mirror of
https://github.com/ZDoom/Raze.git
synced 2024-11-15 08:51:24 +00:00
a3dbfab54b
This actually should check if the two lines are identical but since this is rather expensive and rarely needed it's better handled by returning a distinct value the caller can handle if needed.
234 lines
7.7 KiB
C
234 lines
7.7 KiB
C
#pragma once
|
|
|
|
/*
|
|
** geometry.h
|
|
** basic geometry math routines
|
|
**
|
|
**---------------------------------------------------------------------------
|
|
** Copyright 2005-2022 Christoph Oelckers
|
|
** All rights reserved.
|
|
**
|
|
** Redistribution and use in source and binary forms, with or without
|
|
** modification, are permitted provided that the following conditions
|
|
** are met:
|
|
**
|
|
** 1. Redistributions of source code must retain the above copyright
|
|
** notice, this list of conditions and the following disclaimer.
|
|
** 2. Redistributions in binary form must reproduce the above copyright
|
|
** notice, this list of conditions and the following disclaimer in the
|
|
** documentation and/or other materials provided with the distribution.
|
|
** 3. The name of the author may not be used to endorse or promote products
|
|
** derived from this software without specific prior written permission.
|
|
**
|
|
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
**---------------------------------------------------------------------------
|
|
*/
|
|
|
|
#include "vectors.h"
|
|
|
|
inline DVector2 rotatepoint(const DVector2& pivot, const DVector2& point, DAngle angle)
|
|
{
|
|
return (point - pivot).Rotated(angle) + pivot;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
//
|
|
//
|
|
//==========================================================================
|
|
|
|
inline double PointOnLineSide(double x, double y, double linex, double liney, double deltax, double deltay)
|
|
{
|
|
return (x - linex) * deltay - (y - liney) * deltax;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
//
|
|
//
|
|
//==========================================================================
|
|
|
|
inline double SquareDist(double lx1, double ly1, double lx2, double ly2)
|
|
{
|
|
double dx = lx2 - lx1;
|
|
double dy = ly2 - ly1;
|
|
return dx * dx + dy * dy;
|
|
}
|
|
|
|
// This is for cases where only the factor is needed, and pre-validation was performed.
|
|
inline double NearestPointOnLineFast(double px, double py, double lx1, double ly1, double lx2, double ly2)
|
|
{
|
|
double wall_length = SquareDist(lx1, ly1, lx2, ly2);
|
|
assert(wall_length > 0);
|
|
return ((px - lx1) * (lx2 - lx1) + (py - ly1) * (ly2 - ly1)) / wall_length;
|
|
}
|
|
|
|
|
|
inline DVector2 NearestPointOnLine(double px, double py, double lx1, double ly1, double lx2, double ly2, bool clamp = true)
|
|
{
|
|
double wall_length = SquareDist(lx1, ly1, lx2, ly2);
|
|
|
|
if (wall_length == 0)
|
|
{
|
|
return { lx1, ly1 };
|
|
}
|
|
|
|
double t = ((px - lx1) * (lx2 - lx1) + (py - ly1) * (ly2 - ly1)) / wall_length;
|
|
if (clamp)
|
|
{
|
|
if (t <= 0) return { lx1, ly1 };
|
|
if (t >= 1) return { lx2, ly2 };
|
|
}
|
|
double xx = lx1 + t * (lx2 - lx1);
|
|
double yy = ly1 + t * (ly2 - ly1);
|
|
return { xx, yy };
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
//
|
|
//
|
|
//==========================================================================
|
|
|
|
inline double SquareDistToLine(double px, double py, double lx1, double ly1, double lx2, double ly2)
|
|
{
|
|
double wall_length = SquareDist(lx1, ly1, lx2, ly2);
|
|
|
|
if (wall_length == 0) return SquareDist(px, py, lx1, ly1);
|
|
|
|
double t = ((px - lx1) * (lx2 - lx1) + (py - ly1) * (ly2 - ly1)) / wall_length;
|
|
t = clamp(t, 0., 1.);
|
|
double xx = lx1 + t * (lx2 - lx1);
|
|
double yy = ly1 + t * (ly2 - ly1);
|
|
return SquareDist(px, py, xx, yy);
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// taken from GZDoom with the divline_t parameters removed
|
|
//
|
|
//==========================================================================
|
|
|
|
inline double InterceptVector(double v2x, double v2y, double v2dx, double v2dy, double v1x, double v1y, double v1dx, double v1dy)
|
|
{
|
|
double den = v1dy * v2dx - v1dx * v2dy;
|
|
|
|
if (den == 0)
|
|
return 0; // parallel
|
|
|
|
double num = (v1x - v2x) * v1dy + (v2y - v1y) * v1dx;
|
|
return num / den;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// Essentially two InterceptVector calls. We can reduce the calculations
|
|
// because the denominators for both calculations only differ by their sign.
|
|
//
|
|
//==========================================================================
|
|
|
|
inline double InterceptLineSegments(double v2x, double v2y, double v2dx, double v2dy, double v1x, double v1y, double v1dx, double v1dy, double* pfactor1 = nullptr, bool forcansee = false)
|
|
{
|
|
double den = v1dy * v2dx - v1dx * v2dy;
|
|
|
|
if (den == 0)
|
|
return -2 * (double)FLT_MAX; // parallel (return a magic value different from everything else, just in case it needs to be handled)
|
|
|
|
if (forcansee && den < 0) // cansee does this added check here, aside from that its logic is virtually the same.
|
|
return -1; // hitting the backside
|
|
|
|
// perform the division first for better parallelization.
|
|
den = 1 / den;
|
|
|
|
double factor1 = ((v2x - v1x) * v2dy + (v1y - v2y) * v2dx) * -den;
|
|
if (factor1 < 0 || factor1 > 1) return -FLT_MAX; // no intersection
|
|
if (pfactor1) *pfactor1 = factor1;
|
|
|
|
return ((v1x - v2x) * v1dy + (v2y - v1y) * v1dx) * den; // this one's for the line segment where we want to get the intercept factor for so it needs to be last.
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// calculates intersection between a plane and line in 3D
|
|
//
|
|
//==========================================================================
|
|
|
|
inline double LinePlaneIntersect(const DVector3& start, const DVector3& trace, const DVector3& ppoint, const DVector3& pvec1, const DVector3& pvec2)
|
|
{
|
|
auto normal = pvec1 ^ pvec2; // we do not need a unit vector here.
|
|
double dist = normal.dot(ppoint);
|
|
double dotStart = normal.dot(start);
|
|
double dotTrace = normal.dot(trace);
|
|
if (dotTrace == 0) return -FLT_MAX;
|
|
return (dist - dotStart) / dotTrace; // we are only interested in the factor
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// BoxOnLineSide
|
|
//
|
|
// Based on Doom's, but rewritten to be standalone
|
|
//
|
|
//==========================================================================
|
|
|
|
inline int BoxOnLineSide(const DVector2& boxtl, const DVector2& boxbr, const DVector2& start, const DVector2& delta)
|
|
{
|
|
int p1;
|
|
int p2;
|
|
|
|
if (delta.X == 0)
|
|
{
|
|
p1 = boxbr.X < start.X;
|
|
p2 = boxtl.X < start.X;
|
|
if (delta.Y < 0)
|
|
{
|
|
p1 ^= 1;
|
|
p2 ^= 1;
|
|
}
|
|
}
|
|
else if (delta.Y == 0)
|
|
{
|
|
p1 = boxtl.Y > start.Y;
|
|
p2 = boxbr.Y > start.Y;
|
|
if (delta.X < 0)
|
|
{
|
|
p1 ^= 1;
|
|
p2 ^= 1;
|
|
}
|
|
}
|
|
else if (delta.X * delta.Y <= 0)
|
|
{
|
|
p1 = PointOnLineSide(boxtl.X, boxtl.Y, start.X, start.Y, delta.X, delta.Y) > 0;
|
|
p2 = PointOnLineSide(boxbr.X, boxbr.Y, start.X, start.Y, delta.X, delta.Y) > 0;
|
|
}
|
|
else
|
|
{
|
|
p1 = PointOnLineSide(boxbr.X, boxtl.Y, start.X, start.Y, delta.X, delta.Y) > 0;
|
|
p2 = PointOnLineSide(boxtl.X, boxbr.Y, start.X, start.Y, delta.X, delta.Y) > 0;
|
|
}
|
|
|
|
return (p1 == p2) ? p1 : -1;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// BoxInRange
|
|
//
|
|
//==========================================================================
|
|
|
|
inline bool BoxInRange(const DVector2& boxtl, const DVector2& boxbr, const DVector2& start, const DVector2& end)
|
|
{
|
|
return boxtl.X < max(start.X, end.X) &&
|
|
boxbr.X > min(start.X, end.X) &&
|
|
boxtl.Y < max(start.Y, end.Y) &&
|
|
boxbr.Y > min(start.Y, end.Y);
|
|
}
|