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::map(BufferAccess access)
  65 {
  66         BindRestore _bind(this, type);
  67         return glMapBuffer(type, access);
  68 }
  69
  70 bool Buffer::unmap()
  71 {
  72         BindRestore _bind(this, type);
  73         return glUnmapBuffer(type);
  74 }
  75
  76 void Buffer::bind_to(BufferType t) const
  77 {
  78         if(t!=type)
  79                 require_buffer_type(t);
  80         if(t==ELEMENT_ARRAY_BUFFER)
  81                 if(const Mesh *m = Mesh::current())
  82                 {
  83                         // Don't change the binding in a mesh's vertex array object
  84                         if(this==m->get_index_buffer())
  85                                 return;
  86                         throw invalid_operation("Buffer::bind_to(ELEMENT_ARRAY_BUFFER)");
  87                 }
  88         if(set_current(t, this))
  89                 glBindBuffer(t, id);
  90 }
  91
  92 const Buffer *Buffer::current(BufferType t)
  93 {
  94         if(t==ELEMENT_ARRAY_BUFFER)
  95                 if(const Mesh *m = Mesh::current())
  96                         return m->get_index_buffer();
  97         return binding(t);
  98 }
  99
 100 void Buffer::unbind_from(BufferType type)
 101 {
 102         if(type==ELEMENT_ARRAY_BUFFER && Mesh::current())
 103                 throw invalid_operation("Buffer::unbind_from(ELEMENT_ARRAY_BUFFER)");
 104         if(set_current(type, 0))
 105                 glBindBuffer(type, 0);
 106 }
 107
 108 const Buffer *&Buffer::binding(BufferType type)
 109 {
 110         switch(type)
 111         {
 112         case ARRAY_BUFFER:         return bound[0];
 113         case ELEMENT_ARRAY_BUFFER: return bound[1];
 114         case PIXEL_PACK_BUFFER:    return bound[2];
 115         case PIXEL_UNPACK_BUFFER:  return bound[3];
 116         case UNIFORM_BUFFER:       return bound[4];
 117         default: throw invalid_argument("Buffer::binding");
 118         }
 119 }
 120
 121 bool Buffer::set_current(BufferType type, const Buffer *buf)
 122 {
 123         const Buffer *&ptr = binding(type);
 124         if(ptr==buf)
 125                 return false;
 126
 127         ptr = buf;
 128         return true;
 129 }
 130
 131
 132 vector<const BufferRange *> BufferRange::bound_uniform;
 133
 134 BufferRange::BufferRange(Buffer &b, unsigned o, unsigned s):
 135         buffer(b),
 136         offset(o),
 137         size(s)
 138 {
 139         if(o>buffer.get_size() || o+s>buffer.get_size())
 140                 throw out_of_range("BufferRange::BufferRange");
 141 }
 142
 143 void BufferRange::data(const void *d)
 144 {
 145         buffer.sub_data(offset, size, d);
 146 }
 147
 148 void BufferRange::bind_to(BufferType t, unsigned i)
 149 {
 150         if(t!=buffer.type)
 151                 Buffer::require_buffer_type(t);
 152         // Intentionally using bitwise | to avoid short-circuiting
 153         if(Buffer::set_current(t, &buffer) | set_current(t, i, this))
 154                 glBindBufferRange(t, i, buffer.id, offset, size);
 155 }
 156
 157 void BufferRange::unbind_from(BufferType t, unsigned i)
 158 {
 159         if(set_current(t, i, 0))
 160         {
 161                 Buffer::set_current(t, 0);
 162                 glBindBufferBase(t, i, 0);
 163         }
 164 }
 165
 166 const BufferRange *&BufferRange::binding(BufferType type, unsigned index)
 167 {
 168         if(type==UNIFORM_BUFFER)
 169         {
 170                 if(index>=get_n_uniform_buffer_bindings())
 171                         throw out_of_range("BufferRange::binding");
 172                 if(bound_uniform.size()<=index)
 173                         bound_uniform.resize(index+1);
 174                 return bound_uniform[index];
 175         }
 176         else
 177                 throw invalid_argument("BufferRange::binding");
 178 }
 179
 180 bool BufferRange::set_current(BufferType type, unsigned index, const BufferRange *buf)
 181 {
 182         const BufferRange *&ptr = binding(type, index);
 183         if(ptr==buf)
 184                 return false;
 185
 186         ptr = buf;
 187         return true;
 188 }
 189
 190 unsigned BufferRange::get_n_uniform_buffer_bindings()
 191 {
 192         static unsigned count = get_i(GL_MAX_UNIFORM_BUFFER_BINDINGS);
 193         return count;
 194 }
 195
 196 unsigned BufferRange::get_uniform_buffer_alignment()
 197 {
 198         static unsigned align = get_i(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT);
 199         return align;
 200 }
 201
 202 } // namespace GL
 203 } // namespace Msp