source/buffer.cpp

   1 #include <stdexcept>
   2 #include "arb_vertex_buffer_object.h"
   3 #include "extension.h"
   4 #include "buffer.h"
   5
   6 using namespace std;
   7
   8 namespace Msp {
   9 namespace GL {
  10
  11 Buffer::Buffer(BufferType t):
  12         type(t),
  13         usage(STATIC_DRAW)
  14 {
  15         static RequireExtension _req_vbo("GL_ARB_vertex_buffer_object");
  16         if(type==PIXEL_PACK_BUFFER || type==PIXEL_UNPACK_BUFFER)
  17                 static RequireExtension _req_pbo("GL_ARB_pixel_buffer_object");
  18
  19         glGenBuffersARB(1, &id);
  20 }
  21
  22 Buffer::~Buffer()
  23 {
  24         glDeleteBuffersARB(1, &id);
  25 }
  26
  27 void Buffer::set_usage(BufferUsage u)
  28 {
  29         usage = u;
  30 }
  31
  32 void Buffer::data(unsigned size, const void *d)
  33 {
  34         const Buffer *old = current(type);
  35         bind();
  36         glBufferDataARB(type, size, d, usage);
  37         restore(old, type);
  38 }
  39
  40 void Buffer::sub_data(unsigned offset, unsigned size, const void *d)
  41 {
  42         const Buffer *old = current(type);
  43         bind();
  44         glBufferSubDataARB(type, offset, size, d);
  45         restore(old, type);
  46 }
  47
  48 void Buffer::bind_to(BufferType t) const
  49 {
  50         const Buffer *&ptr = binding(t);
  51         if(ptr!=this)
  52         {
  53                 glBindBufferARB(t, id);
  54                 ptr = this;
  55         }
  56 }
  57
  58 void Buffer::unbind_from(BufferType type)
  59 {
  60         const Buffer *&ptr = binding(type);
  61         if(ptr)
  62         {
  63                 glBindBufferARB(type, 0);
  64                 ptr = 0;
  65         }
  66 }
  67
  68 const Buffer *&Buffer::binding(BufferType type)
  69 {
  70         switch(type)
  71         {
  72         case ARRAY_BUFFER:         return bound[0];
  73         case ELEMENT_ARRAY_BUFFER: return bound[1];
  74         case PIXEL_PACK_BUFFER:    return bound[2];
  75         case PIXEL_UNPACK_BUFFER:  return bound[3];
  76         default: throw invalid_argument("Buffer::binding");
  77         }
  78 }
  79
  80 void Buffer::restore(const Buffer *buf, BufferType type)
  81 {
  82         if(buf!=current(type))
  83         {
  84                 if(buf)
  85                         buf->bind_to(type);
  86                 else
  87                         unbind_from(type);
  88         }
  89 }
  90
  91 const Buffer *Buffer::bound[4] = { 0, 0, 0, 0 };
  92
  93 } // namespace GL
  94 } // namespace Msp