private void VisionControl_Render(object sender, OpenGL.GlControlEventArgs e)
{
#region Draw Basic Picture
// Update image input
_Framebuffer.BindDraw(_GraphicsContext);
Gl.Viewport(0, 0, (int)_Framebuffer.Width, (int)_Framebuffer.Height);
_Framebuffer.Clear(_GraphicsContext, ClearBufferMask.ColorBufferBit);
{ // Draw a quad
Matrix4x4f quadProj = Matrix4x4f.Ortho2D(-1.0f, +1.0f, -1.0f, +1.0f);
Matrix4x4f quadModel = new Matrix4x4f();
_Angle += 1.0f;
quadModel.RotateZ(10.0f * (float)Math.Cos(Angle.ToRadians(_Angle)));
_GraphicsContext.Bind(_ProgramStd);
_ProgramStd.SetUniform(_GraphicsContext, "glo_ModelViewProjection", quadProj * quadModel);
_ProgramStd.SetUniform(_GraphicsContext, "glo_UniformColor", Vertex4f.One);
_ArraysQuad.Draw(_GraphicsContext, _ProgramStd);
}
_Framebuffer.UnbindDraw(_GraphicsContext);
#endregion
#region Track Corners
// Read back image input pixels
using (OpenGL.Objects.Image imageInput = _FramebufferTexture.Get(_GraphicsContext, PixelLayout.RGB24, 0)) {
// Copy the input RGB frame from OpenGL to OpenVX
Rectangle cv_rgb_image_region = new Rectangle();
cv_rgb_image_region.StartX = 0;
cv_rgb_image_region.StartY = 0;
cv_rgb_image_region.EndX = imageInput.Width;
cv_rgb_image_region.EndY = imageInput.Height;
ImagePatchAddressing cv_rgb_image_layout = new ImagePatchAddressing();
cv_rgb_image_layout.StrideX = 3;
cv_rgb_image_layout.StrideY = (int)imageInput.Stride;
VX.CopyImagePatch(_ImageInput, ref cv_rgb_image_region, 0, ref cv_rgb_image_layout, imageInput.ImageBuffer, Accessor.WriteOnly, MemoryType.Host);
}
// Now that input RGB image is ready, just run a graph.
// Run Harris at the beginning to initialize the previous keypoints,
// on other frames run the tracking graph.
VX.ProcessGraph(_DetectCorners ? _GraphHarris : _GraphTrack);
_DetectCorners = false;
#endregion
#region Store Markers on GPU
// To mark the keypoints in display, you need to access the output
// keypoint array and draw each item on the output window using gui.DrawArrow().
UIntPtr num_corners = UIntPtr.Zero;
uint num_tracking = 0;
_KeypointsPrevious = VX.GetReferenceFromDelay(_KeypointsDelay, -1);
_KeypointsCurrent = VX.GetReferenceFromDelay(_KeypointsDelay, 0);
VX.Query(_KeypointsPrevious, ArrayAttribute.Numitems, out num_corners);
if (num_corners.ToUInt64() > 0)
{
UIntPtr kp_old_stride = UIntPtr.Zero, kp_new_stride = UIntPtr.Zero;
MapId kp_old_map = new MapId(), kp_new_map = new MapId();
IntPtr kp_old_buf, kp_new_buf;
VX.MapArrayRange(_KeypointsPrevious, (UIntPtr)0, num_corners, ref kp_old_map, ref kp_old_stride, out kp_old_buf, Accessor.ReadOnly, MemoryType.Host, 0);
VX.MapArrayRange(_KeypointsCurrent, (UIntPtr)0, num_corners, ref kp_new_map, ref kp_new_stride, out kp_new_buf, Accessor.ReadOnly, MemoryType.Host, 0);
_BufferOpticalMarkers.Map(_GraphicsContext, BufferAccess.WriteOnly);
for (uint i = 0; i < num_corners.ToUInt64(); i++)
{
KeyPoint kp_old = VX.ArrayItem <KeyPoint>(kp_old_buf, i, kp_old_stride);
KeyPoint kp_new = VX.ArrayItem <KeyPoint>(kp_new_buf, i, kp_new_stride);
if (kp_new.TrackingStatus != 0)
{
Vertex2f vOld = new Vertex2f(kp_old.X / 1024.0f, kp_old.Y / 1024.0f);
Vertex2f vNew = new Vertex2f(kp_new.X / 1024.0f, kp_new.Y / 1024.0f);
_BufferOpticalMarkers.SetElement(vOld, (num_tracking * 2) + 0, 0);
_BufferOpticalMarkers.SetElement(vNew, (num_tracking * 2) + 1, 0);
num_tracking++;
}
}
_BufferOpticalMarkers.Unmap(_GraphicsContext);
VX.UnmapArrayRange(_KeypointsPrevious, kp_old_map);
VX.UnmapArrayRange(_KeypointsCurrent, kp_new_map);
}
#endregion
Gl.Viewport(0, 0, VisionControl.Width, VisionControl.Height);
Gl.ClearColor(1.0f, 0.0f, 0.0f, 0.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
#region Draw Input Image
_GraphicsContext.Bind(_ProgramStdTex);
_ProgramStdTex.SetUniform(_GraphicsContext, "glo_ModelViewProjection", Matrix4x4f.Ortho2D(0.0f, 1.0f, 0.0f, 1.0f));
_ProgramStdTex.SetUniform(_GraphicsContext, "glo_Texture", _FramebufferTexture);
_ArraysPostQuad.Draw(_GraphicsContext, _ProgramStdTex);
#endregion
#region Draw Markers
if (num_tracking > 0)
{
_GraphicsContext.Bind(_ProgramStd);
_ProgramStd.SetUniform(_GraphicsContext, "glo_ModelViewProjection", Matrix4x4f.Ortho2D(0.0f, 1.0f, 0.0f, 1.0f));
_ProgramStd.SetUniform(_GraphicsContext, "glo_UniformColor", new Vertex4f(1.0f, 0.0f, 0.0f, 1.0f));
_ArraysOpticalMarkers.Draw(_GraphicsContext, _ProgramStd, 0, 0, num_tracking * 2);
}
#endregion
// Increase the age of the delay objects to make the current entry become previous entry
VX.AgeDelay(_PyramidDelay);
VX.AgeDelay(_KeypointsDelay);
}