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scummvm/engines/wintermute/math/math_util.cpp
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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
/*
* This file is based on WME Lite.
* http://dead-code.org/redir.php?target=wmelite
* Copyright (c) 2011 Jan Nedoma
*/
#include "engines/wintermute/math/math_util.h"
#include "common/scummsys.h"
#ifdef ENABLE_WME3D
#include "common/util.h"
#endif
namespace Wintermute {
//////////////////////////////////////////////////////////////////////////
float MathUtil::round(float val) {
float result = floor(val);
if (val - result >= 0.5f) {
result += 1.0;
}
return result;
}
//////////////////////////////////////////////////////////////////////////
float MathUtil::roundUp(float val) {
float result = floor(val);
if (val - result > 0) {
result += 1.0;
}
return result;
}
#ifdef ENABLE_WME3D
bool lineIntersectsTriangle(const Math::Vector3d &origin, const Math::Vector3d &direction,
const Math::Vector3d &v0, const Math::Vector3d &v1, const Math::Vector3d &v2,
float &t, float &u, float &v) {
const float epsilon = 0.0001f;
Math::Vector3d edge1 = v1 - v0;
Math::Vector3d edge2 = v2 - v0;
Math::Vector3d pVector = Math::Vector3d::crossProduct(direction, edge2);
float det = Math::Vector3d::dotProduct(edge1, pVector);
if (ABS(det) < epsilon) {
return false;
}
Math::Vector3d tVector = origin - v0;
u = Math::Vector3d::dotProduct(tVector, pVector) / det;
if (u < 0.0f || u > 1.0f) {
return false;
}
Math::Vector3d qVector = Math::Vector3d::crossProduct(tVector, edge1);
v = Math::Vector3d::dotProduct(direction, qVector) / det;
if (v < 0.0f || u + v > 1.0f) {
return false;
}
t = Math::Vector3d::dotProduct(edge2, qVector) / det;
Math::Vector3d intersectionPoint = origin + direction * t;
t = intersectionPoint.x();
u = intersectionPoint.y();
v = intersectionPoint.z();
return true;
}
bool lineSegmentIntersectsTriangle(const Math::Vector3d &lineStart, const Math::Vector3d &lineEnd,
const Math::Vector3d &v0, const Math::Vector3d &v1, const Math::Vector3d &v2,
Math::Vector3d &intersection, float &distance) {
const float epsilon = 0.0001f;
Math::Vector3d edge1 = v1 - v0;
Math::Vector3d edge2 = v2 - v1;
Math::Vector3d planeNormal = Math::Vector3d::crossProduct(edge1, edge2);
planeNormal.normalize();
Math::Vector3d lineDirection = lineEnd - lineStart;
float lineLength = Math::Vector3d::dotProduct(lineDirection, planeNormal);
if (ABS(lineLength) < epsilon) {
return false;
}
float distFromPlane = Math::Vector3d::dotProduct(v0 - lineStart, planeNormal);
float relativeDistance = distFromPlane / lineLength;
if (relativeDistance < 0.0f || relativeDistance > 1.0f) {
return false;
}
distance = relativeDistance;
intersection = lineStart + lineDirection * relativeDistance;
return true;
}
#endif
} // End of namespace Wintermute