source/buffer.cpp

   1 #include <stdexcept>
   2 #include "arb_pixel_buffer_object.h"
   3 #include "arb_uniform_buffer_object.h"
   4 #include "arb_vertex_buffer_object.h"
   5 #include "buffer.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
  15 Buffer::Buffer(BufferType t):
  16         type(t),
  17         usage(STATIC_DRAW),
  18         size(0)
  19 {
  20         require_buffer_type(type);
  21
  22         glGenBuffers(1, &id);
  23 }
  24
  25 Buffer::~Buffer()
  26 {
  27         glDeleteBuffers(1, &id);
  28 }
  29
  30 void Buffer::require_buffer_type(BufferType type)
  31 {
  32         static Require _req_vbo(ARB_vertex_buffer_object);
  33         if(type==PIXEL_PACK_BUFFER || type==PIXEL_UNPACK_BUFFER)
  34                 static Require _req_pbo(ARB_pixel_buffer_object);
  35         else if(type==UNIFORM_BUFFER)
  36                 static Require _req_ubo(ARB_uniform_buffer_object);
  37 }
  38
  39 void Buffer::set_usage(BufferUsage u)
  40 {
  41         usage = u;
  42 }
  43
  44 void Buffer::data(unsigned sz, const void *d)
  45 {
  46         const Buffer *old = current(type);
  47         bind();
  48         glBufferData(type, sz, d, usage);
  49         size = sz;
  50         restore(old, type);
  51 }
  52
  53 void Buffer::sub_data(unsigned off, unsigned sz, const void *d)
  54 {
  55         const Buffer *old = current(type);
  56         bind();
  57         glBufferSubData(type, off, sz, d);
  58         restore(old, type);
  59 }
  60
  61 BufferRange *Buffer::create_range(unsigned s, unsigned o)
  62 {
  63         return new BufferRange(*this, s, o);
  64 }
  65
  66 void Buffer::bind_to(BufferType t) const
  67 {
  68         if(t!=type)
  69                 require_buffer_type(t);
  70         if(set_current(t, this))
  71                 glBindBuffer(t, id);
  72 }
  73
  74 void Buffer::unbind_from(BufferType type)
  75 {
  76         if(set_current(type, 0))
  77                 glBindBuffer(type, 0);
  78 }
  79
  80 const Buffer *&Buffer::binding(BufferType type)
  81 {
  82         switch(type)
  83         {
  84         case ARRAY_BUFFER:         return bound[0];
  85         case ELEMENT_ARRAY_BUFFER: return bound[1];
  86         case PIXEL_PACK_BUFFER:    return bound[2];
  87         case PIXEL_UNPACK_BUFFER:  return bound[3];
  88         case UNIFORM_BUFFER:       return bound[4];
  89         default: throw invalid_argument("Buffer::binding");
  90         }
  91 }
  92
  93 bool Buffer::set_current(BufferType type, const Buffer *buf)
  94 {
  95         const Buffer *&ptr = binding(type);
  96         if(ptr==buf)
  97                 return false;
  98
  99         ptr = buf;
 100         return true;
 101 }
 102
 103 void Buffer::restore(const Buffer *buf, BufferType type)
 104 {
 105         if(buf!=current(type))
 106         {
 107                 if(buf)
 108                         buf->bind_to(type);
 109                 else
 110                         unbind_from(type);
 111         }
 112 }
 113
 114
 115 vector<const BufferRange *> BufferRange::bound_uniform;
 116
 117 BufferRange::BufferRange(Buffer &b, unsigned o, unsigned s):
 118         buffer(b),
 119         offset(o),
 120         size(s)
 121 {
 122         if(o>buffer.get_size() || o+s>buffer.get_size())
 123                 throw out_of_range("BufferRange::BufferRange");
 124 }
 125
 126 void BufferRange::data(const void *d)
 127 {
 128         buffer.sub_data(offset, size, d);
 129 }
 130
 131 void BufferRange::bind_to(BufferType t, unsigned i)
 132 {
 133         if(t!=buffer.type)
 134                 Buffer::require_buffer_type(t);
 135         // Intentionally using bitwise | to avoid short-circuiting
 136         if(Buffer::set_current(t, &buffer) | set_current(t, i, this))
 137                 glBindBufferRange(t, i, buffer.id, offset, size);
 138 }
 139
 140 void BufferRange::unbind_from(BufferType t, unsigned i)
 141 {
 142         if(set_current(t, i, 0))
 143         {
 144                 Buffer::set_current(t, 0);
 145                 glBindBufferBase(t, i, 0);
 146         }
 147 }
 148
 149 const BufferRange *&BufferRange::binding(BufferType type, unsigned index)
 150 {
 151         if(type==UNIFORM_BUFFER)
 152         {
 153                 if(index>=get_n_uniform_buffer_bindings())
 154                         throw out_of_range("BufferRange::binding");
 155                 if(bound_uniform.size()<=index)
 156                         bound_uniform.resize(index+1);
 157                 return bound_uniform[index];
 158         }
 159         else
 160                 throw invalid_argument("BufferRange::binding");
 161 }
 162
 163 bool BufferRange::set_current(BufferType type, unsigned index, const BufferRange *buf)
 164 {
 165         const BufferRange *&ptr = binding(type, index);
 166         if(ptr==buf)
 167                 return false;
 168
 169         ptr = buf;
 170         return true;
 171 }
 172
 173 unsigned BufferRange::get_n_uniform_buffer_bindings()
 174 {
 175         static unsigned count = get_i(GL_MAX_UNIFORM_BUFFER_BINDINGS);
 176         return count;
 177 }
 178
 179 unsigned BufferRange::get_uniform_buffer_alignment()
 180 {
 181         static unsigned align = get_i(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT);
 182         return align;
 183 }
 184
 185 } // namespace GL
 186 } // namespace Msp