protected override void OnPaint(PaintEventArgs e)
{
// Start the stopwatch so that we can time the rendering.
stopwatch.Restart();
// Make sure it's our instance of openSharpGL that's active.
OpenGL.MakeCurrent();
// Do the scene drawing.
scene.Draw();
// If there is a draw handler, then call it.
DoOpenGLDraw(new RenderEventArgs(e.Graphics));
// Draw the FPS.
if (DrawFPS)
{
OpenGL.DrawText(5, 5, 1.0f, 0.0f, 0.0f, "Courier New", 12.0f,
string.Format("Draw Time: {0:0.0000} ms ~ {1:0.0} FPS", frameTime, 1000.0 / frameTime));
OpenGL.Flush();
}
// Blit our offscreen bitmap.
IntPtr handleDeviceContext = e.Graphics.GetHdc();
OpenGL.Blit(handleDeviceContext);
e.Graphics.ReleaseHdc(handleDeviceContext);
// If's there's a GDI draw handler, then call it.
DoGDIDraw(new RenderEventArgs(e.Graphics));
// Stop the stopwatch.
stopwatch.Stop();
// Store the frame time.
frameTime = stopwatch.Elapsed.TotalMilliseconds;
}
/// <summary>
/// Renders to the specified graphics.
/// </summary>
/// <param name="graphics">The graphics to render to.</param>
protected void Render(Graphics graphics)
{
// Start the stopwatch so that we can time the rendering.
stopwatch.Restart();
// Make sure it's our instance of openSharpGL that's active.
OpenGL.MakeCurrent();
// If there is a draw handler, then call it.
DoOpenGLDraw(new RenderEventArgs(graphics));
// Draw the FPS.
if (DrawFPS)
{
OpenGL.DrawText(5, 5, 1.0f, 0.0f, 0.0f, "Courier New", 12.0f,
string.Format("Draw Time: {0:0.0000} ms ~ {1:0.0} FPS", frameTime, 1000.0 / frameTime));
OpenGL.Flush();
}
// Blit our offscreen bitmap.
var handleDeviceContext = graphics.GetHdc();
OpenGL.Blit(handleDeviceContext);
graphics.ReleaseHdc(handleDeviceContext);
// Perform GDI drawing.
if (OpenGL.RenderContextProvider != null && OpenGL.RenderContextProvider.GDIDrawingEnabled)
{
DoGDIDraw(new RenderEventArgs(graphics));
}
// Stop the stopwatch.
stopwatch.Stop();
// Store the frame time.
frameTime = stopwatch.Elapsed.TotalMilliseconds;
}
private void runGlThread(object args)
{
var inputs = (Tuple<CancellationToken>) args;
var cancelToken = inputs.Item1;
var gl = new OpenGL();
int localRenderWidth = 1;
int localRenderHeight = 1;
if (!createRenderContext(gl, localRenderWidth, localRenderHeight))
{
//TODO better error handling here
Console.WriteLine("*** Unable to create OpenGL Render Context");
return;
}
uint activeVaoHandle;
uint activeGlProgramHandle;
initGLObjects(gl, out activeVaoHandle, out activeGlProgramHandle);
ActiveProgramValues localActiveProgramValues = null;
while (!cancelToken.IsCancellationRequested)
{
bool resizeRenderContext;
lock (this)
{
if (!ReferenceEquals(localActiveProgramValues, activeProgramValues))
{
localActiveProgramValues = activeProgramValues;
if (localActiveProgramValues.Valid)
{
linkProgram(gl, localActiveProgramValues, activeGlProgramHandle);
} else
{
// Leave the old program running. This prevents the user from seeing
// a black screen while they are in the process of modifying a shader.
}
}
resizeRenderContext = localRenderWidth != renderWidth || localRenderHeight != renderHeight;
localRenderWidth = renderWidth;
localRenderHeight = renderHeight;
}
if (resizeRenderContext)
{
localActiveProgramValues = null;
deleteGlObjects(gl, activeVaoHandle, activeGlProgramHandle);
if (!createRenderContext(gl, localRenderWidth, localRenderHeight))
{
//TODO better error handling here
Console.WriteLine("*** Unable to resize OpenGL Render Context");
return;
}
initGLObjects(gl, out activeVaoHandle, out activeGlProgramHandle);
}
gl.Clear(OpenGL.GL_COLOR_BUFFER_BIT);
gl.BindVertexArray(activeVaoHandle);
gl.UseProgram(activeGlProgramHandle);
gl.DrawArrays(OpenGL.GL_TRIANGLES, 0, 3);
// do some other stuff while the image is rendering, to give it a chance to finish
ShaderCompiler.ValidateShaders(gl);
var provider = gl.RenderContextProvider as FBORenderContextProvider;
Debug.Assert(provider != null, "Render context provider is not an FBO renderer");
//TODO this call to blit will probably block. Find a better way to copy the image to CPU memory.
gl.Blit(IntPtr.Zero);
var hBitmap = provider.InternalDIBSection.HBitmap;
if (hBitmap != IntPtr.Zero)
{
var bitmap = GetFormattedBitmapSource(hBitmap);
// the bitmap needs to be frozen in order to share it between threads
bitmap.Freeze();
ImageRendered(bitmap);
}
}
deleteGlObjects(gl, activeVaoHandle, activeGlProgramHandle);
}
