source/backends/opengl/vertexsetup_backend.cpp

   1 #include <algorithm>
   2 #include <msp/gl/extensions/arb_direct_state_access.h>
   3 #include <msp/gl/extensions/arb_instanced_arrays.h>
   4 #include <msp/gl/extensions/arb_vertex_array_object.h>
   5 #include <msp/gl/extensions/arb_vertex_attrib_binding.h>
   6 #include <msp/gl/extensions/arb_vertex_buffer_object.h>
   7 #include <msp/gl/extensions/arb_vertex_shader.h>
   8 #include <msp/gl/extensions/ext_gpu_shader4.h>
   9 #include <msp/gl/extensions/khr_debug.h>
  10 #include "buffer.h"
  11 #include "vertexarray.h"
  12 #include "vertexformat.h"
  13 #include "vertexsetup.h"
  14 #include "vertexsetup_backend.h"
  15
  16 using namespace std;
  17
  18 namespace Msp {
  19 namespace GL {
  20
  21 OpenGLVertexSetup::OpenGLVertexSetup()
  22 {
  23         static Require req(ARB_vertex_array_object);
  24         if(ARB_direct_state_access)
  25                 glCreateVertexArrays(1, &id);
  26         else
  27                 glGenVertexArrays(1, &id);
  28 }
  29
  30 OpenGLVertexSetup::OpenGLVertexSetup(OpenGLVertexSetup &&other):
  31         id(other.id)
  32 {
  33         other.id = 0;
  34 }
  35
  36 OpenGLVertexSetup::~OpenGLVertexSetup()
  37 {
  38         if(id)
  39                 glDeleteVertexArrays(1, &id);
  40 }
  41
  42 void OpenGLVertexSetup::require_format(const VertexFormat &fmt, bool instanced)
  43 {
  44         if(any_of(fmt.begin(), fmt.end(), is_integer_attribute))
  45                 static Require _req(EXT_gpu_shader4);
  46         if(instanced)
  47                 static Require req(ARB_instanced_arrays);
  48 }
  49
  50 void OpenGLVertexSetup::update(unsigned mask) const
  51 {
  52         static bool direct = ARB_direct_state_access && ARB_vertex_attrib_binding;
  53
  54         if(mask&VertexSetup::VERTEX_ARRAY)
  55                 update_vertex_array(*static_cast<const VertexSetup *>(this)->vertex_array, 0, 0, direct);
  56
  57         if(mask&VertexSetup::INSTANCE_ARRAY)
  58                 update_vertex_array(*static_cast<const VertexSetup *>(this)->inst_array, 1, 1, direct);
  59
  60         if(mask&VertexSetup::INDEX_BUFFER)
  61         {
  62                 unsigned buf_id = static_cast<const VertexSetup *>(this)->index_buffer->id;
  63                 if(direct)
  64                         glVertexArrayElementBuffer(id, buf_id);
  65                 else
  66                         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buf_id);
  67         }
  68 }
  69
  70 void OpenGLVertexSetup::update_vertex_array(const VertexArray &array, unsigned binding, unsigned divisor, bool direct) const
  71 {
  72         if(!direct)
  73         {
  74                 OpenGLBuffer::unbind_scratch();
  75                 glBindBuffer(GL_ARRAY_BUFFER, array.get_buffer()->id);
  76         }
  77
  78         const VertexFormat &fmt = array.get_format();
  79         unsigned stride = fmt.stride();
  80         if(direct)
  81         {
  82                 glVertexArrayVertexBuffer(id, binding, array.get_buffer()->id, 0, stride);
  83                 glVertexArrayBindingDivisor(id, binding, divisor);
  84         }
  85
  86         unsigned offset = 0;
  87         for(VertexAttribute a: fmt)
  88         {
  89                 unsigned sem = get_attribute_semantic(a);
  90                 bool integer = is_integer_attribute(a);
  91                 GLenum type = get_gl_type(get_attribute_source_type(a));
  92                 unsigned cc = get_attribute_component_count(a);
  93                 if(direct)
  94                 {
  95                         if(integer)
  96                                 glVertexArrayAttribIFormat(id, sem, cc, type, offset);
  97                         else
  98                                 glVertexArrayAttribFormat(id, sem, cc, type, true, offset);
  99                         glVertexArrayAttribBinding(id, sem, binding);
 100                         glEnableVertexArrayAttrib(id, sem);
 101                 }
 102                 else
 103                 {
 104                         if(integer)
 105                                 glVertexAttribIPointer(sem, cc, type, stride, reinterpret_cast<void *>(offset));
 106                         else
 107                                 glVertexAttribPointer(sem, cc, type, true, stride, reinterpret_cast<void *>(offset));
 108                         if(ARB_instanced_arrays)
 109                                 glVertexAttribDivisor(sem, divisor);
 110                         glEnableVertexAttribArray(sem);
 111                 }
 112                 offset += get_attribute_size(a);
 113         }
 114
 115         if(!direct)
 116                 glBindBuffer(GL_ARRAY_BUFFER, 0);
 117 }
 118
 119 void OpenGLVertexSetup::unload()
 120 {
 121         if(ARB_direct_state_access)
 122         {
 123                 glVertexArrayVertexBuffer(id, 0, 0, 0, 0);
 124                 glVertexArrayVertexBuffer(id, 1, 0, 0, 0);
 125                 glVertexArrayElementBuffer(id, 0);
 126         }
 127         else
 128         {
 129                 glBindVertexArray(id);
 130                 glBindBuffer(GL_ARRAY_BUFFER, 0);
 131
 132                 for(VertexAttribute a: static_cast<const VertexSetup *>(this)->vertex_format)
 133                 {
 134                         unsigned sem = get_attribute_semantic(a);
 135                         glDisableVertexAttribArray(sem);
 136                         glVertexAttribPointer(sem, 1, GL_FLOAT, false, 0, 0);
 137                 }
 138                 for(VertexAttribute a: static_cast<const VertexSetup *>(this)->inst_format)
 139                 {
 140                         unsigned sem = get_attribute_semantic(a);
 141                         glDisableVertexAttribArray(sem);
 142                         glVertexAttribPointer(sem, 1, GL_FLOAT, false, 0, 0);
 143                 }
 144
 145                 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 146         }
 147 }
 148
 149 void OpenGLVertexSetup::set_debug_name(const string &name)
 150 {
 151 #ifdef DEBUG
 152         if(KHR_debug)
 153                 glObjectLabel(GL_VERTEX_ARRAY, id, name.size(), name.c_str());
 154 #else
 155         (void)name;
 156 #endif
 157 }
 158
 159 } // namespace GL
 160 } // namespace Msp