diff options
| -rw-r--r-- | game/geoData.cpp | 39 | ||||
| -rw-r--r-- | game/geoData.h | 13 | ||||
| -rw-r--r-- | test/test-geo.cpp | 40 |
3 files changed, 92 insertions, 0 deletions
diff --git a/game/geoData.cpp b/game/geoData.cpp index c3fb5dc..4537026 100644 --- a/game/geoData.cpp +++ b/game/geoData.cpp @@ -95,6 +95,45 @@ GeoData::positionAt(const glm::vec2 wcoord) const return wcoord || heightMid; } +GeoData::RayTracer::RayTracer(glm::vec2 p0, glm::vec2 p1, float scale) : p {glm::floor(p0)}, d {glm::abs(p1 - p0)} +{ + using Limits = std::numeric_limits<typename glm::vec2::value_type>; + static_assert(Limits::has_infinity); + static constexpr const glm::vec2 inf {Limits::infinity(), -Limits::infinity()}; + + auto byAxis = [this, p0, p1, scale](auto axis) { + if (d[axis] == 0) { + inc[axis] = 0; + return inf[axis]; + } + else if (p1[axis] > p0[axis]) { + inc[axis] = scale; + return (std::floor(p0[axis]) + 1 - p0[axis]) * d[1 - axis]; + } + else { + inc[axis] = -scale; + return (p0[axis] - std::floor(p0[axis])) * d[1 - axis]; + } + }; + + error = byAxis(0); + error -= byAxis(1); + inc.z = scale; +} + +glm::vec2 +GeoData::RayTracer::next() +{ + glm::vec2 cur {p}; + + static constexpr const glm::vec2 m {1, -1}; + const int axis = (error > 0) ? 1 : 0; + p[axis] += inc[axis]; + error += d[1 - axis] * m[axis] * inc.z; + + return cur; +} + unsigned int GeoData::at(glm::ivec2 coord) const { diff --git a/game/geoData.h b/game/geoData.h index ffb7d64..7bd6ae5 100644 --- a/game/geoData.h +++ b/game/geoData.h @@ -32,6 +32,19 @@ public: [[nodiscard]] float getScale() const; [[nodiscard]] std::span<const Node> getNodes() const; + class RayTracer { + public: + RayTracer(glm::vec2 p0, glm::vec2 p1, float scale); + + glm::vec2 next(); + + private: + glm::vec2 p; + const glm::vec2 d; + float error; + glm::vec3 inc; + }; + protected: Limits limit {}; // Base grid limits first(x,y) -> second(x,y) glm::uvec2 size {}; diff --git a/test/test-geo.cpp b/test/test-geo.cpp index 63f192b..f0ed693 100644 --- a/test/test-geo.cpp +++ b/test/test-geo.cpp @@ -97,4 +97,44 @@ BOOST_AUTO_TEST_CASE(get_height_at) BOOST_CHECK_EQUAL(positionAt({2.5F, 2.5F}), glm::vec3(2.5F, 2.5F, 2.5F)); } +using TestRayTracerData = std::tuple<glm::vec2, glm::vec2, float, std::vector<glm::vec2>>; +BOOST_DATA_TEST_CASE(raytracer, + boost::unit_test::data::make<TestRayTracerData>({ + {{0, 0}, {0, 0}, 3, + { + {0, 0}, + }}, + {{0, 0}, {4, 5}, 4, + { + {0, 0}, + {0, 4}, + {4, 4}, + {4, 8}, + {8, 8}, + {8, 12}, + {12, 12}, + {12, 16}, + {16, 16}, + {16, 20}, + }}, + {{-1, -1}, {-4, -5}, 5, + { + {-1, -1}, + {-6, -1}, + {-6, -6}, + {-6, -11}, + {-11, -11}, + {-11, -16}, + {-16, -16}, + {-16, -21}, + }}, + }), + start, end, scale, points) +{ + GeoData::RayTracer rt {start, end, scale}; + for (const auto & point : points) { + BOOST_CHECK_CLOSE_VEC(point, rt.next()); + } +} + BOOST_AUTO_TEST_SUITE_END() |