Introduce GLPlatform::CanCreateGLContext()

Introduce a method to check if a platform supports desktop GL.
Most platforms support desktop GL by default, so for them the
implementation of this method is trivial. For EGL, though, we
have to implement a proper check, since EGL support for non
GLES APIs is optional.

renderdoc/driver/gl/cgl_platform.cpp

@@ -182,6 +182,7 @@ class CGLPlatform : public GLPlatform
 
     return NULL;
   }
+  bool CanCreateGLContext() { return true; }
   bool CanCreateGLESContext() { return false; }
   bool PopulateForReplay() { return CGL.PopulateForReplay(); }
   GLWindowingData MakeOutputWindow(WindowingData window, bool depth, GLWindowingData share_context)

renderdoc/driver/gl/egl_dispatch_table.h

@@ -27,6 +27,7 @@
 #include "gl_common.h"
 
 typedef EGLBoolean(EGLAPIENTRY *PFN_eglBindAPI)(EGLenum api);
+typedef EGLenum(EGLAPIENTRY *PFN_eglQueryAPI)();
 typedef EGLDisplay(EGLAPIENTRY *PFN_eglGetDisplay)(EGLNativeDisplayType display_id);
 typedef EGLDisplay(EGLAPIENTRY *PFN_eglGetPlatformDisplay)(EGLenum platform, void *native_display,
                                                            const EGLAttrib *attrib_list);
@@ -90,6 +91,7 @@ typedef PFNEGLSWAPBUFFERSWITHDAMAGEKHRPROC PFN_eglSwapBuffersWithDamageKHR;
   FUNC(GetCurrentSurface, false, true);    \
   FUNC(GetError, false, true);             \
   FUNC(Initialize, false, true);           \
+  FUNC(QueryAPI, false, true);             \
   FUNC(QueryString, false, true);          \
   FUNC(QuerySurface, false, true);
 

renderdoc/driver/gl/egl_platform.cpp

@@ -326,6 +326,30 @@ class EGLPlatform : public GLPlatform
     return ret;
   }
 
+  bool CanCreateGLContext()
+  {
+#if ENABLED(RDOC_ANDROID)
+    // we don't trust the EGL API query to work reliably on Android, so treat
+    // it as special case
+    return false;
+#else
+    bool success = EGL.PopulateForReplay();
+
+    // if we can't populate our functions we bail now.
+    if(!success)
+      return false;
+
+    EGLenum previousAPI = EGL.QueryAPI();
+    EGLBoolean supportsGL = EGL.BindAPI(EGL_OPENGL_API);
+
+    // restore previous API
+    if(previousAPI != EGL_NONE)
+      EGL.BindAPI(previousAPI);
+
+    return supportsGL == EGL_TRUE;
+#endif
+  }
+
   bool CanCreateGLESContext()
   {
     // as long as we can get libEGL we're fine

renderdoc/driver/gl/gl_common.h

@@ -280,6 +280,7 @@ struct GLPlatform
   virtual void DrawQuads(float width, float height, const std::vector<Vec4f> &vertices) = 0;
 
   // for initialisation at replay time
+  virtual bool CanCreateGLContext() = 0;
   virtual bool CanCreateGLESContext() = 0;
   virtual bool PopulateForReplay() = 0;
   virtual ReplayStatus InitialiseAPI(GLWindowingData &replayContext, RDCDriver api, bool debug) = 0;
@@ -304,6 +305,7 @@ class GLDummyPlatform : public GLPlatform
   virtual void DrawQuads(float width, float height, const std::vector<Vec4f> &vertices) {}
   virtual void *GetReplayFunction(const char *funcname) { return NULL; }
   // for initialisation at replay time
+  virtual bool CanCreateGLContext() { return true; }
   virtual bool CanCreateGLESContext() { return true; }
   virtual bool PopulateForReplay() { return true; }
   virtual ReplayStatus InitialiseAPI(GLWindowingData &replayContext, RDCDriver api, bool debug)

renderdoc/driver/gl/gl_replay.cpp

@@ -3607,6 +3607,12 @@ ReplayStatus GL_CreateReplayDevice(RDCFile *rdc, const ReplayOptions &opts, IRep
 #endif
   }
 
+  if(!gl_platform->CanCreateGLContext())
+  {
+    RDCERR("Platform doesn't support GL contexts");
+    return ReplayStatus::APIInitFailed;
+  }
+
   RDCDEBUG("Creating an OpenGL replay device");
 
   bool load_ok = gl_platform->PopulateForReplay();

renderdoc/driver/gl/glx_platform.cpp

@@ -304,6 +304,13 @@ class GLXPlatform : public GLPlatform
     return ret;
   }
 
+  bool CanCreateGLContext()
+  {
+    Display *dpy = RenderDoc::Inst().GetGlobalEnvironment().xlibDisplay;
+
+    return GetGLHandle() != NULL && dpy != NULL;
+  }
+
   bool CanCreateGLESContext()
   {
     bool success = GLX.PopulateForReplay();

renderdoc/driver/gl/wgl_platform.cpp

@@ -245,6 +245,7 @@ class WGLPlatform : public GLPlatform
     return Process::GetFunctionAddress(Process::LoadModule("opengl32.dll"), funcname);
   }
 
+  bool CanCreateGLContext() { return true; }
   bool CanCreateGLESContext()
   {
     bool success = WGL.PopulateForReplay();