nuclear@0: #include <stdio.h>
nuclear@0: #include <math.h>
nuclear@0: #include "camera.h"
nuclear@0: 
nuclear@0: static void calc_sample_pos_rec(int sidx, float xsz, float ysz, float *pos);
nuclear@0: 
nuclear@0: Camera::Camera()
nuclear@0: {
nuclear@0: 	vfov = M_PI / 4.0;
nuclear@0: 	cached_matrix_valid = false;
nuclear@0: 
nuclear@0: 	rdir_cache_width = rdir_cache_height = 0;
nuclear@0: 	rdir_cache = 0;
nuclear@0: }
nuclear@0: 
nuclear@0: Camera::Camera(const Vector3 &p)
nuclear@0: 	: pos(p)
nuclear@0: {
nuclear@0: 	vfov = M_PI / 4.0;
nuclear@0: 	cached_matrix_valid = false;
nuclear@0: 
nuclear@0: 	rdir_cache_width = rdir_cache_height = 0;
nuclear@0: 	rdir_cache = 0;
nuclear@0: }
nuclear@0: 
nuclear@0: Camera::~Camera()
nuclear@0: {
nuclear@0: 	delete [] rdir_cache;
nuclear@0: }
nuclear@0: 
nuclear@0: void Camera::set_fov(float vfov)
nuclear@0: {
nuclear@0: 	this->vfov = vfov;
nuclear@0: 
nuclear@0: 	// invalidate the dir cache
nuclear@0: 	delete [] rdir_cache;
nuclear@0: }
nuclear@0: 
nuclear@0: float Camera::get_fov() const
nuclear@0: {
nuclear@0: 	return vfov;
nuclear@0: }
nuclear@0: 
nuclear@0: void Camera::set_position(const Vector3 &pos)
nuclear@0: {
nuclear@0: 	this->pos = pos;
nuclear@0: 	cached_matrix_valid = false;	// invalidate the cached matrix
nuclear@0: }
nuclear@0: 
nuclear@0: const Vector3 &Camera::get_position() const
nuclear@0: {
nuclear@0: 	return pos;
nuclear@0: }
nuclear@0: 
nuclear@0: const Matrix4x4 &Camera::get_matrix() const
nuclear@0: {
nuclear@0: 	if(!cached_matrix_valid) {
nuclear@0: 		calc_matrix(&cached_matrix);
nuclear@0: 		cached_matrix_valid = true;
nuclear@0: 	}
nuclear@0: 	return cached_matrix;
nuclear@0: }
nuclear@0: 
nuclear@0: Vector2 Camera::calc_sample_pos(int x, int y, int xsz, int ysz, int sample) const
nuclear@0: {
nuclear@0: 	float ppos[2];
nuclear@0: 	float aspect = (float)xsz / (float)ysz;
nuclear@0: 
nuclear@0: 	float pwidth = 2.0 * aspect / (float)xsz;
nuclear@0: 	float pheight = 2.0 / (float)ysz;
nuclear@0: 
nuclear@0: 	ppos[0] = (float)x * pwidth - aspect;
nuclear@0: 	ppos[1] = 1.0 - (float)y * pheight;
nuclear@0: 
nuclear@0: 	calc_sample_pos_rec(sample, pwidth, pheight, ppos);
nuclear@0: 	return Vector2(ppos[0], ppos[1]);
nuclear@0: }
nuclear@0: 
nuclear@0: Ray Camera::get_primary_ray(int x, int y, int xsz, int ysz, int sample) const
nuclear@0: {
nuclear@0: #pragma omp single
nuclear@0: 	{
nuclear@0: 		if(!rdir_cache || rdir_cache_width != xsz || rdir_cache_height != ysz) {
nuclear@0: 			printf("calculating primary ray direction cache\n");
nuclear@0: 
nuclear@0: 			delete [] rdir_cache;
nuclear@0: 			rdir_cache = new Vector3[xsz * ysz];
nuclear@0: 
nuclear@0: #pragma omp parallel for
nuclear@0: 			for(int i=0; i<ysz; i++) {
nuclear@0: 				Vector3 *rdir = rdir_cache + i * xsz;
nuclear@0: 				for(int j=0; j<xsz; j++) {
nuclear@0: 					Vector2 ppos = calc_sample_pos(j, i, xsz, ysz, 0);
nuclear@0: 
nuclear@0: 					rdir->x = ppos.x;
nuclear@0: 					rdir->y = ppos.y;
nuclear@0: 					rdir->z = 1.0 / tan(vfov / 2.0);
nuclear@0: 					rdir->normalize();
nuclear@0: 
nuclear@0: 					rdir++;
nuclear@0: 				}
nuclear@0: 			}
nuclear@0: 			rdir_cache_width = xsz;
nuclear@0: 			rdir_cache_height = ysz;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	Ray ray;
nuclear@0: 	ray.origin = pos;
nuclear@0: 	ray.dir = rdir_cache[y * xsz + x];
nuclear@0: 
nuclear@0: 	// transform the ray direction with the camera matrix
nuclear@0: 	Matrix4x4 mat = get_matrix();
nuclear@0: 	mat.m[0][3] = mat.m[1][3] = mat.m[2][3] = mat.m[3][0] = mat.m[3][1] = mat.m[3][2] = 0.0;
nuclear@0: 	mat.m[3][3] = 1.0;
nuclear@0: 
nuclear@0: 	ray.dir = ray.dir.transformed(mat);
nuclear@0: 	return ray;
nuclear@0: }
nuclear@0: 
nuclear@0: TargetCamera::TargetCamera() {}
nuclear@0: 
nuclear@0: TargetCamera::TargetCamera(const Vector3 &pos, const Vector3 &targ)
nuclear@0: 	: Camera(pos), target(targ)
nuclear@0: {
nuclear@0: }
nuclear@0: 
nuclear@0: void TargetCamera::set_target(const Vector3 &targ)
nuclear@0: {
nuclear@0: 	target = targ;
nuclear@0: 	cached_matrix_valid = false; // invalidate the cached matrix
nuclear@0: }
nuclear@0: 
nuclear@0: const Vector3 &TargetCamera::get_target() const
nuclear@0: {
nuclear@0: 	return target;
nuclear@0: }
nuclear@0: 
nuclear@0: void TargetCamera::calc_matrix(Matrix4x4 *mat) const
nuclear@0: {
nuclear@0: 	Vector3 up(0, 1, 0);
nuclear@0: 	Vector3 dir = (target - pos).normalized();
nuclear@0: 	Vector3 right = cross_product(up, dir);
nuclear@0: 	up = cross_product(dir, right);
nuclear@0: 
nuclear@0: 	*mat = Matrix4x4(
nuclear@0: 			right.x, up.x, dir.x, pos.x,
nuclear@0: 			right.y, up.y, dir.y, pos.y,
nuclear@0: 			right.z, up.z, dir.z, pos.z,
nuclear@0: 			0.0, 0.0, 0.0, 1.0);
nuclear@0: }
nuclear@0: 
nuclear@0: void FlyCamera::input_move(float x, float y, float z)
nuclear@0: {
nuclear@0: 	static const Vector3 vfwd(0, 0, 1), vright(1, 0, 0);
nuclear@0: 
nuclear@0: 	Vector3 k = vfwd.transformed(rot);
nuclear@0: 	Vector3	i = vright.transformed(rot);
nuclear@0: 	Vector3 j = cross_product(k, i);
nuclear@0: 
nuclear@0: 	pos += i * x + j * y + k * z;
nuclear@0: 	cached_matrix_valid = false;
nuclear@0: }
nuclear@0: 
nuclear@0: void FlyCamera::input_rotate(float x, float y, float z)
nuclear@0: {
nuclear@0: 	Vector3 axis(x, y, z);
nuclear@0: 	float axis_len = axis.length();
nuclear@0: 	if(fabs(axis_len) < 1e-5) {
nuclear@0: 		return;
nuclear@0: 	}
nuclear@0: 	rot.rotate(axis / axis_len, -axis_len);
nuclear@0: 	rot.normalize();
nuclear@0: 
nuclear@0: 	cached_matrix_valid = false;
nuclear@0: }
nuclear@0: 
nuclear@0: void FlyCamera::calc_matrix(Matrix4x4 *mat) const
nuclear@0: {
nuclear@0: 	Matrix4x4 tmat;
nuclear@0: 	tmat.set_translation(pos);
nuclear@0: 
nuclear@0: 	Matrix3x3 rmat = rot.get_rotation_matrix();
nuclear@0: 
nuclear@0: 	*mat = tmat * Matrix4x4(rmat);
nuclear@0: }
nuclear@0: 
nuclear@0: /* generates a sample position for sample number sidx, in the unit square
nuclear@0:  * by recursive subdivision and jittering
nuclear@0:  */
nuclear@0: static void calc_sample_pos_rec(int sidx, float xsz, float ysz, float *pos)
nuclear@0: {
nuclear@0:     static const float subpt[4][2] = {
nuclear@0:         {-0.25, -0.25}, {0.25, -0.25}, {-0.25, 0.25}, {0.25, 0.25}
nuclear@0:     };
nuclear@0: 
nuclear@0:     if(!sidx) {
nuclear@0:         return;
nuclear@0:     }
nuclear@0: 
nuclear@0:     /* determine which quadrant to recurse into */
nuclear@0:     int quadrant = ((sidx - 1) % 4);
nuclear@0:     pos[0] += subpt[quadrant][0] * xsz;
nuclear@0:     pos[1] += subpt[quadrant][1] * ysz;
nuclear@0: 
nuclear@0:     calc_sample_pos_rec((sidx - 1) / 4, xsz / 2, ysz / 2, pos);
nuclear@0: }