source/buffer.cpp

   1 #include <stdexcept>
   2 #include <msp/gl/extensions/arb_pixel_buffer_object.h>
   3 #include <msp/gl/extensions/arb_uniform_buffer_object.h>
   4 #include <msp/gl/extensions/arb_vertex_buffer_object.h>
   5 #include "buffer.h"
   6 #include "error.h"
   7 #include "mesh.h"
   8 #include "misc.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 const Buffer *Buffer::bound[5] = { 0, 0, 0, 0, 0 };
  16
  17 Buffer::Buffer(BufferType t):
  18         type(t),
  19         usage(STATIC_DRAW),
  20         size(0)
  21 {
  22         require_buffer_type(type);
  23
  24         glGenBuffers(1, &id);
  25 }
  26
  27 Buffer::~Buffer()
  28 {
  29         glDeleteBuffers(1, &id);
  30 }
  31
  32 void Buffer::require_buffer_type(BufferType type)
  33 {
  34         static Require _req_vbo(ARB_vertex_buffer_object);
  35         if(type==PIXEL_PACK_BUFFER || type==PIXEL_UNPACK_BUFFER)
  36                 static Require _req_pbo(ARB_pixel_buffer_object);
  37         else if(type==UNIFORM_BUFFER)
  38                 static Require _req_ubo(ARB_uniform_buffer_object);
  39 }
  40
  41 void Buffer::set_usage(BufferUsage u)
  42 {
  43         usage = u;
  44 }
  45
  46 void Buffer::data(unsigned sz, const void *d)
  47 {
  48         BindRestore _bind(this, type);
  49         glBufferData(type, sz, d, usage);
  50         size = sz;
  51 }
  52
  53 void Buffer::sub_data(unsigned off, unsigned sz, const void *d)
  54 {
  55         BindRestore _bind(this, type);
  56         glBufferSubData(type, off, sz, d);
  57 }
  58
  59 BufferRange *Buffer::create_range(unsigned s, unsigned o)
  60 {
  61         return new BufferRange(*this, s, o);
  62 }
  63
  64 void Buffer::bind_to(BufferType t) const
  65 {
  66         if(t!=type)
  67                 require_buffer_type(t);
  68         // Don't change the binding in a mesh's vertex array object
  69         if(t==ELEMENT_ARRAY_BUFFER && Mesh::current())
  70                 throw invalid_operation("Buffer::bind_to(ELEMENT_ARRAY_BUFFER)");
  71         if(set_current(t, this))
  72                 glBindBuffer(t, id);
  73 }
  74
  75 void Buffer::unbind_from(BufferType type)
  76 {
  77         if(type==ELEMENT_ARRAY_BUFFER && Mesh::current())
  78                 throw invalid_operation("Buffer::unbind_from(ELEMENT_ARRAY_BUFFER)");
  79         if(set_current(type, 0))
  80                 glBindBuffer(type, 0);
  81 }
  82
  83 const Buffer *&Buffer::binding(BufferType type)
  84 {
  85         switch(type)
  86         {
  87         case ARRAY_BUFFER:         return bound[0];
  88         case ELEMENT_ARRAY_BUFFER: return bound[1];
  89         case PIXEL_PACK_BUFFER:    return bound[2];
  90         case PIXEL_UNPACK_BUFFER:  return bound[3];
  91         case UNIFORM_BUFFER:       return bound[4];
  92         default: throw invalid_argument("Buffer::binding");
  93         }
  94 }
  95
  96 bool Buffer::set_current(BufferType type, const Buffer *buf)
  97 {
  98         const Buffer *&ptr = binding(type);
  99         if(ptr==buf)
 100                 return false;
 101
 102         ptr = buf;
 103         return true;
 104 }
 105
 106
 107 vector<const BufferRange *> BufferRange::bound_uniform;
 108
 109 BufferRange::BufferRange(Buffer &b, unsigned o, unsigned s):
 110         buffer(b),
 111         offset(o),
 112         size(s)
 113 {
 114         if(o>buffer.get_size() || o+s>buffer.get_size())
 115                 throw out_of_range("BufferRange::BufferRange");
 116 }
 117
 118 void BufferRange::data(const void *d)
 119 {
 120         buffer.sub_data(offset, size, d);
 121 }
 122
 123 void BufferRange::bind_to(BufferType t, unsigned i)
 124 {
 125         if(t!=buffer.type)
 126                 Buffer::require_buffer_type(t);
 127         // Intentionally using bitwise | to avoid short-circuiting
 128         if(Buffer::set_current(t, &buffer) | set_current(t, i, this))
 129                 glBindBufferRange(t, i, buffer.id, offset, size);
 130 }
 131
 132 void BufferRange::unbind_from(BufferType t, unsigned i)
 133 {
 134         if(set_current(t, i, 0))
 135         {
 136                 Buffer::set_current(t, 0);
 137                 glBindBufferBase(t, i, 0);
 138         }
 139 }
 140
 141 const BufferRange *&BufferRange::binding(BufferType type, unsigned index)
 142 {
 143         if(type==UNIFORM_BUFFER)
 144         {
 145                 if(index>=get_n_uniform_buffer_bindings())
 146                         throw out_of_range("BufferRange::binding");
 147                 if(bound_uniform.size()<=index)
 148                         bound_uniform.resize(index+1);
 149                 return bound_uniform[index];
 150         }
 151         else
 152                 throw invalid_argument("BufferRange::binding");
 153 }
 154
 155 bool BufferRange::set_current(BufferType type, unsigned index, const BufferRange *buf)
 156 {
 157         const BufferRange *&ptr = binding(type, index);
 158         if(ptr==buf)
 159                 return false;
 160
 161         ptr = buf;
 162         return true;
 163 }
 164
 165 unsigned BufferRange::get_n_uniform_buffer_bindings()
 166 {
 167         static unsigned count = get_i(GL_MAX_UNIFORM_BUFFER_BINDINGS);
 168         return count;
 169 }
 170
 171 unsigned BufferRange::get_uniform_buffer_alignment()
 172 {
 173         static unsigned align = get_i(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT);
 174         return align;
 175 }
 176
 177 } // namespace GL
 178 } // namespace Msp