only need the normal GLEW include
+    #include <GL/glew.h>
+
+#endif  // __WXGTK__
+
+#endif  // KIGLEW_H_

include/gal/opengl/opengl_compositor.h

@@ -31,10 +31,11 @@
 #ifndef OPENGL_COMPOSITOR_H_
 #define OPENGL_COMPOSITOR_H_
 
+#include <gal/opengl/kiglew.h>    // Must be included first
+
 #include <gal/compositor.h>
 #include <gal/opengl/antialiasing.h>
 #include <gal/gal_display_options.h>
-#include <GL/glew.h>
 #include <deque>
 
 namespace KIGFX

include/gal/opengl/shader.h

@@ -29,7 +29,7 @@
 #ifndef SHADER_H_
 #define SHADER_H_
 
-#include <GL/glew.h>
+#include <gal/opengl/kiglew.h>    // Must be included first
 
 #include <math/vector2d.h>
 

include/gal/opengl/vertex_common.h

@@ -30,8 +30,9 @@
 #ifndef VERTEX_COMMON_H_
 #define VERTEX_COMMON_H_
 
+#include <gal/opengl/kiglew.h>    // Must be included first
+
 #include <math/vector2d.h>
-#include <GL/glew.h>
 
 #include <cstddef>
 

include/gl_utils.h

@@ -24,12 +24,12 @@
 #ifndef GL_UTILS_H
 #define GL_UTILS_H
 
-#ifdef __linux__
+#include <gal/opengl/kiglew.h>    // Must be included first
-#include <GL/glxew.h>
-#endif
 
 #include <limits>
 
+#include <wx/setup.h>
+
 class GL_UTILS
 {
 public:
@@ -40,9 +40,9 @@ public:
      */
     static int SetSwapInterval( int aVal )
     {
-        /// This routine is written for Linux only.  The equivalent functions under Windows would
+        /// This routine is written for Linux using X11 only.  The equivalent functions under Windows would
         /// include <wglext.h> and call wglSwapIntervalEXT
-    #ifdef __linux__
+    #if defined( __linux__ ) && !defined( KICAD_USE_EGL )
         Display *dpy = glXGetCurrentDisplay();
         GLXDrawable drawable = glXGetCurrentDrawable();
 

thirdparty/CMakeLists.txt

@@ -21,6 +21,8 @@
 #  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 #
 
+# Note: The glew folder isn't added here because it is added inside the main CMakeLists.txt
+
 add_subdirectory( clipper )
 add_subdirectory( compoundfilereader )
 add_subdirectory( delaunator )

thirdparty/glew/CMakeLists.txt

@@ -0,0 +1,21 @@
+add_library( glew STATIC )
+
+# Mark the include directory as private so that it doesn't get used by other targets
+# and is only used when building the actual library.
+# The actual include directories will be added to the global include paths as
+# system headers
+target_include_directories( glew PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/include" )
+
+# Definitions for compiling GLEW staticly for EGL (extracted from the main GLEW CMakeLists.txt file)
+add_definitions( -DGLEW_STATIC )
+add_definitions( -DGLEW_EGL )
+add_definitions( -DGLEW_NO_GLU )
+
+target_sources( glew PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/glew.c
+    )
+
+target_link_libraries( glew PUBLIC
+    ${OPENGL_LIBRARIES}
+    ${OPENGL_egl_LIBRARY}
+    )

thirdparty/glew/LICENSE.txt

@@ -0,0 +1,73 @@
+The OpenGL Extension Wrangler Library
+Copyright (C) 2002-2007, Milan Ikits <milan ikits[]ieee org>
+Copyright (C) 2002-2007, Marcelo E. Magallon <mmagallo[]debian org>
+Copyright (C) 2002, Lev Povalahev
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without 
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, 
+  this list of conditions and the following disclaimer.
+* Redistributions in binary form must reproduce the above copyright notice, 
+  this list of conditions and the following disclaimer in the documentation 
+  and/or other materials provided with the distribution.
+* The name of the author may be used to endorse or promote products 
+  derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+THE POSSIBILITY OF SUCH DAMAGE.
+
+
+Mesa 3-D graphics library
+Version:  7.0
+
+Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+Copyright (c) 2007 The Khronos Group Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and/or associated documentation files (the
+"Materials"), to deal in the Materials without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Materials, and to
+permit persons to whom the Materials are furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Materials.
+
+THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.

thirdparty/glew/README.md

@@ -0,0 +1,14 @@
+This directory contains the source code and includes for the GLEW library
+(https://github.com/nigels-com/glew). This library is normally dynamically
+linked to KiCad on all platforms, but wxWidgets 3.1.5+ on Linux requires
+GLEW compiled with EGL support and most distributions do not supply this
+(since compiling GLEW for EGL is mutually exclusive with GLEW for X11).
+
+The source files are generated from the GLEW repo, or can be pulled from
+a recent GLEW release.
+
+As of November 10, 2020 this GLEW version was pulled from its GitHub
+repository and is what should be version upstream version 2.2.0.
+
+This library is licensed under BSD and MIT licenses, with the actual
+license text given in the LICENSE file in this directory.