egldisplay: Support creating headless GLES contexts

See #557

makepanda/makepanda.py

@@ -4494,13 +4494,14 @@ if (GetTarget() == 'windows' and PkgSkip("GL")==0):
 # 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 @@ if (PkgSkip("EGL")==0 and PkgSkip("GLES")==0 and PkgSkip("X11")==0):
 # 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')

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();

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";
     }
@@ -159,7 +159,7 @@ 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
@@ -167,7 +167,7 @@ open_buffer() {
     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(),

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;
+}

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.

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 @@ protected:
                                          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 @@ public:
 
 private:
   static TypeHandle _type_handle;
-
-  friend class eglGraphicsBuffer;
-  friend class eglGraphicsPixmap;
-  friend class eglGraphicsWindow;
 };
 
 #include "eglGraphicsPipe.I"

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;
@@ -167,7 +169,7 @@ 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
@@ -175,7 +177,7 @@ open_buffer() {
     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

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 @@ private:
   static TypeHandle _type_handle;
 };
 
+#endif  // HAVE_X11
+
 #endif

panda/src/egldisplay/eglGraphicsStateGuardian.cxx

@@ -33,11 +33,7 @@ eglGraphicsStateGuardian(GraphicsEngine *engine, GraphicsPipe *pipe,
 {
   _share_context=0;
   _context=0;
-  _display=0;
   _egl_display=0;
-  _screen=0;
-  _visual=0;
-  _visuals=0;
   _fbconfig=0;
 
   if (share_with != nullptr) {
@@ -51,9 +47,6 @@ eglGraphicsStateGuardian(GraphicsEngine *engine, GraphicsPipe *pipe,
  */
 eglGraphicsStateGuardian::
 ~eglGraphicsStateGuardian() {
-  if (_visuals != nullptr) {
-    XFree(_visuals);
-  }
   if (_context != (EGLContext)nullptr) {
     if (!eglDestroyContext(_egl_display, _context)) {
       egldisplay_cat.error() << "Failed to destroy EGL context: "
@@ -108,11 +101,6 @@ get_properties(FrameBufferProperties &properties,
     slow = true;
   }
 
-  if ((surface_type & EGL_WINDOW_BIT)==0) {
-    // We insist on having a context that will support an onscreen window.
-    return;
-  }
-
   properties.set_back_buffers(1);
   properties.set_rgb_color(1);
   properties.set_rgba_bits(red_size, green_size, blue_size, alpha_size);
@@ -131,16 +119,12 @@ get_properties(FrameBufferProperties &properties,
  */
 void eglGraphicsStateGuardian::
 choose_pixel_format(const FrameBufferProperties &properties,
-        X11_Display *display,
-        int screen, bool need_pbuffer, bool need_pixmap) {
+                    eglGraphicsPipe *egl_pipe, bool need_window,
+                    bool need_pbuffer, bool need_pixmap) {
 
-  _display = display;
-  _egl_display = eglGetDisplay((NativeDisplayType) display);
-  _screen = screen;
+  _egl_display = egl_pipe->get_egl_display();
   _context = 0;
   _fbconfig = 0;
-  _visual = 0;
-  _visuals = 0;
   _fbprops.clear();
 
   int attrib_list[] = {
@@ -150,7 +134,7 @@ choose_pixel_format(const FrameBufferProperties &properties,
 #ifdef OPENGLES_2
     EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
 #endif
-    EGL_SURFACE_TYPE, EGL_DONT_CARE,
+    EGL_SURFACE_TYPE, need_window ? EGL_WINDOW_BIT : EGL_DONT_CARE,
     EGL_NONE
   };
 
@@ -206,9 +190,15 @@ choose_pixel_format(const FrameBufferProperties &properties,
       best_props = fbprops;
     }
   }
-  int depth = DefaultDepth(_display, _screen);
-  _visual = new XVisualInfo;
-  XMatchVisualInfo(_display, _screen, depth, TrueColor, _visual);
+#ifdef HAVE_X11
+  X11_Display *display = egl_pipe->get_display();
+  if (display) {
+    int screen = egl_pipe->get_screen();
+    int depth = DefaultDepth(display, screen);
+    _visual = new XVisualInfo;
+    XMatchVisualInfo(display, screen, depth, TrueColor, _visual);
+  }
+#endif
 
   if (best_quality > 0) {
     egldisplay_cat.debug()
@@ -222,7 +212,10 @@ choose_pixel_format(const FrameBufferProperties &properties,
 #endif
     int err = eglGetError();
     if (_context && err == EGL_SUCCESS) {
-      if (_visual) {
+#ifdef HAVE_X11
+      if (!display || _visual)
+#endif
+      {
         _fbprops = best_props;
         delete[] configs;
         return;
@@ -234,8 +227,9 @@ choose_pixel_format(const FrameBufferProperties &properties,
       << get_egl_error_string(err) << "\n";
     _fbconfig = 0;
     _context = 0;
+#ifdef HAVE_X11
     _visual = 0;
-    _visuals = 0;
+#endif
   }
 
   egldisplay_cat.error() <<
@@ -255,12 +249,7 @@ reset() {
   GLESGraphicsStateGuardian::reset();
 #endif
 
-  // If "Mesa" is present, assume software.  However, if "Mesa DRI" is found,
-  // it's actually a Mesa-based OpenGL layer running over a hardware driver.
-  if (_gl_renderer == "Software Rasterizer" ||
-      (_gl_renderer.find("Mesa") != std::string::npos &&
-       _gl_renderer.find("Mesa DRI") == std::string::npos)) {
-    // It's Mesa, therefore probably a software context.
+  if (_gl_renderer == "Software Rasterizer") {
     _fbprops.set_force_software(1);
     _fbprops.set_force_hardware(0);
   } else {
@@ -289,8 +278,10 @@ egl_is_at_least_version(int major_version, int minor_version) const {
  */
 void eglGraphicsStateGuardian::
 gl_flush() const {
+#ifdef HAVE_X11
   // This call requires synchronization with X.
   LightReMutexHolder holder(eglGraphicsPipe::_x_mutex);
+#endif
 #ifdef OPENGLES_2
   GLES2GraphicsStateGuardian::gl_flush();
 #else
@@ -303,8 +294,10 @@ gl_flush() const {
  */
 GLenum eglGraphicsStateGuardian::
 gl_get_error() const {
+#ifdef HAVE_X11
   // This call requires synchronization with X.
   LightReMutexHolder holder(eglGraphicsPipe::_x_mutex);
+#endif
 #ifdef OPENGLES_2
   return GLES2GraphicsStateGuardian::gl_get_error();
 #else

panda/src/egldisplay/eglGraphicsStateGuardian.h

@@ -16,7 +16,10 @@
 
 #include "pandabase.h"
 #include "eglGraphicsPipe.h"
+
+#ifdef HAVE_X11
 #include "get_x11.h"
+#endif
 
 /**
  * A tiny specialization on GLESGraphicsStateGuardian to add some egl-specific
@@ -33,9 +36,8 @@ public:
              bool &pbuffer_supported, bool &pixmap_supported,
                                bool &slow, EGLConfig config);
   void choose_pixel_format(const FrameBufferProperties &properties,
-         X11_Display *_display,
-         int _screen,
-         bool need_pbuffer, bool need_pixmap);
+                           eglGraphicsPipe *egl_pipe, bool need_window,
+                           bool need_pbuffer, bool need_pixmap);
 
   eglGraphicsStateGuardian(GraphicsEngine *engine, GraphicsPipe *pipe,
          eglGraphicsStateGuardian *share_with);
@@ -49,10 +51,9 @@ public:
   EGLContext _share_context;
   EGLContext _context;
   EGLDisplay _egl_display;
-  X11_Display *_display;
-  int _screen;
-  XVisualInfo *_visual;
-  XVisualInfo *_visuals;
+#ifdef HAVE_X11
+  XVisualInfo *_visual = nullptr;
+#endif
   EGLConfig _fbconfig;
   FrameBufferProperties _fbprops;
 

panda/src/egldisplay/eglGraphicsWindow.cxx

@@ -12,6 +12,9 @@
  */
 
 #include "eglGraphicsWindow.h"
+
+#ifdef HAVE_X11
+
 #include "eglGraphicsStateGuardian.h"
 #include "config_egldisplay.h"
 #include "eglGraphicsPipe.h"
@@ -44,7 +47,7 @@ eglGraphicsWindow(GraphicsEngine *engine, GraphicsPipe *pipe,
 {
   eglGraphicsPipe *egl_pipe;
   DCAST_INTO_V(egl_pipe, _pipe);
-  _egl_display = egl_pipe->_egl_display;
+  _egl_display = egl_pipe->get_egl_display();
   _egl_surface = 0;
 }
 
@@ -206,7 +209,7 @@ open_window() {
   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(), false, false);
+    eglgsg->choose_pixel_format(_fb_properties, egl_pipe, true, false, false);
     _gsg = eglgsg;
   } else {
     // If the old gsg has the wrong pixel format, create a new one that shares
@@ -214,7 +217,7 @@ open_window() {
     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(), false, false);
+      eglgsg->choose_pixel_format(_fb_properties, egl_pipe, true, false, false);
       _gsg = eglgsg;
     }
   }
@@ -258,3 +261,5 @@ open_window() {
 
   return true;
 }
+
+#endif  // HAVE_X11

panda/src/egldisplay/eglGraphicsWindow.h

@@ -16,6 +16,8 @@
 
 #include "pandabase.h"
 
+#ifdef HAVE_X11
+
 #include "eglGraphicsPipe.h"
 #include "x11GraphicsWindow.h"
 
@@ -65,4 +67,6 @@ private:
 
 #include "eglGraphicsWindow.I"
 
+#endif  // HAVE_X11
+
 #endif