/// <summary>
/// Создает камеру, которую можно крутить движением мышки
/// </summary>
/// <param name="eventSource">Control,с которого обрабатываются события </param>
/// <param name="cameraLocation">Исходное положение камеры</param>
public TrackballCamera(Control eventSource, Frame3D cameraLocation)
: base(eventSource.ClientSize.Width / (double)eventSource.ClientSize.Height)
{
EventSource = eventSource;
Vector3 tempLoc = cameraLocation.ToDirectXVector();
_cameraLocation = new Vector3(Math.Abs(tempLoc.X), 0, tempLoc.Z);
Angle ang = Geometry.Atan2(tempLoc.Y, tempLoc.X);
_rotationMatrix = Matrix.RotationZ(-(float)ang.Radian);
_radius = _cameraLocation.Length();
Scale = 1;
}
/// <summary>
/// По перемещению мышки вычисляет перемешение камеры:
/// матрицу для поворота и перемещение по вертикальной оси
/// </summary>
/// <param name="currentPosition">Положение мышки</param>
protected virtual void Track(Point currentPosition)
{
Vector3 currentPosition3D = ProjectToTrackball(
_eventSource.ClientRectangle.Width,
_eventSource.ClientRectangle.Height, currentPosition);
Vector3 diff = currentPosition3D - _previousPosition3D;
_rotationMatrix *= Matrix.RotationZ(diff.X);
float tempz = _cameraLocation.Z + diff.Y * 100;
var tempx = (float)Math.Sqrt(_radius * _radius - tempz * tempz);
if (tempx > 1 && tempz > 0)
{
_cameraLocation.X = tempx;
_cameraLocation.Z = tempz;
}
_previousPosition3D = currentPosition3D;
}
/// <summary> Draws a line. </summary>
/// <param name="vecStartPos"> The vector start position. </param>
/// <param name="vecEndPos"> The vector end position. </param>
/// <param name="width"> The width. </param>
/// <param name="color"> The color. </param>
public static void DrawLineEx(Vector3 vecStartPos, Vector3 vecEndPos, float width, Color color)
{
const int numCorners = 20;
Vector3 start = new Vector3(0.5f, 0.0f, 0.0f);
Vector3 end = new Vector3(-0.5f, 0.0f, 0.0f);
if (_lineVertices == null)
{
_lineVertices = new ColoredVertex[numCorners * 2];
for (int i = 0; i < numCorners; i++)
{
Vector3 offset = new Vector3(0.0f, (float)Math.Cos((2.0f * Math.PI) / numCorners * i),
(float)Math.Sin((2.0f * (float)Math.PI) / numCorners * i));
Vector3 startPoint = start + offset;
ColoredVertex startVert = new ColoredVertex(new Vector3(startPoint.X, startPoint.Y, startPoint.Z), color.ToArgb());
_lineVertices[i] = startVert;
Vector3 endPoint = end + offset;
ColoredVertex endVert = new ColoredVertex(new Vector3(endPoint.X, endPoint.Y, endPoint.Z), color.ToArgb());
_lineVertices[numCorners + i] = endVert;
}
}
if (_lineFaceIndices == null)
{
_lineFaceIndices = new int[numCorners * 2 * 3]; // The number of faces is the same as the number of corners: 2 tris per face, 3 inds per tri
for (int i = 0; i < numCorners; i++)
{
_lineFaceIndices[i * 6 + 0] = i; // ring 1, vert i
_lineFaceIndices[i * 6 + 1] = numCorners + i; // ring 2, vert i
_lineFaceIndices[i * 6 + 2] = (i + 1) % numCorners; // ring 1, vert i + 1
_lineFaceIndices[i * 6 + 3] = (i + 1) % numCorners; // ring 1, vert i + 1
_lineFaceIndices[i * 6 + 4] = i == numCorners - 1 ? numCorners : numCorners + i + 1; // ring 2, vert i + 1
_lineFaceIndices[i * 6 + 5] = numCorners + i; // ring 2, vert i
}
}
Vector3 startToEnd = vecEndPos - vecStartPos;
Matrix scaling = Matrix.Scaling(Vector3.Distance(vecStartPos, vecEndPos), width / 2, width / 2);
Matrix rotationY = Matrix.RotationY(-(float)Math.Asin(startToEnd.Z / Vector3.Distance(vecStartPos, vecEndPos)));
Matrix rotationZ = Matrix.RotationZ((float)Math.Atan2(startToEnd.Y, startToEnd.X));
Matrix rotation = Matrix.Multiply(rotationY, rotationZ);
Matrix translation = Matrix.Translation(start.X + startToEnd.X / 2, start.Y + startToEnd.Y / 2, start.Z + startToEnd.Z / 2);
Matrix world = Matrix.Multiply(Matrix.Multiply(scaling, rotation), translation);
Device.SetTransform(TransformState.World, world);
var oldDecl = Device.VertexDeclaration;
using (var newDecl = ColoredVertex.GetDecl(Device))
{
Device.VertexDeclaration = newDecl;
Device.DrawIndexedUserPrimitives(PrimitiveType.TriangleList, 0, numCorners * 2, numCorners * 2, _lineFaceIndices, Format.Index32, _lineVertices, ColoredVertex.Stride);
Device.VertexDeclaration = oldDecl;
}
}
