Files
SingularityViewer/indra/llmath/raytrace.cpp
Inusaito Sayori 8a2e24ecd0 Sync with viewer-tiger~
Syncs up llmath stuffs.

Thanks to Shyotl for the CMakeLists fix for Wbemuuid.
2014-07-11 20:36:19 -04:00

1275 lines
38 KiB
C++

/**
* @file raytrace.cpp
* @brief Functions called by box object scripts.
*
* $LicenseInfo:firstyear=2001&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#include "linden_common.h"
#include "math.h"
//#include "vmath.h"
#include "v3math.h"
#include "llquaternion.h"
#include "m3math.h"
#include "raytrace.h"
BOOL line_plane(const LLVector3 &line_point, const LLVector3 &line_direction,
const LLVector3 &plane_point, const LLVector3 plane_normal,
LLVector3 &intersection)
{
F32 N = line_direction * plane_normal;
if (0.0f == N)
{
// line is perpendicular to plane normal
// so it is either entirely on plane, or not on plane at all
return FALSE;
}
// Ax + By, + Cz + D = 0
// D = - (plane_point * plane_normal)
// N = line_direction * plane_normal
// intersection = line_point - ((D + plane_normal * line_point) / N) * line_direction
intersection = line_point - ((plane_normal * line_point - plane_point * plane_normal) / N) * line_direction;
return TRUE;
}
BOOL ray_plane(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &plane_point, const LLVector3 plane_normal,
LLVector3 &intersection)
{
F32 N = ray_direction * plane_normal;
if (0.0f == N)
{
// ray is perpendicular to plane normal
// so it is either entirely on plane, or not on plane at all
return FALSE;
}
// Ax + By, + Cz + D = 0
// D = - (plane_point * plane_normal)
// N = ray_direction * plane_normal
// intersection = ray_point - ((D + plane_normal * ray_point) / N) * ray_direction
F32 alpha = -(plane_normal * ray_point - plane_point * plane_normal) / N;
if (alpha < 0.0f)
{
// ray points away from plane
return FALSE;
}
intersection = ray_point + alpha * ray_direction;
return TRUE;
}
BOOL ray_circle(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &circle_center, const LLVector3 plane_normal, F32 circle_radius,
LLVector3 &intersection)
{
if (ray_plane(ray_point, ray_direction, circle_center, plane_normal, intersection))
{
if (circle_radius >= (intersection - circle_center).magVec())
{
return TRUE;
}
}
return FALSE;
}
BOOL ray_triangle(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &point_0, const LLVector3 &point_1, const LLVector3 &point_2,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 side_01 = point_1 - point_0;
LLVector3 side_12 = point_2 - point_1;
intersection_normal = side_01 % side_12;
intersection_normal.normVec();
if (ray_plane(ray_point, ray_direction, point_0, intersection_normal, intersection))
{
LLVector3 side_20 = point_0 - point_2;
if (intersection_normal * (side_01 % (intersection - point_0)) >= 0.0f &&
intersection_normal * (side_12 % (intersection - point_1)) >= 0.0f &&
intersection_normal * (side_20 % (intersection - point_2)) >= 0.0f)
{
return TRUE;
}
}
return FALSE;
}
// assumes a parallelogram
BOOL ray_quadrangle(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &point_0, const LLVector3 &point_1, const LLVector3 &point_2,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 side_01 = point_1 - point_0;
LLVector3 side_12 = point_2 - point_1;
intersection_normal = side_01 % side_12;
intersection_normal.normVec();
if (ray_plane(ray_point, ray_direction, point_0, intersection_normal, intersection))
{
LLVector3 point_3 = point_0 + (side_12);
LLVector3 side_23 = point_3 - point_2;
LLVector3 side_30 = point_0 - point_3;
if (intersection_normal * (side_01 % (intersection - point_0)) >= 0.0f &&
intersection_normal * (side_12 % (intersection - point_1)) >= 0.0f &&
intersection_normal * (side_23 % (intersection - point_2)) >= 0.0f &&
intersection_normal * (side_30 % (intersection - point_3)) >= 0.0f)
{
return TRUE;
}
}
return FALSE;
}
BOOL ray_sphere(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &sphere_center, F32 sphere_radius,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_to_sphere = sphere_center - ray_point;
F32 dot = ray_to_sphere * ray_direction;
LLVector3 closest_approach = dot * ray_direction - ray_to_sphere;
F32 shortest_distance = closest_approach.magVecSquared();
F32 radius_squared = sphere_radius * sphere_radius;
if (shortest_distance > radius_squared)
{
return FALSE;
}
F32 half_chord = (F32) sqrt(radius_squared - shortest_distance);
closest_approach = sphere_center + closest_approach; // closest_approach now in absolute coordinates
intersection = closest_approach + half_chord * ray_direction;
dot = ray_direction * (intersection - ray_point);
if (dot < 0.0f)
{
// ray shoots away from sphere and is not inside it
return FALSE;
}
shortest_distance = ray_direction * ((closest_approach - half_chord * ray_direction) - ray_point);
if (shortest_distance > 0.0f)
{
// ray enters sphere
intersection = intersection - (2.0f * half_chord) * ray_direction;
}
else
{
// do nothing
// ray starts inside sphere and intersects as it leaves the sphere
}
intersection_normal = intersection - sphere_center;
if (sphere_radius > 0.0f)
{
intersection_normal *= 1.0f / sphere_radius;
}
else
{
intersection_normal.setVec(0.0f, 0.0f, 0.0f);
}
return TRUE;
}
BOOL ray_cylinder(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &cyl_center, const LLVector3 &cyl_scale, const LLQuaternion &cyl_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
// calculate the centers of the cylinder caps in the absolute frame
LLVector3 cyl_top(0.0f, 0.0f, 0.5f * cyl_scale.mV[VZ]);
LLVector3 cyl_bottom(0.0f, 0.0f, -cyl_top.mV[VZ]);
cyl_top = (cyl_top * cyl_rotation) + cyl_center;
cyl_bottom = (cyl_bottom * cyl_rotation) + cyl_center;
// we only handle cylinders with circular cross-sections at the moment
F32 cyl_radius = 0.5f * llmax(cyl_scale.mV[VX], cyl_scale.mV[VY]); // HACK until scaled cylinders are supported
// This implementation is based on the intcyl() function from Graphics_Gems_IV, page 361
LLVector3 cyl_axis; // axis direction (bottom toward top)
LLVector3 ray_to_cyl; // ray_point to cyl_top
F32 shortest_distance; // shortest distance from ray to axis
F32 cyl_length;
LLVector3 shortest_direction;
LLVector3 temp_vector;
cyl_axis = cyl_bottom - cyl_top;
cyl_length = cyl_axis.normVec();
ray_to_cyl = ray_point - cyl_bottom;
shortest_direction = ray_direction % cyl_axis;
shortest_distance = shortest_direction.normVec(); // recycle shortest_distance
// check for ray parallel to cylinder axis
if (0.0f == shortest_distance)
{
// ray is parallel to cylinder axis
temp_vector = ray_to_cyl - (ray_to_cyl * cyl_axis) * cyl_axis;
shortest_distance = temp_vector.magVec();
if (shortest_distance <= cyl_radius)
{
shortest_distance = ray_to_cyl * cyl_axis;
F32 dot = ray_direction * cyl_axis;
if (shortest_distance > 0.0)
{
if (dot > 0.0f)
{
// ray points away from cylinder bottom
return FALSE;
}
// ray hit bottom of cylinder from outside
intersection = ray_point - shortest_distance * cyl_axis;
intersection_normal = cyl_axis;
}
else if (shortest_distance > -cyl_length)
{
// ray starts inside cylinder
if (dot < 0.0f)
{
// ray hit top from inside
intersection = ray_point - (cyl_length + shortest_distance) * cyl_axis;
intersection_normal = -cyl_axis;
}
else
{
// ray hit bottom from inside
intersection = ray_point - shortest_distance * cyl_axis;
intersection_normal = cyl_axis;
}
}
else
{
if (dot < 0.0f)
{
// ray points away from cylinder bottom
return FALSE;
}
// ray hit top from outside
intersection = ray_point - (shortest_distance + cyl_length) * cyl_axis;
intersection_normal = -cyl_axis;
}
return TRUE;
}
return FALSE;
}
// check for intersection with infinite cylinder
shortest_distance = (F32) fabs(ray_to_cyl * shortest_direction);
if (shortest_distance <= cyl_radius)
{
F32 dist_to_closest_point; // dist from ray_point to closest_point
F32 half_chord_length; // half length of intersection chord
F32 in, out; // distances to entering/exiting points
temp_vector = ray_to_cyl % cyl_axis;
dist_to_closest_point = - (temp_vector * shortest_direction);
temp_vector = shortest_direction % cyl_axis;
temp_vector.normVec();
half_chord_length = (F32) fabs( sqrt(cyl_radius*cyl_radius - shortest_distance * shortest_distance) /
(ray_direction * temp_vector) );
out = dist_to_closest_point + half_chord_length; // dist to exiting point
if (out < 0.0f)
{
// cylinder is behind the ray, so we return FALSE
return FALSE;
}
in = dist_to_closest_point - half_chord_length; // dist to entering point
if (in < 0.0f)
{
// ray_point is inside the cylinder
// so we store the exiting intersection
intersection = ray_point + out * ray_direction;
shortest_distance = out;
}
else
{
// ray hit cylinder from outside
// so we store the entering intersection
intersection = ray_point + in * ray_direction;
shortest_distance = in;
}
// calculate the normal at intersection
if (0.0f == cyl_radius)
{
intersection_normal.setVec(0.0f, 0.0f, 0.0f);
}
else
{
temp_vector = intersection - cyl_bottom;
intersection_normal = temp_vector - (temp_vector * cyl_axis) * cyl_axis;
intersection_normal.normVec();
}
// check for intersection with end caps
// calculate intersection of ray and top plane
if (line_plane(ray_point, ray_direction, cyl_top, -cyl_axis, temp_vector)) // NOTE side-effect: changing temp_vector
{
shortest_distance = (temp_vector - ray_point).magVec();
if ( (ray_direction * cyl_axis) > 0.0f)
{
// ray potentially enters the cylinder at top
if (shortest_distance > out)
{
// ray missed the finite cylinder
return FALSE;
}
if (shortest_distance > in)
{
// ray intersects cylinder at top plane
intersection = temp_vector;
intersection_normal = -cyl_axis;
return TRUE;
}
}
else
{
// ray potentially exits the cylinder at top
if (shortest_distance < in)
{
// missed the finite cylinder
return FALSE;
}
}
// calculate intersection of ray and bottom plane
line_plane(ray_point, ray_direction, cyl_bottom, cyl_axis, temp_vector); // NOTE side-effect: changing temp_vector
shortest_distance = (temp_vector - ray_point).magVec();
if ( (ray_direction * cyl_axis) < 0.0)
{
// ray potentially enters the cylinder at bottom
if (shortest_distance > out)
{
// ray missed the finite cylinder
return FALSE;
}
if (shortest_distance > in)
{
// ray intersects cylinder at bottom plane
intersection = temp_vector;
intersection_normal = cyl_axis;
return TRUE;
}
}
else
{
// ray potentially exits the cylinder at bottom
if (shortest_distance < in)
{
// ray missed the finite cylinder
return FALSE;
}
}
}
else
{
// ray is parallel to end cap planes
temp_vector = cyl_bottom - ray_point;
shortest_distance = temp_vector * cyl_axis;
if (shortest_distance < 0.0f || shortest_distance > cyl_length)
{
// ray missed finite cylinder
return FALSE;
}
}
return TRUE;
}
return FALSE;
}
U32 ray_box(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &box_center, const LLVector3 &box_scale, const LLQuaternion &box_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
// Need to rotate into box frame
LLQuaternion into_box_frame(box_rotation); // rotates things from box frame to absolute
into_box_frame.conjQuat(); // now rotates things into box frame
LLVector3 line_point = (ray_point - box_center) * into_box_frame;
LLVector3 line_direction = ray_direction * into_box_frame;
// Suppose we have a plane: Ax + By + Cz + D = 0
// then, assuming [A, B, C] is a unit vector:
//
// plane_normal = [A, B, C]
// D = - (plane_normal * plane_point)
//
// Suppose we have a line: X = line_point + alpha * line_direction
//
// the intersection of the plane and line determines alpha
//
// alpha = - (D + plane_normal * line_point) / (plane_normal * line_direction)
LLVector3 line_plane_intersection;
F32 pointX = line_point.mV[VX];
F32 pointY = line_point.mV[VY];
F32 pointZ = line_point.mV[VZ];
F32 dirX = line_direction.mV[VX];
F32 dirY = line_direction.mV[VY];
F32 dirZ = line_direction.mV[VZ];
// we'll be using the half-scales of the box
F32 boxX = 0.5f * box_scale.mV[VX];
F32 boxY = 0.5f * box_scale.mV[VY];
F32 boxZ = 0.5f * box_scale.mV[VZ];
// check to see if line_point is OUTSIDE the box
if (pointX < -boxX ||
pointX > boxX ||
pointY < -boxY ||
pointY > boxY ||
pointZ < -boxZ ||
pointZ > boxZ)
{
// -------------- point is OUTSIDE the box ----------------
// front
if (pointX > 0.0f && dirX < 0.0f)
{
// plane_normal = [ 1, 0, 0]
// plane_normal*line_point = pointX
// plane_normal*line_direction = dirX
// D = -boxX
// alpha = - (-boxX + pointX) / dirX
line_plane_intersection = line_point - ((pointX - boxX) / dirX) * line_direction;
if (line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(1.0f, 0.0f, 0.0f) * box_rotation;
return FRONT_SIDE;
}
}
// back
if (pointX < 0.0f && dirX > 0.0f)
{
// plane_normal = [ -1, 0, 0]
// plane_normal*line_point = -pX
// plane_normal*line_direction = -direction.mV[VX]
// D = -bX
// alpha = - (-bX - pX) / (-dirX)
line_plane_intersection = line_point - ((boxX + pointX)/ dirX) * line_direction;
if (line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(-1.0f, 0.0f, 0.0f) * box_rotation;
return BACK_SIDE;
}
}
// left
if (pointY > 0.0f && dirY < 0.0f)
{
// plane_normal = [0, 1, 0]
// plane_normal*line_point = pointY
// plane_normal*line_direction = dirY
// D = -boxY
// alpha = - (-boxY + pointY) / dirY
line_plane_intersection = line_point + ((boxY - pointY)/dirY) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, 1.0f, 0.0f) * box_rotation;
return LEFT_SIDE;
}
}
// right
if (pointY < 0.0f && dirY > 0.0f)
{
// plane_normal = [0, -1, 0]
// plane_normal*line_point = -pointY
// plane_normal*line_direction = -dirY
// D = -boxY
// alpha = - (-boxY - pointY) / (-dirY)
line_plane_intersection = line_point - ((boxY + pointY)/dirY) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, -1.0f, 0.0f) * box_rotation;
return RIGHT_SIDE;
}
}
// top
if (pointZ > 0.0f && dirZ < 0.0f)
{
// plane_normal = [0, 0, 1]
// plane_normal*line_point = pointZ
// plane_normal*line_direction = dirZ
// D = -boxZ
// alpha = - (-boxZ + pointZ) / dirZ
line_plane_intersection = line_point - ((pointZ - boxZ)/dirZ) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, 0.0f, 1.0f) * box_rotation;
return TOP_SIDE;
}
}
// bottom
if (pointZ < 0.0f && dirZ > 0.0f)
{
// plane_normal = [0, 0, -1]
// plane_normal*line_point = -pointZ
// plane_normal*line_direction = -dirZ
// D = -boxZ
// alpha = - (-boxZ - pointZ) / (-dirZ)
line_plane_intersection = line_point - ((boxZ + pointZ)/dirZ) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, 0.0f, -1.0f) * box_rotation;
return BOTTOM_SIDE;
}
}
return NO_SIDE;
}
// -------------- point is INSIDE the box ----------------
// front
if (dirX > 0.0f)
{
// plane_normal = [ 1, 0, 0]
// plane_normal*line_point = pointX
// plane_normal*line_direction = dirX
// D = -boxX
// alpha = - (-boxX + pointX) / dirX
line_plane_intersection = line_point - ((pointX - boxX) / dirX) * line_direction;
if (line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(1.0f, 0.0f, 0.0f) * box_rotation;
return FRONT_SIDE;
}
}
// back
if (dirX < 0.0f)
{
// plane_normal = [ -1, 0, 0]
// plane_normal*line_point = -pX
// plane_normal*line_direction = -direction.mV[VX]
// D = -bX
// alpha = - (-bX - pX) / (-dirX)
line_plane_intersection = line_point - ((boxX + pointX)/ dirX) * line_direction;
if (line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(-1.0f, 0.0f, 0.0f) * box_rotation;
return BACK_SIDE;
}
}
// left
if (dirY > 0.0f)
{
// plane_normal = [0, 1, 0]
// plane_normal*line_point = pointY
// plane_normal*line_direction = dirY
// D = -boxY
// alpha = - (-boxY + pointY) / dirY
line_plane_intersection = line_point + ((boxY - pointY)/dirY) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, 1.0f, 0.0f) * box_rotation;
return LEFT_SIDE;
}
}
// right
if (dirY < 0.0f)
{
// plane_normal = [0, -1, 0]
// plane_normal*line_point = -pointY
// plane_normal*line_direction = -dirY
// D = -boxY
// alpha = - (-boxY - pointY) / (-dirY)
line_plane_intersection = line_point - ((boxY + pointY)/dirY) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VZ] < boxZ &&
line_plane_intersection.mV[VZ] > -boxZ )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, -1.0f, 0.0f) * box_rotation;
return RIGHT_SIDE;
}
}
// top
if (dirZ > 0.0f)
{
// plane_normal = [0, 0, 1]
// plane_normal*line_point = pointZ
// plane_normal*line_direction = dirZ
// D = -boxZ
// alpha = - (-boxZ + pointZ) / dirZ
line_plane_intersection = line_point - ((pointZ - boxZ)/dirZ) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, 0.0f, 1.0f) * box_rotation;
return TOP_SIDE;
}
}
// bottom
if (dirZ < 0.0f)
{
// plane_normal = [0, 0, -1]
// plane_normal*line_point = -pointZ
// plane_normal*line_direction = -dirZ
// D = -boxZ
// alpha = - (-boxZ - pointZ) / (-dirZ)
line_plane_intersection = line_point - ((boxZ + pointZ)/dirZ) * line_direction;
if (line_plane_intersection.mV[VX] < boxX &&
line_plane_intersection.mV[VX] > -boxX &&
line_plane_intersection.mV[VY] < boxY &&
line_plane_intersection.mV[VY] > -boxY )
{
intersection = (line_plane_intersection * box_rotation) + box_center;
intersection_normal = LLVector3(0.0f, 0.0f, -1.0f) * box_rotation;
return BOTTOM_SIDE;
}
}
// should never get here unless line instersects at tangent point on edge or corner
// however such cases will be EXTREMELY rare
return NO_SIDE;
}
BOOL ray_prism(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &prism_center, const LLVector3 &prism_scale, const LLQuaternion &prism_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
// (0) Z
// /| \ .
// (1)| \ /|\ _.Y
// | \ \ | /|
// | |\ \ | /
// | | \(0)\ | /
// | | \ \ |/
// | | \ \ (*)----> X
// |(3)---\---(2)
// |/ \ /
// (4)-------(5)
// need to calculate the points of the prism so we can run ray tests with each face
F32 x = prism_scale.mV[VX];
F32 y = prism_scale.mV[VY];
F32 z = prism_scale.mV[VZ];
F32 tx = x * 2.0f / 3.0f;
F32 ty = y * 0.5f;
F32 tz = z * 2.0f / 3.0f;
LLVector3 point0(tx-x, ty, tz);
LLVector3 point1(tx-x, -ty, tz);
LLVector3 point2(tx, ty, tz-z);
LLVector3 point3(tx-x, ty, tz-z);
LLVector3 point4(tx-x, -ty, tz-z);
LLVector3 point5(tx, -ty, tz-z);
// transform these points into absolute frame
point0 = (point0 * prism_rotation) + prism_center;
point1 = (point1 * prism_rotation) + prism_center;
point2 = (point2 * prism_rotation) + prism_center;
point3 = (point3 * prism_rotation) + prism_center;
point4 = (point4 * prism_rotation) + prism_center;
point5 = (point5 * prism_rotation) + prism_center;
// test ray intersection for each face
BOOL b_hit = FALSE;
LLVector3 face_intersection, face_normal;
F32 distance_squared = 0.0f;
F32 temp;
// face 0
if (ray_direction * ( (point0 - point2) % (point5 - point2)) < 0.0f &&
ray_quadrangle(ray_point, ray_direction, point5, point2, point0, intersection, intersection_normal))
{
distance_squared = (ray_point - intersection).magVecSquared();
b_hit = TRUE;
}
// face 1
if (ray_direction * ( (point0 - point3) % (point2 - point3)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point2, point3, point0, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 2
if (ray_direction * ( (point1 - point4) % (point3 - point4)) < 0.0f &&
ray_quadrangle(ray_point, ray_direction, point3, point4, point1, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 3
if (ray_direction * ( (point5 - point4) % (point1 - point4)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point1, point4, point5, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 4
if (ray_direction * ( (point4 - point5) % (point2 - point5)) < 0.0f &&
ray_quadrangle(ray_point, ray_direction, point2, point5, point4, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
return b_hit;
}
BOOL ray_tetrahedron(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &t_center, const LLVector3 &t_scale, const LLQuaternion &t_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
F32 a = 0.5f * F_SQRT3; // height of unit triangle
F32 b = 1.0f / F_SQRT3; // distance of center of unit triangle to each point
F32 c = F_SQRT2 / F_SQRT3; // height of unit tetrahedron
F32 d = 0.5f * F_SQRT3 / F_SQRT2; // distance of center of tetrahedron to each point
// if we want the tetrahedron to have unit height (c = 1.0) then we need to divide
// each constant by hieght of a unit tetrahedron
F32 oo_c = 1.0f / c;
a = a * oo_c;
b = b * oo_c;
c = 1.0f;
d = d * oo_c;
F32 e = 0.5f * oo_c;
LLVector3 point0( 0.0f, 0.0f, t_scale.mV[VZ] * d);
LLVector3 point1(t_scale.mV[VX] * b, 0.0f, t_scale.mV[VZ] * (d-c));
LLVector3 point2(t_scale.mV[VX] * (b-a), e * t_scale.mV[VY], t_scale.mV[VZ] * (d-c));
LLVector3 point3(t_scale.mV[VX] * (b-a), -e * t_scale.mV[VY], t_scale.mV[VZ] * (d-c));
// transform these points into absolute frame
point0 = (point0 * t_rotation) + t_center;
point1 = (point1 * t_rotation) + t_center;
point2 = (point2 * t_rotation) + t_center;
point3 = (point3 * t_rotation) + t_center;
// test ray intersection for each face
BOOL b_hit = FALSE;
LLVector3 face_intersection, face_normal;
F32 distance_squared = 1.0e12f;
F32 temp;
// face 0
if (ray_direction * ( (point2 - point1) % (point0 - point1)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point1, point2, point0, intersection, intersection_normal))
{
distance_squared = (ray_point - intersection).magVecSquared();
b_hit = TRUE;
}
// face 1
if (ray_direction * ( (point3 - point2) % (point0 - point2)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point2, point3, point0, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 2
if (ray_direction * ( (point1 - point3) % (point0 - point3)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point3, point1, point0, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 3
if (ray_direction * ( (point2 - point3) % (point1 - point3)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point3, point2, point1, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
return b_hit;
}
BOOL ray_pyramid(const LLVector3 &ray_point, const LLVector3 &ray_direction,
const LLVector3 &p_center, const LLVector3 &p_scale, const LLQuaternion &p_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
// center of mass of pyramid is located 1/4 its height from the base
F32 x = 0.5f * p_scale.mV[VX];
F32 y = 0.5f * p_scale.mV[VY];
F32 z = 0.25f * p_scale.mV[VZ];
LLVector3 point0(0.0f, 0.0f, p_scale.mV[VZ] - z);
LLVector3 point1( x, y, -z);
LLVector3 point2(-x, y, -z);
LLVector3 point3(-x, -y, -z);
LLVector3 point4( x, -y, -z);
// transform these points into absolute frame
point0 = (point0 * p_rotation) + p_center;
point1 = (point1 * p_rotation) + p_center;
point2 = (point2 * p_rotation) + p_center;
point3 = (point3 * p_rotation) + p_center;
point4 = (point4 * p_rotation) + p_center;
// test ray intersection for each face
BOOL b_hit = FALSE;
LLVector3 face_intersection, face_normal;
F32 distance_squared = 1.0e12f;
F32 temp;
// face 0
if (ray_direction * ( (point1 - point4) % (point0 - point4)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point4, point1, point0, intersection, intersection_normal))
{
distance_squared = (ray_point - intersection).magVecSquared();
b_hit = TRUE;
}
// face 1
if (ray_direction * ( (point2 - point1) % (point0 - point1)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point1, point2, point0, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 2
if (ray_direction * ( (point3 - point2) % (point0 - point2)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point2, point3, point0, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 3
if (ray_direction * ( (point4 - point3) % (point0 - point3)) < 0.0f &&
ray_triangle(ray_point, ray_direction, point3, point4, point0, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
distance_squared = temp;
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
distance_squared = (ray_point - face_intersection).magVecSquared();
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
// face 4
if (ray_direction * ( (point3 - point4) % (point2 - point4)) < 0.0f &&
ray_quadrangle(ray_point, ray_direction, point4, point3, point2, face_intersection, face_normal))
{
if (TRUE == b_hit)
{
temp = (ray_point - face_intersection).magVecSquared();
if (temp < distance_squared)
{
intersection = face_intersection;
intersection_normal = face_normal;
}
}
else
{
intersection = face_intersection;
intersection_normal = face_normal;
b_hit = TRUE;
}
}
return b_hit;
}
BOOL linesegment_circle(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &circle_center, const LLVector3 plane_normal, F32 circle_radius,
LLVector3 &intersection)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_circle(point_a, ray_direction, circle_center, plane_normal, circle_radius, intersection))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
BOOL linesegment_triangle(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &point_0, const LLVector3 &point_1, const LLVector3 &point_2,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_triangle(point_a, ray_direction, point_0, point_1, point_2, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
BOOL linesegment_quadrangle(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &point_0, const LLVector3 &point_1, const LLVector3 &point_2,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_quadrangle(point_a, ray_direction, point_0, point_1, point_2, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
BOOL linesegment_sphere(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &sphere_center, F32 sphere_radius,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_sphere(point_a, ray_direction, sphere_center, sphere_radius, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
BOOL linesegment_cylinder(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &cyl_center, const LLVector3 &cyl_scale, const LLQuaternion &cyl_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_cylinder(point_a, ray_direction, cyl_center, cyl_scale, cyl_rotation, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
U32 linesegment_box(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &box_center, const LLVector3 &box_scale, const LLQuaternion &box_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 direction = point_b - point_a;
if (direction.isNull())
{
return NO_SIDE;
}
F32 segment_length = direction.normVec();
U32 box_side = ray_box(point_a, direction, box_center, box_scale, box_rotation, intersection, intersection_normal);
if (NO_SIDE == box_side || segment_length < (intersection - point_a).magVec())
{
return NO_SIDE;
}
return box_side;
}
BOOL linesegment_prism(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &prism_center, const LLVector3 &prism_scale, const LLQuaternion &prism_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_prism(point_a, ray_direction, prism_center, prism_scale, prism_rotation, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
BOOL linesegment_tetrahedron(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &t_center, const LLVector3 &t_scale, const LLQuaternion &t_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_tetrahedron(point_a, ray_direction, t_center, t_scale, t_rotation, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}
BOOL linesegment_pyramid(const LLVector3 &point_a, const LLVector3 &point_b,
const LLVector3 &p_center, const LLVector3 &p_scale, const LLQuaternion &p_rotation,
LLVector3 &intersection, LLVector3 &intersection_normal)
{
LLVector3 ray_direction = point_b - point_a;
F32 segment_length = ray_direction.normVec();
if (ray_pyramid(point_a, ray_direction, p_center, p_scale, p_rotation, intersection, intersection_normal))
{
if (segment_length >= (point_a - intersection).magVec())
{
return TRUE;
}
}
return FALSE;
}