* [glcContext] implemented share context for gtk2/glx

uglcContextGtk2GLX.pas

@@ -36,8 +36,14 @@ type
   protected
     procedure OpenContext; override;
   public
-    constructor Create(const aControl: TWinControl; const aPixelFormatSettings: TglcContextPixelFormatSettings); override; overload;
-    constructor Create(const aControl: TWinControl; const aPixelFormatSettings: TglcContextPixelFormatSettings; const aVersionSettings: TglcContextVersionSettings); override; overload;
+    constructor Create(const aControl: TWinControl;
+                       const aPixelFormatSettings: TglcContextPixelFormatSettings;
+                       const aShareContext: TglcContext = nil); overload; override;
+    constructor Create(const aControl: TWinControl;
+                       const aPixelFormatSettings: TglcContextPixelFormatSettings;
+                       const aVersionSettings: TglcContextVersionSettings;
+                       const aShareContext: TglcContext = nil); overload; override;
+
     destructor Destroy; override;
 
     procedure CloseContext; override;
@@ -46,7 +52,6 @@ type
     function IsActive: boolean; override;
     procedure SwapBuffers; override;
     procedure SetSwapInterval(const aInterval: GLint); override;
-    procedure Share(const aContext: TglcContext); override;
 
     class function ChangeDisplaySettings(const aWidth, aHeight,
       aBitPerPixel, aFreq: Integer; const aFlags: TglcDisplayFlags): Boolean; override;
@@ -420,6 +425,7 @@ end;
 
 procedure TglcContextGtk2GLX.OpenContext;
 var
+  share: GLXContext;
   Attribs: array of GLint;
   tmpContext: GLXContext;
   glxID: GLXDrawable;
@@ -429,7 +435,14 @@ begin
   if not Assigned(FVisual) then
     raise EGLXError.Create('Failed to find Visual');
 
-  tmpContext := glXCreateContext(FDisplay, FVisual, nil, true);
+  share := nil;
+  if Assigned(ShareContext) then begin
+     if (ShareContext.ClassName <> ClassName) then
+      raise Exception.Create('share context has invalid type: ' + ShareContext.ClassName);
+     share := (ShareContext as TglcContextGtk2GLX).FContext;
+  end;
+
+  tmpContext := glXCreateContext(FDisplay, FVisual, share, true);
   if fUseVersion and
      (fVersionSettings.Major <> GLC_CONTEXT_VERSION_UNKNOWN) and
      (fVersionSettings.Minor <> GLC_CONTEXT_VERSION_UNKNOWN) then
@@ -461,7 +474,7 @@ begin
       glXDestroyContext(FDisplay, tmpContext);
       raise Exception.Create('GLX_ARB_create_context not supported');
     end;
-    FContext := glXCreateContextAttribsARB(FDisplay, FVisual, nil, true, @Attribs[0]);
+    FContext := glXCreateContextAttribsARB(FDisplay, FVisual, share, true, @Attribs[0]);
 
     glXDestroyContext(FDisplay, tmpContext);
   end else
@@ -472,17 +485,19 @@ begin
 end;
 
 constructor TglcContextGtk2GLX.Create(const aControl: TWinControl;
-  const aPixelFormatSettings: TglcContextPixelFormatSettings);
+  const aPixelFormatSettings: TglcContextPixelFormatSettings;
+  const aShareContext: TglcContext);
 begin
-  inherited Create(aControl, aPixelFormatSettings);
+  inherited Create(aControl, aPixelFormatSettings, aShareContext);
   UpdateVisual(aControl);
 end;
 
 constructor TglcContextGtk2GLX.Create(const aControl: TWinControl;
   const aPixelFormatSettings: TglcContextPixelFormatSettings;
-  const aVersionSettings: TglcContextVersionSettings);
+  const aVersionSettings: TglcContextVersionSettings;
+  const aShareContext: TglcContext);
 begin
-  inherited Create(aControl, aPixelFormatSettings, aVersionSettings);
+  inherited Create(aControl, aPixelFormatSettings, aVersionSettings, aShareContext);
   UpdateVisual(aControl);
 end;
 
@@ -513,6 +528,7 @@ begin
   // make current
   glxID := GDK_DRAWABLE_XID(GTK_WIDGET(FWidget)^.window);
   glXMakeCurrent(FDisplay, glxID, FContext);
+  inherited Activate;
 end;
 
 procedure TglcContextGtk2GLX.Deactivate;
@@ -552,11 +568,6 @@ begin
     glXSwapIntervalEXT(FDisplay, GDK_WINDOW_XWINDOW(drawable), aInterval);
 end;
 
-procedure TglcContextGtk2GLX.Share(const aContext: TglcContext);
-begin
-  raise Exception.Create('not yet implemented');
-end;
-
 class function TglcContextGtk2GLX.{%H-}ChangeDisplaySettings(const aWidth, aHeight,
   aBitPerPixel, aFreq: Integer; const aFlags: TglcDisplayFlags): Boolean;
 begin