Instances buffer data needs to be unmapped before use

Here we change quite a bit to support mapping and unmapping the buffer as required. The instance/free
referencing is still broken though. We add several instances of tree in the render.

4 files changed, 61 insertions, 27 deletions

diff --git a/gfx/gl/instanceVertices.h b/gfx/gl/instanceVertices.h
index dc28a4d..c2ddb1d 100644
--- a/gfx/gl/instanceVertices.h
+++ b/gfx/gl/instanceVertices.h
@@ -9,11 +9,9 @@
 
 template<typename T> class InstanceVertices {
 public:
-	InstanceVertices(size_t initialSize = 16) : data {allocBuffer(buffer, initialSize)}, next {} { }
-
-	~InstanceVertices()
+	InstanceVertices(size_t initialSize = 16)
 	{
-		glUnmapNamedBuffer(buffer);
+		allocBuffer(initialSize);
 	}
 
 	class InstanceProxy {
@@ -50,17 +48,20 @@ public:
 		T &
 		operator=(U && v)
 		{
+			instances->map();
 			return instances->data[index] = std::forward<U>(v);
 		}
 
 		T *
 		get()
 		{
+			instances->map();
 			return &instances->data[index];
 		}
 		const T *
 		get() const
 		{
+			instances->map();
 			return &instances->data[index];
 		}
 		T *
@@ -95,22 +96,24 @@ public:
 	InstanceProxy
 	acquire(Params &&... params)
 	{
+		map();
 		if (!unused.empty()) {
 			auto idx = unused.back();
 			unused.pop_back();
-			new (&data[idx]) T(std::forward<Params>(params)...);
+			new (data + idx) T(std::forward<Params>(params)...);
 			return InstanceProxy {this, idx};
 		}
-		if (next >= data.size()) {
-			resize(data.size() * 2);
+		if (next >= capacity) {
+			resize(capacity * 2);
 		}
-		new (&data[next]) T(std::forward<Params>(params)...);
+		new (data + next) T(std::forward<Params>(params)...);
 		return InstanceProxy {this, next++};
 	}
 
 	void
 	release(const InstanceProxy & p)
 	{
+		map();
 		data[p.index].~T();
 		unused.push_back(p.index);
 	}
@@ -118,42 +121,65 @@ public:
 	const auto &
 	bufferName() const
 	{
+		unmap();
 		return buffer;
 	}
 
 	auto
 	count() const
 	{
+		unmap();
 		return next;
 	}
 
 protected:
 	friend InstanceProxy;
 
-	static std::span<T>
-	allocBuffer(const glBuffer & buffer, std::size_t count)
+	void
+	allocBuffer(std::size_t newCapacity)
 	{
 		glBindBuffer(GL_ARRAY_BUFFER, buffer);
-		glBufferData(GL_ARRAY_BUFFER, static_cast<GLsizeiptr>(sizeof(T) * count), nullptr, GL_DYNAMIC_DRAW);
-		auto data = static_cast<T *>(glMapNamedBuffer(buffer, GL_READ_WRITE));
+		glBufferData(GL_ARRAY_BUFFER, static_cast<GLsizeiptr>(sizeof(T) * newCapacity), nullptr, GL_DYNAMIC_DRAW);
 		glBindBuffer(GL_ARRAY_BUFFER, 0);
-		return {data, count};
+		capacity = newCapacity;
+		data = nullptr;
 	}
 
 	void
 	resize(size_t newCapacity)
 	{
-		const auto maintain = std::min(newCapacity, data.size());
-		const auto maintaind = static_cast<typename decltype(data)::difference_type>(maintain);
+		const auto maintain = std::min(newCapacity, capacity);
 		std::vector<T> existing;
+		const auto maintaind = static_cast<typename decltype(existing)::difference_type>(maintain);
 		existing.reserve(maintain);
-		std::move(data.begin(), data.begin() + maintaind, std::back_inserter(existing));
-		data = allocBuffer(buffer, newCapacity);
-		std::move(existing.begin(), existing.begin() + maintaind, data.begin());
+		map();
+		std::move(data, data + maintain, std::back_inserter(existing));
+		allocBuffer(newCapacity);
+		map();
+		std::move(existing.begin(), existing.begin() + maintaind, data);
+		capacity = newCapacity;
+	}
+
+	void
+	map() const
+	{
+		if (!data) {
+			data = static_cast<T *>(glMapNamedBuffer(buffer, GL_READ_WRITE));
+		}
+	}
+
+	void
+	unmap() const
+	{
+		if (data) {
+			glUnmapNamedBuffer(buffer);
+			data = nullptr;
+		}
 	}
 
 	glBuffer buffer;
-	std::span<T> data;
-	std::size_t next;
+	mutable T * data {};
+	std::size_t capacity {};
+	std::size_t next {};
 	std::vector<size_t> unused;
 };
diff --git a/test/Jamfile.jam b/test/Jamfile.jam
index 9cdcef4..1ce73b7 100644
--- a/test/Jamfile.jam
+++ b/test/Jamfile.jam
@@ -53,7 +53,7 @@ run test-text.cpp ;
 run test-enumDetails.cpp ;
 run test-render.cpp : -- : test-assetFactory : <library>test ;
 run test-glContextBhvr.cpp ;
-run test-assetFactory.cpp : -- : [ sequence.insertion-sort [ glob-tree $(res) : *.* ] fixtures/rgb.txt ] : <library>test ;
+run test-assetFactory.cpp : -- : [ sequence.insertion-sort [ glob-tree $(res) : *.* ] fixtures/rgb.txt test-instancing ] : <library>test ;
 run perf-assetFactory.cpp : -- : test-assetFactory : <library>benchmark <library>test ;
 run perf-persistence.cpp : -- : test-persistence : <library>benchmark <library>test ;
 run test-worker.cpp ;
diff --git a/test/test-assetFactory.cpp b/test/test-assetFactory.cpp
index 817654b..82a1825 100644
--- a/test/test-assetFactory.cpp
+++ b/test/test-assetFactory.cpp
@@ -107,7 +107,10 @@ BOOST_AUTO_TEST_CASE(foliage, *boost::unit_test::timeout(5))
 	auto tree_01_1_f = std::dynamic_pointer_cast<Foliage>(tree_01_1);
 	BOOST_REQUIRE(tree_01_1_f);
 
-	auto plant = std::make_shared<Plant>(tree_01_1_f, Location {{-2, 2, 0}, {}});
+	auto plant1 = std::make_shared<Plant>(tree_01_1_f, Location {{-2, 2, 0}, {0, 0, 0}});
+	auto plant2 = std::make_shared<Plant>(tree_01_1_f, Location {{3, -4, 0}, {0, 1, 0}});
+	auto plant3 = std::make_shared<Plant>(tree_01_1_f, Location {{-2, -4, 0}, {0, 2, 0}});
+	auto plant4 = std::make_shared<Plant>(tree_01_1_f, Location {{3, 2, 0}, {0, 3, 0}});
 	objects.objects.push_back(tree_01_1_f);
 
 	render(5);
diff --git a/test/test-instancing.cpp b/test/test-instancing.cpp
index 7191567..2eb3647 100644
--- a/test/test-instancing.cpp
+++ b/test/test-instancing.cpp
@@ -15,16 +15,21 @@ BOOST_FIXTURE_TEST_SUITE(i, InstanceVertices<int>)
 
 BOOST_AUTO_TEST_CASE(createDestroy)
 {
-	BOOST_REQUIRE(data.data());
+	BOOST_CHECK(!data);
+	map();
+	BOOST_REQUIRE(data);
 	BOOST_CHECK_EQUAL(0, next);
 	BOOST_CHECK(unused.empty());
+	unmap();
+	BOOST_CHECK(!data);
 }
 
 BOOST_AUTO_TEST_CASE(storeRetreive)
 { // Read write raw buffer, not normally allowed
-	std::vector<int> test(data.size());
-	std::copy(test.begin(), test.end(), data.begin());
-	BOOST_CHECK_EQUAL_COLLECTIONS(test.begin(), test.end(), data.begin(), data.end());
+	std::vector<int> test(capacity);
+	map();
+	std::copy(test.begin(), test.end(), data);
+	BOOST_CHECK_EQUAL_COLLECTIONS(test.begin(), test.end(), data, data + capacity);
 }
 
 BOOST_AUTO_TEST_CASE(acquireRelease)
@@ -69,7 +74,7 @@ BOOST_AUTO_TEST_CASE(resize)
 		proxies.push_back(acquire(n));
 		expected.emplace_back(n);
 	}
-	BOOST_CHECK_EQUAL_COLLECTIONS(expected.begin(), expected.end(), data.begin(), data.begin() + COUNT);
+	BOOST_CHECK_EQUAL_COLLECTIONS(expected.begin(), expected.end(), data, data + COUNT);
 	BOOST_CHECK_EQUAL_COLLECTIONS(expected.begin(), expected.end(), proxies.begin(), proxies.end());
 }