/// <summary>
/// Convert <see cref="BeginMode"/> to <see cref="GeometryTypes"/>.
/// </summary>
/// <param name="mode"></param>
/// <returns></returns>
public static GeometryTypes ToGeometryType(this PrimitiveModes mode)
{
GeometryTypes result = GeometryTypes.Point;
switch (mode)
{
case PrimitiveModes.Points:
result = GeometryTypes.Point;
break;
case PrimitiveModes.Lines:
result = GeometryTypes.Line;
break;
case PrimitiveModes.LineLoop:
result = GeometryTypes.Line;
break;
case PrimitiveModes.LineStrip:
result = GeometryTypes.Line;
break;
case PrimitiveModes.Triangles:
result = GeometryTypes.Triangle;
break;
case PrimitiveModes.TriangleStrip:
result = GeometryTypes.Triangle;
break;
case PrimitiveModes.TriangleFan:
result = GeometryTypes.Triangle;
break;
case PrimitiveModes.Quads:
result = GeometryTypes.Quad;
break;
case PrimitiveModes.QuadStrip:
result = GeometryTypes.Quad;
break;
case PrimitiveModes.Polygon:
result = GeometryTypes.Polygon;
break;
default:
throw new NotImplementedException();
}
return(result);
}
/// <summary>
/// Get the primitive of <paramref name="element"/> according to vertex's id.
/// <para>Returns <code>null</code> if <paramref name="element"/> is null or <paramref name="stageVertexID"/> does not belong to any of this <paramref name="element"/>'s vertices.</para>
/// <para>Note: the <paramref name="stageVertexID"/> refers to the last vertex that constructs the primitive. And it's unique in scene's all elements.</para>
/// </summary>
/// <typeparam name="T">Subclass of <see cref="IPickedGeometry"/></typeparam>
/// <param name="element">the scene's element that contains the primitive.</param>
/// <param name="mode">specifies what type of primitive it is.</param>
/// <param name="stageVertexID">Refers to the last vertex that constructs the primitive. And it's unique in scene's all elements.</param>
/// <param name="positions">element's vertices' position array.</param>
/// <returns></returns>
public static T TryPick <T>(
this IColorCodedPicking element, PrimitiveModes mode, uint stageVertexID, float[] positions)
where T : IPickedGeometry, new()
{
if (positions == null)
{
throw new ArgumentNullException("positions");
}
T pickedGeometry = element.TryPick <T>(mode, stageVertexID);
// Fill primitive's positions and colors. This maybe changes much more than lines above in second dev.
if (pickedGeometry != null)
{
uint lastVertexID;
if (element.GetLastVertexIDOfPickedGeometry(stageVertexID, out lastVertexID))
{
int vertexCount = pickedGeometry.GeometryType.GetVertexCount();
if (vertexCount == -1)
{
vertexCount = positions.Length / 3;
}
float[] geometryPositions = new float[vertexCount * 3];
uint i = lastVertexID * 3 + 2;
for (int j = (geometryPositions.Length - 1); j >= 0; i--, j--)
{
if (i == uint.MaxValue)// This is when mode is GL_LINE_LOOP.
{
i = (uint)positions.Length - 1;
}
geometryPositions[j] = positions[i];
}
var poss = new vec3[vertexCount];
for (int t = 0; t < vertexCount; t++)
{
poss[t] = new vec3(geometryPositions[t * 3 + 0], geometryPositions[t * 3 + 1], geometryPositions[t * 3 + 2]);
}
pickedGeometry.positions = poss;
}
}
return(pickedGeometry);
}
/// <summary>
/// Get the primitive of <paramref name="element"/> according to vertex's id.
/// <para>Returns <code>null</code> if <paramref name="element"/> is null or <paramref name="stageVertexID"/> is not in the range of this <paramref name="element"/>.</para>
/// <para>Note: the <paramref name="stageVertexID"/> Refers to the last vertex that constructs the primitive. And it's unique in scene's all elements.</para>
/// <para>Note: The result's positions property is not set up as there will be different kinds of storage mode for positions(float[], IntPtr, etc). You have to initialize the positions property and fill correct position information afterwards.</para>
/// </summary>
/// <typeparam name="T">Sub type of <see cref="IPickedGeometry"/></typeparam>
/// <param name="element">the scene's element that contains the primitive.</param>
/// <param name="mode">specifies what type of primitive it is.</param>
/// <param name="stageVertexID">Refers to the last vertex that constructs the primitive. And it's unique in scene's all elements.</param>
/// <returns></returns>
public static T TryPick <T>(
this IColorCodedPicking element, PrimitiveModes mode, uint stageVertexID)
where T : IPickedGeometry, new()
{
T pickedGeometry = default(T);
if (element != null)
{
uint lastVertexID;
if (element.GetLastVertexIDOfPickedGeometry(stageVertexID, out lastVertexID))
{
pickedGeometry = new T();
pickedGeometry.GeometryType = mode.ToGeometryType();
pickedGeometry.StageVertexID = stageVertexID;
pickedGeometry.From = element;
}
}
return(pickedGeometry);
}
private void InitVAO()
{
primitiveMode = PrimitiveModes.Points;
GL.GenVertexArrays(1, vao);
GL.BindVertexArray(vao[0]);
// Create a vertex buffer for the vertex data.
{
UnmanagedArray <vec3> in_Position = new UnmanagedArray <vec3>(1);
in_Position[0] = this.position;
uint[] ids = new uint[1];
GL.GenBuffers(1, ids);
GL.BindBuffer(BufferTarget.ArrayBuffer, ids[0]);
GL.BufferData(BufferTarget.ArrayBuffer, in_Position, BufferUsage.StaticDraw);
GL.VertexAttribPointer(attributeIndexPosition, 3, GL.GL_FLOAT, false, 0, IntPtr.Zero);
GL.EnableVertexAttribArray(attributeIndexPosition);
}
// Unbind the vertex array, we've finished specifying data for it.
GL.BindVertexArray(0);
}
public static void Begin(PrimitiveModes primitiveMode)
{
GL.Begin((uint)primitiveMode);
}
/// <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);
}
private void InitVAO()
{
primitiveMode = PrimitiveModes.Points;
GL.GenVertexArrays(1, vao);
GL.BindVertexArray(vao[0]);
// Create a vertex buffer for the vertex data.
{
UnmanagedArray<vec3> in_Position = new UnmanagedArray<vec3>(1);
in_Position[0] = this.position;
uint[] ids = new uint[1];
GL.GenBuffers(1, ids);
GL.BindBuffer(BufferTarget.ArrayBuffer, ids[0]);
GL.BufferData(BufferTarget.ArrayBuffer, in_Position, BufferUsage.StaticDraw);
GL.VertexAttribPointer(attributeIndexPosition, 3, GL.GL_FLOAT, false, 0, IntPtr.Zero);
GL.EnableVertexAttribArray(attributeIndexPosition);
}
// Unbind the vertex array, we've finished specifying data for it.
GL.BindVertexArray(0);
}
public static void Begin(PrimitiveModes primitiveMode)
{
GL.Begin((uint)primitiveMode);
}
