diff options
Diffstat (limited to 'libs/assimp/code/Common/PolyTools.h')
| -rw-r--r-- | libs/assimp/code/Common/PolyTools.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/libs/assimp/code/Common/PolyTools.h b/libs/assimp/code/Common/PolyTools.h new file mode 100644 index 0000000..11f6273 --- /dev/null +++ b/libs/assimp/code/Common/PolyTools.h @@ -0,0 +1,226 @@ +/* +Open Asset Import Library (assimp) +---------------------------------------------------------------------- + +Copyright (c) 2006-2022, assimp team + +All rights reserved. + +Redistribution and use of this software in source and binary forms, +with or without modification, are permitted provided that the +following conditions are met: + +* Redistributions of source code must retain the above + copyright notice, this list of conditions and the + following disclaimer. + +* 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. + +* Neither the name of the assimp team, nor the names of its + contributors may be used to endorse or promote products + derived from this software without specific prior + written permission of the assimp team. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"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 COPYRIGHT +OWNER OR CONTRIBUTORS 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. + +---------------------------------------------------------------------- +*/ + +/** @file PolyTools.h, various utilities for our dealings with arbitrary polygons */ + +#pragma once +#ifndef AI_POLYTOOLS_H_INCLUDED +#define AI_POLYTOOLS_H_INCLUDED + +#include <assimp/material.h> +#include <assimp/ai_assert.h> + +namespace Assimp { + +// ------------------------------------------------------------------------------- +/** Compute the signed area of a triangle. + * The function accepts an unconstrained template parameter for use with + * both aiVector3D and aiVector2D, but generally ignores the third coordinate.*/ +template <typename T> +inline double GetArea2D(const T& v1, const T& v2, const T& v3) { + return 0.5 * (v1.x * ((double)v3.y - v2.y) + v2.x * ((double)v1.y - v3.y) + v3.x * ((double)v2.y - v1.y)); +} + +// ------------------------------------------------------------------------------- +/** Test if a given point p2 is on the left side of the line formed by p0-p1. + * The function accepts an unconstrained template parameter for use with + * both aiVector3D and aiVector2D, but generally ignores the third coordinate.*/ +template <typename T> +inline bool OnLeftSideOfLine2D(const T& p0, const T& p1,const T& p2) { + return GetArea2D(p0,p2,p1) > 0; +} + +// ------------------------------------------------------------------------------- +/** Test if a given point is inside a given triangle in R2. + * The function accepts an unconstrained template parameter for use with + * both aiVector3D and aiVector2D, but generally ignores the third coordinate.*/ +template <typename T> +inline bool PointInTriangle2D(const T& p0, const T& p1,const T& p2, const T& pp) { + // Point in triangle test using baryzentric coordinates + const aiVector2D v0 = p1 - p0; + const aiVector2D v1 = p2 - p0; + const aiVector2D v2 = pp - p0; + + double dot00 = v0 * v0; + double dot11 = v1 * v1; + const double dot01 = v0 * v1; + const double dot02 = v0 * v2; + const double dot12 = v1 * v2; + const double denom = dot00 * dot11 - dot01 * dot01; + if (denom == 0.0) { + return false; + } + + const double invDenom = 1.0 / denom; + dot11 = (dot11 * dot02 - dot01 * dot12) * invDenom; + dot00 = (dot00 * dot12 - dot01 * dot02) * invDenom; + + return (dot11 > 0) && (dot00 > 0) && (dot11 + dot00 < 1); +} + + +// ------------------------------------------------------------------------------- +/** Check whether the winding order of a given polygon is counter-clockwise. + * The function accepts an unconstrained template parameter, but is intended + * to be used only with aiVector2D and aiVector3D (z axis is ignored, only + * x and y are taken into account). + * @note Code taken from http://cgm.cs.mcgill.ca/~godfried/teaching/cg-projects/97/Ian/applet1.html and translated to C++ + */ +template <typename T> +inline bool IsCCW(T* in, size_t npoints) { + double aa, bb, cc, b, c, theta; + double convex_turn; + double convex_sum = 0; + + ai_assert(npoints >= 3); + + for (size_t i = 0; i < npoints - 2; i++) { + aa = ((in[i+2].x - in[i].x) * (in[i+2].x - in[i].x)) + + ((-in[i+2].y + in[i].y) * (-in[i+2].y + in[i].y)); + + bb = ((in[i+1].x - in[i].x) * (in[i+1].x - in[i].x)) + + ((-in[i+1].y + in[i].y) * (-in[i+1].y + in[i].y)); + + cc = ((in[i+2].x - in[i+1].x) * + (in[i+2].x - in[i+1].x)) + + ((-in[i+2].y + in[i+1].y) * + (-in[i+2].y + in[i+1].y)); + + b = std::sqrt(bb); + c = std::sqrt(cc); + theta = std::acos((bb + cc - aa) / (2 * b * c)); + + if (OnLeftSideOfLine2D(in[i],in[i+2],in[i+1])) { + // if (convex(in[i].x, in[i].y, + // in[i+1].x, in[i+1].y, + // in[i+2].x, in[i+2].y)) { + convex_turn = AI_MATH_PI_F - theta; + convex_sum += convex_turn; + } else { + convex_sum -= AI_MATH_PI_F - theta; + } + } + aa = ((in[1].x - in[npoints-2].x) * + (in[1].x - in[npoints-2].x)) + + ((-in[1].y + in[npoints-2].y) * + (-in[1].y + in[npoints-2].y)); + + bb = ((in[0].x - in[npoints-2].x) * + (in[0].x - in[npoints-2].x)) + + ((-in[0].y + in[npoints-2].y) * + (-in[0].y + in[npoints-2].y)); + + cc = ((in[1].x - in[0].x) * (in[1].x - in[0].x)) + + ((-in[1].y + in[0].y) * (-in[1].y + in[0].y)); + + b = std::sqrt(bb); + c = std::sqrt(cc); + theta = std::acos((bb + cc - aa) / (2 * b * c)); + + //if (convex(in[npoints-2].x, in[npoints-2].y, + // in[0].x, in[0].y, + // in[1].x, in[1].y)) { + if (OnLeftSideOfLine2D(in[npoints-2],in[1],in[0])) { + convex_turn = AI_MATH_PI_F - theta; + convex_sum += convex_turn; + } else { + convex_sum -= AI_MATH_PI_F - theta; + } + + return convex_sum >= (2 * AI_MATH_PI_F); +} + +// ------------------------------------------------------------------------------- +/** Compute the normal of an arbitrary polygon in R3. + * + * The code is based on Newell's formula, that is a polygons normal is the ratio + * of its area when projected onto the three coordinate axes. + * + * @param out Receives the output normal + * @param num Number of input vertices + * @param x X data source. x[ofs_x*n] is the n'th element. + * @param y Y data source. y[ofs_y*n] is the y'th element + * @param z Z data source. z[ofs_z*n] is the z'th element + * + * @note The data arrays must have storage for at least num+2 elements. Using + * this method is much faster than the 'other' NewellNormal() + */ +template <int ofs_x, int ofs_y, int ofs_z, typename TReal> +inline void NewellNormal (aiVector3t<TReal>& out, int num, TReal* x, TReal* y, TReal* z) { + // Duplicate the first two vertices at the end + x[(num+0)*ofs_x] = x[0]; + x[(num+1)*ofs_x] = x[ofs_x]; + + y[(num+0)*ofs_y] = y[0]; + y[(num+1)*ofs_y] = y[ofs_y]; + + z[(num+0)*ofs_z] = z[0]; + z[(num+1)*ofs_z] = z[ofs_z]; + + TReal sum_xy = 0.0, sum_yz = 0.0, sum_zx = 0.0; + + TReal *xptr = x +ofs_x, *xlow = x, *xhigh = x + ofs_x*2; + TReal *yptr = y +ofs_y, *ylow = y, *yhigh = y + ofs_y*2; + TReal *zptr = z +ofs_z, *zlow = z, *zhigh = z + ofs_z*2; + + for (int tmp=0; tmp < num; tmp++) { + sum_xy += (*xptr) * ( (*yhigh) - (*ylow) ); + sum_yz += (*yptr) * ( (*zhigh) - (*zlow) ); + sum_zx += (*zptr) * ( (*xhigh) - (*xlow) ); + + xptr += ofs_x; + xlow += ofs_x; + xhigh += ofs_x; + + yptr += ofs_y; + ylow += ofs_y; + yhigh += ofs_y; + + zptr += ofs_z; + zlow += ofs_z; + zhigh += ofs_z; + } + out = aiVector3t<TReal>(sum_yz,sum_zx,sum_xy); +} + +} // ! namespace Assimp + +#endif // AI_POLYTOOLS_H_INCLUDED |