/// <summary> /// For custom OpenGL layers, perform immediate drawing. /// </summary> /// <param name="pGlobeViewer"></param> /// <remarks>This is where you should add your drawings on the Globe. This method must be overridden in /// your inheriting class. DrawImmediate together with IGlobeDisplayEvents::BeforeDraw and IGlobeDisplayEvents::AfterDraw /// is the only safe place where the OpenGL state is ready for custom actions.</remarks> public abstract void DrawImmediate(IGlobeViewer pGlobeViewer);
/// <summary>
/// This is where the actual drawing takes place.
/// </summary>
/// <param name="pGlobeViewer"></param>
public override void DrawImmediate(IGlobeViewer pGlobeViewer)
{
//make sure that the layer is valid, visible and that the main table exists
if (!m_bVisible || !m_bValid | null == m_table)
return;
//get the OpenGL rendering mode
uint mode;
unsafe
{
int m;
GL.glGetIntegerv(GL.GL_RENDER_MODE, &m);
mode = (uint)m;
//GL.glGetIntegerv(GL.GL_RENDER_MODE, out mode);
}
//get the OpenGL matrices (required for the viewport filtering and the billboard orientation)
GL.glGetDoublev(GL.GL_MODELVIEW_MATRIX, m_modelViewMatrix);
GL.glGetIntegerv(GL.GL_VIEWPORT, m_viewport);
GL.glGetDoublev(GL.GL_PROJECTION_MATRIX, m_projMatrix);
//populate the billboard matrix
m_billboardMatrix[0] = m_modelViewMatrix[0];
m_billboardMatrix[1] = m_modelViewMatrix[4];
m_billboardMatrix[2] = m_modelViewMatrix[8];
m_billboardMatrix[3] = 0;
m_billboardMatrix[4] = m_modelViewMatrix[1];
m_billboardMatrix[5] = m_modelViewMatrix[5];
m_billboardMatrix[6] = m_modelViewMatrix[9];
m_billboardMatrix[7] = 0;
m_billboardMatrix[8] = m_modelViewMatrix[2];
m_billboardMatrix[9] = m_modelViewMatrix[6];
m_billboardMatrix[10] = m_modelViewMatrix[10];
m_billboardMatrix[11] = 0;
m_billboardMatrix[12] = 0;
m_billboardMatrix[13] = 0;
m_billboardMatrix[14] = 0;
m_billboardMatrix[15] = 1;
ISceneViewer sceneViewer = pGlobeViewer.GlobeDisplay.ActiveViewer;
//only once, create display lists and do initializations
if (!m_bDisplayListCreated)
{
CreateDisplayLists();
m_globeDisplay = pGlobeViewer.GlobeDisplay;
}
//get the globeViewUtil which allow to convert between the different globe coordinate systems
m_globeViewUtil = sceneViewer.Camera as IGlobeViewUtil;
IGlobeViewUtil globeViewUtil = sceneViewer.Camera as IGlobeViewUtil;
IGlobeAdvancedOptions advOpt = m_globeDisplay.AdvancedOptions;
//the ClipNear value is required for the viewport filtering (since we don't
//want to draw an item which is beyond the clipping planes).
double clipNear = advOpt.ClipNear;
double dblObsX, dblObsY, dblObsZ, dMagnitude;
ICamera camera = pGlobeViewer.GlobeDisplay.ActiveViewer.Camera;
//query the camera location in geocentric coordinate (OpenGL coord system)
camera.Observer.QueryCoords(out dblObsX, out dblObsY);
dblObsZ = camera.Observer.Z;
double lat, lon, X = 0.0, Y = 0.0, Z = 0.0;
//iterate through all the records of the layer, test whether the item is within the
//viewport are and draw it onto the globe.
foreach (DataRow rec in m_table.Rows)
{
lat = Convert.ToDouble(rec[3]);
lon = Convert.ToDouble(rec[4]);
X = Convert.ToDouble(rec[5]);
Y = Convert.ToDouble(rec[6]);
Z = Convert.ToDouble(rec[7]);
#region get the OGL geocentric coordinates X,Y,Z
if (X == 0.0 && Y == 0.0 && Z == 0.0)
{
//calculate the geocentric coordinates
globeViewUtil.GeographicToGeocentric(lon, lat, 1000.0, out X, out Y, out Z);
//write the calculated geocentric coordinate to the table
lock (m_table)
{
rec[5] = X;
rec[6] = Y;
rec[7] = Z;
rec.AcceptChanges();
}
}
#endregion
//make sure that the item is inside the viewport, otherwise no need to draw it
if (!InsideViewport(X, Y, Z, clipNear, mode))
continue;
//get the distance from the camera to the drawn item.
//This distance will determine whether to draw the item as a dot or as
//a full icon.
m_vector3D.SetComponents(dblObsX - X, dblObsY - Y, dblObsZ - Z);
dMagnitude = m_vector3D.Magnitude;
//call the drawing method
DrawItem(rec, dMagnitude);
}
}
