From 6b407b2778c69314ba034e9ea265697a51f331d4 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sat, 28 Feb 2026 13:30:46 +0000
Subject: Use RelativeDistance in Camera near/fear and expose member variables

---
 gfx/camera.cpp       |  9 ++++-----
 gfx/camera.h         | 24 +++++++++++++++++++++---
 test/test-render.cpp |  4 ++--
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/gfx/camera.cpp b/gfx/camera.cpp
index 3bb785d..db748e9 100644
--- a/gfx/camera.cpp
+++ b/gfx/camera.cpp
@@ -4,13 +4,13 @@
 #include <maths.h>
 #include <ray.h>
 
-Camera::Camera(GlobalPosition3D pos, Angle fov, Angle aspect, GlobalDistance near, GlobalDistance far) :
+Camera::Camera(GlobalPosition3D pos, Angle fov, Angle aspect, RelativeDistance near, RelativeDistance far) :
 	Camera {pos, fov, aspect, near, far, glm::lookAt({}, ::north, ::up),
 			glm::perspective(fov, aspect, static_cast<RelativeDistance>(near), static_cast<RelativeDistance>(far))}
 {
 }
 
-Camera::Camera(GlobalPosition3D pos, Angle fov, Angle aspect, GlobalDistance near, GlobalDistance far,
+Camera::Camera(GlobalPosition3D pos, Angle fov, Angle aspect, RelativeDistance near, RelativeDistance far,
 		const glm::mat4 & view, const glm::mat4 & projection) :
 	Frustum {pos, view, projection}, fov {fov}, aspect {aspect}, forward {::north}, up {::up}, near {near}, far {far}
 {
@@ -58,9 +58,8 @@ Camera::extentsAtDist(const GlobalDistance dist) const
 		}
 		return {target, dist};
 	};
-	const auto depth = -(2.F * (static_cast<float>(dist - near)) * static_cast<float>(far))
-					/ (static_cast<float>(dist) * (static_cast<float>(near - far)))
-			- 1.F;
+	const auto depth
+			= -(2.F * (static_cast<float>(dist) - near) * far) / (static_cast<float>(dist) * (near - far)) - 1.F;
 	static constexpr const std::array extents {-1.F, 1.F};
 	static constexpr const auto cartesianExtents = extents * extents;
 	return cartesianExtents * [&depth, this, &clampToSeaFloor](const auto & extent) {
diff --git a/gfx/camera.h b/gfx/camera.h
index b17bcbb..b78827a 100644
--- a/gfx/camera.h
+++ b/gfx/camera.h
@@ -8,7 +8,7 @@
 
 class Camera : public Frustum {
 public:
-	Camera(GlobalPosition3D position, Angle fov, Angle aspect, GlobalDistance near, GlobalDistance far);
+	Camera(GlobalPosition3D position, Angle fov, Angle aspect, RelativeDistance near, RelativeDistance far);
 
 	[[nodiscard]] Ray<GlobalPosition3D> unProject(const ScreenRelCoord &) const;
 
@@ -61,17 +61,35 @@ public:
 		return forward;
 	}
 
+	[[nodiscard]] auto
+	getNear() const
+	{
+		return near;
+	}
+
+	[[nodiscard]] auto
+	getFar() const
+	{
+		return far;
+	}
+
+	[[nodiscard]] auto
+	getDepth() const
+	{
+		return far - near;
+	}
+
 	[[nodiscard]] std::array<GlobalPosition4D, 4> extentsAtDist(GlobalDistance) const;
 
 	[[nodiscard]] static Direction3D upFromForward(const Direction3D & forward);
 
 private:
-	Camera(GlobalPosition3D position, Angle fov, Angle aspect, GlobalDistance near, GlobalDistance far,
+	Camera(GlobalPosition3D position, Angle fov, Angle aspect, RelativeDistance near, RelativeDistance far,
 			const glm::mat4 & view, const glm::mat4 & projection);
 	void updateView();
 
 	Angle fov, aspect;
 	Direction3D forward;
 	Direction3D up;
-	GlobalDistance near, far;
+	RelativeDistance near, far;
 };
diff --git a/test/test-render.cpp b/test/test-render.cpp
index da7d572..1a6e1ae 100644
--- a/test/test-render.cpp
+++ b/test/test-render.cpp
@@ -126,8 +126,8 @@ namespace {
 BOOST_GLOBAL_FIXTURE(TestMainWindowAppBase);
 
 BOOST_DATA_TEST_CASE(Cam,
-		boost::unit_test::data::xrange(500, 30000, 1300) * boost::unit_test::data::xrange(500, 10000, 300)
-				* boost::unit_test::data::xrange(50000, 500000, 70000),
+		boost::unit_test::data::xrange(500, 30000, 1300) * boost::unit_test::data::xrange(500.F, 10000.F, 300.F)
+				* boost::unit_test::data::xrange(50000.F, 500000.F, 70000.F),
 		dist, near, far)
 {
 	static constexpr GlobalPosition4D POS {-10, -10, 60000, 0};
-- 
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