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