From 94806801e34ee05fe801bdaad43dfa4b74cef1fd Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Tue, 23 Mar 2021 15:04:20 +0100
Subject: [PATCH] Add p3headlessgl render plug-in on Linux using EGL as
 fallback for GLX

Fixes #1086
---
 direct/src/dist/commands.py                   |  2 +-
 makepanda/makepanda.py                        | 35 ++++++++++++++++---
 makepanda/makewheel.py                        |  3 +-
 panda/metalibs/pandagl/pandagl.cxx            | 13 +++++--
 panda/metalibs/pandagl/pandagl.h              |  4 +++
 panda/src/egldisplay/config_egldisplay.cxx    |  2 +-
 panda/src/egldisplay/eglGraphicsPipe.cxx      |  6 ++--
 panda/src/egldisplay/eglGraphicsPipe.h        |  4 ++-
 panda/src/egldisplay/eglGraphicsPixmap.cxx    |  4 +--
 panda/src/egldisplay/eglGraphicsPixmap.h      |  4 +--
 .../egldisplay/eglGraphicsStateGuardian.cxx   | 10 +++---
 .../src/egldisplay/eglGraphicsStateGuardian.h |  4 +--
 panda/src/egldisplay/eglGraphicsWindow.cxx    |  4 +--
 panda/src/egldisplay/eglGraphicsWindow.h      |  4 +--
 14 files changed, 69 insertions(+), 30 deletions(-)

diff --git a/direct/src/dist/commands.py b/direct/src/dist/commands.py
index b51c2dd642..ca2b1aa519 100644
--- a/direct/src/dist/commands.py
+++ b/direct/src/dist/commands.py
@@ -277,7 +277,7 @@ class build_apps(setuptools.Command):
             'libpthread.so.*', 'libc.so.*', 'ld-linux-x86-64.so.*',
             'libgl.so.*', 'libx11.so.*', 'libncursesw.so.*', 'libz.so.*',
             'librt.so.*', 'libutil.so.*', 'libnsl.so.1', 'libXext.so.6',
-            'libXrender.so.1', 'libICE.so.6', 'libSM.so.6',
+            'libXrender.so.1', 'libICE.so.6', 'libSM.so.6', 'libEGL.so.1',
             'libgobject-2.0.so.0', 'libgthread-2.0.so.0', 'libglib-2.0.so.0',
 
             # macOS
diff --git a/makepanda/makepanda.py b/makepanda/makepanda.py
index c457a7fe12..71f8c00e3e 100755
--- a/makepanda/makepanda.py
+++ b/makepanda/makepanda.py
@@ -1255,6 +1255,14 @@ if not PkgSkip("EIGEN"):
             # will turn them into runtime assertions.
             DefSymbol("ALWAYS", "EIGEN_NO_STATIC_ASSERT")
 
+if not PkgSkip("EGL"):
+    DefSymbol('EGL', 'HAVE_EGL', '')
+    if PkgSkip("X11"):
+        DefSymbol('EGL', 'EGL_NO_X11', '')
+
+if not PkgSkip("X11"):
+    DefSymbol('X11', 'USE_X11', '')
+
 ########################################################################
 ##
 ## Give a Status Report on Command-Line Options
@@ -3243,6 +3251,8 @@ configprc = configprc.replace('\r\n', '\n')
 
 if (GetTarget() == 'windows'):
     configprc = configprc.replace("$XDG_CACHE_HOME/panda3d", "$USER_APPDATA/Panda3D-%s" % MAJOR_VERSION)
+elif not PkgSkip("X11") and not PkgSkip("GL") and not PkgSkip("EGL") and not GetLinkAllStatic():
+    configprc = configprc.replace("#load-display pandadx9", "aux-display p3headlessgl")
 else:
     configprc = configprc.replace("aux-display pandadx9", "")
 
@@ -3591,9 +3601,10 @@ elif GetTarget() == 'darwin':
 elif GetTarget() == 'android':
     CopyAllHeaders('panda/src/android')
     CopyAllHeaders('panda/src/androiddisplay')
-else:
+if not PkgSkip('X11'):
     CopyAllHeaders('panda/src/x11display')
-    CopyAllHeaders('panda/src/glxdisplay')
+    if not PkgSkip('GL'):
+        CopyAllHeaders('panda/src/glxdisplay')
 CopyAllHeaders('panda/src/egldisplay')
 CopyAllHeaders('panda/metalibs/pandagl')
 CopyAllHeaders('panda/metalibs/pandagles')
@@ -5156,7 +5167,6 @@ if (GetTarget() == 'windows' and PkgSkip("GL")==0 and not RUNTIME):
 # If we're not compiling with any windowing system at all, but we do have EGL,
 # we can use that to create a headless libpandagl instead.
 if not PkgSkip("EGL") and not PkgSkip("GL") and PkgSkip("X11") and GetTarget() not in ('windows', 'darwin') and not RUNTIME:
-  DefSymbol('EGL', 'HAVE_EGL', '')
   OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGL', 'GL', 'EGL']
   TargetAdd('pandagl_egldisplay_composite1.obj', opts=OPTS, input='p3egldisplay_composite1.cxx')
   OPTS=['DIR:panda/metalibs/pandagl', 'BUILDING:PANDAGL', 'GL', 'EGL']
@@ -5168,13 +5178,28 @@ if not PkgSkip("EGL") and not PkgSkip("GL") and PkgSkip("X11") and GetTarget() n
   TargetAdd('libpandagl.dll', input=COMMON_PANDA_LIBS)
   TargetAdd('libpandagl.dll', opts=['MODULE', 'GL', 'EGL', 'CGGL'])
 
+elif not PkgSkip("EGL") and not PkgSkip("GL") and GetTarget() not in ('windows', 'darwin') and not RUNTIME:
+  # As a temporary solution for #1086, build this module, which we can use as a
+  # fallback to OpenGL for headless systems.
+  DefSymbol('EGL', 'HAVE_EGL', '')
+  OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGL', 'GL', 'EGL']
+  TargetAdd('p3headlessgl_egldisplay_composite1.obj', opts=OPTS, input='p3egldisplay_composite1.cxx')
+  OPTS=['DIR:panda/metalibs/pandagl', 'BUILDING:PANDAGL', 'GL', 'EGL']
+  TargetAdd('p3headlessgl_pandagl.obj', opts=OPTS, input='pandagl.cxx')
+  TargetAdd('libp3headlessgl.dll', input='p3headlessgl_pandagl.obj')
+  TargetAdd('libp3headlessgl.dll', input='p3glgsg_config_glgsg.obj')
+  TargetAdd('libp3headlessgl.dll', input='p3glgsg_glgsg.obj')
+  TargetAdd('libp3headlessgl.dll', input='p3headlessgl_egldisplay_composite1.obj')
+  TargetAdd('libp3headlessgl.dll', input=COMMON_PANDA_LIBS)
+  TargetAdd('libp3headlessgl.dll', opts=['MODULE', 'GL', 'EGL', 'CGGL'])
+
 #
 # DIRECTORY: panda/src/egldisplay/
 #
 
 if (PkgSkip("EGL")==0 and PkgSkip("GLES")==0 and not RUNTIME):
   DefSymbol('GLES', 'OPENGLES_1', '')
-  OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGLES',  'GLES', 'EGL']
+  OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGLES', 'GLES', 'EGL', 'X11']
   TargetAdd('pandagles_egldisplay_composite1.obj', opts=OPTS, input='p3egldisplay_composite1.cxx')
   OPTS=['DIR:panda/metalibs/pandagles', 'BUILDING:PANDAGLES', 'GLES', 'EGL']
   TargetAdd('pandagles_pandagles.obj', opts=OPTS, input='pandagles.cxx')
@@ -5193,7 +5218,7 @@ if (PkgSkip("EGL")==0 and PkgSkip("GLES")==0 and not RUNTIME):
 
 if (PkgSkip("EGL")==0 and PkgSkip("GLES2")==0 and not RUNTIME):
   DefSymbol('GLES2', 'OPENGLES_2', '')
-  OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGLES2',  'GLES2', 'EGL']
+  OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGLES2', 'GLES2', 'EGL', 'X11']
   TargetAdd('pandagles2_egldisplay_composite1.obj', opts=OPTS, input='p3egldisplay_composite1.cxx')
   OPTS=['DIR:panda/metalibs/pandagles2', 'BUILDING:PANDAGLES2', 'GLES2', 'EGL']
   TargetAdd('pandagles2_pandagles2.obj', opts=OPTS, input='pandagles2.cxx')
diff --git a/makepanda/makewheel.py b/makepanda/makewheel.py
index aaf7efa24e..57d0fe2242 100644
--- a/makepanda/makewheel.py
+++ b/makepanda/makewheel.py
@@ -90,7 +90,7 @@ ABI_TAG = get_abi_tag()
 EXCLUDE_EXT = [".pyc", ".pyo", ".N", ".prebuilt", ".xcf", ".plist", ".vcproj", ".sln"]
 
 # Plug-ins to install.
-PLUGIN_LIBS = ["pandagl", "pandagles", "pandagles2", "pandadx9", "p3tinydisplay", "p3ptloader", "p3assimp", "p3ffmpeg", "p3openal_audio", "p3fmod_audio"]
+PLUGIN_LIBS = ["pandagl", "pandagles", "pandagles2", "pandadx9", "p3tinydisplay", "p3ptloader", "p3assimp", "p3ffmpeg", "p3openal_audio", "p3fmod_audio", "p3headlessgl"]
 
 # Libraries included in manylinux ABI that should be ignored.  See PEP 513/571/599.
 MANYLINUX_LIBS = [
@@ -103,6 +103,7 @@ MANYLINUX_LIBS = [
     # These are not mentioned in manylinux1 spec but should nonetheless always
     # be excluded.
     "linux-vdso.so.1", "linux-gate.so.1", "ld-linux.so.2", "libdrm.so.2",
+    "libEGL.so.1",
 ]
 
 # Binaries to never scan for dependencies on non-Windows systems.
diff --git a/panda/metalibs/pandagl/pandagl.cxx b/panda/metalibs/pandagl/pandagl.cxx
index e6f01d9ce2..1a317fbdca 100644
--- a/panda/metalibs/pandagl/pandagl.cxx
+++ b/panda/metalibs/pandagl/pandagl.cxx
@@ -26,7 +26,7 @@
 #include "glxGraphicsPipe.h"
 #endif
 
-#if defined(HAVE_EGL) && !defined(HAVE_X11)
+#ifdef HAVE_EGL
 #include "config_egldisplay.h"
 #include "eglGraphicsPipe.h"
 #endif
@@ -59,7 +59,7 @@ init_libpandagl() {
   init_libglxdisplay();
 #endif
 
-#if defined(HAVE_EGL) && !defined(HAVE_X11)
+#ifdef HAVE_EGL
   init_libegldisplay();
 #endif
 }
@@ -84,9 +84,16 @@ get_pipe_type_pandagl() {
   return glxGraphicsPipe::get_class_type().get_index();
 #endif
 
-#if defined(HAVE_EGL) && !defined(HAVE_X11)
+#ifdef HAVE_EGL
   return eglGraphicsPipe::get_class_type().get_index();
 #endif
 
   return 0;
 }
+
+#if defined(HAVE_EGL) && !defined(USE_X11)
+int
+get_pipe_type_p3headlessgl() {
+  return eglGraphicsPipe::get_class_type().get_index();
+}
+#endif
diff --git a/panda/metalibs/pandagl/pandagl.h b/panda/metalibs/pandagl/pandagl.h
index 2a25a86587..3fb84b2152 100644
--- a/panda/metalibs/pandagl/pandagl.h
+++ b/panda/metalibs/pandagl/pandagl.h
@@ -12,4 +12,8 @@
 EXPCL_PANDAGL void init_libpandagl();
 extern "C" EXPCL_PANDAGL int get_pipe_type_pandagl();
 
+#if defined(HAVE_EGL) && !defined(USE_X11)
+extern "C" EXPCL_PANDAGL int get_pipe_type_p3headlessgl();
+#endif
+
 #endif
diff --git a/panda/src/egldisplay/config_egldisplay.cxx b/panda/src/egldisplay/config_egldisplay.cxx
index e80137290d..0903a3bd88 100644
--- a/panda/src/egldisplay/config_egldisplay.cxx
+++ b/panda/src/egldisplay/config_egldisplay.cxx
@@ -48,7 +48,7 @@ init_libegldisplay() {
 
   eglGraphicsBuffer::init_type();
   eglGraphicsPipe::init_type();
-#ifdef HAVE_X11
+#ifdef USE_X11
   eglGraphicsPixmap::init_type();
   eglGraphicsWindow::init_type();
 #endif
diff --git a/panda/src/egldisplay/eglGraphicsPipe.cxx b/panda/src/egldisplay/eglGraphicsPipe.cxx
index 6ce38433cb..a75aec5170 100644
--- a/panda/src/egldisplay/eglGraphicsPipe.cxx
+++ b/panda/src/egldisplay/eglGraphicsPipe.cxx
@@ -53,7 +53,7 @@ eglGraphicsPipe() {
 
   //NB. if the X11 display failed to open, _display will be 0, which is a valid
   // input to eglGetDisplay - it means to open the default display.
-#ifdef HAVE_X11
+#ifdef USE_X11
   _egl_display = eglGetDisplay((NativeDisplayType) _display);
 #else
   _egl_display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
@@ -207,7 +207,7 @@ make_output(const std::string &name,
   // First thing to try: an eglGraphicsWindow
 
   if (retry == 0) {
-#ifdef HAVE_X11
+#ifdef USE_X11
     if (!_display) {
       return nullptr;
     }
@@ -290,7 +290,7 @@ make_output(const std::string &name,
 
   // Fourth thing to try: an eglGraphicsPixmap.
   if (retry == 3) {
-#ifdef HAVE_X11
+#ifdef USE_X11
     if (!_display) {
       return nullptr;
     }
diff --git a/panda/src/egldisplay/eglGraphicsPipe.h b/panda/src/egldisplay/eglGraphicsPipe.h
index def344a61c..ec99f4a446 100644
--- a/panda/src/egldisplay/eglGraphicsPipe.h
+++ b/panda/src/egldisplay/eglGraphicsPipe.h
@@ -16,12 +16,14 @@
 
 #include "pandabase.h"
 
-#ifdef HAVE_X11
+#ifdef USE_X11
 #include "x11GraphicsPipe.h"
 typedef x11GraphicsPipe BaseGraphicsPipe;
 #else
 #include "graphicsPipe.h"
 typedef GraphicsPipe BaseGraphicsPipe;
+#undef EGL_NO_X11
+#define EGL_NO_X11 1
 #endif
 
 #ifdef OPENGLES_2
diff --git a/panda/src/egldisplay/eglGraphicsPixmap.cxx b/panda/src/egldisplay/eglGraphicsPixmap.cxx
index 946499746c..64630e43de 100644
--- a/panda/src/egldisplay/eglGraphicsPixmap.cxx
+++ b/panda/src/egldisplay/eglGraphicsPixmap.cxx
@@ -13,7 +13,7 @@
 
 #include "eglGraphicsPixmap.h"
 
-#ifdef HAVE_X11
+#ifdef USE_X11
 
 #include "eglGraphicsWindow.h"
 #include "eglGraphicsStateGuardian.h"
@@ -245,4 +245,4 @@ open_buffer() {
   return true;
 }
 
-#endif  // HAVE_X11
+#endif  // USE_X11
diff --git a/panda/src/egldisplay/eglGraphicsPixmap.h b/panda/src/egldisplay/eglGraphicsPixmap.h
index 95cb7842c0..cddb3430d3 100644
--- a/panda/src/egldisplay/eglGraphicsPixmap.h
+++ b/panda/src/egldisplay/eglGraphicsPixmap.h
@@ -16,7 +16,7 @@
 
 #include "pandabase.h"
 
-#ifdef HAVE_X11
+#ifdef USE_X11
 
 #include "eglGraphicsPipe.h"
 #include "graphicsBuffer.h"
@@ -69,6 +69,6 @@ private:
   static TypeHandle _type_handle;
 };
 
-#endif  // HAVE_X11
+#endif  // USE_X11
 
 #endif
diff --git a/panda/src/egldisplay/eglGraphicsStateGuardian.cxx b/panda/src/egldisplay/eglGraphicsStateGuardian.cxx
index 26f55f3b74..70924505ad 100644
--- a/panda/src/egldisplay/eglGraphicsStateGuardian.cxx
+++ b/panda/src/egldisplay/eglGraphicsStateGuardian.cxx
@@ -187,7 +187,7 @@ choose_pixel_format(const FrameBufferProperties &properties,
       best_props = fbprops;
     }
   }
-#ifdef HAVE_X11
+#ifdef USE_X11
   X11_Display *display = egl_pipe->get_display();
   if (display) {
     int screen = egl_pipe->get_screen();
@@ -233,7 +233,7 @@ choose_pixel_format(const FrameBufferProperties &properties,
 
     int err = eglGetError();
     if (_context && err == EGL_SUCCESS) {
-#ifdef HAVE_X11
+#ifdef USE_X11
       if (!display || _visual)
 #endif
       {
@@ -262,7 +262,7 @@ choose_pixel_format(const FrameBufferProperties &properties,
       << get_egl_error_string(err) << "\n";
     _fbconfig = 0;
     _context = 0;
-#ifdef HAVE_X11
+#ifdef USE_X11
     _visual = 0;
 #endif
   }
@@ -306,7 +306,7 @@ egl_is_at_least_version(int major_version, int minor_version) const {
  */
 void eglGraphicsStateGuardian::
 gl_flush() const {
-#ifdef HAVE_X11
+#ifdef USE_X11
   // This call requires synchronization with X.
   LightReMutexHolder holder(eglGraphicsPipe::_x_mutex);
 #endif
@@ -318,7 +318,7 @@ gl_flush() const {
  */
 GLenum eglGraphicsStateGuardian::
 gl_get_error() const {
-#ifdef HAVE_X11
+#ifdef USE_X11
   // This call requires synchronization with X.
   LightReMutexHolder holder(eglGraphicsPipe::_x_mutex);
 #endif
diff --git a/panda/src/egldisplay/eglGraphicsStateGuardian.h b/panda/src/egldisplay/eglGraphicsStateGuardian.h
index 608e9aa080..1a7a036609 100644
--- a/panda/src/egldisplay/eglGraphicsStateGuardian.h
+++ b/panda/src/egldisplay/eglGraphicsStateGuardian.h
@@ -17,7 +17,7 @@
 #include "pandabase.h"
 #include "eglGraphicsPipe.h"
 
-#ifdef HAVE_X11
+#ifdef USE_X11
 #include "get_x11.h"
 #endif
 
@@ -55,7 +55,7 @@ public:
   EGLContext _share_context;
   EGLContext _context;
   EGLDisplay _egl_display;
-#ifdef HAVE_X11
+#ifdef USE_X11
   XVisualInfo *_visual = nullptr;
 #endif
   EGLConfig _fbconfig;
diff --git a/panda/src/egldisplay/eglGraphicsWindow.cxx b/panda/src/egldisplay/eglGraphicsWindow.cxx
index c85ff9d8df..31002c9fa6 100644
--- a/panda/src/egldisplay/eglGraphicsWindow.cxx
+++ b/panda/src/egldisplay/eglGraphicsWindow.cxx
@@ -13,7 +13,7 @@
 
 #include "eglGraphicsWindow.h"
 
-#ifdef HAVE_X11
+#ifdef USE_X11
 
 #include "eglGraphicsStateGuardian.h"
 #include "config_egldisplay.h"
@@ -279,4 +279,4 @@ open_window() {
   return true;
 }
 
-#endif  // HAVE_X11
+#endif  // USE_X11
diff --git a/panda/src/egldisplay/eglGraphicsWindow.h b/panda/src/egldisplay/eglGraphicsWindow.h
index 1c359aa666..1a5efad7fd 100644
--- a/panda/src/egldisplay/eglGraphicsWindow.h
+++ b/panda/src/egldisplay/eglGraphicsWindow.h
@@ -16,7 +16,7 @@
 
 #include "pandabase.h"
 
-#ifdef HAVE_X11
+#ifdef USE_X11
 
 #include "eglGraphicsPipe.h"
 #include "x11GraphicsWindow.h"
@@ -67,6 +67,6 @@ private:
 
 #include "eglGraphicsWindow.I"
 
-#endif  // HAVE_X11
+#endif  // USE_X11
 
 #endif