godot-cpp/src/core/Transform2D.cpp

347 lines
6.9 KiB
C++

#include "Transform2D.hpp"
#include "Vector2.hpp"
#include "String.hpp"
#include "Rect2.hpp"
#include <algorithm>
namespace godot {
Transform2D::Transform2D(real_t xx, real_t xy, real_t yx, real_t yy, real_t ox, real_t oy) {
elements[0][0] = xx;
elements[0][1] = xy;
elements[1][0] = yx;
elements[1][1] = yy;
elements[2][0] = ox;
elements[2][1] = oy;
}
Vector2 Transform2D::basis_xform(const Vector2& v) const {
return Vector2(
tdotx(v),
tdoty(v)
);
}
Vector2 Transform2D::basis_xform_inv(const Vector2& v) const{
return Vector2(
elements[0].dot(v),
elements[1].dot(v)
);
}
Vector2 Transform2D::xform(const Vector2& v) const {
return Vector2(
tdotx(v),
tdoty(v)
) + elements[2];
}
Vector2 Transform2D::xform_inv(const Vector2& p_vec) const {
Vector2 v = p_vec - elements[2];
return Vector2(
elements[0].dot(v),
elements[1].dot(v)
);
}
Rect2 Transform2D::xform(const Rect2& p_rect) const {
Vector2 x=elements[0]*p_rect.size.x;
Vector2 y=elements[1]*p_rect.size.y;
Vector2 pos = xform( p_rect.pos );
Rect2 new_rect;
new_rect.pos=pos;
new_rect.expand_to( pos+x );
new_rect.expand_to( pos+y );
new_rect.expand_to( pos+x+y );
return new_rect;
}
void Transform2D::set_rotation_and_scale(real_t p_rot,const Size2& p_scale) {
elements[0][0]=::cos(p_rot)*p_scale.x;
elements[1][1]=::cos(p_rot)*p_scale.y;
elements[1][0]=-::sin(p_rot)*p_scale.y;
elements[0][1]=::sin(p_rot)*p_scale.x;
}
Rect2 Transform2D::xform_inv(const Rect2& p_rect) const {
Vector2 ends[4]={
xform_inv( p_rect.pos ),
xform_inv( Vector2(p_rect.pos.x,p_rect.pos.y+p_rect.size.y ) ),
xform_inv( Vector2(p_rect.pos.x+p_rect.size.x,p_rect.pos.y+p_rect.size.y ) ),
xform_inv( Vector2(p_rect.pos.x+p_rect.size.x,p_rect.pos.y ) )
};
Rect2 new_rect;
new_rect.pos=ends[0];
new_rect.expand_to(ends[1]);
new_rect.expand_to(ends[2]);
new_rect.expand_to(ends[3]);
return new_rect;
}
void Transform2D::invert() {
// FIXME: this function assumes the basis is a rotation matrix, with no scaling.
// Transform2D::affine_inverse can handle matrices with scaling, so GDScript should eventually use that.
std::swap(elements[0][1],elements[1][0]);
elements[2] = basis_xform(-elements[2]);
}
Transform2D Transform2D::inverse() const {
Transform2D inv=*this;
inv.invert();
return inv;
}
void Transform2D::affine_invert() {
real_t det = basis_determinant();
ERR_FAIL_COND(det==0);
real_t idet = 1.0 / det;
std::swap( elements[0][0],elements[1][1] );
elements[0]*=Vector2(idet,-idet);
elements[1]*=Vector2(-idet,idet);
elements[2] = basis_xform(-elements[2]);
}
Transform2D Transform2D::affine_inverse() const {
Transform2D inv=*this;
inv.affine_invert();
return inv;
}
void Transform2D::rotate(real_t p_phi) {
*this = Transform2D(p_phi,Vector2()) * (*this);
}
real_t Transform2D::get_rotation() const {
real_t det = basis_determinant();
Transform2D m = orthonormalized();
if (det < 0) {
m.scale_basis(Size2(-1,-1));
}
return ::atan2(m[0].y,m[0].x);
}
void Transform2D::set_rotation(real_t p_rot) {
real_t cr = ::cos(p_rot);
real_t sr = ::sin(p_rot);
elements[0][0]=cr;
elements[0][1]=sr;
elements[1][0]=-sr;
elements[1][1]=cr;
}
Transform2D::Transform2D(real_t p_rot, const Vector2& p_pos) {
real_t cr = ::cos(p_rot);
real_t sr = ::sin(p_rot);
elements[0][0]=cr;
elements[0][1]=sr;
elements[1][0]=-sr;
elements[1][1]=cr;
elements[2]=p_pos;
}
Size2 Transform2D::get_scale() const {
real_t det_sign = basis_determinant() > 0 ? 1 : -1;
return det_sign * Size2( elements[0].length(), elements[1].length() );
}
void Transform2D::scale(const Size2& p_scale) {
scale_basis(p_scale);
elements[2]*=p_scale;
}
void Transform2D::scale_basis(const Size2& p_scale) {
elements[0][0]*=p_scale.x;
elements[0][1]*=p_scale.y;
elements[1][0]*=p_scale.x;
elements[1][1]*=p_scale.y;
}
void Transform2D::translate( real_t p_tx, real_t p_ty) {
translate(Vector2(p_tx,p_ty));
}
void Transform2D::translate( const Vector2& p_translation ) {
elements[2]+=basis_xform(p_translation);
}
void Transform2D::orthonormalize() {
// Gram-Schmidt Process
Vector2 x=elements[0];
Vector2 y=elements[1];
x.normalize();
y = (y-x*(x.dot(y)));
y.normalize();
elements[0]=x;
elements[1]=y;
}
Transform2D Transform2D::orthonormalized() const {
Transform2D on=*this;
on.orthonormalize();
return on;
}
bool Transform2D::operator==(const Transform2D& p_transform) const {
for(int i=0;i<3;i++) {
if (elements[i]!=p_transform.elements[i])
return false;
}
return true;
}
bool Transform2D::operator!=(const Transform2D& p_transform) const {
for(int i=0;i<3;i++) {
if (elements[i]!=p_transform.elements[i])
return true;
}
return false;
}
void Transform2D::operator*=(const Transform2D& p_transform) {
elements[2] = xform(p_transform.elements[2]);
real_t x0,x1,y0,y1;
x0 = tdotx(p_transform.elements[0]);
x1 = tdoty(p_transform.elements[0]);
y0 = tdotx(p_transform.elements[1]);
y1 = tdoty(p_transform.elements[1]);
elements[0][0]=x0;
elements[0][1]=x1;
elements[1][0]=y0;
elements[1][1]=y1;
}
Transform2D Transform2D::operator*(const Transform2D& p_transform) const {
Transform2D t = *this;
t*=p_transform;
return t;
}
Transform2D Transform2D::scaled(const Size2& p_scale) const {
Transform2D copy=*this;
copy.scale(p_scale);
return copy;
}
Transform2D Transform2D::basis_scaled(const Size2& p_scale) const {
Transform2D copy=*this;
copy.scale_basis(p_scale);
return copy;
}
Transform2D Transform2D::untranslated() const {
Transform2D copy=*this;
copy.elements[2]=Vector2();
return copy;
}
Transform2D Transform2D::translated(const Vector2& p_offset) const {
Transform2D copy=*this;
copy.translate(p_offset);
return copy;
}
Transform2D Transform2D::rotated(real_t p_phi) const {
Transform2D copy=*this;
copy.rotate(p_phi);
return copy;
}
real_t Transform2D::basis_determinant() const {
return elements[0].x * elements[1].y - elements[0].y * elements[1].x;
}
Transform2D Transform2D::interpolate_with(const Transform2D& p_transform, real_t p_c) const {
//extract parameters
Vector2 p1 = get_origin();
Vector2 p2 = p_transform.get_origin();
real_t r1 = get_rotation();
real_t r2 = p_transform.get_rotation();
Size2 s1 = get_scale();
Size2 s2 = p_transform.get_scale();
//slerp rotation
Vector2 v1(::cos(r1), ::sin(r1));
Vector2 v2(::cos(r2), ::sin(r2));
real_t dot = v1.dot(v2);
dot = (dot < -1.0) ? -1.0 : ((dot > 1.0) ? 1.0 : dot); //clamp dot to [-1,1]
Vector2 v;
if (dot > 0.9995) {
v = Vector2::linear_interpolate(v1, v2, p_c).normalized(); //linearly interpolate to avoid numerical precision issues
} else {
real_t angle = p_c*::acos(dot);
Vector2 v3 = (v2 - v1*dot).normalized();
v = v1*::cos(angle) + v3*::sin(angle);
}
//construct matrix
Transform2D res(::atan2(v.y, v.x), Vector2::linear_interpolate(p1, p2, p_c));
res.scale_basis(Vector2::linear_interpolate(s1, s2, p_c));
return res;
}
Transform2D::operator String() const {
return String(String() + elements[0] + ", " + elements[1] + ", " + elements[2]);
}
}