From 27ba0701dcb7ce441cb91a10a570e4f4b05db5c4 Mon Sep 17 00:00:00 2001 From: Dan Goodliffe Date: Sun, 14 Feb 2021 13:19:37 +0000 Subject: Support getting the position at a point along a link --- game/network/link.h | 3 +++ game/network/rail.cpp | 26 ++++++++++++++++++++++++++ game/network/rail.h | 2 ++ 3 files changed, 31 insertions(+) (limited to 'game/network') diff --git a/game/network/link.h b/game/network/link.h index c9fbedb..3fabf05 100644 --- a/game/network/link.h +++ b/game/network/link.h @@ -2,6 +2,7 @@ #define LINK_H #include +#include #include #include #include @@ -36,6 +37,8 @@ public: NO_COPY(Link); NO_MOVE(Link); + virtual Transform positionAt(float dist, unsigned char start) const = 0; + std::array ends; float length; using Next = std::pair; diff --git a/game/network/rail.cpp b/game/network/rail.cpp index 4e09e29..a765a4f 100644 --- a/game/network/rail.cpp +++ b/game/network/rail.cpp @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -95,6 +96,15 @@ RailLinkStraight::RailLinkStraight(NodePtr a, NodePtr b, const glm::vec3 & diff) defaultMesh(); } +Transform +RailLinkStraight::positionAt(float dist, unsigned char start) const +{ + const auto es {std::make_pair(ends[start].first, ends[1 - start].first)}; + const auto diff {es.second->pos - es.first->pos}; + const auto dir {glm::normalize(diff)}; + return Transform {es.first->pos + dir * dist, {0, flat_angle(diff) /*, std::atan2(diff.x, -diff.z)*/, 0}}; +} + RailLinkCurve::RailLinkCurve(const NodePtr & a, const NodePtr & b, glm::vec2 c) : RailLinkCurve(a, b, {c.x, a->pos.y, c.y}, {!c, a->pos, b->pos}) { @@ -124,3 +134,19 @@ RailLinkCurve::RailLinkCurve(const NodePtr & a, const NodePtr & b, glm::vec3 c, } defaultMesh(); } + +Transform +RailLinkCurve::positionAt(float dist, unsigned char start) const +{ + static constexpr std::array dirOffset {half_pi, -half_pi}; + const auto frac {dist / length}; + const auto es {std::make_pair(ends[start].first, ends[1 - start].first)}; + const auto as {std::make_pair(arc[start], arc[1 - start])}; + const auto ang {as.first + ((as.second - as.first) * frac)}; + const auto angArc {ang - half_pi}; + const auto relPos {glm::vec3 {std::cos(angArc), 0, -std::sin(angArc)} * radius}; + const auto relClimb { + glm::vec3 {0, -centreBase.y + es.first->pos.y + ((es.second->pos.y - es.first->pos.y) * frac), 0}}; + + return Transform {relPos + relClimb + centreBase, {0, normalize(ang + dirOffset[start]), 0}}; +} diff --git a/game/network/rail.h b/game/network/rail.h index f50ef3c..58c26c3 100644 --- a/game/network/rail.h +++ b/game/network/rail.h @@ -36,6 +36,7 @@ protected: class RailLinkStraight : public RailLink { public: RailLinkStraight(const NodePtr &, const NodePtr &); + Transform positionAt(float dist, unsigned char start) const override; private: RailLinkStraight(NodePtr, NodePtr, const glm::vec3 & diff); @@ -44,6 +45,7 @@ private: class RailLinkCurve : public RailLink { public: RailLinkCurve(const NodePtr &, const NodePtr &, glm::vec2); + Transform positionAt(float dist, unsigned char start) const override; private: RailLinkCurve(const NodePtr &, const NodePtr &, glm::vec3, const Arc); -- cgit v1.2.3