void main()
{
VECTOR3D plane_n; // plane normal
POINT3D plane_p; // point on plane
PLANE3D plane; // the plane
printf("\n3D Plane-Parametric Line Intersector\n");
// get the normal to the plane
printf("\nEnter normal to plane: nx, ny, nz?");
scanf("%f, %f, %f", &plane_n.x, &plane_n.y, &plane_n.z);
// get a point on the plane
printf("\nEnter a point on the plane: x,y,z?");
scanf("%f, %f, %f", &plane_p.x, &plane_p.y, &plane_p.z);
// create the plane from the point and normal
PLANE3D_Init(&plane, &plane_p, &plane_n, TRUE);
POINT3D p1, p2; // our endpoints
PARMLINE3D pl1; // our line
while(1) {
printf("\nEnter coords parametric line from p1 to p2 in form: x1,y1,z1, x2,y2,z2?");
scanf("%f, %f, %f, %f, %f, %f",&p1.x, &p1.y, &p1.z, &p2.x, &p2.y, &p2.z);
// create a parametric line from p1 to p2
Init_Parm_Line3D(&p1, &p2, &pl1);
float t; // intersection parameter
POINT3D pt; // intersection point
// compute intersection
int intersection_type = Intersect_Parm_Line3D_Plane3D(&pl1, &plane, &t, &pt);
// based on type of intersection display results
switch(intersection_type)
{
case PARM_LINE_NO_INTERSECT:
{
printf("\nThe plane and line does not intersect!");
} break;
case PARM_LINE_INTERSECT_IN_SEGMENT:
{
POINT3D pt;
Compute_Parm_Line3D(&pl1, t, &pt);
printf("\nThe line and plane intersects when t=%f at (%f, %f, %f)",t,pt.x, pt.y, pt.z);
} break;
case PARM_LINE_INTERSECT_OUT_SEGMENT:
{
POINT3D pt;
Compute_Parm_Line3D(&pl1, t, &pt);
printf("\nThe line and plane intersects when t=%f at (%f, %f, %f)",t,pt.x, pt.y, pt.z);
printf("\nNote that the intersection occurs out of range of the line segment");
} break;
default: break;
} // end switch
} // end while
} // end main
void Init_CAM4D(CAM4D_PTR cam,
int cam_attr,
Vector4d *cam_pos,
Vector4d *cam_dir,
Vector4d *cam_target,
float near_clip_z,
float far_clip_z,
float fov,
float viewport_width,
float viewport_height)
{
cam->attr = cam_attr;
cam->pos = (*cam_pos);
cam->dir = (*cam_dir);
cam->u = Vector4d(1, 0, 0, 1);
cam->v = Vector4d(0, 1, 0, 1);
cam->n = Vector4d(0, 0, 1, 1);
if (cam_target != NULL) {
cam->target = (*cam_target);
} else {
cam->target = Vector4d(0, 0, 0, 1);
}
cam->near_clip_z = near_clip_z;
cam->far_clip_z = far_clip_z;
cam->viewport_width = viewport_width;
cam->viewport_height = viewport_height;
cam->viewport_center_x = (viewport_width - 1) / 2;
cam->viewport_center_y = (viewport_height - 1) / 2;
cam->aspect_ratio = (float)viewport_width / (float)viewport_height;
// Init matrixs to be identity matrix
cam->mcam = Matrix4d::Identity(4, 4);
cam->mper = Matrix4d::Identity(4, 4);
cam->mscr = Matrix4d::Identity(4, 4);
cam->fov = fov;
cam->viewplane_width = 2.0;
cam->viewplane_height = 2.0f / cam->aspect_ratio;
float tan_fov_div2 = tan(DEG_TO_RAD(fov / 2));
cam->view_dist = 0.5 * (cam->viewplane_width) * tan_fov_div2;
if (fov == 90.0) {
Vector3d pt_origin = Vector3d(0, 0, 0);
Vector3d vn;
// Init clip plane
vn = Vector3d(1, 0, -1);
PLANE3D_Init(&cam->rt_clip_plane, &pt_origin, &vn, 1);
vn = Vector3d(-1, 0, -1);
PLANE3D_Init(&cam->lt_clip_plane, &pt_origin, &vn, 1);
vn = Vector3d(0, 1, -1);
PLANE3D_Init(&cam->tp_clip_plane, &pt_origin, &vn, 1);
vn = Vector3d(0, -1, -1);
PLANE3D_Init(&cam->bt_clip_plane, &pt_origin, &vn, 1);
} else {
Vector3d pt_origin = Vector3d(0, 0, 0);
Vector3d vn;
// Init clip plane
vn = Vector3d(cam->view_dist, 0, -cam->viewplane_width / 2.0);
PLANE3D_Init(&cam->rt_clip_plane, &pt_origin, &vn, 1);
vn = Vector3d(-cam->view_dist, 0, -cam->viewplane_width / 2.0);
PLANE3D_Init(&cam->lt_clip_plane, &pt_origin, &vn, 1);
vn = Vector3d(0, cam->view_dist, -cam->viewplane_width / 2.0);
PLANE3D_Init(&cam->tp_clip_plane, &pt_origin, &vn, 1);
vn = Vector3d(0, -cam->view_dist, -cam->viewplane_width / 2.0);
PLANE3D_Init(&cam->bt_clip_plane, &pt_origin, &vn, 1);
}
}
void Init_CAM4DV1(CAM4DV1_PTR cam, int cam_attr, POINT4D_PTR cam_pos, VECTOR4D_PTR cam_dir
, POINT4D_PTR cam_target, float near_clip_z, float far_clip_z, float fov, float viewport_width, float viewport_height)
{
cam->attr = cam_attr;
VECTOR4D_COPY(&cam->pos, cam_pos);
VECTOR4D_COPY(&cam->dir, cam_dir);
VECTOR4D_INITXYZ(&cam->u, 1.f, .0f, .0f);
VECTOR4D_INITXYZ(&cam->v, 0.f, 1.f, .0f);
VECTOR4D_INITXYZ(&cam->n, .0f, .0f, 1.f);
if (cam_pos != NULL)
VECTOR4D_COPY(&cam->target, cam_target);
else
VECTOR4D_ZERO(&cam->target);
cam->near_clip_z = near_clip_z;
cam->far_clip_z = far_clip_z;
cam->viewport_width = viewport_width;
cam->viewport_height = viewport_height;
cam->viewport_center_x = (viewport_width - 1) / 2;
cam->viewport_center_y = (viewport_height - 1) / 2;
cam->aspect_ratio = (float)viewport_width / (float)viewport_height;
MAT_IDENTITY_4X4(&cam->mcam);
MAT_IDENTITY_4X4(&cam->mper);
MAT_IDENTITY_4X4(&cam->mscr);
cam->fov = fov;
cam->viewplane_width = 2;
cam->viewplane_height = 2 / cam->aspect_ratio;
float tan_fov_div2 = tan(DEG_TO_RAD(fov / 2));
//cam->view_dist = 0.5f * cam->viewplane_width * tan_fov_div2;
cam->view_dist = 0.5f * cam->viewplane_width / tan_fov_div2;
cam->viewport_dist = 0.5f * cam->viewport_width / tan_fov_div2;
if (fov == 90.0)
{
POINT3D pt_origin;
VECTOR3D_INITXYZ(&pt_origin, 0, 0, 0);
VECTOR3D vn;
//ÓҲüôÃæ
VECTOR3D_INITXYZ(&vn, 1, 0, 11);
PLANE3D_Init(&cam->rt_clip_plane, &pt_origin, &vn, 1);
//×ó²Ã¼ôÃæ
VECTOR3D_INITXYZ(&vn, -1, 0, 1);
PLANE3D_Init(&cam->lt_clip_plane, &pt_origin, &vn, 1);
//ÉϲüôÃæ
VECTOR3D_INITXYZ(&vn, 0, 1, 1);
PLANE3D_Init(&cam->tp_clip_plane, &pt_origin, &vn, 1);
//ϲüôÃæ
VECTOR3D_INITXYZ(&vn, 0, -1, 1);
PLANE3D_Init(&cam->bt_clip_plane, &pt_origin, &vn, 1);
}
else
{
POINT3D pt_origin;
VECTOR3D_INITXYZ(&pt_origin, 0, 0, 0);
VECTOR3D vn;
VECTOR3D_INITXYZ(&vn, cam->view_dist, 0, cam->viewplane_width / 2.0f);
PLANE3D_Init(&cam->rt_clip_plane, &pt_origin, &vn, 1);
VECTOR3D_INITXYZ(&vn, -cam->view_dist, 0, cam->viewplane_width / 2.0f);
PLANE3D_Init(&cam->lt_clip_plane, &pt_origin, &vn, 1);
VECTOR3D_INITXYZ(&vn, 0, cam->view_dist, cam->viewplane_width / 2.0f);
PLANE3D_Init(&cam->rt_clip_plane, &pt_origin, &vn, 1);
VECTOR3D_INITXYZ(&vn, 0, -cam->view_dist, cam->viewplane_width / 2.0f);
PLANE3D_Init(&cam->rt_clip_plane, &pt_origin, &vn, 1);
}
}