* [glcContext] check return value from wglShareLists

* [glcFrameBufferObject] fixed bug with glDrawBuffer/glReadBuffer

uglcContextWGL.pas

@@ -399,7 +399,8 @@ end;
 
 procedure TglcContextWGL.Share(const aContext: TglcContext);
 begin
-  wglShareLists(FRC, (aContext as TglcContextWGL).FRC);
+  if not wglShareLists(FRC, (aContext as TglcContextWGL).FRC) then
+    raise EGLError.Create('wglShareLists failed: ' + IntToStr(GetLastError()));
 end;
 
 class function TglcContextWGL.ChangeDisplaySettings(const aWidth, aHeight,

uglcFrameBufferObject.pas

@@ -322,7 +322,6 @@ constructor TglcTextureBuffer.Create(const aFormat: TglcFormat; const aInternalF
 begin
   inherited Create;
   fBufferType := btTextureBuffer;
-
   glGenTextures(1, @fID);
   Bind(false);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, {$IFNDEF OPENGL_ES}GL_CLAMP{$ELSE}GL_CLAMP_TO_EDGE{$ENDIF});
@@ -330,7 +329,6 @@ begin
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   Unbind(false);
-
   fFormat := aFormat;
   fInternalFormat := aInternalFormat;
   SetSize(64, 64);
@@ -495,11 +493,11 @@ procedure TglcFrameBufferObject.UpdateAndCheckFBO;
 
 var
   buff: array of GLenum;
-{$IFNDEF OPENGL_ES}
-  b: GLboolean;
-{$ENDIF}
   i: Integer;
+  {$IFNDEF OPENGL_ES}DoubleBuffered: GLboolean;{$ENDIF}
 begin
+  {$IFNDEF OPENGL_ES}glGetBooleanv(GL_DOUBLEBUFFER, @DoubleBuffered);{$ENDIF}
+
   if (fBuffers.Count = 0) then
     exit;
   Bind(false);
@@ -525,8 +523,7 @@ begin
   end else begin
     glDrawBuffers(Length(buff), @buff[0]);
 {$IFNDEF OPENGL_ES}
-    glGetBooleanv(GL_DOUBLEBUFFER, @b);
-    if b then
+    if DoubleBuffered then
       glReadBuffer(GL_BACK)
     else
       glReadBuffer(GL_FRONT);