source/backends/opengl/buffer_backend.cpp

   1 #include <msp/gl/extensions/arb_buffer_storage.h>
   2 #include <msp/gl/extensions/arb_direct_state_access.h>
   3 #include <msp/gl/extensions/arb_map_buffer_range.h>
   4 #include <msp/gl/extensions/arb_vertex_buffer_object.h>
   5 #include <msp/gl/extensions/khr_debug.h>
   6 #include <msp/gl/extensions/oes_mapbuffer.h>
   7 #include "buffer.h"
   8 #include "buffer_backend.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 OpenGLBuffer *OpenGLBuffer::scratch_binding = 0;
  16
  17 OpenGLBuffer::OpenGLBuffer()
  18 {
  19         static Require _req(ARB_vertex_buffer_object);
  20
  21         if(ARB_direct_state_access)
  22                 glCreateBuffers(1, &id);
  23         else
  24                 glGenBuffers(1, &id);
  25 }
  26
  27 OpenGLBuffer::OpenGLBuffer(OpenGLBuffer &&other):
  28         id(other.id)
  29 {
  30         other.id = 0;
  31 }
  32
  33 OpenGLBuffer::~OpenGLBuffer()
  34 {
  35         if(this==scratch_binding)
  36                 unbind_scratch();
  37         if(id)
  38                 glDeleteBuffers(1, &id);
  39 }
  40
  41 void OpenGLBuffer::allocate()
  42 {
  43         size_t size = static_cast<const Buffer *>(this)->size;
  44
  45         if(ARB_buffer_storage)
  46         {
  47                 static const int flags = GL_MAP_READ_BIT|GL_MAP_WRITE_BIT|GL_DYNAMIC_STORAGE_BIT;
  48                 if(ARB_direct_state_access)
  49                         glNamedBufferStorage(id, size, 0, flags);
  50                 else
  51                 {
  52                         bind_scratch();
  53                         glBufferStorage(GL_ARRAY_BUFFER, size, 0, flags);
  54                 }
  55         }
  56         else if(ARB_direct_state_access)
  57                 glNamedBufferData(id, size, 0, GL_STATIC_DRAW);
  58         else
  59         {
  60                 bind_scratch();
  61                 glBufferData(GL_ARRAY_BUFFER, size, 0, GL_STATIC_DRAW);
  62         }
  63 }
  64
  65 void OpenGLBuffer::sub_data(size_t off, size_t sz, const void *d)
  66 {
  67         if(ARB_direct_state_access)
  68                 glNamedBufferSubData(id, off, sz, d);
  69         else
  70         {
  71                 bind_scratch();
  72                 glBufferSubData(GL_ARRAY_BUFFER, off, sz, d);
  73         }
  74 }
  75
  76 void *OpenGLBuffer::map()
  77 {
  78         static Require _req(ARB_map_buffer_range);
  79
  80         size_t size = static_cast<const Buffer *>(this)->size;
  81
  82         if(ARB_direct_state_access)
  83                 return glMapNamedBufferRange(id, 0, size, GL_MAP_READ_BIT|GL_MAP_WRITE_BIT);
  84         else
  85         {
  86                 bind_scratch();
  87                 void *result = glMapBufferRange(GL_ARRAY_BUFFER, 0, size, GL_MAP_READ_BIT|GL_MAP_WRITE_BIT);
  88                 return result;
  89         }
  90 }
  91
  92 bool OpenGLBuffer::unmap()
  93 {
  94         if(ARB_direct_state_access)
  95                 return glUnmapNamedBuffer(id);
  96         else if(OES_mapbuffer)
  97         {
  98                 bind_scratch();
  99                 bool result = glUnmapBuffer(GL_ARRAY_BUFFER);
 100                 return result;
 101         }
 102         else
 103                 return true;
 104 }
 105
 106 void OpenGLBuffer::set_debug_name(const string &name)
 107 {
 108 #ifdef DEBUG
 109         if(KHR_debug)
 110                 glObjectLabel(GL_BUFFER, id, name.size(), name.c_str());
 111 #else
 112         (void)name;
 113 #endif
 114 }
 115
 116 void OpenGLBuffer::bind_scratch()
 117 {
 118         if(scratch_binding!=this)
 119         {
 120                 glBindBuffer(GL_ARRAY_BUFFER, id);
 121                 scratch_binding = this;
 122         }
 123 }
 124
 125 void OpenGLBuffer::unbind_scratch()
 126 {
 127         if(scratch_binding)
 128         {
 129                 glBindBuffer(GL_ARRAY_BUFFER, 0);
 130                 scratch_binding = 0;
 131         }
 132 }
 133
 134 } // namespace GL
 135 } // namespace Msp