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