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         const Buffer *old = current(type);
  49         bind();
  50         glBufferData(type, sz, d, usage);
  51         size = sz;
  52         restore(old, type);
  53 }
  54
  55 void Buffer::sub_data(unsigned off, unsigned sz, const void *d)
  56 {
  57         const Buffer *old = current(type);
  58         bind();
  59         glBufferSubData(type, off, sz, d);
  60         restore(old, type);
  61 }
  62
  63 BufferRange *Buffer::create_range(unsigned s, unsigned o)
  64 {
  65         return new BufferRange(*this, s, o);
  66 }
  67
  68 void Buffer::bind_to(BufferType t) const
  69 {
  70         if(t!=type)
  71                 require_buffer_type(t);
  72         // Don't change the binding in a mesh's vertex array object
  73         if(t==ELEMENT_ARRAY_BUFFER && Mesh::current())
  74                 throw invalid_operation("Buffer::bind_to(ELEMENT_ARRAY_BUFFER)");
  75         if(set_current(t, this))
  76                 glBindBuffer(t, id);
  77 }
  78
  79 void Buffer::unbind_from(BufferType type)
  80 {
  81         if(type==ELEMENT_ARRAY_BUFFER && Mesh::current())
  82                 throw invalid_operation("Buffer::unbind_from(ELEMENT_ARRAY_BUFFER)");
  83         if(set_current(type, 0))
  84                 glBindBuffer(type, 0);
  85 }
  86
  87 const Buffer *&Buffer::binding(BufferType type)
  88 {
  89         switch(type)
  90         {
  91         case ARRAY_BUFFER:         return bound[0];
  92         case ELEMENT_ARRAY_BUFFER: return bound[1];
  93         case PIXEL_PACK_BUFFER:    return bound[2];
  94         case PIXEL_UNPACK_BUFFER:  return bound[3];
  95         case UNIFORM_BUFFER:       return bound[4];
  96         default: throw invalid_argument("Buffer::binding");
  97         }
  98 }
  99
 100 bool Buffer::set_current(BufferType type, const Buffer *buf)
 101 {
 102         const Buffer *&ptr = binding(type);
 103         if(ptr==buf)
 104                 return false;
 105
 106         ptr = buf;
 107         return true;
 108 }
 109
 110 void Buffer::restore(const Buffer *buf, BufferType type)
 111 {
 112         if(buf!=current(type))
 113         {
 114                 if(buf)
 115                         buf->bind_to(type);
 116                 else
 117                         unbind_from(type);
 118         }
 119 }
 120
 121
 122 vector<const BufferRange *> BufferRange::bound_uniform;
 123
 124 BufferRange::BufferRange(Buffer &b, unsigned o, unsigned s):
 125         buffer(b),
 126         offset(o),
 127         size(s)
 128 {
 129         if(o>buffer.get_size() || o+s>buffer.get_size())
 130                 throw out_of_range("BufferRange::BufferRange");
 131 }
 132
 133 void BufferRange::data(const void *d)
 134 {
 135         buffer.sub_data(offset, size, d);
 136 }
 137
 138 void BufferRange::bind_to(BufferType t, unsigned i)
 139 {
 140         if(t!=buffer.type)
 141                 Buffer::require_buffer_type(t);
 142         // Intentionally using bitwise | to avoid short-circuiting
 143         if(Buffer::set_current(t, &buffer) | set_current(t, i, this))
 144                 glBindBufferRange(t, i, buffer.id, offset, size);
 145 }
 146
 147 void BufferRange::unbind_from(BufferType t, unsigned i)
 148 {
 149         if(set_current(t, i, 0))
 150         {
 151                 Buffer::set_current(t, 0);
 152                 glBindBufferBase(t, i, 0);
 153         }
 154 }
 155
 156 const BufferRange *&BufferRange::binding(BufferType type, unsigned index)
 157 {
 158         if(type==UNIFORM_BUFFER)
 159         {
 160                 if(index>=get_n_uniform_buffer_bindings())
 161                         throw out_of_range("BufferRange::binding");
 162                 if(bound_uniform.size()<=index)
 163                         bound_uniform.resize(index+1);
 164                 return bound_uniform[index];
 165         }
 166         else
 167                 throw invalid_argument("BufferRange::binding");
 168 }
 169
 170 bool BufferRange::set_current(BufferType type, unsigned index, const BufferRange *buf)
 171 {
 172         const BufferRange *&ptr = binding(type, index);
 173         if(ptr==buf)
 174                 return false;
 175
 176         ptr = buf;
 177         return true;
 178 }
 179
 180 unsigned BufferRange::get_n_uniform_buffer_bindings()
 181 {
 182         static unsigned count = get_i(GL_MAX_UNIFORM_BUFFER_BINDINGS);
 183         return count;
 184 }
 185
 186 unsigned BufferRange::get_uniform_buffer_alignment()
 187 {
 188         static unsigned align = get_i(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT);
 189         return align;
 190 }
 191
 192 } // namespace GL
 193 } // namespace Msp