X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fcore%2Fbufferable.h;fp=source%2Fcore%2Fbufferable.h;h=cbbde4e1b93f1e07266c097c150774f2b5621d3c;hb=7aaec9a70b8d7733429bec043f8e33e02956f266;hp=0000000000000000000000000000000000000000;hpb=bec07999d95b76f4b47cffcc564d0cd0afc0435e;p=libs%2Fgl.git

diff --git a/source/core/bufferable.h b/source/core/bufferable.h
new file mode 100644
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+++ b/source/core/bufferable.h
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+#ifndef MSP_GL_BUFFERABLE_H_
+#define MSP_GL_BUFFERABLE_H_
+
+namespace Msp {
+namespace GL {
+
+class Buffer;
+
+/**
+Base class for things that can store data in buffers.  Supports buffer sharing.
+A dirty flag is provided for derived classes.  It should be set when the data
+in the buffer is considered out of date, and is cleared by Bufferable after
+uploading fresh data to the buffer.
+*/
+class Bufferable
+{
+public:
+	class AsyncUpdater
+	{
+	private:
+		const Bufferable &bufferable;
+		char *mapped_address;
+
+	public:
+		AsyncUpdater(const Bufferable &);
+		~AsyncUpdater();
+
+		void upload_data();
+	};
+
+private:
+	Buffer *buffer;
+	unsigned offset;
+	Bufferable *next_in_buffer;
+	Bufferable *prev_in_buffer;
+	mutable bool location_dirty;
+protected:
+	mutable bool dirty;
+
+	Bufferable();
+public:
+	virtual ~Bufferable();
+
+	/** Sets the buffer to use.  If prev is not null, it must use the same
+	buffer, and this object is inserted after it. */
+	void use_buffer(Buffer *buf, Bufferable *prev = 0);
+
+	/** Sets the buffer for the entire chain of objects. */
+	void change_buffer(Buffer *);
+
+	/** Returns the total amount of storage required by this object and others
+	in the same chain, including any alignment between objects. */
+	unsigned get_required_buffer_size() const;
+
+	/** Uploads new data into the buffer if necessary. */
+	void refresh() const { if(buffer && dirty) upload_data(0); }
+
+	/** Returns an object which can be used to upload data to the buffer using
+	mapped memory. */
+	AsyncUpdater *refresh_async() const;
+
+private:
+	void unlink_from_buffer();
+
+public:
+	/** Returns the buffer in which the data is stored. */
+	const Buffer *get_buffer() const { return buffer; }
+
+protected:
+	/** Returns the amount of data to be stored in the buffer, in bytes. */
+	virtual unsigned get_data_size() const = 0;
+
+	/** Returns a pointer to the start of data in client memory. */
+	virtual const void *get_data_pointer() const = 0;
+
+	/** Returns the alignment required for the data, in bytes.  The offset is
+	guaranteed to be a multiple of this. */
+	virtual unsigned get_alignment() const { return 1; }
+
+	/** Updates the offsets for the chain so that data from different objects
+	does not overlap.  Should be called if either data size or alignment
+	changes. */
+	void update_offset();
+
+	/** Returns the offset where the data should be uploaded. */
+	unsigned get_offset() const { return offset; }
+
+	/** Called when the target buffer or offset within it has changed. */
+	virtual void location_changed(Buffer *, unsigned, unsigned) const { }
+
+private:
+	/** Uploads data to the buffer.  Receives pointer to mapped buffer memory as
+	parameter, or null to use the buffer upload interface. */
+	void upload_data(char *) const;
+};
+
+} // namespace GL
+} // namespace Msp
+
+#endif