comparison: src/geometry.cpp
src/geometry.cpp
- changeset 369
- 57de8fab2237
- parent 297
- bc92f97498f7
- child 371
- 171d3f9638a9
equal
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inserted
replaced
| 368:9444de9762c3 | 369:57de8fab2237 |
|---|---|
| 196 glm::vec2{rectangle.right(), rectangle.top()}, | 196 glm::vec2{rectangle.right(), rectangle.top()}, |
| 197 glm::vec2{rectangle.right(), rectangle.bottom()} | 197 glm::vec2{rectangle.right(), rectangle.bottom()} |
| 198 }; | 198 }; |
| 199 } | 199 } |
| 200 | 200 |
| 201 bool isConvex(const Quadrilateral& quad) | 201 static convexity_e determine_convexity(const glm::vec3* begin, const glm::vec3* end) |
| 202 { | 202 { |
| 203 glm::vec3 crosses[4] = { | 203 auto test_concave_dot_product = [begin](const glm::vec3& vector) { |
| 204 return glm::dot(*begin, vector) < 1e-6; | |
| 205 }; | |
| 206 if (std::any_of(begin + 1, end, test_concave_dot_product)) | |
| 207 { | |
| 208 return convexity_e::concave; | |
| 209 } | |
| 210 else | |
| 211 { | |
| 212 return convexity_e::convex; | |
| 213 } | |
| 214 } | |
| 215 | |
| 216 convexity_e quadrilateral_convexity(const Quadrilateral& quad) | |
| 217 { | |
| 218 const glm::vec3 crosses[4] = { | |
| 204 glm::cross(quad.p4 - quad.p1, quad.p2 - quad.p1), | 219 glm::cross(quad.p4 - quad.p1, quad.p2 - quad.p1), |
| 205 glm::cross(quad.p1 - quad.p2, quad.p3 - quad.p2), | 220 glm::cross(quad.p1 - quad.p2, quad.p3 - quad.p2), |
| 206 glm::cross(quad.p2 - quad.p3, quad.p4 - quad.p3), | 221 glm::cross(quad.p2 - quad.p3, quad.p4 - quad.p3), |
| 207 glm::cross(quad.p3 - quad.p4, quad.p1 - quad.p4), | 222 glm::cross(quad.p3 - quad.p4, quad.p1 - quad.p4), |
| 208 }; | 223 }; |
| 209 return not std::any_of( | 224 return determine_convexity(&crosses[0], &crosses[4]); |
| 210 &crosses[1], | 225 } |
| 211 &crosses[4], | 226 |
| 212 [&crosses](const glm::vec3& vector) { | 227 convexity_e polygon_convexity(const std::vector<glm::vec3>& polygon) |
| 213 return glm::dot(crosses[0], vector) < 1e-6; | |
| 214 }); | |
| 215 } | |
| 216 | |
| 217 bool isConvex(const std::vector<glm::vec3>& polygon) | |
| 218 { | 228 { |
| 219 const std::size_t n = polygon.size(); | 229 const std::size_t n = polygon.size(); |
| 220 std::vector<glm::vec3> crosses; | 230 std::vector<glm::vec3> crosses; |
| 221 crosses.resize(n); | 231 crosses.resize(n); |
| 222 for (std::size_t i = 0; i < n; i += 1) | 232 for (std::size_t i = 0; i < n; i += 1) |
| 224 const glm::vec3 v1 = polygon[(i + n - 1) % n]; | 234 const glm::vec3 v1 = polygon[(i + n - 1) % n]; |
| 225 const glm::vec3 v2 = polygon[i]; | 235 const glm::vec3 v2 = polygon[i]; |
| 226 const glm::vec3 v3 = polygon[(i + 1) % n]; | 236 const glm::vec3 v3 = polygon[(i + 1) % n]; |
| 227 crosses[i] = glm::cross(v1 - v2, v3 - v2); | 237 crosses[i] = glm::cross(v1 - v2, v3 - v2); |
| 228 } | 238 } |
| 229 return not std::any_of( | 239 return determine_convexity(&crosses[0], &crosses[n]); |
| 230 crosses.begin() + 1, | |
| 231 crosses.end(), | |
| 232 [&crosses](const glm::vec3& vector) | |
| 233 { | |
| 234 return glm::dot(crosses[0], vector) < 1e-6; | |
| 235 }); | |
| 236 } | 240 } |
| 237 | 241 |
| 238 /** | 242 /** |
| 239 * @brief Determines the winding of a 2d polygon | 243 * @brief Determines the winding of a 2d polygon |
| 240 * @param polygon | 244 * @param polygon |
