/// <summary>
/// Attempts to begin drawing the control. Returns an error message string
/// if this was not possible, which can happen if the graphics device is
/// lost, or if we are running inside the Form designer.
/// </summary>
void BeginDraw(RenderingError error)
{
// If we have no graphics device, we must be running in the designer.
if (graphicsDeviceService == null)
{
error.Message = Text + "\n\n" + GetType();
}
if (error.HasErrors == false || error.GraphicsDeviceNeedsReset)
{
TryHandleDeviceReset(error);
}
if (!error.HasErrors)
{
// Many GraphicsDeviceControl instances can be sharing the same
// GraphicsDevice. The device backbuffer will be resized to fit the
// largest of these controls. But what if we are currently drawing
// a smaller control? To avoid unwanted stretching, we set the
// viewport to only use the top left portion of the full backbuffer.
Viewport viewport = new Viewport();
viewport.X = 0;
viewport.Y = 0;
viewport.Width = ClientSize.Width;
viewport.Height = ClientSize.Height;
viewport.MinDepth = 0;
viewport.MaxDepth = 1;
GraphicsDevice.Viewport = viewport;
}
}
/// <summary>
/// Helper used by BeginDraw. This checks the graphics device status,
/// making sure it is big enough for drawing the current control, and
/// that the device is not lost. Returns an error string if the device
/// could not be reset.
/// </summary>
void TryHandleDeviceReset(RenderingError error)
{
switch (GraphicsDevice.GraphicsDeviceStatus)
{
case GraphicsDeviceStatus.Lost:
// If the graphics device is lost, but we can try to reset it
error.Message = "Graphics device lost";
error.GraphicsDeviceLost = true;
break;
case GraphicsDeviceStatus.NotReset:
// If device is in the not-reset state, we should try to reset it.
error.GraphicsDeviceNeedsReset = true;
error.Message = "Graphics device needs reset";
break;
default:
// If the device state is ok, check whether it is big enough.
PresentationParameters pp = GraphicsDevice.PresentationParameters;
bool deviceNeedsReset = (ClientSize.Width > pp.BackBufferWidth) ||
(ClientSize.Height > pp.BackBufferHeight);
if (deviceNeedsReset)
{
error.Message = "Resolution has changed, needs reset";
error.GraphicsDeviceNeedsReset = true;
}
break;
}
// Do we need to reset the device?
if (error.GraphicsDeviceNeedsReset)
{
try
{
graphicsDeviceService.ResetDevice(ClientSize.Width,
ClientSize.Height);
error.Message = null;
error.GraphicsDeviceNeedsReset = false;
}
catch (Exception e)
{
error.GraphicsDeviceNeedsReset = false;
error.Message = "Graphics device reset failed\n\n" + e;
}
}
}
/// <summary>
/// Helper used by BeginDraw. This checks the graphics device status,
/// making sure it is big enough for drawing the current control, and
/// that the device is not lost. Returns an error string if the device
/// could not be reset.
/// </summary>
void TryHandleDeviceReset(RenderingError error)
{
switch (GraphicsDevice.GraphicsDeviceStatus)
{
case GraphicsDeviceStatus.Lost:
// If the graphics device is lost, but we can try to reset it
error.Message = "Graphics device lost";
error.GraphicsDeviceLost = true;
break;
case GraphicsDeviceStatus.NotReset:
// If device is in the not-reset state, we should try to reset it.
error.GraphicsDeviceNeedsReset = true;
error.Message = "Graphics device needs reset";
break;
default:
// If the device state is ok, check whether it is big enough.
PresentationParameters pp = GraphicsDevice.PresentationParameters;
bool deviceNeedsReset = (ClientSize.Width > pp.BackBufferWidth) ||
(ClientSize.Height > pp.BackBufferHeight);
if(deviceNeedsReset)
{
error.Message = "Resolution has changed, needs reset";
error.GraphicsDeviceNeedsReset = true;
}
break;
}
// Do we need to reset the device?
if (error.GraphicsDeviceNeedsReset)
{
try
{
graphicsDeviceService.ResetDevice(ClientSize.Width,
ClientSize.Height);
error.Message = null;
error.GraphicsDeviceNeedsReset = false;
}
catch (Exception e)
{
error.GraphicsDeviceNeedsReset = false;
error.Message = "Graphics device reset failed\n\n" + e;
}
}
}
/// <summary>
/// Attempts to begin drawing the control. Returns an error message string
/// if this was not possible, which can happen if the graphics device is
/// lost, or if we are running inside the Form designer.
/// </summary>
void BeginDraw(RenderingError error)
{
// If we have no graphics device, we must be running in the designer.
if (graphicsDeviceService == null)
{
error.Message = Text + "\n\n" + GetType();
}
if (error.HasErrors == false || error.GraphicsDeviceNeedsReset)
{
TryHandleDeviceReset(error);
}
if (!error.HasErrors)
{
// Many GraphicsDeviceControl instances can be sharing the same
// GraphicsDevice. The device backbuffer will be resized to fit the
// largest of these controls. But what if we are currently drawing
// a smaller control? To avoid unwanted stretching, we set the
// viewport to only use the top left portion of the full backbuffer.
Viewport viewport = new Viewport();
viewport.X = 0;
viewport.Y = 0;
viewport.Width = ClientSize.Width;
viewport.Height = ClientSize.Height;
viewport.MinDepth = 0;
viewport.MaxDepth = 1;
GraphicsDevice.Viewport = viewport;
}
}
