egldisplay: Support creating headless GLES contexts

See #557
panda3d · May 19, 2020 · fbc4947 · fbc4947
1 parent c218af2
commit fbc4947
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Showing 12 changed files with 120 additions and 62 deletions.
diff --git a/makepanda/makepanda.py b/makepanda/makepanda.py
@@ -4494,13 +4494,14 @@ def get_config_express():
 # DIRECTORY: panda/src/egldisplay/
 #
 
-if (PkgSkip("EGL")==0 and PkgSkip("GLES")==0 and PkgSkip("X11")==0):
+if (PkgSkip("EGL")==0 and PkgSkip("GLES")==0):
   DefSymbol('GLES', 'OPENGLES_1', '')
   OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGLES',  'GLES', 'EGL']
   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')
-  TargetAdd('libpandagles.dll', input='p3x11display_composite1.obj')
+  if not PkgSkip("X11"):
+    TargetAdd('libpandagles.dll', input='p3x11display_composite1.obj')
   TargetAdd('libpandagles.dll', input='pandagles_pandagles.obj')
   TargetAdd('libpandagles.dll', input='p3glesgsg_config_glesgsg.obj')
   TargetAdd('libpandagles.dll', input='p3glesgsg_glesgsg.obj')
@@ -4512,13 +4513,14 @@ def get_config_express():
 # DIRECTORY: panda/src/egldisplay/
 #
 
-if (PkgSkip("EGL")==0 and PkgSkip("GLES2")==0 and PkgSkip("X11")==0):
+if (PkgSkip("EGL")==0 and PkgSkip("GLES2")==0):
   DefSymbol('GLES2', 'OPENGLES_2', '')
   OPTS=['DIR:panda/src/egldisplay', 'DIR:panda/src/glstuff', 'BUILDING:PANDAGLES2',  'GLES2', 'EGL']
   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')
-  TargetAdd('libpandagles2.dll', input='p3x11display_composite1.obj')
+  if not PkgSkip("X11"):
+    TargetAdd('libpandagles2.dll', input='p3x11display_composite1.obj')
   TargetAdd('libpandagles2.dll', input='pandagles2_pandagles2.obj')
   TargetAdd('libpandagles2.dll', input='p3gles2gsg_config_gles2gsg.obj')
   TargetAdd('libpandagles2.dll', input='p3gles2gsg_gles2gsg.obj')

diff --git a/panda/src/egldisplay/config_egldisplay.cxx b/panda/src/egldisplay/config_egldisplay.cxx
@@ -45,7 +45,9 @@ init_libegldisplay() {
   initialized = true;
 
   eglGraphicsPipe::init_type();
+#ifdef HAVE_X11
   eglGraphicsWindow::init_type();
+#endif
   eglGraphicsStateGuardian::init_type();
 
   GraphicsPipeSelection *selection = GraphicsPipeSelection::get_global_ptr();

diff --git a/panda/src/egldisplay/eglGraphicsBuffer.cxx b/panda/src/egldisplay/eglGraphicsBuffer.cxx
@@ -127,7 +127,7 @@ close_buffer() {
   if (_gsg != nullptr) {
     eglGraphicsStateGuardian *eglgsg;
     DCAST_INTO_V(eglgsg, _gsg);
-    if (!eglMakeCurrent(eglgsg->_egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT)) {
+    if (!eglMakeCurrent(_egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT)) {
       egldisplay_cat.error() << "Failed to call eglMakeCurrent: "
         << get_egl_error_string(eglGetError()) << "\n";
     }
@@ -159,15 +159,15 @@ open_buffer() {
   if (_gsg == 0) {
     // There is no old gsg.  Create a new one.
     eglgsg = new eglGraphicsStateGuardian(_engine, _pipe, nullptr);
-    eglgsg->choose_pixel_format(_fb_properties, egl_pipe->get_display(), egl_pipe->get_screen(), true, false);
+    eglgsg->choose_pixel_format(_fb_properties, egl_pipe, false, true, false);
     _gsg = eglgsg;
   } else {
     // If the old gsg has the wrong pixel format, create a new one that shares
     // with the old gsg.
     DCAST_INTO_R(eglgsg, _gsg, false);
     if (!eglgsg->get_fb_properties().subsumes(_fb_properties)) {
       eglgsg = new eglGraphicsStateGuardian(_engine, _pipe, eglgsg);
-      eglgsg->choose_pixel_format(_fb_properties, egl_pipe->get_display(), egl_pipe->get_screen(), true, false);
+      eglgsg->choose_pixel_format(_fb_properties, egl_pipe, false, true, false);
       _gsg = eglgsg;
     }
   }
@@ -178,6 +178,8 @@ open_buffer() {
     return false;
   }
 
+  _egl_display = eglgsg->_egl_display;
+
   int attrib_list[] = {
     EGL_WIDTH, _size.get_x(),
     EGL_HEIGHT, _size.get_y(),

diff --git a/panda/src/egldisplay/eglGraphicsPipe.I b/panda/src/egldisplay/eglGraphicsPipe.I
@@ -10,3 +10,11 @@
  * @author rdb
  * @date 2009-05-21
  */
+
+/**
+ *
+ */
+INLINE EGLDisplay eglGraphicsPipe::
+get_egl_display() const {
+  return _egl_display;
+}
diff --git a/panda/src/egldisplay/eglGraphicsPipe.cxx b/panda/src/egldisplay/eglGraphicsPipe.cxx
@@ -25,19 +25,32 @@ TypeHandle eglGraphicsPipe::_type_handle;
  *
  */
 eglGraphicsPipe::
-eglGraphicsPipe(const std::string &display) : x11GraphicsPipe(display) {
+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
   _egl_display = eglGetDisplay((NativeDisplayType) _display);
+#else
+  _egl_display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+#endif
   if (!eglInitialize(_egl_display, nullptr, nullptr)) {
     egldisplay_cat.error()
       << "Couldn't initialize the EGL display: "
       << get_egl_error_string(eglGetError()) << "\n";
+    _is_valid = false;
+    return;
   }
 
   if (!eglBindAPI(EGL_OPENGL_ES_API)) {
     egldisplay_cat.error()
       << "Couldn't bind EGL to the OpenGL ES API: "
       << get_egl_error_string(eglGetError()) << "\n";
+    _is_valid = false;
+    return;
   }
+
+  // Even if we don't have an X11 display, we can still render headless.
+  _is_valid = true;
 }
 
 /**
@@ -110,6 +123,10 @@ make_output(const std::string &name,
   // First thing to try: an eglGraphicsWindow
 
   if (retry == 0) {
+#ifdef HAVE_X11
+    if (!_display) {
+      return nullptr;
+    }
     if (((flags&BF_require_parasite)!=0)||
         ((flags&BF_refuse_window)!=0)||
         ((flags&BF_resizeable)!=0)||
@@ -121,6 +138,9 @@ make_output(const std::string &name,
     }
     return new eglGraphicsWindow(engine, this, name, fb_prop, win_prop,
                                  flags, gsg, host);
+#else
+    return nullptr;
+#endif
   }
 
   // Second thing to try: a GLES(2)GraphicsBuffer
@@ -184,6 +204,10 @@ make_output(const std::string &name,
 
   // Fourth thing to try: an eglGraphicsPixmap.
   if (retry == 3) {
+#ifdef HAVE_X11
+    if (!_display) {
+      return nullptr;
+    }
     if (((flags&BF_require_parasite)!=0)||
         ((flags&BF_require_window)!=0)||
         ((flags&BF_resizeable)!=0)||
@@ -198,6 +222,9 @@ make_output(const std::string &name,
 
     return new eglGraphicsPixmap(engine, this, name, fb_prop, win_prop,
                                  flags, gsg, host);
+#else
+    return nullptr;
+#endif
   }
 
   // Nothing else left to try.

diff --git a/panda/src/egldisplay/eglGraphicsPipe.h b/panda/src/egldisplay/eglGraphicsPipe.h
@@ -15,7 +15,14 @@
 #define EGLGRAPHICSPIPE_H
 
 #include "pandabase.h"
+
+#ifdef HAVE_X11
 #include "x11GraphicsPipe.h"
+typedef x11GraphicsPipe BaseGraphicsPipe;
+#else
+#include "graphicsPipe.h"
+typedef GraphicsPipe BaseGraphicsPipe;
+#endif
 
 #ifdef OPENGLES_2
   #include "gles2gsg.h"
@@ -42,14 +49,16 @@ class eglGraphicsWindow;
  * This graphics pipe represents the interface for creating OpenGL ES graphics
  * windows on an X-based (e.g.  Unix) client.
  */
-class eglGraphicsPipe : public x11GraphicsPipe {
+class eglGraphicsPipe : public BaseGraphicsPipe {
 public:
-  eglGraphicsPipe(const std::string &display = std::string());
+  eglGraphicsPipe();
   virtual ~eglGraphicsPipe();
 
   virtual std::string get_interface_name() const;
   static PT(GraphicsPipe) pipe_constructor();
 
+  INLINE EGLDisplay get_egl_display() const;
+
 protected:
   virtual PT(GraphicsOutput) make_output(const std::string &name,
                                          const FrameBufferProperties &fb_prop,
@@ -62,16 +71,16 @@ class eglGraphicsPipe : public x11GraphicsPipe {
                                          bool &precertify);
 
 private:
-  EGLDisplay _egl_display;
+  EGLDisplay _egl_display = 0;
 
 public:
   static TypeHandle get_class_type() {
     return _type_handle;
   }
   static void init_type() {
-    x11GraphicsPipe::init_type();
+    BaseGraphicsPipe::init_type();
     register_type(_type_handle, "eglGraphicsPipe",
-                  x11GraphicsPipe::get_class_type());
+                  BaseGraphicsPipe::get_class_type());
   }
   virtual TypeHandle get_type() const {
     return get_class_type();
@@ -80,10 +89,6 @@ class eglGraphicsPipe : public x11GraphicsPipe {
 
 private:
   static TypeHandle _type_handle;
-
-  friend class eglGraphicsBuffer;
-  friend class eglGraphicsPixmap;
-  friend class eglGraphicsWindow;
 };
 
 #include "eglGraphicsPipe.I"

diff --git a/panda/src/egldisplay/eglGraphicsPixmap.cxx b/panda/src/egldisplay/eglGraphicsPixmap.cxx
@@ -12,6 +12,9 @@
  */
 
 #include "eglGraphicsPixmap.h"
+
+#ifdef HAVE_X11
+
 #include "eglGraphicsWindow.h"
 #include "eglGraphicsStateGuardian.h"
 #include "config_egldisplay.h"
@@ -37,8 +40,7 @@ eglGraphicsPixmap(GraphicsEngine *engine, GraphicsPipe *pipe,
 {
   eglGraphicsPipe *egl_pipe;
   DCAST_INTO_V(egl_pipe, _pipe);
-  _display = egl_pipe->get_display();
-  _egl_display = egl_pipe->_egl_display;
+  _egl_display = egl_pipe->get_egl_display();
   _drawable = None;
   _x_pixmap = None;
   _egl_surface = EGL_NO_SURFACE;
@@ -167,15 +169,15 @@ open_buffer() {
   if (_gsg == 0) {
     // There is no old gsg.  Create a new one.
     eglgsg = new eglGraphicsStateGuardian(_engine, _pipe, nullptr);
-    eglgsg->choose_pixel_format(_fb_properties, _display, egl_pipe->get_screen(), false, true);
+    eglgsg->choose_pixel_format(_fb_properties, egl_pipe, false, false, true);
     _gsg = eglgsg;
   } else {
     // If the old gsg has the wrong pixel format, create a new one that shares
     // with the old gsg.
     DCAST_INTO_R(eglgsg, _gsg, false);
     if (!eglgsg->get_fb_properties().subsumes(_fb_properties)) {
       eglgsg = new eglGraphicsStateGuardian(_engine, _pipe, eglgsg);
-      eglgsg->choose_pixel_format(_fb_properties, _display, egl_pipe->get_screen(), false, true);
+      eglgsg->choose_pixel_format(_fb_properties, egl_pipe, false, false, true);
       _gsg = eglgsg;
     }
   }
@@ -194,6 +196,7 @@ open_buffer() {
     return false;
   }
 
+  _display = egl_pipe->get_display();
   _drawable = egl_pipe->get_root();
   if (_host != nullptr) {
     if (_host->is_of_type(eglGraphicsWindow::get_class_type())) {
@@ -241,3 +244,5 @@ open_buffer() {
   _is_valid = true;
   return true;
 }
+
+#endif  // HAVE_X11
diff --git a/panda/src/egldisplay/eglGraphicsPixmap.h b/panda/src/egldisplay/eglGraphicsPixmap.h
@@ -16,6 +16,8 @@
 
 #include "pandabase.h"
 
+#ifdef HAVE_X11
+
 #include "eglGraphicsPipe.h"
 #include "graphicsBuffer.h"
 
@@ -67,4 +69,6 @@ class eglGraphicsPixmap : public GraphicsBuffer {
   static TypeHandle _type_handle;
 };
 
+#endif  // HAVE_X11
+
 #endif