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         require_buffer_type(type);
  19
  20         glGenBuffersARB(1, &id);
  21 }
  22
  23 Buffer::~Buffer()
  24 {
  25         glDeleteBuffersARB(1, &id);
  26 }
  27
  28 void Buffer::require_buffer_type(BufferType type)
  29 {
  30         static RequireExtension _req_vbo("GL_ARB_vertex_buffer_object");
  31         if(type==PIXEL_PACK_BUFFER || type==PIXEL_UNPACK_BUFFER)
  32                 static RequireExtension _req_pbo("GL_ARB_pixel_buffer_object");
  33 }
  34
  35 void Buffer::set_usage(BufferUsage u)
  36 {
  37         usage = u;
  38 }
  39
  40 void Buffer::data(unsigned sz, const void *d)
  41 {
  42         const Buffer *old = current(type);
  43         bind();
  44         glBufferDataARB(type, sz, d, usage);
  45         size = sz;
  46         restore(old, type);
  47 }
  48
  49 void Buffer::sub_data(unsigned off, unsigned sz, const void *d)
  50 {
  51         const Buffer *old = current(type);
  52         bind();
  53         glBufferSubDataARB(type, off, sz, d);
  54         restore(old, type);
  55 }
  56
  57 void Buffer::bind_to(BufferType t) const
  58 {
  59         if(t!=type)
  60                 require_buffer_type(t);
  61         if(set_current(t, this))
  62                 glBindBufferARB(t, id);
  63 }
  64
  65 void Buffer::unbind_from(BufferType type)
  66 {
  67         if(set_current(type, 0))
  68                 glBindBufferARB(type, 0);
  69 }
  70
  71 const Buffer *&Buffer::binding(BufferType type)
  72 {
  73         switch(type)
  74         {
  75         case ARRAY_BUFFER:         return bound[0];
  76         case ELEMENT_ARRAY_BUFFER: return bound[1];
  77         case PIXEL_PACK_BUFFER:    return bound[2];
  78         case PIXEL_UNPACK_BUFFER:  return bound[3];
  79         default: throw invalid_argument("Buffer::binding");
  80         }
  81 }
  82
  83 bool Buffer::set_current(BufferType type, const Buffer *buf)
  84 {
  85         const Buffer *&ptr = binding(type);
  86         if(ptr==buf)
  87                 return false;
  88
  89         ptr = buf;
  90         return true;
  91 }
  92
  93 void Buffer::restore(const Buffer *buf, BufferType type)
  94 {
  95         if(buf!=current(type))
  96         {
  97                 if(buf)
  98                         buf->bind_to(type);
  99                 else
 100                         unbind_from(type);
 101         }
 102 }
 103
 104 } // namespace GL
 105 } // namespace Msp