3 This file is part of libmspgl
4 Copyright © 2010 Mikko Rasa, Mikkosoft Productions
5 Distributed under the LGPL
11 #include "projection.h"
25 for(unsigned i=0; i<16; ++i)
26 matrix[i] = (i%5 ? 0 : 1);
30 void Camera::set_field_of_view(float f)
35 void Camera::set_aspect(float a)
40 void Camera::set_depth_clip(float n, float f)
46 void Camera::set_position(const Vector3 &p)
52 void Camera::set_up_direction(const Vector3 &u)
54 float len = sqrt(u.x*u.x+u.y*u.y+u.z*u.z);
63 void Camera::set_look_direction(const Vector3 &l)
65 float len = sqrt(l.x*l.x+l.y*l.y+l.z*l.z);
74 void Camera::look_at(const Vector3 &p)
76 set_look_direction(Vector3(p.x-position.x, p.y-position.y, p.z-position.z));
79 Vector3 Camera::project(const Vector4 &p) const
81 float frustum_h = tan(fov/2);
82 float frustum_w = frustum_h*aspect;
83 float z_range = clip_far-clip_near;
85 float eye_x = matrix[0]*p.x+matrix[4]*p.y+matrix[8]*p.z+matrix[12]*p.w;
86 float eye_y = matrix[1]*p.x+matrix[5]*p.y+matrix[9]*p.z+matrix[13]*p.w;
87 float eye_z = matrix[2]*p.x+matrix[6]*p.y+matrix[10]*p.z+matrix[14]*p.w;
89 return Vector3(eye_x/frustum_w/-eye_z, eye_y/frustum_h/-eye_z,
90 (clip_far+clip_near)/z_range+2*clip_far*clip_near/(eye_z*z_range));
93 Vector4 Camera::unproject(const Vector4 &p) const
95 float frustum_h = tan(fov/2);
96 float frustum_w = frustum_h*aspect;
97 float z_range = clip_far-clip_near;
99 float z = (2*clip_far*clip_near)/(p.z*z_range-(clip_far+clip_near))-matrix[14]*p.w;
100 float x = p.x*-z*frustum_w-matrix[12]*p.w;
101 float y = p.y*-z*frustum_h-matrix[13]*p.w;
103 return Vector4(matrix[0]*x+matrix[1]*y+matrix[2]*z,
104 matrix[4]*x+matrix[5]*y+matrix[6]*z,
105 matrix[8]*x+matrix[9]*y+matrix[10]*z,
109 void Camera::apply() const
111 float h = tan(fov/2)*2*clip_near;
113 matrix_mode(PROJECTION);
115 frustum_centered(h*aspect, h, clip_near, clip_far);
117 matrix_mode(MODELVIEW);
121 void Camera::compute_matrix()
123 float x = look_dir.y*up_dir.z-look_dir.z*up_dir.y;
124 float y = look_dir.z*up_dir.x-look_dir.x*up_dir.z;
125 float z = look_dir.x*up_dir.y-look_dir.y*up_dir.x;
126 float len = sqrt(x*x+y*y+z*z);
132 matrix[1] = matrix[4]*look_dir.z-matrix[8]*look_dir.y;
133 matrix[5] = matrix[8]*look_dir.x-matrix[0]*look_dir.z;
134 matrix[9] = matrix[0]*look_dir.y-matrix[4]*look_dir.x;
136 matrix[2] = -look_dir.x;
137 matrix[6] = -look_dir.y;
138 matrix[10] = -look_dir.z;
140 matrix[12] = -position.x*matrix[0]-position.y*matrix[4]-position.z*matrix[8];
141 matrix[13] = -position.x*matrix[1]-position.y*matrix[5]-position.z*matrix[9];
142 matrix[14] = -position.x*matrix[2]-position.y*matrix[6]-position.z*matrix[10];