From e825724fd7de4b24ab637d62c259e26c1d18d0fa Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 26 Jan 2025 17:02:45 +0200
Subject: [PATCH] Add a builder for turning geometric shapes into meshes

---
 source/builders/shape.cpp | 48 +++++++++++++++++++++++++++++++++++++++
 source/builders/shape.h   | 29 +++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 source/builders/shape.cpp
 create mode 100644 source/builders/shape.h

diff --git a/source/builders/shape.cpp b/source/builders/shape.cpp
new file mode 100644
index 00000000..234f5b85
--- /dev/null
+++ b/source/builders/shape.cpp
@@ -0,0 +1,48 @@
+#include <msp/geometry/extrudedshape.h>
+#include <msp/geometry/hyperbox.h>
+#include <msp/geometry/hypersphere.h>
+#include <msp/gl/error.h>
+#include "box.h"
+#include "cylinder.h"
+#include "shape.h"
+#include "sphere.h"
+
+using namespace std;
+
+namespace Msp {
+namespace GL {
+
+ShapeBuilder::ShapeBuilder(const Geometry::Shape<float, 3> &s, unsigned d):
+	shape(s),
+	detail(d)
+{
+	if(detail<1)
+		detail = 1;
+}
+
+void ShapeBuilder::build(PrimitiveBuilder &builder) const
+{
+	if(const auto *sphere = dynamic_cast<const Geometry::HyperSphere<float, 3> *>(&shape))
+		return make_builder<IcoSphereBuilder>(sphere->get_radius(), detail).build(builder);
+	else if(const auto *box = dynamic_cast<const Geometry::HyperBox<float, 3> *>(&shape))
+		return make_builder<BoxBuilder>(box->get_dimension(0), box->get_dimension(1), box->get_dimension(2)).build(builder);
+	else if(const auto *ext = dynamic_cast<const Geometry::ExtrudedShape<float, 3> *>(&shape))
+	{
+		if(const auto *circle = dynamic_cast<const Geometry::HyperSphere<float, 2> *>(&ext->get_base()))
+			return make_builder<CylinderBuilder>(circle->get_radius(), ext->get_length(), detail*6).build(builder);
+	}
+
+	throw invalid_operation("ShapeBuilder::build");
+}
+
+template<typename T, typename... Args>
+T ShapeBuilder::make_builder(Args &&... args) const
+{
+	T bld(forward<Args>(args)...);
+	bld.tangents(generate_tan);
+	bld.texture_fit(tex_fit);
+	return bld;
+}
+
+} // namespace GL
+} // namespace Msp
diff --git a/source/builders/shape.h b/source/builders/shape.h
new file mode 100644
index 00000000..f6807446
--- /dev/null
+++ b/source/builders/shape.h
@@ -0,0 +1,29 @@
+#ifndef MSP_GL_SHAPE_H_
+#define MSP_GL_SHAPE_H_
+
+#include <msp/geometry/shape.h>
+#include "geometrybuilder.h"
+
+namespace Msp {
+namespace GL {
+
+class MSPGL_API ShapeBuilder: public GeometryBuilder
+{
+private:
+	const Geometry::Shape<float, 3> &shape;
+	unsigned detail = 1;
+
+public:
+	ShapeBuilder(const Geometry::Shape<float, 3> &, unsigned);
+
+	using GeometryBuilder::build;
+	void build(PrimitiveBuilder &) const override;
+private:
+	template<typename T, typename... Args>
+	T make_builder(Args &&...) const;
+};
+
+} // namespace GL
+} // namespace Msp
+
+#endif
-- 
2.45.2