source/bufferable.cpp

   1 #include <stdexcept>
   2 #include "bindable.h"
   3 #include "buffer.h"
   4 #include "bufferable.h"
   5
   6 using namespace std;
   7
   8 namespace Msp {
   9 namespace GL {
  10
  11 Bufferable::Bufferable():
  12         buffer(0),
  13         offset(0),
  14         next_in_buffer(0),
  15         prev_in_buffer(0),
  16         dirty(false)
  17 { }
  18
  19 Bufferable::~Bufferable()
  20 {
  21         unlink_from_buffer();
  22 }
  23
  24 void Bufferable::use_buffer(Buffer *buf, Bufferable *prev)
  25 {
  26         if(prev && buf!=prev->buffer)
  27                 throw invalid_argument("Bufferable::use_buffer");
  28
  29         if(buffer)
  30                 unlink_from_buffer();
  31
  32         buffer = buf;
  33         if(buffer)
  34         {
  35                 prev_in_buffer = prev;
  36                 if(prev_in_buffer)
  37                 {
  38                         next_in_buffer = prev_in_buffer->next_in_buffer;
  39                         prev_in_buffer->next_in_buffer = this;
  40                 }
  41         }
  42
  43         update_offset();
  44 }
  45
  46 void Bufferable::unlink_from_buffer()
  47 {
  48         if(prev_in_buffer)
  49                 prev_in_buffer->next_in_buffer = next_in_buffer;
  50         if(next_in_buffer)
  51         {
  52                 next_in_buffer->prev_in_buffer = prev_in_buffer;
  53                 next_in_buffer->update_offset();
  54         }
  55         prev_in_buffer = 0;
  56         next_in_buffer = 0;
  57         buffer = 0;
  58 }
  59
  60 void Bufferable::update_offset()
  61 {
  62         unsigned new_offset = 0;
  63         if(prev_in_buffer)
  64                 new_offset = prev_in_buffer->offset+prev_in_buffer->get_data_size();
  65
  66         unsigned align = get_alignment();
  67         new_offset += align-1;
  68         new_offset -= new_offset%align;
  69         if(new_offset!=offset)
  70         {
  71                 offset = new_offset;
  72                 dirty = true;
  73                 offset_changed();
  74         }
  75
  76         if(next_in_buffer)
  77                 next_in_buffer->update_offset();
  78
  79         /* Do not resize the buffer here, as more bufferables may be added before
  80         the buffer is actually used. */
  81 }
  82
  83 bool Bufferable::resize_buffer() const
  84 {
  85         if(offset+get_data_size()>=buffer->get_size())
  86         {
  87                 const Bufferable *last = this;
  88                 for(; last->next_in_buffer; last=last->next_in_buffer) ;
  89
  90                 unsigned total_size = last->offset+last->get_data_size();
  91
  92                 if(total_size>buffer->get_size())
  93                 {
  94                         buffer->data(total_size, 0);
  95                         return true;
  96                 }
  97         }
  98
  99         return false;
 100 }
 101
 102 void Bufferable::update_buffer() const
 103 {
 104         BindRestore bind(buffer, buffer->get_type());
 105         if(resize_buffer())
 106         {
 107                 /* Resizing the buffer invalidates its contents.  Non-dirty data may
 108                 be in use, so reupload it. */
 109                 for(const Bufferable *b=prev_in_buffer; b; b=b->prev_in_buffer)
 110                         if(!b->dirty)
 111                                 b->upload_data();
 112                 for(const Bufferable *b=next_in_buffer; b; b=b->next_in_buffer)
 113                         if(!b->dirty)
 114                                 b->upload_data();
 115         }
 116
 117         upload_data();
 118         dirty = false;
 119 }
 120
 121 void Bufferable::upload_data() const
 122 {
 123         buffer->sub_data(offset, get_data_size(), get_data_pointer());
 124 }
 125
 126 } // namespace GL
 127 } // namespace Msp