--- /dev/null
+
+/*] Copyright (c) 2009-2010, Charles McGarvey [**************************
+**] All rights reserved.
+*
+* vi:ts=4 sw=4 tw=75
+*
+* Distributable under the terms and conditions of the 2-clause BSD license;
+* see the file COPYING for a complete text of the license.
+*
+**************************************************************************/
+
+#ifndef _MOOF_LINE_HH_
+#define _MOOF_LINE_HH_
+
+/**
+ * \file line.hh
+ * Classes related to line segments.
+ */
+
+#include <moof/contact.hh>
+#include <moof/drawable.hh>
+#include <moof/log.hh>
+#include <moof/math.hh>
+#include <moof/opengl.hh>
+#include <moof/ray.hh>
+#include <moof/shape.hh>
+#include <moof/sphere.hh>
+#include <moof/texture.hh>
+
+
+namespace moof {
+
+
+template <int D>
+struct line : public drawable, public shape<D>
+{
+ typedef moof::vector< scalar, fixed<D> > vector;
+
+
+ vector a;
+ vector b;
+
+
+ line() {}
+
+ line(const vector& point1, const vector& point2) :
+ a(point1),
+ b(point2) {}
+
+
+ vector direction() const
+ {
+ return b - a;
+ }
+
+ scalar length() const
+ {
+ return direction().length();
+ }
+
+
+ bool intersect(const line& other, contact<D>& hit) const
+ {
+ scalar d = (other.b[1] - other.a[1]) * (b[0] - a[0]) -
+ (other.b[0] - other.a[0]) * (b[1] - a[1]);
+
+ if (d == SCALAR(0.0)) return false; // lines are parallel
+ // ignoring the (somewhat remote) possibility of coincidence
+
+ scalar m = ((other.b[0] - other.a[0]) * (a[1] - other.a[1]) -
+ (other.b[1] - other.a[1]) * (a[0] - other.a[0])) / d;
+
+ scalar n = ((b[0] - a[0]) * (b[1] - other.a[1]) -
+ (b[1] - a[1]) * (b[0] - other.a[0])) / d;
+
+ if (m < SCALAR(0.0) || m > SCALAR(1.0) || // not intersecting
+ n < SCALAR(0.0) || n > SCALAR(1.0)) return false;
+
+ vector2 tangent = b - a;
+ vector2 normal = perp(tangent).normalize();
+
+ if (dot(normal, other.a - other.b) < SCALAR(0.0))
+ {
+ normal = -normal;
+ }
+
+ hit.point = a + m * tangent;
+ hit.normal = normal;
+ hit.distance = (other.b - hit.point).length();
+
+ return true;
+ }
+
+ bool intersect(const sphere<D>& other, contact<D>& hit) const
+ {
+ vector surface = b - a;
+ vector toPoint = other.point - a;
+
+ scalar surfaceLength = surface.length();
+ surface.normalize();
+
+ scalar projection = dot(surface, toPoint);
+
+ if (projection < SCALAR(0.0) || projection > surfaceLength)
+ {
+ // try endpoints
+
+ if (other.intersect(a, hit))
+ {
+ hit.normal = -hit.normal;
+ hit.point = a;
+ return true;
+ }
+ else if (other.intersect(b, hit))
+ {
+ hit.normal = -hit.normal;
+ hit.point = b;
+ return true;
+ }
+
+ return false;
+ }
+
+ vector point = a + surface * projection;
+ vector normal = other.point - point;
+
+ scalar distance = normal.length();
+
+ if (distance > other.radius) false; // not intersecting
+
+ normal.normalize();
+
+ hit.distance = other.radius - distance;
+ hit.point = point;
+ hit.normal = normal;
+
+ return true;
+ }
+
+
+ bool intersect_ray(const ray<2>& ray, ray<2>::contact& hit) const
+ {
+ vector2 v1 = a - ray.point;
+ scalar a1 = signed_angle_2D(v1, b - ray.point);
+
+ //log_warning << "angle:::::::::: " << a1 << std::endl;
+
+ if (a1 == constants::pi())
+ {
+ hit.distance = 5.4321;
+ return true;
+ }
+ else if (a1 == SCALAR(0.0))
+ {
+ hit.distance = 99999.0;
+ return true;
+ }
+
+ scalar a2 = signed_angle_2D(v1, ray.direction);
+
+ if (a2 < SCALAR(0.0) || a2 > a1) return false;
+
+ //hit.distance = 1.23456;
+ //hit.normal = vector2(0.0, 0.0);
+
+ vector2 n = (b - a).normalize();
+ scalar z = dot(ray.point - a, n);
+ vector2 p = a + n * z;
+ hit.distance = (ray.point - p).length();
+ hit.normal = perp(a - b);
+ return true;
+
+
+ /*
+ // solve: Cx + r*Dx = Ax + s(Bx - Ax)
+ // Cy + r*Dy = Ay + s(By - Ay)
+ // where: 0 <= s <= 1 if intersection
+ // given: A = a
+ // B = b
+ // C = ray.point
+ // D = ray.direction
+
+ scalar denom = ray.direction[0] * (b[1] - a[1]) +
+ ray.direction[1] * (a[0] - b[0]);
+
+ // check if the ray and line are parallel
+ //if (is_equal(denom, SCALAR(0.0)))
+ if (denom == SCALAR(0.0))
+ {
+ scalar numer = a[0] * (ray.point[1] - b[1]) +
+ b[0] * (a[1] - ray.point[1]) +
+ ray.point[0] * (b[1] - a[1]);
+
+ // check if they are collinear
+ if (is_equal(numer, SCALAR(0.0)))
+ {
+ hit.distance = SCALAR(0.0);
+ hit.normal.set(0.0, 0.0);
+ return true;
+ }
+
+ return false;
+ }
+
+ scalar s = (ray.direction[0] * (ray.point[1] - a[1]) +
+ ray.direction[1] * (a[0] - ray.point[0])) / denom;
+
+ // check if the ray hits the segment
+ if (s < SCALAR(0.0) || s > SCALAR(1.0)) return false;
+
+ hit.distance = -(a[0] * (ray.point[1] - b[1]) +
+ b[0] * (a[1] - ray.point[1]) +
+ ray.point[0] * (b[1] - a[1])) / denom;
+
+ // check if the intersection is behind the ray
+ if (hit.distance < SCALAR(0.0)) return false;
+
+ vector normal = perp(a - b);
+ if (dot(a - ray.point, normal) < 0) hit.normal = normal;
+ else hit.normal = -normal;
+ return true;
+ */
+ }
+
+
+ void draw(scalar alpha = 0.0) const
+ {
+ texture::reset_binding();
+ glBegin(GL_LINES);
+ glVertex(a);
+ glVertex(b);
+ glEnd();
+ }
+};
+
+
+typedef line<2> line2;
+typedef line<3> line3;
+
+
+template <int D, int N>
+struct polygon : public drawable, public shape<D>
+{
+ typedef moof::vector< scalar, fixed<D> > vector;
+
+ vector points[N];
+
+ polygon() {}
+
+ bool intersect_ray(const ray<D>& ray, typename ray<D>::contact& hit)
+ {
+ return false;
+ }
+
+ void draw(scalar alpha = 0.0) const
+ {
+ texture::reset_binding();
+ glBegin(GL_POLYGON);
+ for (int i = 0; i < D; ++i)
+ {
+ glVertex(points[0]);
+ }
+ glEnd();
+ }
+};
+
+
+typedef polygon<2,3> triangle2;
+typedef polygon<3,3> triangle3;
+
+
+template <int D>
+bool intersect(const line<D>& line, const sphere<D>& sphere,
+ contact<D>& hit)
+{
+ return false;
+}
+
+
+} // namespace moof
+
+#endif // _MOOF_LINE_HH_
+
projects / chaz / yoink / blobdiff