Improvements to Bufferable

Most members are now private, with read-only accessors, since the derived
classes should not modify them.  Some names were changed.

Add documentation to the class and all public/protected methods.

diff --git a/source/bufferable.cpp b/source/bufferable.cpp
index abd10b3a865baa44bbc078c0745b65cb5682fba6..60df3eec92c1bd188dbab825e998baf1dd97e7b4 100644 (file)
--- a/source/bufferable.cpp
+++ b/source/bufferable.cpp
@@ -9,7 +9,7 @@ namespace GL {
 
 Bufferable::Bufferable():
        buffer(0),
-       buffer_offset(0),
+       offset(0),
        next_in_buffer(0),
        prev_in_buffer(0),
        dirty(false)
@@ -33,10 +33,13 @@ void Bufferable::use_buffer(Buffer *buf, Bufferable *prev)
        {
                prev_in_buffer = prev;
                if(prev_in_buffer)
+               {
+                       next_in_buffer = prev_in_buffer->next_in_buffer;
                        prev_in_buffer->next_in_buffer = this;
+               }
        }
 
-       update_buffer_offset();
+       update_offset();
 }
 
 void Bufferable::unlink_from_buffer()
@@ -46,43 +49,44 @@ void Bufferable::unlink_from_buffer()
        if(next_in_buffer)
        {
                next_in_buffer->prev_in_buffer = prev_in_buffer;
-               next_in_buffer->update_buffer_offset();
+               next_in_buffer->update_offset();
        }
        prev_in_buffer = 0;
        next_in_buffer = 0;
+       buffer = 0;
 }
 
-void Bufferable::update_buffer_offset()
+void Bufferable::update_offset()
 {
-       unsigned offset = 0;
+       unsigned new_offset = 0;
        if(prev_in_buffer)
-               offset = prev_in_buffer->buffer_offset+prev_in_buffer->get_data_size();
+               new_offset = prev_in_buffer->offset+prev_in_buffer->get_data_size();
 
        unsigned align = get_alignment();
-       offset += align-1;
-       offset -= offset%align;
-       if(offset!=buffer_offset)
+       new_offset += align-1;
+       new_offset -= new_offset%align;
+       if(new_offset!=offset)
        {
-               buffer_offset = offset;
+               offset = new_offset;
                dirty = true;
                offset_changed();
        }
 
        if(next_in_buffer)
-               next_in_buffer->update_buffer_offset();
+               next_in_buffer->update_offset();
 
-       /* Do not resize the buffer here, as the offsets may change multiple times
-       before the buffer is actually used */
+       /* Do not resize the buffer here, as more bufferables may be added before
+       the buffer is actually used. */
 }
 
-void Bufferable::update_buffer_data() const
+void Bufferable::update_buffer() const
 {
-       if(buffer_offset+get_data_size()>=buffer->get_size())
+       if(offset+get_data_size()>=buffer->get_size())
        {
                const Bufferable *last = this;
                for(; last->next_in_buffer; last=last->next_in_buffer) ;
 
-               unsigned total_size = last->buffer_offset+last->get_data_size();
+               unsigned total_size = last->offset+last->get_data_size();
 
                if(total_size>buffer->get_size())
                {

diff --git a/source/bufferable.h b/source/bufferable.h
index f5ae043cb5144b498cf08d389248f7a66f25eefa..0a30e80e817e8343b374094651008a7d03935714 100644 (file)
--- a/source/bufferable.h
+++ b/source/bufferable.h
@@ -6,31 +6,60 @@ 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
 {
-protected:
+private:
        Buffer *buffer;
-       unsigned buffer_offset;
+       unsigned offset;
        Bufferable *next_in_buffer;
        Bufferable *prev_in_buffer;
+protected:
        mutable bool dirty;
 
+protected:
        Bufferable();
 public:
        virtual ~Bufferable();
 
-       void use_buffer(Buffer *, Bufferable * = 0);
+       /** 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);
+
 private:
        void unlink_from_buffer();
 
 protected:
+       /** Returns the buffer in which the data is stored. */
+       Buffer *get_buffer() const { return buffer; }
+
+       /** Returns the amount of data to be stored in the buffer, in bytes. */
        virtual unsigned get_data_size() 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; }
 
-       void update_buffer_offset();
+       /** 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 offset for the data has changed. */
        virtual void offset_changed() { }
 
-       void update_buffer_data() const;
+       /** Resizes the buffer if necessary and calls upload_data(). */
+       void update_buffer() const;
+
+       /** Uploads data to the buffer. */
        virtual void upload_data() const = 0;
 };
 

diff --git a/source/uniformblock.cpp b/source/uniformblock.cpp
index a87a6a42386ed39ee04b7368524796decd64ecfe..6b9de26931995e46446ef52e4dd57c81a3381ca0 100644 (file)
--- a/source/uniformblock.cpp
+++ b/source/uniformblock.cpp
@@ -41,7 +41,7 @@ void UniformBlock::offset_changed()
 void UniformBlock::upload_data() const
 {
        if(!buf_range)
-               buf_range = new BufferRange(*buffer, buffer_offset, size);
+               buf_range = new BufferRange(*get_buffer(), get_offset(), size);
        buf_range->data(&data[0]);
 }
 
@@ -53,7 +53,7 @@ void UniformBlock::attach(int index, const Uniform &uni)
 void UniformBlock::attach(const Program::UniformInfo &info, const Uniform &uni)
 {
        uniforms[info.location] = &uni;
-       if(buffer)
+       if(get_buffer())
        {
                uni.store(info, &data[info.location]);
                dirty = true;
@@ -62,13 +62,13 @@ void UniformBlock::attach(const Program::UniformInfo &info, const Uniform &uni)
 
 void UniformBlock::apply(int index) const
 {
-       if((index>=0) != (buffer!=0))
+       if((index>=0) != (get_buffer()!=0))
                throw invalid_operation("UniformBlock::apply");
 
-       if(buffer)
+       if(get_buffer())
        {
                if(dirty)
-                       update_buffer_data();
+                       update_buffer();
                buf_range->bind_to(UNIFORM_BUFFER, index);
        }
        else