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         buffer_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                         prev_in_buffer->next_in_buffer = this;
  37         }
  38
  39         update_buffer_offset();
  40 }
  41
  42 void Bufferable::unlink_from_buffer()
  43 {
  44         if(prev_in_buffer)
  45                 prev_in_buffer->next_in_buffer = next_in_buffer;
  46         if(next_in_buffer)
  47         {
  48                 next_in_buffer->prev_in_buffer = prev_in_buffer;
  49                 next_in_buffer->update_buffer_offset();
  50         }
  51         prev_in_buffer = 0;
  52         next_in_buffer = 0;
  53 }
  54
  55 void Bufferable::update_buffer_offset()
  56 {
  57         unsigned offset = 0;
  58         if(prev_in_buffer)
  59                 offset = prev_in_buffer->buffer_offset+prev_in_buffer->get_data_size();
  60
  61         if(offset!=buffer_offset)
  62         {
  63                 buffer_offset = offset;
  64                 dirty = true;
  65                 offset_changed();
  66         }
  67
  68         if(next_in_buffer)
  69                 next_in_buffer->update_buffer_offset();
  70
  71         /* Do not resize the buffer here, as the offsets may change multiple times
  72         before the buffer is actually used */
  73 }
  74
  75 void Bufferable::update_buffer_data() const
  76 {
  77         if(buffer_offset+get_data_size()>=buffer->get_size())
  78         {
  79                 const Bufferable *last = this;
  80                 for(; last->next_in_buffer; last=last->next_in_buffer) ;
  81
  82                 unsigned total_size = last->buffer_offset+last->get_data_size();
  83
  84                 if(total_size>buffer->get_size())
  85                 {
  86                         buffer->data(total_size, 0);
  87                         /* Resizing the buffer invalidates its contents.  Non-dirty data may
  88                         be in use, so reupload it. */
  89                         for(const Bufferable *b=last; b; b=b->prev_in_buffer)
  90                                 if(!b->dirty)
  91                                         b->upload_data();
  92                 }
  93         }
  94
  95         upload_data();
  96         dirty = false;
  97 }
  98
  99 } // namespace GL
 100 } // namespace Msp