source/buffer.cpp

   1 #include <stdexcept>
   2 #include <msp/gl/extensions/arb_map_buffer_range.h>
   3 #include "buffer.h"
   4 #include "error.h"
   5 #include "mesh.h"
   6 #include "misc.h"
   7
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 const Buffer *Buffer::bound[5] = { 0, 0, 0, 0, 0 };
  14 BufferType buffer_types[] = { ARRAY_BUFFER, ELEMENT_ARRAY_BUFFER, PIXEL_PACK_BUFFER, PIXEL_UNPACK_BUFFER, UNIFORM_BUFFER };
  15
  16 Buffer::Buffer(BufferType t):
  17         type(t),
  18         usage(STATIC_DRAW),
  19         size(0)
  20 {
  21         require_buffer_type(type);
  22
  23         glGenBuffers(1, &id);
  24 }
  25
  26 Buffer::~Buffer()
  27 {
  28         for(unsigned i=0; i<5; ++i)
  29                 if(bound[i]==this)
  30                         unbind_from(buffer_types[i]);
  31         glDeleteBuffers(1, &id);
  32 }
  33
  34 void Buffer::require_buffer_type(BufferType type)
  35 {
  36         static Require _req_vbo(ARB_vertex_buffer_object);
  37         if(type==PIXEL_PACK_BUFFER || type==PIXEL_UNPACK_BUFFER)
  38                 static Require _req_pbo(ARB_pixel_buffer_object);
  39         else if(type==UNIFORM_BUFFER)
  40                 static Require _req_ubo(ARB_uniform_buffer_object);
  41 }
  42
  43 void Buffer::set_usage(BufferUsage u)
  44 {
  45         usage = u;
  46 }
  47
  48 void Buffer::data(unsigned sz, const void *d)
  49 {
  50         BindRestore _bind(this, type);
  51         glBufferData(type, sz, d, usage);
  52         size = sz;
  53 }
  54
  55 void Buffer::sub_data(unsigned off, unsigned sz, const void *d)
  56 {
  57         BindRestore _bind(this, type);
  58         glBufferSubData(type, off, sz, d);
  59 }
  60
  61 BufferRange *Buffer::create_range(unsigned s, unsigned o)
  62 {
  63         return new BufferRange(*this, s, o);
  64 }
  65
  66 void *Buffer::map(BufferAccess access)
  67 {
  68         if(ARB_map_buffer_range)
  69         {
  70                 BindRestore _bind(this, type);
  71                 GLenum access_bits = 0;
  72                 if(access==READ_ONLY)
  73                         access_bits = GL_MAP_READ_BIT;
  74                 else if(access==WRITE_ONLY)
  75                         access_bits = GL_MAP_WRITE_BIT;
  76                 else if(access==READ_WRITE)
  77                         access_bits = GL_MAP_READ_BIT|GL_MAP_WRITE_BIT;
  78                 return glMapBufferRange(type, 0, size, access_bits);
  79         }
  80         else
  81         {
  82                 BindRestore _bind(this, type);
  83                 return glMapBuffer(type, access);
  84         }
  85 }
  86
  87 bool Buffer::unmap()
  88 {
  89         BindRestore _bind(this, type);
  90         return glUnmapBuffer(type);
  91 }
  92
  93 void Buffer::bind_to(BufferType t) const
  94 {
  95         if(t!=type)
  96                 require_buffer_type(t);
  97         if(t==ELEMENT_ARRAY_BUFFER)
  98                 if(const Mesh *m = Mesh::current())
  99                 {
 100                         // Don't change the binding in a mesh's vertex array object
 101                         if(this==m->get_index_buffer())
 102                                 return;
 103                         throw invalid_operation("Buffer::bind_to(ELEMENT_ARRAY_BUFFER)");
 104                 }
 105         if(set_current(t, this))
 106                 glBindBuffer(t, id);
 107 }
 108
 109 const Buffer *Buffer::current(BufferType t)
 110 {
 111         if(t==ELEMENT_ARRAY_BUFFER)
 112                 if(const Mesh *m = Mesh::current())
 113                         return m->get_index_buffer();
 114         return binding(t);
 115 }
 116
 117 void Buffer::unbind_from(BufferType type)
 118 {
 119         if(type==ELEMENT_ARRAY_BUFFER && Mesh::current())
 120                 throw invalid_operation("Buffer::unbind_from(ELEMENT_ARRAY_BUFFER)");
 121         if(set_current(type, 0))
 122                 glBindBuffer(type, 0);
 123 }
 124
 125 const Buffer *&Buffer::binding(BufferType type)
 126 {
 127         switch(type)
 128         {
 129         case ARRAY_BUFFER:         return bound[0];
 130         case ELEMENT_ARRAY_BUFFER: return bound[1];
 131         case PIXEL_PACK_BUFFER:    return bound[2];
 132         case PIXEL_UNPACK_BUFFER:  return bound[3];
 133         case UNIFORM_BUFFER:       return bound[4];
 134         default: throw invalid_argument("Buffer::binding");
 135         }
 136 }
 137
 138 bool Buffer::set_current(BufferType type, const Buffer *buf)
 139 {
 140         const Buffer *&ptr = binding(type);
 141         if(ptr==buf)
 142                 return false;
 143
 144         ptr = buf;
 145         return true;
 146 }
 147
 148
 149 vector<const BufferRange *> BufferRange::bound_uniform;
 150
 151 BufferRange::BufferRange(Buffer &b, unsigned o, unsigned s):
 152         buffer(b),
 153         offset(o),
 154         size(s)
 155 {
 156         if(o>buffer.get_size() || o+s>buffer.get_size())
 157                 throw out_of_range("BufferRange::BufferRange");
 158 }
 159
 160 BufferRange::~BufferRange()
 161 {
 162         for(unsigned i=0; i<bound_uniform.size(); ++i)
 163                 if(bound_uniform[i]==this)
 164                         unbind_from(UNIFORM_BUFFER, i);
 165 }
 166
 167 void BufferRange::data(const void *d)
 168 {
 169         buffer.sub_data(offset, size, d);
 170 }
 171
 172 void BufferRange::bind_to(BufferType t, unsigned i)
 173 {
 174         if(t!=buffer.type)
 175                 Buffer::require_buffer_type(t);
 176         if(set_current(t, i, this))
 177         {
 178                 // The buffer gets bound as a side effect
 179                 Buffer::set_current(t, &buffer);
 180                 glBindBufferRange(t, i, buffer.id, offset, size);
 181         }
 182 }
 183
 184 void BufferRange::unbind_from(BufferType t, unsigned i)
 185 {
 186         if(set_current(t, i, 0))
 187         {
 188                 Buffer::set_current(t, 0);
 189                 glBindBufferBase(t, i, 0);
 190         }
 191 }
 192
 193 const BufferRange *&BufferRange::binding(BufferType type, unsigned index)
 194 {
 195         if(type==UNIFORM_BUFFER)
 196         {
 197                 if(index>=get_n_uniform_buffer_bindings())
 198                         throw out_of_range("BufferRange::binding");
 199                 if(bound_uniform.size()<=index)
 200                         bound_uniform.resize(index+1);
 201                 return bound_uniform[index];
 202         }
 203         else
 204                 throw invalid_argument("BufferRange::binding");
 205 }
 206
 207 bool BufferRange::set_current(BufferType type, unsigned index, const BufferRange *buf)
 208 {
 209         const BufferRange *&ptr = binding(type, index);
 210         if(ptr==buf)
 211                 return false;
 212
 213         ptr = buf;
 214         return true;
 215 }
 216
 217 unsigned BufferRange::get_n_uniform_buffer_bindings()
 218 {
 219         static unsigned count = get_i(GL_MAX_UNIFORM_BUFFER_BINDINGS);
 220         return count;
 221 }
 222
 223 unsigned BufferRange::get_uniform_buffer_alignment()
 224 {
 225         static unsigned align = get_i(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT);
 226         return align;
 227 }
 228
 229 } // namespace GL
 230 } // namespace Msp