source/batch.cpp

   1 #include <msp/gl/extensions/arb_draw_instanced.h>
   2 #include <msp/gl/extensions/msp_primitive_restart.h>
   3 #include "batch.h"
   4 #include "bindable.h"
   5 #include "buffer.h"
   6 #include "error.h"
   7 #include "mesh.h"
   8 #include "vertexarray.h"
   9
  10 using namespace std;
  11
  12 namespace {
  13
  14 template<typename T>
  15 void append(vector<unsigned char> &data, T i)
  16 {
  17         data.insert(data.end(), sizeof(T), 0);
  18         *(T *)(&data[data.size()-sizeof(T)]) = i;
  19 }
  20
  21 template<typename T, typename U>
  22 U convert(T n)
  23 {
  24         if(!static_cast<T>(~n))
  25                 return ~0;
  26         else
  27                 return n;
  28 }
  29
  30 template<typename T, typename U>
  31 void expand(vector<unsigned char> &data)
  32 {
  33         unsigned count = data.size()/sizeof(T);
  34         data.resize(count*sizeof(U));
  35         for(unsigned i=count; i--;)
  36                 *(U *)(&data[i*sizeof(U)]) = convert<T, U>(*(T *)(&data[i*sizeof(T)]));
  37 }
  38
  39 template<typename T, typename U>
  40 void shrink(vector<unsigned char> &data)
  41 {
  42         unsigned count = data.size()/sizeof(T);
  43         for(unsigned i=0; i<count; ++i)
  44                 *(U *)(&data[i*sizeof(U)]) = convert<T, U>(*(T *)(&data[i*sizeof(T)]));
  45         data.resize(count*sizeof(U));
  46 }
  47
  48 }
  49
  50 namespace Msp {
  51 namespace GL {
  52
  53 unsigned Batch::restart_index = 0;
  54
  55 Batch::Batch(PrimitiveType t):
  56         prim_type(t),
  57         data_type(UNSIGNED_BYTE),
  58         max_index(0),
  59         restart(false)
  60 { }
  61
  62 Batch::~Batch()
  63 {
  64 }
  65
  66 void Batch::set_data_type(DataType t)
  67 {
  68         if(t!=UNSIGNED_BYTE && t!=UNSIGNED_SHORT && t!=UNSIGNED_INT)
  69                 throw invalid_argument("Batch::set_data_type");
  70         if(t==UNSIGNED_BYTE && max_index>0xFE)
  71                 throw invalid_operation("Batch::set_data_type");
  72         else if(t==UNSIGNED_SHORT && max_index>0xFFFE)
  73                 throw invalid_operation("Batch::set_data_type");
  74
  75         if(data_type==UNSIGNED_BYTE && t==UNSIGNED_SHORT)
  76                 expand<unsigned char, unsigned short>(data);
  77         else if(data_type==UNSIGNED_BYTE && t==UNSIGNED_INT)
  78                 expand<unsigned char, unsigned>(data);
  79         else if(data_type==UNSIGNED_SHORT && t==UNSIGNED_INT)
  80                 expand<unsigned short, unsigned>(data);
  81         else if(data_type==UNSIGNED_INT && t==UNSIGNED_BYTE)
  82                 shrink<unsigned, unsigned char>(data);
  83         else if(data_type==UNSIGNED_INT && t==UNSIGNED_SHORT)
  84                 shrink<unsigned, unsigned short>(data);
  85         else if(data_type==UNSIGNED_SHORT && t==UNSIGNED_BYTE)
  86                 shrink<unsigned short, unsigned char>(data);
  87
  88         data_type = t;
  89         update_offset();
  90         dirty = true;
  91 }
  92
  93 Batch &Batch::append(unsigned i)
  94 {
  95         append_index(i);
  96
  97         update_offset();
  98         dirty = true;
  99
 100         return *this;
 101 }
 102
 103 Batch &Batch::append(const vector<unsigned> &ind)
 104 {
 105         if(ind.empty())
 106                 return *this;
 107
 108         data.reserve(data.size()+ind.size()*get_index_size());
 109         for(vector<unsigned>::const_iterator i=ind.begin(); i!=ind.end(); ++i)
 110                 append_index(*i);
 111
 112         update_offset();
 113         dirty = true;
 114
 115         return *this;
 116 }
 117
 118 bool Batch::can_append(PrimitiveType other_type)
 119 {
 120         if(other_type!=prim_type)
 121                 return false;
 122         else if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
 123                 return MSP_primitive_restart;
 124         else
 125                 return true;
 126 }
 127
 128 Batch &Batch::append(const Batch &other)
 129 {
 130         if(other.prim_type!=prim_type)
 131                 throw invalid_argument("Batch::append");
 132         if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
 133                 static Require _req(MSP_primitive_restart);
 134
 135         if(other.data.empty())
 136                 return *this;
 137
 138         if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES)
 139                 ;
 140         else if(MSP_primitive_restart)
 141         {
 142                 restart = true;
 143                 if(data_type==UNSIGNED_SHORT)
 144                         ::append<unsigned short>(data, 0xFFFF);
 145                 else if(data_type==UNSIGNED_INT)
 146                         ::append<unsigned>(data, 0xFFFFFFFF);
 147                 else
 148                         data.push_back(0xFF);
 149         }
 150         else if(prim_type==TRIANGLE_STRIP)
 151         {
 152                 append(get_index(size()-1));
 153                 append(other.get_index(0));
 154                 if(size()&1)
 155                         append(other.get_index(0));
 156         }
 157
 158         unsigned count = other.size();
 159         for(unsigned i=0; i<count; ++i)
 160                 append_index(other.get_index(i));
 161
 162         update_offset();
 163         dirty = true;
 164
 165         return *this;
 166 }
 167
 168 void Batch::append_index(unsigned i)
 169 {
 170         if(data.empty())
 171                 max_index = i;
 172         else
 173                 max_index = max(max_index, i);
 174
 175         if((data_type==UNSIGNED_BYTE || data_type==UNSIGNED_SHORT) && max_index>0xFFFE)
 176                 set_data_type(UNSIGNED_INT);
 177         else if(data_type==UNSIGNED_BYTE && max_index>0xFE)
 178                 set_data_type(UNSIGNED_SHORT);
 179
 180         if(data_type==UNSIGNED_SHORT)
 181                 ::append<unsigned short>(data, i);
 182         else if(data_type==UNSIGNED_INT)
 183                 ::append<unsigned>(data, i);
 184         else
 185                 data.push_back(i);
 186 }
 187
 188 unsigned Batch::get_index_size() const
 189 {
 190         if(data_type==UNSIGNED_SHORT)
 191                 return sizeof(unsigned short);
 192         else if(data_type==UNSIGNED_INT)
 193                 return sizeof(unsigned);
 194         return sizeof(unsigned char);
 195 }
 196
 197 unsigned Batch::get_index(unsigned i) const
 198 {
 199         if(data_type==UNSIGNED_SHORT)
 200                 return *(unsigned short *)&data[i*sizeof(unsigned short)];
 201         else if(data_type==UNSIGNED_INT)
 202                 return *(unsigned *)&data[i*sizeof(unsigned )];
 203         else
 204                 return data[i];
 205 }
 206
 207 void Batch::draw() const
 208 {
 209         BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
 210         const void *data_ptr = setup_draw();
 211
 212         glDrawElements(prim_type, size(), data_type, data_ptr);
 213 }
 214
 215 void Batch::draw_instanced(unsigned count) const
 216 {
 217         static Require req(ARB_draw_instanced);
 218
 219         BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
 220         const void *data_ptr = setup_draw();
 221
 222         glDrawElementsInstanced(prim_type, size(), data_type, data_ptr, count);
 223 }
 224
 225 const void *Batch::setup_draw() const
 226 {
 227         if(restart)
 228         {
 229                 unsigned index;
 230                 if(data_type==UNSIGNED_SHORT)
 231                         index = 0xFFFF;
 232                 else if(data_type==UNSIGNED_INT)
 233                         index = 0xFFFFFFFF;
 234                 else
 235                         index = 0xFF;
 236
 237                 if(index!=restart_index)
 238                         set_restart_index(index);
 239         }
 240         else if(restart_index && restart_index<=max_index)
 241                 set_restart_index(0);
 242
 243         if(get_buffer())
 244         {
 245                 if(dirty)
 246                         update_buffer();
 247
 248                 return reinterpret_cast<const void *>(get_offset());
 249         }
 250         else
 251                 return &data[0];
 252 }
 253
 254 void Batch::set_restart_index(unsigned index)
 255 {
 256         if(index>0)
 257         {
 258                 if(!restart_index)
 259                         glEnable(GL_PRIMITIVE_RESTART);
 260                 glPrimitiveRestartIndex(index);
 261         }
 262         else
 263                 glDisable(GL_PRIMITIVE_RESTART);
 264
 265         restart_index = index;
 266 }
 267
 268
 269 Batch::Loader::Loader(Batch &b):
 270         DataFile::ObjectLoader<Batch>(b)
 271 {
 272         add("indices", &Loader::indices);
 273 }
 274
 275 void Batch::Loader::indices(const vector<unsigned> &ind)
 276 {
 277         obj.append(ind);
 278 }
 279
 280 } // namespace GL
 281 } // namespace Msp