public Triangle(Mesh owner, Vertex3 va, Vertex3 vb, Vertex3 vc)
{
Owner = owner;
this.va = va;
this.vb = vb;
this.vc = vc;
}
public void Draw(Camera camera)
{
var point1 = ((va.Position * Scale).Rotate(Rotation) + Position + camera.Position).Rotate(camera.Rotation).Project(Owner.Engine, camera).FromNdc(Owner.Engine);
var point2 = ((vb.Position * Scale).Rotate(Rotation) + Position + camera.Position).Rotate(camera.Rotation).Project(Owner.Engine, camera).FromNdc(Owner.Engine);
var point3 = ((vc.Position * Scale).Rotate(Rotation) + Position + camera.Position).Rotate(camera.Rotation).Project(Owner.Engine, camera).FromNdc(Owner.Engine);
var vertex1 = new Vertex3(point1, va.Uv);
var vertex2 = new Vertex3(point2, vb.Uv);
var vertex3 = new Vertex3(point3, vc.Uv);
DrawTriangleScanLines(vertex1, vertex2, vertex3);
}
private void DrawScanline(int y, Vertex3 left1, Vertex3 left2, Vertex3 right1, Vertex3 right2)
{
float deltaL = 1f;
float deltaR = 1f;
if (left1.Y != left2.Y)
{
deltaL = (y - left1.Y)/(left2.Y - left1.Y);
}
if (right1.Y != right2.Y)
{
deltaR = (y - right1.Y) / (right2.Y - right1.Y);
}
int left = (int) left1.X.Lerp(left2.X, deltaL);
int right = (int) right1.X.Lerp(right2.X, deltaR);
float zLeft = left1.Z.Lerp(left2.Z, deltaL);
float zRight = right1.Z.Lerp(right2.Z, deltaR);
Vector2 uStart = Vector2.One;
Vector2 uEnd = Vector2.One;
if (left1.Uv != Vector2.Zero) {
uStart = left1.Uv.Lerp(left2.Uv, deltaL);
uEnd = right1.Uv.Lerp(right2.Uv, deltaR);
}
for (int x = left > 0 ? left : 0; x < right; x++)
{
float deltaZ = ((float)x - left)/((float)right - left);
float z = zLeft.Lerp(zRight, deltaZ);
Color4 color;
if (left1.Uv != Vector2.Zero)
{
// texture
var uV = uStart.Lerp(uEnd, deltaZ);
uV.Y = 1 - uV.Y;
color = TextureMap(uV);
}
else
{
color = Color;
}
DrawHelper.PutPixel(Owner.Engine.WorkingTexture, x, y, z, color);
}
}
private void DrawTriangleScanLines(Vertex3 point1, Vertex3 point2, Vertex3 point3)
{
var p1 = point1;
var p2 = point2;
var p3 = point3;
if (p1.Y > p2.Y)
{
var t = p1;
p1 = p2;
p2 = t;
}
if (p2.Y > p3.Y)
{
var t = p2;
p2 = p3;
p3 = t;
}
if (p1.Y > p2.Y)
{
var t = p1;
p1 = p2;
p2 = t;
}
// inversed slope = dX / dY
float slopeP1P2 = (p2.X - p1.X) / (p2.Y - p1.Y);
float slopeP1P3 = (p3.X - p1.X) / (p3.Y - p1.Y);
if (slopeP1P3 > slopeP1P2) // p2 left
{
for (int y = (int) p1.Y; y <= (int) p3.Y; y++)
{
if (y < p2.Y) // first part
{
DrawScanline(y, p1, p2, p1, p3);
} else // second part
{
DrawScanline(y, p2, p3, p1, p3);
}
}
}
else // p2 right
{
for (int y = (int)p1.Y; y <= (int)p3.Y; y++)
{
if (y < p2.Y) // first part
{
DrawScanline(y, p1, p3, p1, p2);
}
else // second part
{
DrawScanline(y, p1, p3, p2, p3);
}
}
}
}
private void LoadObjFile(string fileName)
{
var vertexList = new List<Vector3>();
var trianglesVertexList = new List<int[]>();
foreach (var line in File.ReadLines(fileName))
{
var items = line.Replace(" ", " ").Split(' ');
// vertex
if (items[0] == "v")
{
vertexList.Add(new Vector3(
float.Parse(items[1], CultureInfo.InvariantCulture),
float.Parse(items[2], CultureInfo.InvariantCulture),
float.Parse(items[3], CultureInfo.InvariantCulture) - 1f
)
);
}
if (items[0] == "vt")
{
UvList.Add(new Vector2(
float.Parse(items[1], CultureInfo.InvariantCulture),
float.Parse(items[2], CultureInfo.InvariantCulture)
)
);
}
if (items[0] == "vn")
{
NormalsList.Add(new Vector3(
float.Parse(items[1], CultureInfo.InvariantCulture),
float.Parse(items[2], CultureInfo.InvariantCulture),
float.Parse(items[3], CultureInfo.InvariantCulture)
)
);
}
if (items[0] == "f")
{
var v1 = items[1].Split('/');
var v2 = items[2].Split('/');
var v3 = items[3].Split('/');
trianglesVertexList.Add(new[]
{
// vertexes
int.Parse(v1[0]) - 1,
int.Parse(v2[0]) - 1,
int.Parse(v3[0]) - 1,
// materials
int.Parse(v1[1]) - 1,
int.Parse(v2[1]) - 1,
int.Parse(v3[1]) - 1
});
//// normals
//int.Parse(v1[2]) - 1,
//int.Parse(v2[2]) - 1,
//int.Parse(v3[2]) - 1
}
}
foreach (var args in trianglesVertexList)
{
var vertex1 = new Vertex3(vertexList[args[0]], UvList[args[3]]);
var vertex2 = new Vertex3(vertexList[args[1]], UvList[args[4]]);
var vertex3 = new Vertex3(vertexList[args[2]], UvList[args[5]]);
var triangle = new Triangle(
null,
vertex1, vertex2, vertex3
/*normalsList[args[5]],
normalsList[args[6]],
normalsList[args[7]]*/
);
TriangleList.Add(triangle);
}
}