X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fcore%2Fbuffer.h;h=17678fd4b4008f68a7dd2f3745916fd237526a10;hb=e98188ff6c9bba9761b71f2a69f3be7eb89ba3da;hp=0d656131dd331b75ec3af57ff81581c9e2b2a3a5;hpb=6065f6622cc275dc0b20baaf7c267e71169d18f3;p=libs%2Fgl.git

diff --git a/source/core/buffer.h b/source/core/buffer.h
index 0d656131..17678fd4 100644
--- a/source/core/buffer.h
+++ b/source/core/buffer.h
@@ -3,8 +3,7 @@
 
 #include <stdexcept>
 #include <string>
-#include <vector>
-#include "gl.h"
+#include "buffer_backend.h"
 
 namespace Msp {
 namespace GL {
@@ -16,59 +15,57 @@ public:
 	virtual ~buffer_too_small() throw() { }
 };
 
-class BufferRange;
+enum BufferUsage
+{
+	STATIC,
+	STREAMING
+};
 
 /**
-A buffer for storing data in GL memory.  Putting vertex and index data in
-buffers can improve rendering performance.  The VertexArray, Mesh and
-UniformBlock classes contain built-in support for buffers.
-*/
-class Buffer
-{
-private:
-	unsigned id;
-	unsigned size;
-	bool allocated;
+Stores data in GPU memory.
 
-	static Buffer *scratch_binding;
+Memory must be allocated for the buffer by calling storage().  Contents can
+then be modified either synchronously with the data() and sub_data() functions,
+or asynchronously by memory-mapping the buffer.
 
-public:
-	Buffer();
-	~Buffer();
+Buffers can have a static or streaming usage pattern.  Streaming buffers can be
+memory mapped for less update overhead, but memory space is more limited.  If
+the buffer is updated only rarely, static is recommended.
 
-	/** Returns the OpenGL ID of the buffer.  For internal use only. */
-	unsigned get_id() const { return id; }
+Applications normally don't need to deal with Buffers directly.  They're
+managed by other classes such as Mesh and ProgramData.
+*/
+class Buffer: public BufferBackend
+{
+	friend BufferBackend;
 
-	/** Defines the storage size of the buffer.  Must be called before data can
-	be uploaded.  Storage cannot be changed once set. */
-	void storage(unsigned);
+private:
+	std::size_t size = 0;
+	BufferUsage usage = STATIC;
+	bool mapped = false;
 
-	/** Allocates storage for the buffer.  The contents are initially undefined.
-	If storage has already been allocated, does nothing. */
-	void allocate();
+public:
+	/** Sets storage size and usage pattern and allocates memory for the buffer.
+	Size and usage cannot be changed once set. */
+	void storage(std::size_t, BufferUsage);
 
-	/** Uploads data into the buffer, completely replacing any previous
-	contents.  Storage must be defined beforehand.  The data must have size
-	matching the defined storage. */
+	/** Replaces contents of the entire buffer.  Allocated storage must exist.
+	The data must have size matching the defined storage. */
 	void data(const void *);
 
-	/** Overwrites part of the buffer data with new data.  Storage must be
-	defined beforehand. */
-	void sub_data(unsigned, unsigned, const void *);
+	/** Replaces a range of bytes in the buffer.  Allocated storage must exist.
+	The range must be fully inside the buffer. */
+	void sub_data(std::size_t, std::size_t, const void *);
 
-	unsigned get_size() const { return size; }
+	std::size_t get_size() const { return size; }
+	BufferUsage get_usage() const { return usage; }
 
-	void require_size(unsigned) const;
+	void require_size(std::size_t) const;
 
 	void *map();
 	bool unmap();
 
-	void set_debug_name(const std::string &);
-
-private:
-	void bind_scratch();
-public:
-	static void unbind_scratch();
+	using BufferBackend::set_debug_name;
 };
 
 } // namespace GL