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()
  28 {
  29         if(this==scratch_binding)
  30                 unbind_scratch();
  31         glDeleteBuffers(1, &id);
  32 }
  33
  34 void OpenGLBuffer::allocate()
  35 {
  36         size_t size = static_cast<const Buffer *>(this)->size;
  37
  38         if(ARB_buffer_storage)
  39         {
  40                 static const int flags = GL_MAP_READ_BIT|GL_MAP_WRITE_BIT|GL_DYNAMIC_STORAGE_BIT;
  41                 if(ARB_direct_state_access)
  42                         glNamedBufferStorage(id, size, 0, flags);
  43                 else
  44                 {
  45                         bind_scratch();
  46                         glBufferStorage(GL_ARRAY_BUFFER, size, 0, flags);
  47                 }
  48         }
  49         else if(ARB_direct_state_access)
  50                 glNamedBufferData(id, size, 0, GL_STATIC_DRAW);
  51         else
  52         {
  53                 bind_scratch();
  54                 glBufferData(GL_ARRAY_BUFFER, size, 0, GL_STATIC_DRAW);
  55         }
  56 }
  57
  58 void OpenGLBuffer::sub_data(size_t off, size_t sz, const void *d)
  59 {
  60         if(ARB_direct_state_access)
  61                 glNamedBufferSubData(id, off, sz, d);
  62         else
  63         {
  64                 bind_scratch();
  65                 glBufferSubData(GL_ARRAY_BUFFER, off, sz, d);
  66         }
  67 }
  68
  69 void *OpenGLBuffer::map()
  70 {
  71         static Require _req(ARB_map_buffer_range);
  72
  73         size_t size = static_cast<const Buffer *>(this)->size;
  74
  75         if(ARB_direct_state_access)
  76                 return glMapNamedBufferRange(id, 0, size, GL_MAP_READ_BIT|GL_MAP_WRITE_BIT);
  77         else
  78         {
  79                 bind_scratch();
  80                 void *result = glMapBufferRange(GL_ARRAY_BUFFER, 0, size, GL_MAP_READ_BIT|GL_MAP_WRITE_BIT);
  81                 return result;
  82         }
  83 }
  84
  85 bool OpenGLBuffer::unmap()
  86 {
  87         // TODO check if it's mapped
  88         if(ARB_direct_state_access)
  89                 return glUnmapNamedBuffer(id);
  90         else if(OES_mapbuffer)
  91         {
  92                 bind_scratch();
  93                 bool result = glUnmapBuffer(GL_ARRAY_BUFFER);
  94                 return result;
  95         }
  96         else
  97                 return true;
  98 }
  99
 100 void OpenGLBuffer::set_debug_name(const string &name)
 101 {
 102 #ifdef DEBUG
 103         if(KHR_debug)
 104                 glObjectLabel(GL_BUFFER, id, name.size(), name.c_str());
 105 #else
 106         (void)name;
 107 #endif
 108 }
 109
 110 void OpenGLBuffer::bind_scratch()
 111 {
 112         if(scratch_binding!=this)
 113         {
 114                 glBindBuffer(GL_ARRAY_BUFFER, id);
 115                 scratch_binding = this;
 116         }
 117 }
 118
 119 void OpenGLBuffer::unbind_scratch()
 120 {
 121         if(scratch_binding)
 122         {
 123                 glBindBuffer(GL_ARRAY_BUFFER, 0);
 124                 scratch_binding = 0;
 125         }
 126 }
 127
 128 } // namespace GL
 129 } // namespace Msp