private void AddFaceToZBuffer(
Face face,
int meshDimension,
ref Matrix4x4 modelToView,
ref Matrix4x4 viewToScreen,
ref Matrix4x4 screenToWindow)
{
// Reset the vertices to model space values
face.ResetVertices();
// Draw outline if needed ??
if (face.DrawOutline)
{
DrawEdge(face.p1, face.p2, Color.Black, ref modelToView, ref viewToScreen);
DrawEdge(face.p1, face.p3, Color.Black, ref modelToView, ref viewToScreen);
DrawEdge(face.p2, face.p3, Color.Black, ref modelToView, ref viewToScreen);
}
// Move the face from model space to view space
face.ApplyMatrix(modelToView);
if (meshDimension == 3)
{
// Discard the face if it is not visible from the camera's point of view
if ((Vector3D)face.p1 * Vector3D.NormalFromPlane((Vector3D)face.p1, (Vector3D)face.p2, (Vector3D)face.p3) >= 0)
{
return;
}
}
// Clip the face in view space
Queue <Face> faceClip = new();
faceClip.Enqueue(face);
if (!Clipping.ClipFaces(faceClip, this.ViewClippingPlanes))
{
return;
}
// Move the new triangles from view space to screen space, including a correction for perspective
foreach (Face clippedFace in faceClip)
{
clippedFace.ApplyMatrix(viewToScreen);
if (this is PerspectiveCamera)
{
clippedFace.p1 /= clippedFace.p1.w;
clippedFace.p2 /= clippedFace.p2.w;
clippedFace.p3 /= clippedFace.p3.w;
if (face.HasTexture)
{
clippedFace.t1 /= clippedFace.p1.w;
clippedFace.t2 /= clippedFace.p2.w;
clippedFace.t3 /= clippedFace.p3.w;
}
}
}
// Clip the face in screen space
if (Settings.Screen_Space_Clip && !Clipping.ClipFaces(faceClip, ScreenClippingPlanes))
{
return;
} // anything outside cube?
foreach (Face clippedFace in faceClip)
{
// Skip the face if it is flat
if ((clippedFace.p1.x == clippedFace.p2.x && clippedFace.p2.x == clippedFace.p3.x) ||
(clippedFace.p1.y == clippedFace.p2.y && clippedFace.p2.y == clippedFace.p3.y))
{
continue;
}
// Move the new triangles from screen space to window space
clippedFace.ApplyMatrix(screenToWindow);
// Round the vertices
int x1 = clippedFace.p1.x.RoundToInt();
int y1 = clippedFace.p1.y.RoundToInt();
float z1 = clippedFace.p1.z;
int x2 = clippedFace.p2.x.RoundToInt();
int y2 = clippedFace.p2.y.RoundToInt();
float z2 = clippedFace.p2.z;
int x3 = clippedFace.p3.x.RoundToInt();
int y3 = clippedFace.p3.y.RoundToInt();
float z3 = clippedFace.p3.z;
// Check if the face has a texture
if (face.HasTexture)
{
// Scale the texture co-ordinates
int textureWidth = face.Texture_Object.File.Width - 1;
int textureHeight = face.Texture_Object.File.Height - 1;
// afterwards?
float tx1 = face.T1.x * textureWidth;
float ty1 = face.T1.y * textureHeight;
float tz1 = face.T1.z;
float tx2 = face.T2.x * textureWidth;
float ty2 = face.T2.y * textureHeight;
float tz2 = face.T2.z;
float tx3 = face.T3.x * textureWidth;
float ty3 = face.T3.y * textureHeight;
float tz3 = face.T3.z;
// Sort the vertices by their y-co-ordinate
NumericManipulation.TexturedSortByY
(
ref x1, ref y1, ref tx1, ref ty1, ref tz1,
ref x2, ref y2, ref tx2, ref ty2, ref tz2,
ref x3, ref y3, ref tx3, ref ty3, ref tz3
);
// Generate z-buffer
Textured_Triangle
(
face.Texture_Object.File,
x1, y1, tx1, ty1, tz1,
x2, y2, tx2, ty2, tz2,
x3, y3, tx3, ty3, tz3
);
}
else
{
// Sort the vertices by their y-co-ordinate
NumericManipulation.SortByY
(
ref x1, ref y1, ref z1,
ref x2, ref y2, ref z2,
ref x3, ref y3, ref z3
);
// Generate z-buffer
Interpolation.InterpolateTriangle
(
ZBufferCheck,
face.Colour,
x1, y1, z1,
x2, y2, z2,
x3, y3, z3
);
}
}
}
