From 7c03d93c367b842c464dca30e121bc4c20547c36 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sat, 1 Jan 2022 16:44:19 +0000
Subject: Generic solution for glGen/glDel arrays, then tidy-up the uses

---
 lib/glArrays.h | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 lib/glArrays.h

(limited to 'lib/glArrays.h')

diff --git a/lib/glArrays.h b/lib/glArrays.h
new file mode 100644
index 0000000..ed05eeb
--- /dev/null
+++ b/lib/glArrays.h
@@ -0,0 +1,76 @@
+#pragma once
+
+#include <GL/glew.h>
+#include <algorithm> // IWYU pragma: keep
+#include <array>
+#include <cstddef>
+#include <special_members.hpp>
+
+template<size_t N> class glArraysBase {
+	static_assert(N > 0);
+
+public:
+	~glArraysBase() = default;
+	NO_COPY(glArraysBase);
+	CUSTOM_MOVE(glArraysBase);
+
+	// NOLINTNEXTLINE(hicpp-explicit-conversions)
+	inline operator GLuint() const
+	{
+		static_assert(N == 1, "Implicit cast only if N == 1");
+		return ids.front();
+	}
+
+	inline auto
+	operator[](size_t n) const
+	{
+		return ids[n];
+	}
+
+	constexpr static auto size {N};
+
+protected:
+	glArraysBase() noexcept = default;
+	std::array<GLuint, N> ids {};
+};
+
+template<size_t N> inline glArraysBase<N>::glArraysBase(glArraysBase<N> && src) noexcept : ids {src.ids}
+{
+	std::fill(src.ids.begin(), src.ids.end(), 0);
+}
+
+template<size_t N>
+inline glArraysBase<N> &
+glArraysBase<N>::operator=(glArraysBase<N> && src) noexcept
+{
+	ids = src.ids;
+	std::fill(src.ids.begin(), src.ids.end(), 0);
+	return *this;
+}
+
+template<size_t N, auto Gen, auto Del> class glArrays : public glArraysBase<N> {
+public:
+	using glArraysBase<N>::glArraysBase;
+	using glArraysBase<N>::operator=;
+
+	DEFAULT_MOVE_COPY(glArrays);
+
+	inline glArrays() noexcept
+	{
+		(*Gen)(N, this->ids.data());
+	}
+
+	inline ~glArrays() noexcept
+	{
+		if (this->ids.front()) {
+			(*Del)(N, this->ids.data());
+		}
+	}
+};
+
+template<size_t N> using glVertexArrays = glArrays<N, &glGenVertexArrays, &glDeleteVertexArrays>;
+using glVertexArray = glVertexArrays<1>;
+template<size_t N> using glBuffers = glArrays<N, &glGenBuffers, &glDeleteBuffers>;
+using glBuffer = glBuffers<1>;
+template<size_t N> using glTextures = glArrays<N, &glGenTextures, &glDeleteTextures>;
+using glTexture = glTextures<1>;
-- 
cgit v1.2.3