public void Set(Perspective Other)
{
sx = Other.sx;
shy = Other.shy;
w0 = Other.w0;
shx = Other.shx;
sy = Other.sy;
w1 = Other.w1;
tx = Other.tx;
ty = Other.ty;
w2 = Other.w2;
}
//-------------------------------------- Quadrilateral transformations
// The arguments are double[8] that are mapped to quadrilaterals:
// x1,y1, x2,y2, x3,y3, x4,y4
public bool quad_to_quad(double[] qs, double[] qd)
{
Perspective p = new Perspective();
if (!quad_to_square(qs))
return false;
if (!p.square_to_quad(qd))
return false;
multiply(p);
return true;
}
public void scaling(out double x, out double y)
{
double x1 = 0.0;
double y1 = 0.0;
double x2 = 1.0;
double y2 = 1.0;
Perspective t = new Perspective(this);
t *= Affine.NewRotation(-rotation());
t.Transform(ref x1, ref y1);
t.Transform(ref x2, ref y2);
x = x2 - x1;
y = y2 - y1;
}
public iterator_x(double px, double py, double step, Perspective m)
{
den = (px * m.w0 + py * m.w1 + m.w2);
den_step = (m.w0 * step);
nom_x = (px * m.sx + py * m.shx + m.tx);
nom_x_step = (step * m.sx);
nom_y = (px * m.shy + py * m.sy + m.ty);
nom_y_step = (step * m.shy);
x = (nom_x / den);
y = (nom_y / den);
}
public bool is_equal(Perspective m)
{
return is_equal(m, affine_epsilon);
}
public bool is_equal(Perspective m, double epsilon)
{
return agg_basics.is_equal_eps(sx, m.sx, epsilon) &&
agg_basics.is_equal_eps(shy, m.shy, epsilon) &&
agg_basics.is_equal_eps(w0, m.w0, epsilon) &&
agg_basics.is_equal_eps(shx, m.shx, epsilon) &&
agg_basics.is_equal_eps(sy, m.sy, epsilon) &&
agg_basics.is_equal_eps(w1, m.w1, epsilon) &&
agg_basics.is_equal_eps(tx, m.tx, epsilon) &&
agg_basics.is_equal_eps(ty, m.ty, epsilon) &&
agg_basics.is_equal_eps(w2, m.w2, epsilon);
}
// Inverse transformation of x and y. It works slow because
// it explicitly inverts the matrix on every call. For massive
// operations it's better to invert() the matrix and then use
// direct transformations.
public void inverse_transform(ref double x, ref double y)
{
Perspective t = new Perspective(this);
if (t.invert()) t.Transform(ref x, ref y);
}
// From trans_perspective
public Perspective(Perspective a)
{
sx = (a.sx); shy = (a.shy); w0 = a.w0;
shx = (a.shx); sy = (a.sy); w1 = a.w1;
tx = (a.tx); ty = (a.ty); w2 = a.w2;
}
//------------------------------------------------------------------------
public Perspective premultiply_inv(Perspective m)
{
Perspective t = m;
t.invert();
Set(t.multiply(this));
return this;
}
// Multiply inverse of "m" by "this" and assign the result to "this"
public Perspective premultiply_inv(Affine m)
{
Perspective t = new Perspective(m);
t.invert();
Set(t.multiply(this));
return this;
}
//------------------------------------------------------------------------
public Perspective multiply_inv(Perspective m)
{
Perspective t = m;
t.invert();
return multiply(t);
}
//------------------------------------------------------------------------
public Perspective premultiply(Affine b)
{
Perspective a = new Perspective(this);
sx = a.sx * b.sx + a.shx * b.shy;
shx = a.sx * b.shx + a.shx * b.sy;
tx = a.sx * b.tx + a.shx * b.ty + a.tx;
shy = a.shy * b.sx + a.sy * b.shy;
sy = a.shy * b.shx + a.sy * b.sy;
ty = a.shy * b.tx + a.sy * b.ty + a.ty;
w0 = a.w0 * b.sx + a.w1 * b.shy;
w1 = a.w0 * b.shx + a.w1 * b.sy;
w2 = a.w0 * b.tx + a.w1 * b.ty + a.w2;
return this;
}
//------------------------------------------------------------------------
public Perspective premultiply(Perspective b)
{
Perspective a = new Perspective(this);
sx = a.sx * b.sx + a.shx * b.shy + a.tx * b.w0;
shx = a.sx * b.shx + a.shx * b.sy + a.tx * b.w1;
tx = a.sx * b.tx + a.shx * b.ty + a.tx * b.w2;
shy = a.shy * b.sx + a.sy * b.shy + a.ty * b.w0;
sy = a.shy * b.shx + a.sy * b.sy + a.ty * b.w1;
ty = a.shy * b.tx + a.sy * b.ty + a.ty * b.w2;
w0 = a.w0 * b.sx + a.w1 * b.shy + a.w2 * b.w0;
w1 = a.w0 * b.shx + a.w1 * b.sy + a.w2 * b.w1;
w2 = a.w0 * b.tx + a.w1 * b.ty + a.w2 * b.w2;
return this;
}
//------------------------------------------------------------------------
public Perspective multiply(Affine a)
{
Perspective b = new Perspective(this);
sx = a.sx * b.sx + a.shx * b.shy + a.tx * b.w0;
shx = a.sx * b.shx + a.shx * b.sy + a.tx * b.w1;
tx = a.sx * b.tx + a.shx * b.ty + a.tx * b.w2;
shy = a.shy * b.sx + a.sy * b.shy + a.ty * b.w0;
sy = a.shy * b.shx + a.sy * b.sy + a.ty * b.w1;
ty = a.shy * b.tx + a.sy * b.ty + a.ty * b.w2;
return this;
}
// Invert matrix. Returns false in degenerate case
public bool invert()
{
double d0 = sy * w2 - w1 * ty;
double d1 = w0 * ty - shy * w2;
double d2 = shy * w1 - w0 * sy;
double d = sx * d0 + shx * d1 + tx * d2;
if (d == 0.0)
{
sx = shy = w0 = shx = sy = w1 = tx = ty = w2 = 0.0;
return false;
}
d = 1.0 / d;
Perspective a = new Perspective(this);
sx = d * d0;
shy = d * d1;
w0 = d * d2;
shx = d * (a.w1 * a.tx - a.shx * a.w2);
sy = d * (a.sx * a.w2 - a.w0 * a.tx);
w1 = d * (a.w0 * a.shx - a.sx * a.w1);
tx = d * (a.shx * a.ty - a.sy * a.tx);
ty = d * (a.shy * a.tx - a.sx * a.ty);
w2 = d * (a.sx * a.sy - a.shy * a.shx);
return true;
}
