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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <sys/types.h>
#include "v3dhf.h"
#include "sfm.h"
#include "obj.h"
#include "simutils.h"
#include "simsurface.h"
#include "sar.h"
float SARSimSupportSurfaceHeight(
sar_object_struct *obj_ptr,
const sar_contact_bounds_struct *cb,
const sar_position_struct *pos,
float z_tolor
);
float SARSimHFGetGroundHeight(
sar_object_struct *obj_ptr,
const sar_position_struct *pos
);
#define MAX(a,b) (((a) > (b)) ? (a) : (b))
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#define CLIP(a,l,h) (MIN(MAX((a),(l)),(h)))
/*
* Checks the contact bounds cb (which should have come from
* obj_ptr) against the given pos.
*
* z_tolor must be 0 or a positive value that will be added to
* the given position's z compoent for each check.
*
* Returns the z value of the obj_ptr's position plus any contact
* bound increased z offsets if and only if the given source pos
* is over the obj_ptr. Checks here take into consideration the
* hollowness of the target object, if the source position is below
* the contact bounds of the target object then the z value of the
* target object position is not returned.
*
* Calls to this function should already check if cb's crash_flags
* specify SAR_CRASH_FLAG_SUPPORT_SURFACE before calling this
* function. So this function assumes the contact bounds specify
* the object to have a landable/walkable surface.
*/
float SARSimSupportSurfaceHeight(
sar_object_struct *obj_ptr, /* Target */
const sar_contact_bounds_struct *cb, /* Target */
const sar_position_struct *pos, /* Source */
float z_tolor /* In meters */
)
{
float dx, dy, dx2, dy2, dr, cr;
float x_min, x_max, y_min, y_max;
float cur_z_height = 0.0f;
const sar_contact_bounds_struct *cb_tar = cb;
const sar_position_struct *pos_src = pos,
*pos_tar = &obj_ptr->pos;
if(z_tolor < 0.0f)
z_tolor = 0.0f;
/* Handle by target object contact bounds shape */
switch(cb_tar->contact_shape)
{
case SAR_CONTACT_SHAPE_SPHERICAL:
dx = pos_src->x - pos_tar->x;
dy = pos_src->y - pos_tar->y;
cr = cb_tar->contact_radius;
dr = (float)SFMHypot2(dx, dy);
/* Delta distance apart equal or less than contact radius? */
if(dr <= cr)
{
/* Use spherical radius as contact z height offset */
float check_z = pos_tar->z + cr;
/* Is source position is under the target surface? */
if((pos_src->z + z_tolor) < check_z)
{
/* Source object is under, so do not account for
* surface
*
* This will make any source position under
* the target surface "hollow"
*/
}
else
{
cur_z_height = check_z;
}
}
break;
case SAR_CONTACT_SHAPE_CYLENDRICAL:
dx = pos_src->x - pos_tar->x;
dy = pos_src->y - pos_tar->y;
cr = cb_tar->contact_radius;
dr = (float)SFMHypot2(dx, dy);
/* Delta distance apart equal or less than contact radius? */
if(dr <= cr)
{
float check_z = pos_tar->z + cb_tar->contact_h_max;
/* Is source position is under the target surface? */
if((pos_src->z + z_tolor) < check_z)
{
/* Source object is under, so do not account for
* surface. This will make any source position under
* the target surface `hollow'.
*/
}
else
{
cur_z_height = check_z;
}
}
break;
case SAR_CONTACT_SHAPE_RECTANGULAR:
dx = pos_src->x - pos_tar->x;
dy = pos_src->y - pos_tar->y;
/* Is source object under the top surface of the target
* object?
*/
if((pos_src->z + z_tolor) < (pos_tar->z + cb_tar->contact_z_max))
{
/* Source object is under, so do not account for surface */
}
else
{
/* Rotate dx and dy about the center of the target
* object inversly incase target object has a rotated
* heading.
*/
dx2 = (cb_tar->cos_heading * dx) +
(cb_tar->sin_heading * dy);
dy2 = (cb_tar->cos_heading * dy) -
(cb_tar->sin_heading * dx);
/* Calculate x and y bounds */
x_min = cb_tar->contact_x_min;
x_max = cb_tar->contact_x_max;
y_min = cb_tar->contact_y_min;
y_max = cb_tar->contact_y_max;
/* Check if rotated dx2 and dy2 are in bounds */
if((dx2 >= x_min) && (dx2 <= x_max) &&
(dy2 >= y_min) && (dy2 <= y_max)
)
cur_z_height = pos_tar->z + cb_tar->contact_z_max;
}
break;
}
return(cur_z_height);
}
/*
* Returns the elevation of (not to) the object of type
* ground given the position pos (z coordinate will be
* ignored and msl elevation offset will be ignored).
*
* The object must be of type ground, the return value will
* be either the ground object's set elevation or from
* its heighfield data (if any), whichever is higher.
*/
float SARSimHFGetGroundHeight(
sar_object_struct *obj_ptr,
const sar_position_struct *pos
)
{
float d, dx, dy;
float cur_z_height = 0.0, z_result;
float contact_radius;
const sar_position_struct *pos_tar = pos, *pos_src;
sar_object_ground_struct *obj_ground_ptr;
/* Is this object of type ground? */
obj_ground_ptr = SAR_OBJ_GET_GROUND(obj_ptr);
if(obj_ground_ptr == NULL)
return(cur_z_height);
if(obj_ground_ptr == NULL)
return(cur_z_height);
/* Note: Target refers to the specified position and source
* refers to the SAR_OBJ_TYPE_GROUND object
*/
/* Get flat contact radius of ground object */
contact_radius = SARSimGetFlatContactRadius(obj_ptr);
/* All SAR_OBJ_TYPE_GROUND objects have cylendrical solid
* surfaces, where the radius is specified by the ground
* object's contact bounds (which can be a radius of 0.0)
*
* Get position of ground object and check distance,
* see if outside the ground object's contact radius
*/
pos_src = &obj_ptr->pos;
/* Calculate deltas, target position to source position.
* Note dy needs to be `top left' oriented
*/
dx = pos_tar->x - (pos_src->x + obj_ground_ptr->x_trans);
dy = (pos_src->y + obj_ground_ptr->y_trans) - pos_tar->y;
d = (float)SFMHypot2(dx, dy);
if(d <= contact_radius)
{
/* Compare flat elevation first, by checking the ground
* object's specified elevation from 0. Note that ground
* objects completly ignore the scene structure defined
* ground_elevation_msl value
*/
if((obj_ground_ptr->elevation + pos_src->z +
obj_ground_ptr->z_trans) > cur_z_height
)
cur_z_height = obj_ground_ptr->elevation + pos_src->z +
obj_ground_ptr->z_trans;
}
/* Get heightfield Z position of target position */
z_result = (float)V3DHFGetHeightFromWorldPosition(
pos_tar->x, pos_tar->y, /* The world position */
pos_src->x + obj_ground_ptr->x_trans,
pos_src->y + obj_ground_ptr->y_trans,
pos_src->z + obj_ground_ptr->z_trans,
obj_ptr->dir.heading,
obj_ground_ptr->x_len, obj_ground_ptr->y_len,
obj_ground_ptr->grid_z_spacing,
obj_ground_ptr->grid_points_x, obj_ground_ptr->grid_points_y,
obj_ground_ptr->z_point_value
);
if(cur_z_height < z_result)
cur_z_height = z_result;
return(cur_z_height);
}
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