108 lines
2.5 KiB
C++
108 lines
2.5 KiB
C++
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#include "Transform.h"
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#include <math.h>
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Transform::Transform()
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{
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}
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Transform Transform::getInverse()
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{
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Transform inv;
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inv.m_matrix = m_matrix.getInverse();
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return inv;
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}
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void Transform::lookAt(const Vector & eye,
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const Vector & focus,
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const Vector & up)
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{
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Vector forward = focus - eye;
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forward.normalize();
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Vector up_projected_onto_forward = forward * (up % forward) / up.mag2();
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Vector perpendicular_up = (up - up_projected_onto_forward).normalize();
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Vector right = forward * perpendicular_up;
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Matrix mult;
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mult[0][0] = right[0];
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mult[0][1] = right[1];
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mult[0][2] = right[2];
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mult[1][0] = forward[0];
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mult[1][1] = forward[1];
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mult[1][2] = forward[2];
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mult[2][0] = perpendicular_up[0];
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mult[2][1] = perpendicular_up[1];
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mult[2][2] = perpendicular_up[2];
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m_matrix *= mult;
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translate(-eye[0], -eye[1], -eye[2]);
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}
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void Transform::translate(double x, double y, double z)
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{
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Matrix t = Matrix::identity();
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t[0][3] = x;
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t[1][3] = y;
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t[2][3] = z;
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m_matrix *= t;
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}
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void Transform::rotate(double angle, double xv, double yv, double zv)
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{
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/* formula from http://en.wikipedia.org/wiki/Rotation_matrix */
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Vector l(xv, yv, zv);
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l.normalize();
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double c = cos(M_PI * angle / 180.0);
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double s = sin(M_PI * angle / 180.0);
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double lx2 = l[0] * l[0];
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double ly2 = l[1] * l[1];
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double lz2 = l[2] * l[2];
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Matrix t = Matrix::identity();
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t[0][0] = lx2 + (1 - lx2) * c;
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t[0][1] = l[0] * l[1] * (1 - c) - l[2] * s;
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t[0][2] = l[0] * l[2] * (1 - c) + l[1] * s;
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t[1][0] = l[0] * l[1] * (1 - c) + l[2] * s;
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t[1][1] = ly2 + (1 - ly2) * c;
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t[1][2] = l[1] * l[2] * (1 - c) - l[0] * s;
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t[2][0] = l[0] * l[2] * (1 - c) - l[1] * s;
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t[2][1] = l[1] * l[2] * (1 - c) + l[0] * s;
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t[2][2] = lz2 + (1 - lz2) * c;
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m_matrix *= t;
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}
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void Transform::scale(double xs, double ys, double zs)
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{
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Matrix t = Matrix::identity();
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t[0][0] = xs;
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t[1][1] = ys;
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t[2][2] = zs;
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m_matrix *= t;
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}
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Vector Transform::transform_point(const Vector & v)
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{
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return m_matrix * v;
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}
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Vector Transform::transform_direction(const Vector & v)
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{
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return m_matrix % v;
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}
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Vector Transform::transform_normal(const Vector & v)
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{
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return (m_matrix % v).normalize();
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}
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Ray Transform::transform_ray(const Ray & r)
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{
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Vector newPosition = m_matrix * r.getOrigin();
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Vector newDirection = m_matrix % r.getDirection();
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Ray res(newPosition, newDirection);
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return res;
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}
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