public static TVertex CrossProduct(TVertex P1, TVertex P2)
{
TVertex Result = new TVertex(P1.Y * P2.Z - P1.Z * P2.Y,
P1.Z * P2.X - P1.X * P2.Z,
P1.X * P2.Y - P1.Y * P2.X);
return(Result);
}
public void AddChildObject(CObject3D ChildObj, TVertex AxisPointA, TVertex AxisPointB)
{
Children.Add(ChildObj);
ChildObj.Father = this;
ChildObj.OriginalAxisPointA = AxisPointA;
ChildObj.TransformedAxisPointA = AxisPointA;
ChildObj.OriginalAxisPointB = AxisPointB;
ChildObj.TransformedAxisPointB = AxisPointB;
}
public void SetPos(TVertex NewPos)
{
CurrentPos = NewPos;
TMat4x4 TransMat = TMat4x4.ZeroMat();
TransMat.SetTrans(NewPos.X, NewPos.Y, NewPos.Z);
SetMatrix(TransMat);
}
public TVertex MulVertex(TVertex v)
{
TVertex Result;
Result.X = v.X * m00 + v.Y * m10 + v.Z * m20 + m30;
Result.Y = v.X * m01 + v.Y * m11 + v.Z * m21 + m31;
Result.Z = v.X * m02 + v.Y * m12 + v.Z * m22 + m32;
return(Result);
}
public TVertex FindNewPosXZ(float DeltaStep)
{
float AngleInRad = Math3D.Deg2Rad(Orientation);
TVertex Result = new TVertex(CurrentPos.X + (float)Math.Sin(AngleInRad) * DeltaStep,
CurrentPos.Y,
CurrentPos.Z + (float)Math.Cos(AngleInRad) * DeltaStep);
return(Result);
}
// Return a normalized vector
public static TVertex CalcNormalizedVec(TVertex p1, TVertex p2)
{
float Mag;
TVertex Result;
Mag = (float)Math.Sqrt(Sqr(p1.X - p2.X) + Sqr(p1.Y - p2.Y) + Sqr(p1.Z - p2.Z));
Result.X = (p2.X - p1.X) / Mag;
Result.Y = (p2.Y - p1.Y) / Mag;
Result.Z = (p2.Z - p1.Z) / Mag;
return(Result);
}
public void GotoNewPosXZ(TVertex NewPos)
{
TMat4x4 TransMat = TMat4x4.ZeroMat();
TMat4x4 RotMatY = TMat4x4.ZeroMat();
CurrentPos = NewPos;
TransMat.SetTrans(NewPos.X, NewPos.Y, NewPos.Z);
RotMatY.SetRotateY(Math3D.Deg2Rad(Orientation + OrientationOffset));
SetMatrix(RotMatY.MulMat(TransMat));
}
public static TVertex CalcFaceNormal(TVertex P1, TVertex P2, TVertex P3)
{
P2.X = P2.X - P1.X;
P2.Y = P2.Y - P1.Y;
P2.Z = P2.Z - P1.Z;
P3.X = P3.X - P1.X;
P3.Y = P3.Y - P1.Y;
P3.Z = P3.Z - P1.Z;
return(CrossProduct(P2, P3));
}
public void Assign(CObject3D CopyFrom)
{
ObjectMat = CopyFrom.ObjectMat;
VertexTable = new TVertex[CopyFrom.VertexTable.Length];
Array.Copy(CopyFrom.VertexTable, VertexTable, VertexTable.Length);
FaceTable = new TFace3D[CopyFrom.FaceTable.Length];
Array.Copy(CopyFrom.FaceTable, FaceTable, FaceTable.Length);
ObjectMat = CopyFrom.ObjectMat;
CombinedMatrix = CopyFrom.CombinedMatrix;
Children = CopyFrom.Children;
ChildrenAxes = CopyFrom.ChildrenAxes;
Father = CopyFrom.Father;
OriginalAxisPointA = CopyFrom.OriginalAxisPointA;
OriginalAxisPointB = CopyFrom.OriginalAxisPointB;
}
private void CalculatePolygonFactors(TVertex Normal, TVertex PointOnPlane, float PerspFactor, out float M, out float N, out float K)
{
float A, B, C, D;
A = Normal.X;
B = Normal.Y;
C = Normal.Z;
D = Math3D.DotProduct(Normal, PointOnPlane);
if (D != 0)
{
M = A / (D * PerspFactor);
N = B / (D * PerspFactor);
K = C / D;
}
else
{
M = 0;
N = 0;
K = 0;
}
}
public TVertex TransformVertex(TVertex v)
{
return(CombinedMatrix.MulVertex(v));
}
// Set rotation matrix around arbitrary axis
public void SetArbitraryRot(TVertex P1, TVertex P2, float Angle)
{
TMat4x4 MTra = ZeroMat(), MRo_X = ZeroMat(), MRo_Y = ZeroMat(), MRo_Z = ZeroMat(), TempM = ZeroMat();
float D;
// Find the direction cosines of the arbitrary axis P1-->P2 .
// The direction cosines will be in C
TVertex C = Math3D.CalcNormalizedVec(P1, P2);
D = (float)Math.Sqrt(Math3D.Sqr(C.Y) + Math3D.Sqr(C.Z));
// Special case for the X axis
if (D == 0)
{
MTra.SetTrans(-P1.X, -P1.Y, -P1.Z);
MRo_X.SetRotateX(Angle);
TempM = MTra.MulMat(MRo_X);
MTra.SetTrans(P1.X, P1.Y, P1.Z);
this = TempM.MulMat(MTra);
}
else
{
MTra.SetTrans(-P1.X, -P1.Y, -P1.Z);
// Prepare matrix rotation about axis X with angle Alfa Cos(Alfa) = C.z / D Sin(Alfa) = C.y / D }
MRo_X.SetUnit();
MRo_X.m11 = C.Z / D;
MRo_X.m22 = MRo_X.m11;
MRo_X.m12 = C.Y / D;
MRo_X.m21 = -MRo_X.m12;
// prepare matrix rotation about axis Y with angle Beta Cos(Beta) = D Sin(Beta) = -C.x
MRo_Y.SetUnit();
MRo_Y.m00 = D;
MRo_Y.m22 = MRo_Y.m00;
MRo_Y.m02 = C.X;
MRo_Y.m20 = -MRo_Y.m02;
TMat4x4 M;
// M= Trans * Rot about axis X * Rot about axis Y
TempM = MTra.MulMat(MRo_X);
M = TempM.MulMat(MRo_Y);
// prepare matrix rotation about axis Z with angle Angle
MRo_Z.SetRotateZ(Angle);
// TempM= Trans * Rot axis X * Rot axis Y * Rot about axis Z by angle Angle
TempM = M.MulMat(MRo_Z);
// Find inverse Y matrix
MRo_Y.m00 = D;
MRo_Y.m22 = D;
MRo_Y.m02 = -C.X;
MRo_Y.m20 = C.X;
M = TempM.MulMat(MRo_Y);
// Find inverse x matrix
MRo_X.m11 = C.Z / D;
MRo_X.m22 = MRo_X.m11;
MRo_X.m21 = C.Y / D;
MRo_X.m12 = -MRo_X.m21;
TempM = M.MulMat(MRo_X);
// Find inverse translation matrix
MTra.SetTrans(P1.X, P1.Y, P1.Z);
this = TempM.MulMat(MTra);
}
}
public static float DotProduct(TVertex P1, TVertex P2)
{
return(P1.X * P2.X + P1.Y * P2.Y + P1.Z * P2.Z);
}
// The distance from point P1 to P2
public static float PointDistance(TVertex P1, TVertex P2)
{
return((float)Math.Sqrt(Sqr(P1.X - P2.X) + Sqr(P1.Y - P2.Y) + Sqr(P1.Z - P2.Z)));
}
private void TransformAxis(TMat4x4 Mat)
{
TransformedAxisPointA = Mat.MulVertex(OriginalAxisPointA);
TransformedAxisPointB = Mat.MulVertex(OriginalAxisPointB);
}
private bool TestForBackClipping(TVertex V1, TVertex V2, TVertex V3)
{
return(!((V1.Z < 0) && (V2.Z < 0) && (V3.Z < 0)));
}
// Perform rendering on a specific context
public void Render(CRenderContext Context)
{
if (!Visible)
{
return;
}
// Calculate transform matrix
TMat4x4 Mat = GetTransformMatrix(Context);
// Calculate the inverse matrix
TMat4x4 InverseMat = Mat.FindInverseMat();
// Clear translation effect
InverseMat.ClearTranslation();
// Calculate the viewer position in object coordinates
TVertex ViewDirection = Context.GetViewDirection();
TVertex ViewerPosInObjCoords = InverseMat.MulVertex(ViewDirection);
float PerspectiveFactor = Context.GetPerspectiveFactor();
Color IlluminatedFaceColor;
foreach (TFace3D Face in FaceTable)
{
bool FaceVisible;
float FaceDotProd = 0;
if (!Context.IsBackfaceCullingMode())
{
// No backface culling, the face is always visible
FaceVisible = true;
}
else
{
// Do backface culling
FaceDotProd = Math3D.DotProduct(ViewerPosInObjCoords, Face.Normal);
// Perspective mode
if (Context.IsPerspectiveMode())
{
// Remember if the face is visible
FaceVisible = (FaceDotProd > THRESHOLD_FOR_CULLING);
}
else
{
FaceVisible = (FaceDotProd > 0);
}
}
if (FaceVisible)
{
// Get current face vertices and transform to world coordinates
TVertex[] FaceVertex = new TVertex[3] {
Mat.MulVertex(VertexTable[Face.AIndex]),
Mat.MulVertex(VertexTable[Face.BIndex]),
Mat.MulVertex(VertexTable[Face.CIndex])
};
Point[] ScreenCoords = new Point[3];
if (TestForBackClipping(FaceVertex[0], FaceVertex[1], FaceVertex[2]))
{
bool PreventFaceDraw = false;
// Perspective mode
if (Context.IsPerspectiveMode())
{
// Transform the from world coordinates to screen coordinates
for (int i = 0; i < 3; i++)
{
if (Math.Abs(FaceVertex[i].Z) < POLYGON_Z_MIN_VALUE)
{
PreventFaceDraw = true;
break;
}
ScreenCoords[i].X = (int)(FaceVertex[i].X * PerspectiveFactor / FaceVertex[i].Z);
ScreenCoords[i].Y = (int)(FaceVertex[i].Y * PerspectiveFactor / FaceVertex[i].Z);
if ((Math.Abs(ScreenCoords[i].X) > POLYGON_COORD_MAX_VALUE) || (Math.Abs(ScreenCoords[i].Y) > POLYGON_COORD_MAX_VALUE))
{
PreventFaceDraw = true;
break;
}
}
}
else
// Orthogonal projection
{
PreventFaceDraw = false;
// Transform the from world coordinates to screen coordinates
for (int i = 0; i < 3; i++)
{
ScreenCoords[i].X = (int)(FaceVertex[i].X / ORTHO_PROJECTION_SCALING);
ScreenCoords[i].Y = (int)(FaceVertex[i].Y / ORTHO_PROJECTION_SCALING);
}
}
if (!PreventFaceDraw)
{
T2DTriangle ScreenTriangle = new T2DTriangle(ScreenCoords[0], ScreenCoords[1], ScreenCoords[2]);
if (Context.IsWireFrameMode())
{
Context.DrawTriangle(ScreenTriangle);
}
else
// Filled triangles mode
{
float LightLevel = FaceDotProd + MIN_LIGHT_LEVEL;
// Clip to maximum light level
if (LightLevel > 1.0)
{
LightLevel = 1.0f;
}
// Calculate face color
int ARGBColor = ClipColorChn(Face.Color.R, LightLevel);
ARGBColor |= ClipColorChn(Face.Color.G, LightLevel) << 8;
ARGBColor |= ClipColorChn(Face.Color.B, LightLevel) << 16;
// Set maximum alpha channel value
ARGBColor = (int)((uint)ARGBColor | 0xff000000);
IlluminatedFaceColor = Color.FromArgb(ARGBColor);
// Calculate factors for the polygon filling routine
TVertex FaceNormal = Math3D.CalcFaceNormal(FaceVertex[0], FaceVertex[1], FaceVertex[2]);
float M, N, K;
CalculatePolygonFactors(FaceNormal, FaceVertex[1], PerspectiveFactor, out M, out N, out K);
TriangleFiller.DrawFilledTriangle(ScreenTriangle, Context, IlluminatedFaceColor, M, N, K);
}
}
}
}
}
RenderChildObjects(Context);
}
