public void ComputePoly(ref Poly poly)
{
var v1p = Camera.ScreenProection(poly.v1.Position);
var v2p = Camera.ScreenProection(poly.v2.Position);
var v3p = Camera.ScreenProection(poly.v3.Position);
if (v1p.X > v2p.X)
{
var w = v1p; v1p = v2p; v2p = w; var v = poly.v1; poly.v1 = poly.v2; poly.v2 = v;
}
if (v2p.X > v3p.X)
{
var w = v2p; v2p = v3p; v3p = w; var v = poly.v2; poly.v2 = poly.v3; poly.v3 = v;
}
if (v1p.X > v2p.X)
{
var w = v1p; v1p = v2p; v2p = w; var v = poly.v1; poly.v1 = poly.v2; poly.v2 = v;
}
int x1 = (int)v1p.X;
int x2 = (int)v2p.X;
int x3 = (int)v3p.X;
int x12 = x2 - x1;
int x13 = x3 - x1;
int x32 = x3 - x2;
Vector3 u, d, du, dd, nu, nd, dnu, dnd;
Vector2 tu, td, dtu, dtd;
float pu, pd, dpu, dpd;
int rDiff;
if (x2 > 0 && x1 < Width)
{
u = poly.v1.Position;
d = poly.v1.Position;
tu = poly.v1.TextureCoord;
td = poly.v1.TextureCoord;
nu = poly.v1.Normal;
nd = poly.v1.Normal;
pu = v1p.Y;
pd = v1p.Y;
if (x12 != 0)
{
dpu = (v2p.Y - v1p.Y) / x12;
dpd = (v3p.Y - v1p.Y) / x13;
if (dpu > dpd)
{
du = (poly.v2.Position - poly.v1.Position) / x12;
dtu = (poly.v2.TextureCoord - poly.v1.TextureCoord) / x12;
dnu = (poly.v2.Normal - poly.v1.Normal) / x12;
dd = (poly.v3.Position - poly.v1.Position) / x13;
dtd = (poly.v3.TextureCoord - poly.v1.TextureCoord) / x13;
dnd = (poly.v3.Normal - poly.v1.Normal) / x13;
}
else
{
var t = dpu; dpu = dpd; dpd = t;
du = (poly.v3.Position - poly.v1.Position) / x13;
dtu = (poly.v3.TextureCoord - poly.v1.TextureCoord) / x13;
dnu = (poly.v3.Normal - poly.v1.Normal) / x13;
dd = (poly.v2.Position - poly.v1.Position) / x12;
dtd = (poly.v2.TextureCoord - poly.v1.TextureCoord) / x12;
dnd = (poly.v2.Normal - poly.v1.Normal) / x12;
}
}
else
{
dpu = 0;
dpd = 0;
dtu = Vector2.Zero;
dtd = Vector2.Zero;
dnu = Vector3.Zero;
dnd = Vector3.Zero;
du = Vector3.Zero;
dd = Vector3.Zero;
}
rDiff = Width - 1 - x2;
if (rDiff < 0)
{
x12 += rDiff;
}
if (x1 < 0)
{
x12 += x1;
u -= du * x1;
d -= dd * x1;
tu -= dtu * x1;
td -= dtd * x1;
nu -= dnu * x1;
nd -= dnd * x1;
pu -= dpu * x1;
pd -= dpd * x1;
x1 = 0;
}
//method for computing part of poly
for (int i = 0; i <= x12; i++)
{
Vector3 pos = d;
Vector3 norm = nd;
Vector2 tex = td;
Vector3 delta, deltaNormal;
Vector2 deltaTexture;
if (pu > 0)
{
int steps;
int up = (int)pu, down = (int)pd;
int diffU = Height - 1 - up;
if (diffU < 0)
{
up = Height - 1;
}
steps = up - down;
if (steps != 0)
{
delta = (u - d) / steps;
deltaTexture = (tu - td) / steps;
deltaNormal = (nu - nd) / steps;
}
else
{
delta = Vector3.Zero;
deltaNormal = Vector3.Zero;
deltaTexture = Vector2.Zero;
}
if (down < 0)
{
pos -= delta * down;
tex -= deltaTexture * down;
norm -= deltaNormal * down;
steps += down;
down = 0;
}
int x = x1 + i;
for (int g = 0; g <= steps; g++)
{
int y = down + g;
int index = y * Width + x;
if (ZBuffer[index].Position.Z == 0)
{
ZBuffer[index] = new Vertex(pos, new TGAColor(), tex, norm, poly.v1.Primitive);
VisibleIndexes[VisibleCount] = index;
VisibleCount++;
}
else if (ZBuffer[index].Position.Z > pos.Z)
{
ZBuffer[index] = new Vertex(pos, new TGAColor(), tex, norm, poly.v1.Primitive);;
}
pos += delta;
norm += deltaNormal;
tex += deltaTexture;
}
}
d += dd;
u += du;
pu += dpu;
pd += dpd;
nu += dnu;
nd += dnd;
tu += dtu;
td += dtd;
}
//*method for computing part of poly
}
if (x2 < Width && x3 > 0)
{
u = poly.v3.Position;
d = poly.v3.Position;
tu = poly.v3.TextureCoord;
td = poly.v3.TextureCoord;
nu = poly.v3.Normal;
nd = poly.v3.Normal;
pu = v3p.Y;
pd = v3p.Y;
if (x32 != 0)
{
dpu = (v2p.Y - v3p.Y) / x32;
dpd = (v1p.Y - v3p.Y) / x13;
if (dpu > dpd)
{
du = (poly.v2.Position - poly.v3.Position) / x32;
dtu = (poly.v2.TextureCoord - poly.v3.TextureCoord) / x32;
dnu = (poly.v2.Normal - poly.v3.Normal) / x32;
dd = (poly.v1.Position - poly.v3.Position) / x13;
dtd = (poly.v1.TextureCoord - poly.v3.TextureCoord) / x13;
dnd = (poly.v1.Normal - poly.v3.Normal) / x13;
}
else
{
var t = dpu; dpu = dpd; dpd = t;
du = (poly.v1.Position - poly.v3.Position) / x13;
dtu = (poly.v1.TextureCoord - poly.v3.TextureCoord) / x13;
dnu = (poly.v1.Normal - poly.v3.Normal) / x13;
dd = (poly.v2.Position - poly.v3.Position) / x32;
dtd = (poly.v2.TextureCoord - poly.v3.TextureCoord) / x32;
dnd = (poly.v2.Normal - poly.v3.Normal) / x32;
}
}
else
{
dpu = 0;
dpd = 0;
dtu = Vector2.Zero;
dtd = Vector2.Zero;
dnu = Vector3.Zero;
dnd = Vector3.Zero;
du = Vector3.Zero;
dd = Vector3.Zero;
}
if (x2 < 0)
{
x32 += x2;
x2 = 0;
}
rDiff = Width - 1 - x3;
if (rDiff < 0)
{
x32 += rDiff;
u -= du * rDiff;
d -= dd * rDiff;
tu -= dtu * rDiff;
td -= dtd * rDiff;
nu -= dnu * rDiff;
nd -= dnd * rDiff;
pu -= dpu * rDiff;
pd -= dpd * rDiff;
x3 = Width - 1;
}
//method for computing part of poly
for (int i = 0; i <= x32; i++)
{
Vector3 pos = d;
Vector3 norm = nd;
Vector2 tex = td;
Vector3 delta, deltaNormal;
Vector2 deltaTexture;
if (pu > 0)
{
int steps;
int up = (int)pu, down = (int)pd;
int diffU = Height - 1 - up;
if (diffU < 0)
{
up = Height - 1;
}
steps = up - down;
if (steps != 0)
{
delta = (u - d) / steps;
deltaTexture = (tu - td) / steps;
deltaNormal = (nu - nd) / steps;
}
else
{
delta = Vector3.Zero;
deltaNormal = Vector3.Zero;
deltaTexture = Vector2.Zero;
}
if (down < 0)
{
pos -= delta * down;
tex -= deltaTexture * down;
norm -= deltaNormal * down;
steps += down;
down = 0;
}
int x = x3 - i;
for (int g = 0; g <= steps; g++)
{
int y = down + g;
int index = y * Width + x;
if (ZBuffer[index].Position.Z == 0)
{
ZBuffer[index] = new Vertex(pos, new TGAColor(), tex, norm, poly.v1.Primitive);
VisibleIndexes[VisibleCount] = index;
VisibleCount++;
}
else if (ZBuffer[index].Position.Z > pos.Z)
{
ZBuffer[index] = new Vertex(pos, new TGAColor(), tex, norm, poly.v1.Primitive);;
}
pos += delta;
norm += deltaNormal;
tex += deltaTexture;
}
}
d += dd;
u += du;
pu += dpu;
pd += dpd;
nu += dnu;
nd += dnd;
tu += dtu;
td += dtd;
}
//*method for computing part of poly
}
}
public bool Observed(ref Poly p)
{
return(Camera.InObserve(p.v1.Position) ||
Camera.InObserve(p.v2.Position) || Camera.InObserve(p.v3.Position));
}