src/geometry.cpp

Thu, 27 Feb 2020 14:38:48 +0200

author
Teemu Piippo <teemu@hecknology.net>
date
Thu, 27 Feb 2020 14:38:48 +0200
changeset 59
60650929dc82
parent 58
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child 64
f99d52b1646b
permissions
-rw-r--r--

fixed testing of whether screenToModelCoordinates's result value is behind the camera

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1 #include "geometry.h"
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2
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3 /**
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4 * @brief Computes a line from two points
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5 * @param point_1
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6 * @param point_2
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7 * @return line
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8 */
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9 geom::Line geom::lineFromPoints(const glm::vec3& point_1, const glm::vec3 point_2)
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10 {
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11 return {point_2 - point_1, point_1};
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12 }
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13
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14 /**
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15 * @brief Computes line-plane intersection
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16 * @param line
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17 * @param plane
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18 * @return point of intersection. Does not return a value if the line is in parallel to the plane.
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19 */
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20 std::optional<glm::vec3> geom::linePlaneIntersection(const geom::Line& line, const geom::Plane& plane, const float epsilon)
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21 {
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22 const float denominator = glm::dot(line.direction, plane.normal);
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23 if (std::abs(denominator) < epsilon)
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24 {
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25 return {};
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26 }
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27 else
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28 {
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29 const float d = glm::dot(plane.anchor - line.anchor, plane.normal) / denominator;
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30 return line.anchor + d * line.direction;
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31 }
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32 }
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33
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34 /**
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35 * @brief Computes the plane of a triangle
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36 * @param triangle
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37 * @return plane
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38 */
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39 geom::Plane geom::planeFromTriangle(const geom::Triangle& triangle)
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40 {
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41 return geom::Plane{triangle.points[0], normalVector(triangle)};
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42 }
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43
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44 /**
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45 * @brief Computes the normal vector of a triangle
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46 * @param triangle
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47 * @return normal vector
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48 */
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49 glm::vec3 geom::normalVector(const geom::Triangle& triangle)
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50 {
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51 return glm::normalize(
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52 glm::cross(
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53 triangle.points[1] - triangle.points[0],
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54 triangle.points[2] - triangle.points[0]));
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55 }

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