source/bufferable.cpp

   1 #include <stdexcept>
   2 #include "buffer.h"
   3 #include "bufferable.h"
   4
   5 using namespace std;
   6
   7 namespace Msp {
   8 namespace GL {
   9
  10 Bufferable::Bufferable():
  11         buffer(0),
  12         offset(0),
  13         next_in_buffer(0),
  14         prev_in_buffer(0),
  15         dirty(false)
  16 { }
  17
  18 Bufferable::~Bufferable()
  19 {
  20         unlink_from_buffer();
  21 }
  22
  23 void Bufferable::use_buffer(Buffer *buf, Bufferable *prev)
  24 {
  25         if(prev && buf!=prev->buffer)
  26                 throw invalid_argument("Bufferable::use_buffer");
  27
  28         if(buffer)
  29                 unlink_from_buffer();
  30
  31         buffer = buf;
  32         if(buffer)
  33         {
  34                 prev_in_buffer = prev;
  35                 if(prev_in_buffer)
  36                 {
  37                         next_in_buffer = prev_in_buffer->next_in_buffer;
  38                         prev_in_buffer->next_in_buffer = this;
  39                 }
  40         }
  41
  42         update_offset();
  43 }
  44
  45 void Bufferable::unlink_from_buffer()
  46 {
  47         if(prev_in_buffer)
  48                 prev_in_buffer->next_in_buffer = next_in_buffer;
  49         if(next_in_buffer)
  50         {
  51                 next_in_buffer->prev_in_buffer = prev_in_buffer;
  52                 next_in_buffer->update_offset();
  53         }
  54         prev_in_buffer = 0;
  55         next_in_buffer = 0;
  56         buffer = 0;
  57 }
  58
  59 void Bufferable::update_offset()
  60 {
  61         unsigned new_offset = 0;
  62         if(prev_in_buffer)
  63                 new_offset = prev_in_buffer->offset+prev_in_buffer->get_data_size();
  64
  65         unsigned align = get_alignment();
  66         new_offset += align-1;
  67         new_offset -= new_offset%align;
  68         if(new_offset!=offset)
  69         {
  70                 offset = new_offset;
  71                 dirty = true;
  72                 offset_changed();
  73         }
  74
  75         if(next_in_buffer)
  76                 next_in_buffer->update_offset();
  77
  78         /* Do not resize the buffer here, as more bufferables may be added before
  79         the buffer is actually used. */
  80 }
  81
  82 void Bufferable::update_buffer() const
  83 {
  84         const Buffer *old_buffer = Buffer::current(buffer->get_type());
  85         buffer->bind();
  86         if(offset+get_data_size()>=buffer->get_size())
  87         {
  88                 const Bufferable *last = this;
  89                 for(; last->next_in_buffer; last=last->next_in_buffer) ;
  90
  91                 unsigned total_size = last->offset+last->get_data_size();
  92
  93                 if(total_size>buffer->get_size())
  94                 {
  95                         buffer->data(total_size, 0);
  96                         /* Resizing the buffer invalidates its contents.  Non-dirty data may
  97                         be in use, so reupload it. */
  98                         for(const Bufferable *b=last; b; b=b->prev_in_buffer)
  99                                 if(!b->dirty)
 100                                         b->upload_data();
 101                 }
 102         }
 103
 104         upload_data();
 105         if(old_buffer)
 106                 old_buffer->bind_to(buffer->get_type());
 107         else
 108                 buffer->unbind();
 109         dirty = false;
 110 }
 111
 112 } // namespace GL
 113 } // namespace Msp