//----------------------------------------------------------------
public void begin(double x, double y, int len)
{
// Calculate transformed coordinates at x1,y1
double xt = x;
double yt = y;
m_trans_dir.transform(ref xt, ref yt);
int x1 = agg_basics.iround(xt * subpixel_scale);
int y1 = agg_basics.iround(yt * subpixel_scale);
double dx;
double dy;
double delta = 1 / (double)subpixel_scale;
// Calculate scale by X at x1,y1
dx = xt + delta;
dy = yt;
m_trans_inv.transform(ref dx, ref dy);
dx -= x;
dy -= y;
int sx1 = (int)agg_basics.uround(subpixel_scale / Math.Sqrt(dx * dx + dy * dy)) >> subpixel_shift;
// Calculate scale by Y at x1,y1
dx = xt;
dy = yt + delta;
m_trans_inv.transform(ref dx, ref dy);
dx -= x;
dy -= y;
int sy1 = (int)agg_basics.uround(subpixel_scale / Math.Sqrt(dx * dx + dy * dy)) >> subpixel_shift;
// Calculate transformed coordinates at x2,y2
x += len;
xt = x;
yt = y;
m_trans_dir.transform(ref xt, ref yt);
int x2 = agg_basics.iround(xt * subpixel_scale);
int y2 = agg_basics.iround(yt * subpixel_scale);
// Calculate scale by X at x2,y2
dx = xt + delta;
dy = yt;
m_trans_inv.transform(ref dx, ref dy);
dx -= x;
dy -= y;
int sx2 = (int)agg_basics.uround(subpixel_scale / Math.Sqrt(dx * dx + dy * dy)) >> subpixel_shift;
// Calculate scale by Y at x2,y2
dx = xt;
dy = yt + delta;
m_trans_inv.transform(ref dx, ref dy);
dx -= x;
dy -= y;
int sy2 = (int)agg_basics.uround(subpixel_scale / Math.Sqrt(dx * dx + dy * dy)) >> subpixel_shift;
// Initialize the interpolators
m_coord_x = new dda2_line_interpolator(x1, x2, (int)len);
m_coord_y = new dda2_line_interpolator(y1, y2, (int)len);
m_scale_x = new dda2_line_interpolator(sx1, sx2, (int)len);
m_scale_y = new dda2_line_interpolator(sy1, sy2, (int)len);
}
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;
}
// 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);
}
}
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;
}
// 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);
}
