From 98d26f76cfd10e6fce70914c2c7d93513697ae10 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Fri, 7 May 2021 18:20:59 +0300
Subject: [PATCH] Refactor phys2d engine interface

---
 examples/physics_2d.cpp                     |  6 ++---
 libs/phys/include/psemek/phys/engine_2d.hpp | 10 +++++---
 libs/phys/source/engine_2d.cpp              | 27 +++++++++++++++------
 3 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/examples/physics_2d.cpp b/examples/physics_2d.cpp
index a73d0828..be688e36 100644
--- a/examples/physics_2d.cpp
+++ b/examples/physics_2d.cpp
@@ -436,7 +436,7 @@ struct physics_2d_app
 			auto p = physics.group_static_state(ball_group)[i].position;
 			auto a = physics.group_static_state(ball_group)[i].rotation;
 
-			float r = std::get<phys2d::ball>(physics.shape(ball_group, i)).radius;
+			float r = std::get<phys2d::ball const *>(physics.get_shape(physics.get_object(ball_group, i).shape))->radius;
 
 			painter.circle(p, r, gfx::black);
 			painter.circle(p, r - line_width, gfx::light(gfx::blue, selected ? 0.8f : 1.f).as_color_rgba());
@@ -455,8 +455,8 @@ struct physics_2d_app
 			auto p = physics.group_static_state(box_group)[i].position;
 			auto a = physics.group_static_state(box_group)[i].rotation;
 
-			float w = std::get<phys2d::box>(physics.shape(box_group, i)).width / 2.f;
-			float h = std::get<phys2d::box>(physics.shape(box_group, i)).height / 2.f;
+			float w = std::get<phys2d::box const *>(physics.get_shape(physics.get_object(box_group, i).shape))->width / 2.f;
+			float h = std::get<phys2d::box const *>(physics.get_shape(physics.get_object(box_group, i).shape))->height / 2.f;
 
 			geom::vector<float, 2> q[4];
 			q[0] = {-w, -h};
diff --git a/libs/phys/include/psemek/phys/engine_2d.hpp b/libs/phys/include/psemek/phys/engine_2d.hpp
index 7d880283..496a7de8 100644
--- a/libs/phys/include/psemek/phys/engine_2d.hpp
+++ b/libs/phys/include/psemek/phys/engine_2d.hpp
@@ -25,6 +25,8 @@ namespace psemek::phys2d
 		shape_handle add_shape(half_space const & s);
 		shape_handle add_shape(box const & b);
 
+		std::variant<ball const *, half_space const *, box const *> get_shape(shape_handle handle) const;
+
 		void remove_shape(shape_handle handle);
 
 		// Material management
@@ -32,6 +34,10 @@ namespace psemek::phys2d
 		using material_handle = std::uint32_t;
 
 		material_handle add_material(material const & m);
+
+		material const & get_material(material_handle handle) const;
+		material & get_material(material_handle handle);
+
 		void remove_material(material_handle handle);
 
 		// Group & body management
@@ -58,9 +64,7 @@ namespace psemek::phys2d
 			float inv_inertia;
 		};
 
-		object_info const & info(group_handle group, std::size_t index);
-
-		std::variant<ball, half_space, box> shape(group_handle group, std::size_t index);
+		object_info const & get_object(group_handle group, std::size_t index);
 
 		// Global system properties
 
diff --git a/libs/phys/source/engine_2d.cpp b/libs/phys/source/engine_2d.cpp
index b747c675..cb59bbb9 100644
--- a/libs/phys/source/engine_2d.cpp
+++ b/libs/phys/source/engine_2d.cpp
@@ -1022,6 +1022,14 @@ namespace psemek::phys2d
 		return impl().shapes.insert(wrap(b));
 	}
 
+	std::variant<ball const *, half_space const *, box const *> engine::get_shape(shape_handle handle) const
+	{
+		using result_type = std::variant<ball const *, half_space const *, box const *>;
+		return impl().shapes.visit([](auto const & w) -> result_type {
+			return &(w.shape);
+		}, handle);
+	}
+
 	void engine::remove_shape(shape_handle handle)
 	{
 		impl().shapes.erase(handle);
@@ -1032,6 +1040,16 @@ namespace psemek::phys2d
 		return impl().materials.insert(m);
 	}
 
+	material const & engine::get_material(material_handle handle) const
+	{
+		return impl().materials[handle];
+	}
+
+	material & engine::get_material(material_handle handle)
+	{
+		return impl().materials[handle];
+	}
+
 	void engine::remove_material(material_handle handle)
 	{
 		impl().materials.erase(handle);
@@ -1099,18 +1117,11 @@ namespace psemek::phys2d
 		g.dynamic_states.erase(g.dynamic_states.begin() + index);
 	}
 
-	engine::object_info const & engine::info(group_handle group, std::size_t index)
+	engine::object_info const & engine::get_object(group_handle group, std::size_t index)
 	{
 		return impl().groups[group].infos[index];
 	}
 
-	std::variant<ball, half_space, box> engine::shape(group_handle group, std::size_t index)
-	{
-		using result = std::variant<ball, half_space, box>;
-		auto sh = impl().groups[group].infos[index].shape;
-		return impl().shapes.visit([](auto const & s) -> result { return s.shape; }, sh);
-	}
-
 	void engine::set_gravity(geom::vector<float, 2> const & g)
 	{
 		impl().gravity = g;