Replace glew with epoxy

Glew has the problem that it has to be selected at build time if GLX or
EGL is supported by the library, and this in not encoded in the library
name, nor ABI, nor anything.

Then it's easy to get into the situation that a binary is built but
cannot run because glew supports an API different from the one used by
wxWidgets, or the binary fails to link in the end after all objects are
compiled.

epoxy can support both with the same library avoiding this problem.

epoxy is not initialized explicitly, replaced initialization with
version check where one was not done already.

It seems to be available as vcpkg https://vcpkg.link/ports/libepoxy

There are problems related to GL context switching on Windows which does
not seem to be used in kicad
https://github.com/anholt/libepoxy#known-issues-when-running-on-windows
There is also a problem related to multithreaded rendering on Windows
anholt/libepoxy#265 It's harder to tell if
threading is used for rendering but it does not look like kicad is doing
anything complex enough to warrant using multiple rendering threads.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/20630
Fixes https://gitlab.com/kicad/code/kicad/-/issues/12543

Author: hramrach

3d-viewer/3d_canvas/eda_3d_canvas.cpp

@@ -22,7 +22,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  */
 
-#include <gal/opengl/kiglew.h>    // Must be included first
+#include <gal/opengl/kiepoxy.h> // Must be included first
 #include <gal/opengl/gl_utils.h>
 #include <wx/tokenzr.h>
 
@@ -226,21 +226,12 @@ bool  EDA_3D_CANVAS::initializeOpenGL()
 {
     wxLogTrace( m_logTrace, wxT( "EDA_3D_CANVAS::initializeOpenGL" ) );
 
-    const GLenum err = glewInit();
-
-    if( GLEW_OK != err )
+    // Check the OpenGL version (minimum 2.1 is required)
+    if( epoxy_gl_version() < 21 )
     {
-        const wxString msgError = (const char*) glewGetErrorString( err );
-
-        wxLogMessage( msgError );
-
+        wxLogMessage( wxS( "OpenGL 2.1 or higher is required!" ) );
         return false;
     }
-    else
-    {
-        wxLogTrace( m_logTrace, wxT( "EDA_3D_CANVAS::initializeOpenGL Using GLEW version %s" ),
-                    From_UTF8( (char*) glewGetString( GLEW_VERSION ) ) );
-    }
 
     SetOpenGLInfo( (const char*) glGetString( GL_VENDOR ), (const char*) glGetString( GL_RENDERER ),
                    (const char*) glGetString( GL_VERSION ) );

3d-viewer/3d_model_viewer/eda_3d_model_viewer.cpp

@@ -27,7 +27,7 @@
  * 3d models that come in the original data from the files without any transformations.
  */
 
-#include <gal/opengl/kiglew.h>    // Must be included first
+#include <gal/opengl/kiepoxy.h> // Must be included first
 #include <iostream>
 #include "3d_rendering/opengl/3d_model.h"
 #include "eda_3d_model_viewer.h"
@@ -183,23 +183,17 @@ void EDA_3D_MODEL_VIEWER::Clear3DModel()
 
 void EDA_3D_MODEL_VIEWER::ogl_initialize()
 {
-    const GLenum err = glewInit();
-
-    if( GLEW_OK != err )
-    {
-        const wxString msgError = (const char*) glewGetErrorString( err );
-
-        wxLogMessage( msgError );
-    }
-    else
-    {
-        wxLogTrace( m_logTrace, wxT( "EDA_3D_MODEL_VIEWER::ogl_initialize Using GLEW version %s" ),
-                    From_UTF8( (char*) glewGetString( GLEW_VERSION ) ) );
-    }
+    // Check the OpenGL version (minimum 2.1 is required)
+    if( epoxy_gl_version() < 21 )
+        wxLogMessage( wxS( "OpenGL 2.1 or higher is required!" ) );
 
     SetOpenGLInfo( (const char*) glGetString( GL_VENDOR ), (const char*) glGetString( GL_RENDERER ),
                    (const char*) glGetString( GL_VERSION ) );
 
+    wxString version = From_UTF8( (char*) glGetString( GL_VERSION ) );
+
+    wxLogTrace( m_logTrace, wxS( "EDA_3D_MODEL_VIEWER::%s OpenGL version string %s." ), __WXFUNCTION__, version );
+
     glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST );
     glHint( GL_LINE_SMOOTH_HINT, GL_NICEST );
     glHint( GL_POLYGON_SMOOTH_HINT, GL_NICEST );

3d-viewer/3d_rendering/opengl/3d_model.cpp

@@ -28,7 +28,7 @@
  */
 #include <algorithm>
 #include <stdexcept>
-#include <gal/opengl/kiglew.h>    // Must be included first
+#include <gal/opengl/kiepoxy.h> // Must be included first
 
 #include "3d_model.h"
 #include "../common_ogl/ogl_utils.h"

3d-viewer/3d_rendering/opengl/render_3d_opengl.cpp

@@ -24,7 +24,7 @@
  */
 
 #include <cstdint>
-#include <gal/opengl/kiglew.h>    // Must be included first
+#include <gal/opengl/kiepoxy.h> // Must be included first
 
 #include "plugins/3dapi/xv3d_types.h"
 #include "render_3d_opengl.h"

3d-viewer/3d_rendering/raytracing/render_3d_raytrace_gl.cpp

@@ -23,7 +23,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  */
 
-#include <gal/opengl/kiglew.h>    // Must be included first
+#include <gal/opengl/kiepoxy.h> // Must be included first
 
 #include <algorithm>
 #include <atomic>
@@ -217,7 +217,7 @@ bool RENDER_3D_RAYTRACE_GL::Redraw( bool aIsMoving, REPORTER* aStatusReporter,
 
 void RENDER_3D_RAYTRACE_GL::initPbo()
 {
-    if( GLEW_ARB_pixel_buffer_object )
+    if( epoxy_has_gl_extension( "GL_ARB_pixel_buffer_object" ) )
     {
         m_openglSupportsVertexBufferObjects = true;
 
@@ -238,7 +238,6 @@ void RENDER_3D_RAYTRACE_GL::initPbo()
         glBufferDataARB( GL_PIXEL_UNPACK_BUFFER_ARB, m_pboDataSize, 0, GL_STREAM_DRAW_ARB );
         glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, 0 );
 
-        wxLogTrace( m_logTrace,
-                    wxT( "RENDER_3D_RAYTRACE_GL:: GLEW_ARB_pixel_buffer_object is supported" ) );
+        wxLogTrace( m_logTrace, wxS( "RENDER_3D_RAYTRACE_GL:: GL_ARB_pixel_buffer_object is supported" ) );
     }
 }

3d-viewer/common_ogl/ogl_utils.cpp

@@ -28,7 +28,7 @@
  */
 
 #include <stdexcept>
-#include <gal/opengl/kiglew.h>    // Must be included first
+#include <gal/opengl/kiepoxy.h> // Must be included first
 
 #include "openGL_includes.h"
 #include "ogl_utils.h"

CMakeLists.txt

@@ -115,17 +115,6 @@ option( KICAD_UPDATE_CHECK
     "Build in update check"
     ON )
 
-# EGL is only needed on Linux with Wayland
-cmake_dependent_option( KICAD_USE_EGL
-    "Build KiCad with EGL backend support for Wayland."
-    OFF "UNIX_NOT_APPLE"
-    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 )
-
 cmake_dependent_option( KICAD_WAYLAND
     "Support Wayland features"
     ON "KICAD_USE_EGL"
@@ -286,16 +275,6 @@ add_compile_definitions( $<$<BOOL:${KICAD_GAL_PROFILE}>:KICAD_GAL_PROFILE> )
 add_compile_definitions( $<$<BOOL:${KICAD_WIN32_VERIFY_CODESIGN}>:KICAD_WIN32_VERIFY_CODESIGN> )
 add_compile_definitions( $<$<BOOL:${KICAD_UPDATE_CHECK}>:KICAD_UPDATE_CHECK> )
 
-if( KICAD_USE_EGL )
-    message( STATUS "Configuring KiCad for the wxGLCanvas EGL backend" )
-    add_compile_definitions( KICAD_USE_EGL )
-endif()
-
-if( KICAD_WAYLAND )
-    message( STATUS "Configuring KiCad to support Wayland features" )
-    add_compile_definitions( KICAD_WAYLAND )
-endif()
-
 if( KICAD_IPC_API )
     add_definitions( -DKICAD_IPC_API )
 endif()
@@ -755,50 +734,6 @@ if( KICAD_BUILD_I18N )
     find_package( Gettext REQUIRED )
 endif()
 
-#
-# Find OpenGL library, required
-#
-if( KICAD_USE_EGL )
-    find_package( OpenGL REQUIRED COMPONENTS OpenGL EGL )
-else()
-    set( OpenGL_GL_PREFERENCE "LEGACY" )     # CMake 3.11+ setting; see 'cmake --help-policy CMP0072'
-    find_package( OpenGL REQUIRED )
-endif()
-
-#
-# Find GLEW library, required
-#
-# 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,INCLUDE_DIRECTORIES> )
-else()
-    find_package( GLEW REQUIRED )
-    check_find_package_result( GLEW_FOUND "GLEW" )
-    include_directories( SYSTEM ${GLEW_INCLUDE_DIR} )
-endif()
-
-#
-# Find GLM library, required
-#
-find_package( GLM 0.9.8 REQUIRED )
-add_compile_definitions( GLM_FORCE_CTOR_INIT )
-include_directories( SYSTEM ${GLM_INCLUDE_DIR} )
-
 #
 # Find zlib library, required
 #
@@ -1077,6 +1012,8 @@ else()
     message( FATAL_ERROR "Unable to detect wxWidgets port")
 endif()
 
+message(STATUS "wxUSE_GLCANVAS_EGL=${wxWidgets_GLCANVAS_EGL}")
+
 if( NOT MSVC )
     if( ${wxWidgets_VERSION_STRING} VERSION_LESS 3.2 )
         message( FATAL_ERROR "wxWidgets 3.2.0 or greater is required" )
@@ -1111,6 +1048,45 @@ if( APPLE )
         )
 endif()
 
+#
+# Find OpenGL library, required
+#
+if( wxWidgets_GLCANVAS_EGL EQUAL 1 )
+    set( KICAD_USE_EGL ON )
+    find_package( OpenGL REQUIRED COMPONENTS OpenGL EGL )
+else()
+    set( KICAD_USE_EGL OFF )
+    set( OpenGL_GL_PREFERENCE "LEGACY" )     # CMake 3.11+ setting; see 'cmake --help-policy CMP0072'
+    find_package( OpenGL REQUIRED )
+endif()
+if( NOT OPENGL_GLU_FOUND )
+    MESSAGE( FATAL_ERROR "The OpenGL GLU library is required." )
+endif()
+
+if( KICAD_USE_EGL )
+    message( STATUS "Configuring KiCad for the wxGLCanvas EGL backend" )
+    add_compile_definitions( KICAD_USE_EGL )
+endif()
+
+if( KICAD_WAYLAND )
+    message( STATUS "Configuring KiCad to support Wayland features" )
+    add_compile_definitions( KICAD_WAYLAND )
+endif()
+
+#
+# Find Epoxy library, required
+#
+find_package( epoxy REQUIRED )
+check_find_package_result( EPOXY_FOUND "epoxy" )
+include_directories( SYSTEM ${epoxy_INCLUDE_DIR} )
+
+#
+# Find GLM library, required
+#
+find_package( GLM 0.9.8 REQUIRED )
+add_compile_definitions( GLM_FORCE_CTOR_INIT )
+include_directories( SYSTEM ${GLM_INCLUDE_DIR} )
+
 
 if( KICAD_USE_SENTRY )
     set( KICAD_SENTRY_DSN "" CACHE STRING "The sentry DSN used with sentry integration" )

LICENSE.README

@@ -35,8 +35,6 @@ Licensed under MIT:
 - sentry-native in thirdparty/sentry-native
 - thread-pool in thirdparty/thread-pool
 - tinyspline_lib in thirdparty/tinyspline_lib
-Licensed under MIT and BSD:
-- glew in thirdparty/glew
 Licensed under BSD:
 - pybind11 in thirdparty/pybind11
 Licensed under BSD2: