+
+/*******************************************************************************
+
+ Copyright (c) 2009, Charles McGarvey
+ All rights reserved.
+
+ Redistribution and use 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.
+
+ 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 HOLDER 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.
+
+*******************************************************************************/
+
+#ifndef _MOOF_LINE_HH_
+#define _MOOF_LINE_HH_
+
+#include <Moof/Drawable.hh>
+#include <Moof/Math.hh>
+#include <Moof/OpenGL.hh>
+#include <Moof/Ray.hh>
+#include <Moof/Texture.hh>
+
+#include <Moof/Log.hh>
+
+
+namespace Mf {
+
+
+template <int D>
+struct Line : public Drawable, public Shape<D>
+{
+ typedef cml::vector< Scalar, cml::fixed<D> > Vector;
+
+ Vector a;
+ Vector b;
+
+ Scalar intersectRay(const Ray<2>& ray, Ray<2>::Intersection& intersection)
+ {
+ // 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 (isEqual(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 (isEqual(numer, SCALAR(0.0)))
+ {
+ intersection.point = ray.point;
+ intersection.normal.set(0.0, 0.0);
+ return SCALAR(0.0);
+ }
+
+ return SCALAR(-1.0);
+ }
+
+ 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 SCALAR(-1.0);
+
+ Scalar r = -(a[0] * (ray.point[1] - b[1]) +
+ b[0] * (a[1] - ray.point[1]) +
+ ray.point[0] * (b[1] - a[1])) / denom;
+
+ // make sure we're dealing with the right side of the ray
+ if (r < SCALAR(0.0)) return SCALAR(-1.0);
+
+ intersection.point = ray.point + r * ray.direction;
+
+ // gotta use the correct normal
+ Vector n = cml::perp(a - b);
+ if (cml::dot(a - ray.point, n) < 0) intersection.normal = n;
+ else intersection.normal = -n;
+
+ return r;
+ }
+
+ void draw(Scalar alpha = 0.0) const
+ {
+ Mf::Texture::resetBind();
+ glBegin(GL_LINES);
+ glVertex(a);
+ glVertex(b);
+ glEnd();
+ }
+};
+
+
+template <int D, int N>
+struct Polygon : public Shape<D>
+{
+ typedef cml::vector< Scalar, cml::fixed<D> > Vector;
+
+ Vector points[N];
+};
+
+
+} // namespace Mf
+
+#endif // _MOOF_LINE_HH_
+
+/** vim: set ts=4 sw=4 tw=80: *************************************************/
+