X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Frender%2Finstancearray.h;h=f2a9b2c00be5930c281a8341851d838af949ba1f;hb=274b6fb1b02692cc422bad9040d1abe5d545505a;hp=627051f75b123a973ef878546fddd762708afe59;hpb=7aaec9a70b8d7733429bec043f8e33e02956f266;p=libs%2Fgl.git

diff --git a/source/render/instancearray.h b/source/render/instancearray.h
index 627051f7..f2a9b2c0 100644
--- a/source/render/instancearray.h
+++ b/source/render/instancearray.h
@@ -2,8 +2,11 @@
 #define MSP_GL_INSTANCEARRAY_H_
 
 #include <vector>
+#include <msp/core/noncopyable.h>
 #include "programdata.h"
 #include "renderable.h"
+#include "vertexarray.h"
+#include "vertexsetup.h"
 
 namespace Msp {
 namespace GL {
@@ -11,19 +14,117 @@ namespace GL {
 class Buffer;
 class Object;
 class ObjectInstance;
-class VertexArray;
-class VertexSetup;
+
+class InstanceArrayBase: public Renderable, public NonCopyable
+{
+private:
+	struct Block
+	{
+		char *begin = 0;
+		char *end = 0;
+	};
+
+	struct Slot
+	{
+		bool used = false;
+		union
+		{
+			std::uint16_t array_index;
+			std::uint16_t next_free;
+		};
+		std::uint16_t block_index;
+		std::uint16_t index_in_block;
+	};
+
+	const Object &object;
+	VertexArray instance_data;
+	Buffer *instance_buffer = 0;
+	VertexSetup vtx_setup;
+	int matrix_location = -1;
+	unsigned matrix_offset = 0;
+	std::size_t instance_size;
+	std::size_t default_count;
+	std::vector<Block> storage;
+	std::vector<Slot> slots;
+	std::vector<int> array_order;
+	int first_free = -1;
+	int last_free = -1;
+	std::size_t instance_count = 0;
+
+protected:
+	InstanceArrayBase(const Object &, std::size_t);
+	~InstanceArrayBase();
+
+private:
+	void add_block(std::size_t);
+	std::size_t allocate();
+	char *get_address(std::size_t) const;
+	std::size_t find_index(char *) const;
+	void release(std::size_t);
+protected:
+	template<typename T, typename A>
+	T *create(A &);
+
+	template<typename T>
+	void destroy(T *);
+
+	template<typename T>
+	void destroy_all();
+
+	void update_instance_matrix(std::size_t, const Matrix &);
+
+public:
+	std::size_t size() const { return instance_count; }
+
+	virtual void render(Renderer &, Tag) const;
+};
+
+template<typename T, typename A>
+inline T *InstanceArrayBase::create(A &array)
+{
+	size_t index = allocate();
+	return new(get_address(index)) T(object, array, index);
+}
+
+template<typename T>
+inline void InstanceArrayBase::destroy(T *obj)
+{
+	char *addr = reinterpret_cast<char *>(obj);
+	obj->~T();
+	release(find_index(addr));
+}
+
+template<typename T>
+inline void InstanceArrayBase::destroy_all()
+{
+	for(unsigned i=0; i<slots.size(); ++i)
+		if(slots[i].used)
+			reinterpret_cast<T *>(get_address(i))->~T();
+}
+
 
 /**
-Renders multiple instances of an Object in an efficient manner.  If instanced
-rendering is supported, only one draw call per Batch needs to be issued.
+Stores and renders multiple instances of an Object in an efficient manner.
+
+The instance specific transform is passed to the shader in an attribute with
+the name instance_transform.  The attribute should have the type vec4[3].  Each
+elements of the array corresponds to a row of the transform matrix.
 
-Changing the Mesh of the Object while an InstanceArray exists is not supported.
+If the Mesh or Technique of the Object is changed during the lifetime of the
+InstanceArray, behaviour is undefined.
+
+The instance type must have a constructor accepting a const Object &.  If it
+has a virtual function with the signature void set_matrix(const Matrix &), it
+will be used to update the instance matrix.  The original function is also
+called.
+
+Instance created by the array have stable addresses.  However after an instance
+is removed, its address may later be reused for another instance.
 */
-class InstanceArray: public Renderable
+template<typename T = ObjectInstance>
+class InstanceArray: public InstanceArrayBase
 {
-public:
-	template<typename T>
+private:
 	class Instance: public T
 	{
 	private:
@@ -36,45 +137,20 @@ public:
 		virtual void set_matrix(const Matrix &);
 	};
 
-private:
-	const Object &object;
-	std::vector<ObjectInstance *> instances;
-	VertexArray *instance_data;
-	Buffer *instance_buffer;
-	VertexSetup *vtx_setup;
-	int matrix_location;
-	unsigned matrix_offset;
-
-public:
-	InstanceArray(const Object &);
-	~InstanceArray();
-
-	void set_matrix_attribute(const std::string &);
-
-	template<typename T = ObjectInstance>
-	T &append();
-private:
-	void append(ObjectInstance *);
-	void update_instance_matrix(unsigned);
 public:
-	void remove(ObjectInstance &);
+	InstanceArray(const Object &o): InstanceArrayBase(o, sizeof(Instance)) { }
+	~InstanceArray() { destroy_all<T>(); }
 
-	virtual void render(Renderer &, const Tag &) const;
+	T &append() { return *create<Instance>(*this); }
+	void remove(T &obj) { destroy(&obj); }
 };
 
-template<typename T>
-T &InstanceArray::append()
-{
-	Instance<T> *inst = new Instance<T>(object, *this, instances.size());
-	append(inst);
-	return *inst;
-}
 
 template<typename T>
-void InstanceArray::Instance<T>::set_matrix(const Matrix &m)
+inline void InstanceArray<T>::Instance::set_matrix(const Matrix &m)
 {
 	T::set_matrix(m);
-	array.update_instance_matrix(index);
+	array.update_instance_matrix(index, *this->get_matrix());
 }
 
 } // namespace GL