bool only_translation(agg::trans_affine& mat, double epsilon)
{
double temp[6];
mat.store_to(temp);
return (f_eq(temp[0], 1.0) && f_eq(temp[1], 0.0) &&
f_eq(temp[2], 0.0) && f_eq(temp[3], 1.0));
}
void get_translation(agg::trans_affine& m, double* tx, double* ty)
{
double temp[6];
m.store_to(temp);
*tx = temp[4];
*ty = temp[5];
}
void get_scale(agg::trans_affine& m, double* dx, double* dy)
{
{
double temp[6];
m.store_to(temp);
*dx = temp[0];
*dy = temp[3];
}
}
bool is_identity(agg::trans_affine& mat, double epsilon)
{
double temp[6];
mat.store_to(temp);
return (f_eq(temp[0], 1.0) && f_eq(temp[1], 0.0) &&
f_eq(temp[2], 0.0) && f_eq(temp[3], 1.0) &&
f_eq(temp[4], 0.0) && f_eq(temp[5], 0.0));
// return (temp[0] == 1.0 && temp[1] == 0.0 &&
// temp[2] == 0.0 && temp[3] == 1.0 &&
// temp[4] == 0.0 && temp[5] == 0.0);
}
void cairo_context::add_image(agg::trans_affine const& tr, image_rgba8 const& data, double opacity)
{
cairo_pattern pattern(data);
if (!tr.is_identity())
{
double m[6];
tr.store_to(m);
cairo_matrix_t cairo_matrix;
cairo_matrix_init(&cairo_matrix,m[0],m[1],m[2],m[3],m[4],m[5]);
cairo_matrix_invert(&cairo_matrix);
pattern.set_matrix(cairo_matrix);
}
cairo_save(cairo_.get());
cairo_set_source(cairo_.get(), const_cast<cairo_pattern_t*>(pattern.pattern()));
cairo_paint_with_alpha(cairo_.get(), opacity);
cairo_restore(cairo_.get());
check_object_status_and_throw_exception(*this);
}