/// <summary>
/// Returns last vertex's id of picked geometry if the geometry represented by <paramref name="stageVertexID"/> belongs to this <paramref name="element"/> instance.
/// <para>Returns false if <paramref name="stageVertexID"/> the primitive is in some other element.</para>
/// </summary>
/// <param name="element"></param>
/// <param name="stageVertexID"></param>
/// <param name="lastVertexID"></param>
/// <returns></returns>
public static bool GetLastVertexIDOfPickedGeometry(this IColorCodedPicking element, uint stageVertexID, out uint lastVertexID)
{
lastVertexID = uint.MaxValue;
bool result = false;
if (element != null)
{
if (stageVertexID < element.PickingBaseID) // ID is in some previous element.
{
return(false);
}
uint vertexCount = element.GetVertexCount();
uint id = stageVertexID - element.PickingBaseID;
if (id < vertexCount)
{
lastVertexID = id;
result = true;
}
else // ID is in some subsequent element.
{
result = false;
}
}
return(result);
}
/// <summary>
/// Render the element that inherts <see cref="IColorCodedPicking"/> for color coded picking.
/// </summary>
/// <param name="pickable"></param>
/// <param name="gl"></param>
/// <param name="renderMode"></param>
public virtual void RenderForPicking(IColorCodedPicking pickable, RenderEventArgs e)
{
if (pickable != null)
{
pickable.PickingBaseID = this.RenderedVertexCount;
// render the element.
pickable.Render(e);
uint rendered = this.RenderedVertexCount + pickable.GetVertexCount();
if (this.RenderedVertexCount <= rendered)
{
this.RenderedVertexCount = rendered;
}
else
{
throw new OverflowException(
string.Format("Too many geometries({0} + {1} > {2}) for color coded picking.",
this.RenderedVertexCount, pickable.GetVertexCount(), uint.MaxValue));
}
}
}
/// <summary>
/// Render the element that inherts <see cref="IColorCodedPicking"/> for color coded picking.
/// </summary>
/// <param name="pickable"></param>
/// <param name="gl"></param>
/// <param name="renderMode"></param>
public virtual void RenderForPicking(IColorCodedPicking pickable, RenderEventArgs e)
{
if (pickable != null)
{
pickable.PickingBaseID = this.RenderedVertexCount;
// render the element.
IRenderable renderable = pickable;
renderable.Render(e);
uint rendered = this.RenderedVertexCount + pickable.GetVertexCount();
if (this.RenderedVertexCount <= rendered)
{
this.RenderedVertexCount = rendered;
}
else
{
throw new OverflowException(
string.Format("Too many geometries({0} + {1} > {2}) for color coded picking.",
this.RenderedVertexCount, pickable.GetVertexCount(), uint.MaxValue));
}
}
}
/// <summary>
/// Render the element that inherts <see cref="IColorCodedPicking"/> for color coded picking.
/// </summary>
/// <param name="picking"></param>
/// <param name="gl"></param>
/// <param name="renderMode"></param>
public virtual void RenderForPicking(IColorCodedPicking picking, OpenGL gl, SceneGraph.Core.RenderMode renderMode)
{
if (picking != null)
{
picking.PickingBaseID = this.RenderedVertexCount;
// render the element.
SharpGL.SceneGraph.Core.IRenderable renderable = picking;
renderable.Render(gl, renderMode);
uint rendered = this.RenderedVertexCount + picking.GetVertexCount();
if (this.RenderedVertexCount <= rendered)
{
this.RenderedVertexCount = rendered;
}
else
{
throw new OverflowException(
string.Format("Too many geometries({0} + {1} > {2}) for color coded picking.",
this.RenderedVertexCount, picking.GetVertexCount(), uint.MaxValue));
}
}
}
/// <summary>
/// Get geometry's count according to specified <paramref name="mode"/>.
/// <para>Returns false if the <paramref name="element"/> is null.</para>
/// </summary>
/// <param name="element"></param>
/// <param name="mode"></param>
/// <param name="count"></param>
/// <returns></returns>
public static bool GetGeometryCount(this IColorCodedPicking element, PrimitiveModes mode, out uint count)
{
bool result = false;
count = uint.MaxValue;
if (element != null)
{
uint vertexCount = element.GetVertexCount();
switch (mode)
{
case PrimitiveModes.Points:
count = vertexCount;
break;
case PrimitiveModes.Lines:
count = vertexCount / 2;
break;
case PrimitiveModes.LineLoop:
count = vertexCount;
break;
case PrimitiveModes.LineStrip:
count = vertexCount - 1;
break;
case PrimitiveModes.Triangles:
count = vertexCount / 3;
break;
case PrimitiveModes.TriangleStrip:
count = vertexCount - 2;
break;
case PrimitiveModes.TriangleFan:
count = vertexCount - 2;
break;
case PrimitiveModes.Quads:
count = vertexCount / 4;
break;
case PrimitiveModes.QuadStrip:
count = vertexCount / 2 - 1;
break;
case PrimitiveModes.Polygon:
count = 1;
break;
default:
throw new NotImplementedException();
}
result = true;
}
return(result);
}
/// <summary>
/// Get geometry's index(start from 0) according to <paramref name="lastVertexID"/> and <paramref name="mode"/>.
/// <para>Returns false if failed.</para>
/// </summary>
/// <param name="element"></param>
/// <param name="mode"></param>
/// <param name="lastVertexID">Refers to the last vertex that constructs the primitive.
/// <para>Ranges from 0 to (<paramref name="element"/>'s vertices' count - 1).</para></param>
/// <param name="index"></param>
/// <returns></returns>
public static bool GetGeometryIndex(this IColorCodedPicking element, PrimitiveModes mode, uint lastVertexID, out uint index)
{
index = uint.MaxValue;
if (element == null)
{
return(false);
}
uint vertexCount = element.GetVertexCount();
if (lastVertexID < vertexCount)
{
switch (mode)
{
case PrimitiveModes.Points:
// vertexID should range from 0 to vertexCount - 1.
index = lastVertexID;
break;
case PrimitiveModes.Lines:
// vertexID should range from 0 to vertexCount - 1.
index = lastVertexID / 2;
break;
case PrimitiveModes.LineLoop:
// vertexID should range from 0 to vertexCount.
if (lastVertexID == 0) // This is the last primitive.
{
index = vertexCount - 1;
}
else
{
index = lastVertexID - 1;
}
break;
case PrimitiveModes.LineStrip:
index = lastVertexID - 1; // If lastVertexID is 0, this returns -1.
break;
case PrimitiveModes.Triangles:
index = lastVertexID / 3;
break;
case PrimitiveModes.TriangleStrip:
index = lastVertexID - 2; // if lastVertexID is 0 or 1, this returns -2 or -1.
break;
case PrimitiveModes.TriangleFan:
index = lastVertexID - 2; // if lastVertexID is 0 or 1, this returns -2 or -1.
break;
case PrimitiveModes.Quads:
index = lastVertexID / 4;
break;
case PrimitiveModes.QuadStrip:
index = lastVertexID / 2 - 1; // If lastVertexID is 0 or 1, this returns -1.
break;
case PrimitiveModes.Polygon:
index = 0;
break;
default:
throw new NotImplementedException();
}
}
return(true);
}
