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