From 064864eac61e936af909470fcccc5c67ef6d3169 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 11 Aug 2024 19:32:23 +0100
Subject: Calculate centre and size of mesh, wrap it all in a Dimensions object

---
 gfx/models/mesh.cpp | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

(limited to 'gfx/models/mesh.cpp')

diff --git a/gfx/models/mesh.cpp b/gfx/models/mesh.cpp
index 1b6ecda..2eae160 100644
--- a/gfx/models/mesh.cpp
+++ b/gfx/models/mesh.cpp
@@ -1,10 +1,33 @@
 #include "mesh.h"
 
-MeshBase::MeshBase(GLsizei m_numIndices, GLenum mode, std::pair<RelativePosition3D, RelativePosition3D> minmax) :
-	m_numIndices {m_numIndices}, mode {mode}, min {minmax.first}, max {minmax.second}
+MeshBase::MeshBase(GLsizei m_numIndices, GLenum mode, const std::vector<RelativePosition3D> & positions) :
+	m_numIndices {m_numIndices}, mode {mode}, dimensions {positions}
 {
 }
 
+MeshBase::Dimensions::Dimensions(const std::span<const RelativePosition3D> positions) :
+	Dimensions {positions, {extents(positions, 0), extents(positions, 1), extents(positions, 2)}}
+{
+}
+
+MeshBase::Dimensions::Dimensions(
+		const std::span<const RelativePosition3D> positions, const std::array<Extents1D, 3> & extents1ds) :
+	minExtent(extents1ds[0].min, extents1ds[1].min, extents1ds[2].min),
+	maxExtent(extents1ds[0].max, extents1ds[1].max, extents1ds[2].max), centre {(minExtent + maxExtent) / 2.0F},
+	size {std::ranges::max(positions | std::views::transform([this](const auto & v) {
+		return glm::distance(v, centre);
+	}))}
+{
+}
+
+MeshBase::Dimensions::Extents1D
+MeshBase::Dimensions::extents(const std::span<const RelativePosition3D> positions, glm::length_t D)
+{
+	return std::ranges::minmax(positions | std::views::transform([D](const auto & v) {
+		return v[D];
+	}));
+}
+
 void
 MeshBase::Draw() const
 {
-- 
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