dhewm3-sdk/idlib/geometry/Winding2D.cpp
Daniel Gibson 85a1020490 Fix pot. Crash in idWinding2D::ExpandForAxialBox()
it could happen that i is 1 but numPlanes is still 0
(=> if for i = 0:  ( p[j] - p[i] ).LengthSqr() < 0.01f )
so planes[-1] would be accessed which of course is invalid and can crash
2018-12-09 04:23:41 +01:00

751 lines
16 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code ("Doom 3 Source Code").
Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 Source Code 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "sys/platform.h"
#include "idlib/Lib.h"
#include "framework/Common.h"
#include "idlib/geometry/Winding2D.h"
/*
============
GetAxialBevel
============
*/
bool GetAxialBevel( const idVec3 &plane1, const idVec3 &plane2, const idVec2 &point, idVec3 &bevel ) {
if ( FLOATSIGNBITSET( plane1.x ) ^ FLOATSIGNBITSET( plane2.x ) ) {
if ( idMath::Fabs( plane1.x ) > 0.1f && idMath::Fabs( plane2.x ) > 0.1f ) {
bevel.x = 0.0f;
if ( FLOATSIGNBITSET( plane1.y ) ) {
bevel.y = -1.0f;
}
else {
bevel.y = 1.0f;
}
bevel.z = - ( point.x * bevel.x + point.y * bevel.y );
return true;
}
}
if ( FLOATSIGNBITSET( plane1.y ) ^ FLOATSIGNBITSET( plane2.y ) ) {
if ( idMath::Fabs( plane1.y ) > 0.1f && idMath::Fabs( plane2.y ) > 0.1f ) {
bevel.y = 0.0f;
if ( FLOATSIGNBITSET( plane1.x ) ) {
bevel.x = -1.0f;
}
else {
bevel.x = 1.0f;
}
bevel.z = - ( point.x * bevel.x + point.y * bevel.y );
return true;
}
}
return false;
}
/*
============
idWinding2D::ExpandForAxialBox
============
*/
void idWinding2D::ExpandForAxialBox( const idVec2 bounds[2] ) {
int i, j, numPlanes;
idVec2 v;
idVec3 planes[MAX_POINTS_ON_WINDING_2D], plane, bevel;
// get planes for the edges and add bevels
for ( numPlanes = i = 0; i < numPoints; i++ ) {
j = (i+1) % numPoints;
if ( ( p[j] - p[i] ).LengthSqr() < 0.01f ) {
continue;
}
plane = Plane2DFromPoints( p[i], p[j], true );
if ( numPlanes > 0 ) {
if ( GetAxialBevel( planes[numPlanes-1], plane, p[i], bevel ) ) {
planes[numPlanes++] = bevel;
}
}
assert( numPlanes < MAX_POINTS_ON_WINDING_2D );
planes[numPlanes++] = plane;
}
if ( GetAxialBevel( planes[numPlanes-1], planes[0], p[0], bevel ) ) {
planes[numPlanes++] = bevel;
}
// expand the planes
for ( i = 0; i < numPlanes; i++ ) {
v.x = bounds[ FLOATSIGNBITSET( planes[i].x ) ].x;
v.y = bounds[ FLOATSIGNBITSET( planes[i].y ) ].y;
planes[i].z += v.x * planes[i].x + v.y * planes[i].y;
}
// get intersection points of the planes
for ( numPoints = i = 0; i < numPlanes; i++ ) {
if ( Plane2DIntersection( planes[(i+numPlanes-1) % numPlanes], planes[i], p[numPoints] ) ) {
numPoints++;
}
}
}
/*
============
idWinding2D::Expand
============
*/
void idWinding2D::Expand( const float d ) {
int i;
idVec2 edgeNormals[MAX_POINTS_ON_WINDING_2D];
for ( i = 0; i < numPoints; i++ ) {
idVec2 &start = p[i];
idVec2 &end = p[(i+1)%numPoints];
edgeNormals[i].x = start.y - end.y;
edgeNormals[i].y = end.x - start.x;
edgeNormals[i].Normalize();
edgeNormals[i] *= d;
}
for ( i = 0; i < numPoints; i++ ) {
p[i] += edgeNormals[i] + edgeNormals[(i+numPoints-1)%numPoints];
}
}
/*
=============
idWinding2D::Split
=============
*/
int idWinding2D::Split( const idVec3 &plane, const float epsilon, idWinding2D **front, idWinding2D **back ) const {
float dists[MAX_POINTS_ON_WINDING_2D];
byte sides[MAX_POINTS_ON_WINDING_2D];
int counts[3];
float dot;
int i, j;
const idVec2 * p1, *p2;
idVec2 mid;
idWinding2D * f;
idWinding2D * b;
counts[0] = counts[1] = counts[2] = 0;
// determine sides for each point
for ( i = 0; i < numPoints; i++ ) {
dists[i] = dot = plane.x * p[i].x + plane.y * p[i].y + plane.z;
if ( dot > epsilon ) {
sides[i] = SIDE_FRONT;
} else if ( dot < -epsilon ) {
sides[i] = SIDE_BACK;
} else {
sides[i] = SIDE_ON;
}
counts[sides[i]]++;
}
sides[i] = sides[0];
dists[i] = dists[0];
*front = *back = NULL;
// if nothing at the front of the clipping plane
if ( !counts[SIDE_FRONT] ) {
*back = Copy();
return SIDE_BACK;
}
// if nothing at the back of the clipping plane
if ( !counts[SIDE_BACK] ) {
*front = Copy();
return SIDE_FRONT;
}
*front = f = new idWinding2D;
*back = b = new idWinding2D;
for ( i = 0; i < numPoints; i++ ) {
p1 = &p[i];
if ( sides[i] == SIDE_ON ) {
f->p[f->numPoints] = *p1;
f->numPoints++;
b->p[b->numPoints] = *p1;
b->numPoints++;
continue;
}
if ( sides[i] == SIDE_FRONT ) {
f->p[f->numPoints] = *p1;
f->numPoints++;
}
if ( sides[i] == SIDE_BACK ) {
b->p[b->numPoints] = *p1;
b->numPoints++;
}
if ( sides[i+1] == SIDE_ON || sides[i+1] == sides[i] ) {
continue;
}
// generate a split point
p2 = &p[(i+1)%numPoints];
// always calculate the split going from the same side
// or minor epsilon issues can happen
if ( sides[i] == SIDE_FRONT ) {
dot = dists[i] / ( dists[i] - dists[i+1] );
for ( j = 0; j < 2; j++ ) {
// avoid round off error when possible
if ( plane[j] == 1.0f ) {
mid[j] = plane.z;
} else if ( plane[j] == -1.0f ) {
mid[j] = -plane.z;
} else {
mid[j] = (*p1)[j] + dot * ((*p2)[j] - (*p1)[j]);
}
}
} else {
dot = dists[i+1] / ( dists[i+1] - dists[i] );
for ( j = 0; j < 2; j++ ) {
// avoid round off error when possible
if ( plane[j] == 1.0f ) {
mid[j] = plane.z;
} else if ( plane[j] == -1.0f ) {
mid[j] = -plane.z;
} else {
mid[j] = (*p2)[j] + dot * ( (*p1)[j] - (*p2)[j] );
}
}
}
f->p[f->numPoints] = mid;
f->numPoints++;
b->p[b->numPoints] = mid;
b->numPoints++;
}
return SIDE_CROSS;
}
/*
============
idWinding2D::ClipInPlace
============
*/
bool idWinding2D::ClipInPlace( const idVec3 &plane, const float epsilon, const bool keepOn ) {
int i, j, maxpts, newNumPoints;
int sides[MAX_POINTS_ON_WINDING_2D+1], counts[3];
float dot, dists[MAX_POINTS_ON_WINDING_2D+1];
idVec2 *p1, *p2, mid, newPoints[MAX_POINTS_ON_WINDING_2D+4];
counts[SIDE_FRONT] = counts[SIDE_BACK] = counts[SIDE_ON] = 0;
for ( i = 0; i < numPoints; i++ ) {
dists[i] = dot = plane.x * p[i].x + plane.y * p[i].y + plane.z;
if ( dot > epsilon ) {
sides[i] = SIDE_FRONT;
} else if ( dot < -epsilon ) {
sides[i] = SIDE_BACK;
} else {
sides[i] = SIDE_ON;
}
counts[sides[i]]++;
}
sides[i] = sides[0];
dists[i] = dists[0];
// if the winding is on the plane and we should keep it
if ( keepOn && !counts[SIDE_FRONT] && !counts[SIDE_BACK] ) {
return true;
}
if ( !counts[SIDE_FRONT] ) {
numPoints = 0;
return false;
}
if ( !counts[SIDE_BACK] ) {
return true;
}
maxpts = numPoints + 4; // cant use counts[0]+2 because of fp grouping errors
newNumPoints = 0;
for ( i = 0; i < numPoints; i++ ) {
p1 = &p[i];
if ( newNumPoints+1 > maxpts ) {
return true; // can't split -- fall back to original
}
if ( sides[i] == SIDE_ON ) {
newPoints[newNumPoints] = *p1;
newNumPoints++;
continue;
}
if ( sides[i] == SIDE_FRONT ) {
newPoints[newNumPoints] = *p1;
newNumPoints++;
}
if ( sides[i+1] == SIDE_ON || sides[i+1] == sides[i] ) {
continue;
}
if ( newNumPoints+1 > maxpts ) {
return true; // can't split -- fall back to original
}
// generate a split point
p2 = &p[(i+1)%numPoints];
dot = dists[i] / (dists[i] - dists[i+1]);
for ( j = 0; j < 2; j++ ) {
// avoid round off error when possible
if ( plane[j] == 1.0f ) {
mid[j] = plane.z;
} else if ( plane[j] == -1.0f ) {
mid[j] = -plane.z;
} else {
mid[j] = (*p1)[j] + dot * ((*p2)[j] - (*p1)[j]);
}
}
newPoints[newNumPoints] = mid;
newNumPoints++;
}
if ( newNumPoints >= MAX_POINTS_ON_WINDING_2D ) {
return true;
}
numPoints = newNumPoints;
memcpy( p, newPoints, newNumPoints * sizeof(idVec2) );
return true;
}
/*
=============
idWinding2D::Copy
=============
*/
idWinding2D *idWinding2D::Copy( void ) const {
idWinding2D *w;
w = new idWinding2D;
w->numPoints = numPoints;
memcpy( w->p, p, numPoints * sizeof( p[0] ) );
return w;
}
/*
=============
idWinding2D::Reverse
=============
*/
idWinding2D *idWinding2D::Reverse( void ) const {
idWinding2D *w;
int i;
w = new idWinding2D;
w->numPoints = numPoints;
for ( i = 0; i < numPoints; i++ ) {
w->p[ numPoints - i - 1 ] = p[i];
}
return w;
}
/*
============
idWinding2D::GetArea
============
*/
float idWinding2D::GetArea( void ) const {
int i;
idVec2 d1, d2;
float total;
total = 0.0f;
for ( i = 2; i < numPoints; i++ ) {
d1 = p[i-1] - p[0];
d2 = p[i] - p[0];
total += d1.x * d2.y - d1.y * d2.x;
}
return total * 0.5f;
}
/*
============
idWinding2D::GetCenter
============
*/
idVec2 idWinding2D::GetCenter( void ) const {
int i;
idVec2 center;
center.Zero();
for ( i = 0; i < numPoints; i++ ) {
center += p[i];
}
center *= ( 1.0f / numPoints );
return center;
}
/*
============
idWinding2D::GetRadius
============
*/
float idWinding2D::GetRadius( const idVec2 &center ) const {
int i;
float radius, r;
idVec2 dir;
radius = 0.0f;
for ( i = 0; i < numPoints; i++ ) {
dir = p[i] - center;
r = dir * dir;
if ( r > radius ) {
radius = r;
}
}
return idMath::Sqrt( radius );
}
/*
============
idWinding2D::GetBounds
============
*/
void idWinding2D::GetBounds( idVec2 bounds[2] ) const {
int i;
if ( !numPoints ) {
bounds[0].x = bounds[0].y = idMath::INFINITY;
bounds[1].x = bounds[1].y = -idMath::INFINITY;
return;
}
bounds[0] = bounds[1] = p[0];
for ( i = 1; i < numPoints; i++ ) {
if ( p[i].x < bounds[0].x ) {
bounds[0].x = p[i].x;
} else if ( p[i].x > bounds[1].x ) {
bounds[1].x = p[i].x;
}
if ( p[i].y < bounds[0].y ) {
bounds[0].y = p[i].y;
} else if ( p[i].y > bounds[1].y ) {
bounds[1].y = p[i].y;
}
}
}
/*
=============
idWinding2D::IsTiny
=============
*/
#define EDGE_LENGTH 0.2f
bool idWinding2D::IsTiny( void ) const {
int i;
float len;
idVec2 delta;
int edges;
edges = 0;
for ( i = 0; i < numPoints; i++ ) {
delta = p[(i+1)%numPoints] - p[i];
len = delta.Length();
if ( len > EDGE_LENGTH ) {
if ( ++edges == 3 ) {
return false;
}
}
}
return true;
}
/*
=============
idWinding2D::IsHuge
=============
*/
bool idWinding2D::IsHuge( void ) const {
int i, j;
for ( i = 0; i < numPoints; i++ ) {
for ( j = 0; j < 2; j++ ) {
if ( p[i][j] <= MIN_WORLD_COORD || p[i][j] >= MAX_WORLD_COORD ) {
return true;
}
}
}
return false;
}
/*
=============
idWinding2D::Print
=============
*/
void idWinding2D::Print( void ) const {
int i;
for ( i = 0; i < numPoints; i++ ) {
idLib::common->Printf( "(%5.1f, %5.1f)\n", p[i][0], p[i][1] );
}
}
/*
=============
idWinding2D::PlaneDistance
=============
*/
float idWinding2D::PlaneDistance( const idVec3 &plane ) const {
int i;
float d, min, max;
min = idMath::INFINITY;
max = -min;
for ( i = 0; i < numPoints; i++ ) {
d = plane.x * p[i].x + plane.y * p[i].y + plane.z;
if ( d < min ) {
min = d;
if ( FLOATSIGNBITSET( min ) & FLOATSIGNBITNOTSET( max ) ) {
return 0.0f;
}
}
if ( d > max ) {
max = d;
if ( FLOATSIGNBITSET( min ) & FLOATSIGNBITNOTSET( max ) ) {
return 0.0f;
}
}
}
if ( FLOATSIGNBITNOTSET( min ) ) {
return min;
}
if ( FLOATSIGNBITSET( max ) ) {
return max;
}
return 0.0f;
}
/*
=============
idWinding2D::PlaneSide
=============
*/
int idWinding2D::PlaneSide( const idVec3 &plane, const float epsilon ) const {
bool front, back;
int i;
float d;
front = false;
back = false;
for ( i = 0; i < numPoints; i++ ) {
d = plane.x * p[i].x + plane.y * p[i].y + plane.z;
if ( d < -epsilon ) {
if ( front ) {
return SIDE_CROSS;
}
back = true;
continue;
}
else if ( d > epsilon ) {
if ( back ) {
return SIDE_CROSS;
}
front = true;
continue;
}
}
if ( back ) {
return SIDE_BACK;
}
if ( front ) {
return SIDE_FRONT;
}
return SIDE_ON;
}
/*
============
idWinding2D::PointInside
============
*/
bool idWinding2D::PointInside( const idVec2 &point, const float epsilon ) const {
int i;
float d;
idVec3 plane;
for ( i = 0; i < numPoints; i++ ) {
plane = Plane2DFromPoints( p[i], p[(i+1) % numPoints] );
d = plane.x * point.x + plane.y * point.y + plane.z;
if ( d > epsilon ) {
return false;
}
}
return true;
}
/*
============
idWinding2D::LineIntersection
============
*/
bool idWinding2D::LineIntersection( const idVec2 &start, const idVec2 &end ) const {
int i, numEdges;
int sides[MAX_POINTS_ON_WINDING_2D+1], counts[3];
float d1, d2, epsilon = 0.1f;
idVec3 plane, edges[2];
counts[SIDE_FRONT] = counts[SIDE_BACK] = counts[SIDE_ON] = 0;
plane = Plane2DFromPoints( start, end );
for ( i = 0; i < numPoints; i++ ) {
d1 = plane.x * p[i].x + plane.y * p[i].y + plane.z;
if ( d1 > epsilon ) {
sides[i] = SIDE_FRONT;
}
else if ( d1 < -epsilon ) {
sides[i] = SIDE_BACK;
}
else {
sides[i] = SIDE_ON;
}
counts[sides[i]]++;
}
sides[i] = sides[0];
if ( !counts[SIDE_FRONT] ) {
return false;
}
if ( !counts[SIDE_BACK] ) {
return false;
}
numEdges = 0;
for ( i = 0; i < numPoints; i++ ) {
if ( sides[i] != sides[i+1] && sides[i+1] != SIDE_ON ) {
edges[numEdges++] = Plane2DFromPoints( p[i], p[(i+1)%numPoints] );
if ( numEdges >= 2 ) {
break;
}
}
}
if ( numEdges < 2 ) {
return false;
}
d1 = edges[0].x * start.x + edges[0].y * start.y + edges[0].z;
d2 = edges[0].x * end.x + edges[0].y * end.y + edges[0].z;
if ( FLOATSIGNBITNOTSET( d1 ) & FLOATSIGNBITNOTSET( d2 ) ) {
return false;
}
d1 = edges[1].x * start.x + edges[1].y * start.y + edges[1].z;
d2 = edges[1].x * end.x + edges[1].y * end.y + edges[1].z;
if ( FLOATSIGNBITNOTSET( d1 ) & FLOATSIGNBITNOTSET( d2 ) ) {
return false;
}
return true;
}
/*
============
idWinding2D::RayIntersection
============
*/
bool idWinding2D::RayIntersection( const idVec2 &start, const idVec2 &dir, float &scale1, float &scale2, int *edgeNums ) const {
int i, numEdges, localEdgeNums[2];
int sides[MAX_POINTS_ON_WINDING_2D+1], counts[3];
float d1, d2, epsilon = 0.1f;
idVec3 plane, edges[2];
scale1 = scale2 = 0.0f;
counts[SIDE_FRONT] = counts[SIDE_BACK] = counts[SIDE_ON] = 0;
plane = Plane2DFromVecs( start, dir );
for ( i = 0; i < numPoints; i++ ) {
d1 = plane.x * p[i].x + plane.y * p[i].y + plane.z;
if ( d1 > epsilon ) {
sides[i] = SIDE_FRONT;
}
else if ( d1 < -epsilon ) {
sides[i] = SIDE_BACK;
}
else {
sides[i] = SIDE_ON;
}
counts[sides[i]]++;
}
sides[i] = sides[0];
if ( !counts[SIDE_FRONT] ) {
return false;
}
if ( !counts[SIDE_BACK] ) {
return false;
}
numEdges = 0;
for ( i = 0; i < numPoints; i++ ) {
if ( sides[i] != sides[i+1] && sides[i+1] != SIDE_ON ) {
localEdgeNums[numEdges] = i;
edges[numEdges++] = Plane2DFromPoints( p[i], p[(i+1)%numPoints] );
if ( numEdges >= 2 ) {
break;
}
}
}
if ( numEdges < 2 ) {
return false;
}
d1 = edges[0].x * start.x + edges[0].y * start.y + edges[0].z;
d2 = - ( edges[0].x * dir.x + edges[0].y * dir.y );
if ( d2 == 0.0f ) {
return false;
}
scale1 = d1 / d2;
d1 = edges[1].x * start.x + edges[1].y * start.y + edges[1].z;
d2 = - ( edges[1].x * dir.x + edges[1].y * dir.y );
if ( d2 == 0.0f ) {
return false;
}
scale2 = d1 / d2;
if ( idMath::Fabs( scale1 ) > idMath::Fabs( scale2 ) ) {
idSwap( scale1, scale2 );
idSwap( localEdgeNums[0], localEdgeNums[1] );
}
if ( edgeNums ) {
edgeNums[0] = localEdgeNums[0];
edgeNums[1] = localEdgeNums[1];
}
return true;
}