source/core/vertexsetup.cpp

   1 #include <msp/core/raii.h>
   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 "buffer.h"
   9 #include "error.h"
  10 #include "gl.h"
  11 #include "vertexarray.h"
  12 #include "vertexsetup.h"
  13
  14 using namespace std;
  15
  16 namespace Msp {
  17 namespace GL {
  18
  19 VertexSetup::VertexSetup():
  20         dirty(0),
  21         vertex_array(0),
  22         inst_array(0),
  23         index_buffer(0)
  24 {
  25         static Require req(ARB_vertex_array_object);
  26         if(ARB_direct_state_access)
  27                 glCreateVertexArrays(1, &id);
  28         else
  29                 glGenVertexArrays(1, &id);
  30 }
  31
  32 VertexSetup::~VertexSetup()
  33 {
  34         if(current()==this)
  35                 unbind();
  36         glDeleteVertexArrays(1, &id);
  37 }
  38
  39 void VertexSetup::set_vertex_array(const VertexArray &a)
  40 {
  41         if(!a.get_buffer())
  42                 throw invalid_argument("VertexSetup::set_vertex_array");
  43
  44         vertex_array = &a;
  45         update(get_update_mask(VERTEX_ARRAY, vertex_format, *vertex_array));
  46         vertex_format = vertex_array->get_format();
  47 }
  48
  49 void VertexSetup::set_instance_array(const VertexArray *a)
  50 {
  51         if(a)
  52         {
  53                 if(!a->get_buffer())
  54                         throw invalid_argument("VertexSetup::set_instance_array");
  55
  56                 static Require req(ARB_instanced_arrays);
  57         }
  58
  59         inst_array = a;
  60         update(get_update_mask(INSTANCE_ARRAY, inst_format, *inst_array));
  61         inst_format = inst_array->get_format();
  62 }
  63
  64 void VertexSetup::set_index_buffer(const Buffer &ibuf)
  65 {
  66         index_buffer = &ibuf;
  67         update(INDEX_BUFFER);
  68 }
  69
  70 void VertexSetup::refresh()
  71 {
  72         if(vertex_array && vertex_array->get_format()!=vertex_format)
  73                 set_vertex_array(*vertex_array);
  74
  75         if(inst_array && inst_array->get_format()!=inst_format)
  76                 set_instance_array(inst_array);
  77 }
  78
  79 unsigned VertexSetup::get_attribs(const VertexFormat &fmt)
  80 {
  81         unsigned mask = 0;
  82         for(const unsigned char *a=fmt.begin(); a!=fmt.end(); ++a)
  83                 mask |= 1<<get_attribute_semantic(*a);
  84         return mask;
  85 }
  86
  87 unsigned VertexSetup::get_update_mask(unsigned base, const VertexFormat &cur_fmt, const VertexArray &new_array)
  88 {
  89         unsigned unused = get_attribs(cur_fmt)&~get_attribs(new_array.get_format());
  90         return base | (unused ? UNUSED_ATTRIBS | (unused<<ATTRIB_SHIFT) : 0);
  91 }
  92
  93 void VertexSetup::update(unsigned mask) const
  94 {
  95         static bool direct = ARB_direct_state_access && ARB_vertex_attrib_binding;
  96         if(!direct && current()!=this)
  97         {
  98                 dirty |= mask;
  99                 return;
 100         }
 101
 102         if(mask&UNUSED_ATTRIBS)
 103         {
 104                 for(unsigned i=0, am=mask>>ATTRIB_SHIFT; am; ++i, am>>=1)
 105                         if(am&1)
 106                         {
 107                                 if(direct)
 108                                         glDisableVertexArrayAttrib(id, i);
 109                                 else
 110                                         glDisableVertexAttribArray(i);
 111                         }
 112         }
 113
 114         if(mask&VERTEX_ARRAY)
 115                 update_vertex_array(*vertex_array, 0, 0, direct);
 116
 117         if((mask&INSTANCE_ARRAY) && inst_array)
 118                 update_vertex_array(*inst_array, 1, 1, direct);
 119
 120         if(mask&INDEX_BUFFER)
 121         {
 122                 if(direct)
 123                         glVertexArrayElementBuffer(id, index_buffer->get_id());
 124                 else
 125                         glBindBuffer(ELEMENT_ARRAY_BUFFER, index_buffer->get_id());
 126         }
 127 }
 128
 129 void VertexSetup::update_vertex_array(const VertexArray &array, unsigned binding, unsigned divisor, bool direct) const
 130 {
 131         Conditional<Bind> bind_vbuf(!direct, array.get_buffer(), ARRAY_BUFFER);
 132
 133         const VertexFormat &fmt = array.get_format();
 134         unsigned stride = fmt.stride()*sizeof(float);
 135         if(direct)
 136         {
 137                 glVertexArrayVertexBuffer(id, binding, array.get_buffer()->get_id(), 0, stride);
 138                 glVertexArrayBindingDivisor(id, binding, divisor);
 139         }
 140
 141         unsigned offset = 0;
 142         for(const unsigned char *a=fmt.begin(); a!=fmt.end(); ++a)
 143         {
 144                 unsigned sem = get_attribute_semantic(*a);
 145                 unsigned sz = get_attribute_size(*a);
 146                 if(direct)
 147                 {
 148                         if(*a==COLOR4_UBYTE)
 149                                 glVertexArrayAttribFormat(id, sem, 4, GL_UNSIGNED_BYTE, true, offset);
 150                         else
 151                                 glVertexArrayAttribFormat(id, sem, sz, GL_FLOAT, false, offset);
 152                         glVertexArrayAttribBinding(id, sem, binding);
 153                         glEnableVertexArrayAttrib(id, sem);
 154                 }
 155                 else
 156                 {
 157                         if(*a==COLOR4_UBYTE)
 158                                 glVertexAttribPointer(sem, 4, GL_UNSIGNED_BYTE, true, stride, reinterpret_cast<unsigned char *>(offset));
 159                         else
 160                                 glVertexAttribPointer(sem, sz, GL_FLOAT, false, stride, reinterpret_cast<float *>(offset));
 161                         if(ARB_instanced_arrays)
 162                                 glVertexAttribDivisor(sem, divisor);
 163                         glEnableVertexAttribArray(sem);
 164                 }
 165                 offset += sz*sizeof(float);
 166         }
 167 }
 168
 169 void VertexSetup::bind() const
 170 {
 171         if(!vertex_array || !index_buffer)
 172                 throw invalid_operation("VertexSetup::bind");
 173
 174         if(set_current(this))
 175         {
 176                 vertex_array->refresh();
 177                 if(inst_array)
 178                         inst_array->refresh();
 179                 glBindVertexArray(id);
 180                 if(dirty)
 181                 {
 182                         update(dirty);
 183                         dirty = 0;
 184                 }
 185         }
 186 }
 187
 188 void VertexSetup::unbind()
 189 {
 190         if(set_current(0))
 191                 glBindVertexArray(0);
 192 }
 193
 194 } // namespace GL
 195 } // namespace Msp