source/batch.cpp

   1 #include <msp/gl/extensions/arb_draw_instanced.h>
   2 #include <msp/gl/extensions/ext_draw_range_elements.h>
   3 #include <msp/gl/extensions/msp_legacy_features.h>
   4 #include <msp/gl/extensions/msp_primitive_restart.h>
   5 #include <msp/gl/extensions/nv_primitive_restart.h>
   6 #include "batch.h"
   7 #include "bindable.h"
   8 #include "buffer.h"
   9 #include "error.h"
  10 #include "mesh.h"
  11 #include "vertexarray.h"
  12
  13 using namespace std;
  14
  15 namespace {
  16
  17 template<typename T>
  18 void append(vector<unsigned char> &data, T i)
  19 {
  20         data.insert(data.end(), sizeof(T), 0);
  21         *(T *)(&data[data.size()-sizeof(T)]) = i;
  22 }
  23
  24 template<typename T, typename U>
  25 U convert(T n)
  26 {
  27         if(!static_cast<T>(~n))
  28                 return ~0;
  29         else
  30                 return n;
  31 }
  32
  33 template<typename T, typename U>
  34 void expand(vector<unsigned char> &data)
  35 {
  36         unsigned count = data.size()/sizeof(T);
  37         data.resize(count*sizeof(U));
  38         for(unsigned i=count; i--;)
  39                 *(U *)(&data[i*sizeof(U)]) = convert<T, U>(*(T *)(&data[i*sizeof(T)]));
  40 }
  41
  42 template<typename T, typename U>
  43 void shrink(vector<unsigned char> &data)
  44 {
  45         unsigned count = data.size()/sizeof(T);
  46         for(unsigned i=0; i<count; ++i)
  47                 *(U *)(&data[i*sizeof(U)]) = convert<T, U>(*(T *)(&data[i*sizeof(T)]));
  48         data.resize(count*sizeof(U));
  49 }
  50
  51 }
  52
  53 namespace Msp {
  54 namespace GL {
  55
  56 unsigned Batch::restart_index = 0;
  57
  58 Batch::Batch(PrimitiveType t):
  59         prim_type(t),
  60         data_type(UNSIGNED_BYTE),
  61         min_index(0),
  62         max_index(0),
  63         restart(false)
  64 { }
  65
  66 Batch::~Batch()
  67 {
  68 }
  69
  70 void Batch::set_data_type(DataType t)
  71 {
  72         if(t!=UNSIGNED_BYTE && t!=UNSIGNED_SHORT && t!=UNSIGNED_INT)
  73                 throw invalid_argument("Batch::set_data_type");
  74         if(t==UNSIGNED_BYTE && max_index>0xFE)
  75                 throw invalid_operation("Batch::set_data_type");
  76         else if(t==UNSIGNED_SHORT && max_index>0xFFFE)
  77                 throw invalid_operation("Batch::set_data_type");
  78
  79         if(data_type==UNSIGNED_BYTE && t==UNSIGNED_SHORT)
  80                 expand<unsigned char, unsigned short>(data);
  81         else if(data_type==UNSIGNED_BYTE && t==UNSIGNED_INT)
  82                 expand<unsigned char, unsigned>(data);
  83         else if(data_type==UNSIGNED_SHORT && t==UNSIGNED_INT)
  84                 expand<unsigned short, unsigned>(data);
  85         else if(data_type==UNSIGNED_INT && t==UNSIGNED_BYTE)
  86                 shrink<unsigned, unsigned char>(data);
  87         else if(data_type==UNSIGNED_INT && t==UNSIGNED_SHORT)
  88                 shrink<unsigned, unsigned short>(data);
  89         else if(data_type==UNSIGNED_SHORT && t==UNSIGNED_BYTE)
  90                 shrink<unsigned short, unsigned char>(data);
  91
  92         data_type = t;
  93         update_offset();
  94         dirty = true;
  95 }
  96
  97 Batch &Batch::append(unsigned i)
  98 {
  99         append_index(i);
 100
 101         update_offset();
 102         dirty = true;
 103
 104         return *this;
 105 }
 106
 107 Batch &Batch::append(const vector<unsigned> &ind)
 108 {
 109         if(ind.empty())
 110                 return *this;
 111
 112         data.reserve(data.size()+ind.size()*get_index_size());
 113         for(vector<unsigned>::const_iterator i=ind.begin(); i!=ind.end(); ++i)
 114                 append_index(*i);
 115
 116         update_offset();
 117         dirty = true;
 118
 119         return *this;
 120 }
 121
 122 bool Batch::can_append(PrimitiveType other_type)
 123 {
 124         if(other_type!=prim_type)
 125                 return false;
 126         else if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
 127                 return MSP_primitive_restart || NV_primitive_restart;
 128         else
 129                 return true;
 130 }
 131
 132 Batch &Batch::append(const Batch &other)
 133 {
 134         if(other.prim_type!=prim_type)
 135                 throw invalid_argument("Batch::append");
 136         if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
 137         {
 138                 if(!MSP_primitive_restart)
 139                 {
 140                         static Require _req(NV_primitive_restart);
 141                         // Make sure we have glEnable/DisableClientState as well
 142                         static Require _req2(MSP_legacy_features);
 143                 }
 144         }
 145
 146         if(other.data.empty())
 147                 return *this;
 148
 149         if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES || prim_type==QUADS)
 150                 ;
 151         else if(MSP_primitive_restart || NV_primitive_restart)
 152         {
 153                 restart = true;
 154                 if(data_type==UNSIGNED_SHORT)
 155                         ::append<unsigned short>(data, 0xFFFF);
 156                 else if(data_type==UNSIGNED_INT)
 157                         ::append<unsigned>(data, 0xFFFFFFFF);
 158                 else
 159                         data.push_back(0xFF);
 160         }
 161         else if(prim_type==TRIANGLE_STRIP)
 162         {
 163                 append(get_index(size()-1));
 164                 append(other.get_index(0));
 165                 if(size()&1)
 166                         append(other.get_index(0));
 167         }
 168         else if(prim_type==QUAD_STRIP)
 169         {
 170                 append(get_index(size()-1));
 171                 append(get_index(size()-1));
 172                 append(other.get_index(0));
 173                 append(other.get_index(0));
 174         }
 175
 176         unsigned count = other.size();
 177         for(unsigned i=0; i<count; ++i)
 178                 append_index(other.get_index(i));
 179
 180         update_offset();
 181         dirty = true;
 182
 183         return *this;
 184 }
 185
 186 void Batch::append_index(unsigned i)
 187 {
 188         if(data.empty())
 189                 min_index = max_index = i;
 190         else
 191         {
 192                 min_index = min(min_index, i);
 193                 max_index = max(max_index, i);
 194         }
 195
 196         if((data_type==UNSIGNED_BYTE || data_type==UNSIGNED_SHORT) && max_index>0xFFFE)
 197                 set_data_type(UNSIGNED_INT);
 198         else if(data_type==UNSIGNED_BYTE && max_index>0xFE)
 199                 set_data_type(UNSIGNED_SHORT);
 200
 201         if(data_type==UNSIGNED_SHORT)
 202                 ::append<unsigned short>(data, i);
 203         else if(data_type==UNSIGNED_INT)
 204                 ::append<unsigned>(data, i);
 205         else
 206                 data.push_back(i);
 207 }
 208
 209 unsigned Batch::get_index_size() const
 210 {
 211         if(data_type==UNSIGNED_SHORT)
 212                 return sizeof(unsigned short);
 213         else if(data_type==UNSIGNED_INT)
 214                 return sizeof(unsigned);
 215         return sizeof(unsigned char);
 216 }
 217
 218 unsigned Batch::get_index(unsigned i) const
 219 {
 220         if(data_type==UNSIGNED_SHORT)
 221                 return *(unsigned short *)&data[i*sizeof(unsigned short)];
 222         else if(data_type==UNSIGNED_INT)
 223                 return *(unsigned *)&data[i*sizeof(unsigned )];
 224         else
 225                 return data[i];
 226 }
 227
 228 void Batch::draw() const
 229 {
 230         BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
 231         const void *data_ptr = setup_draw();
 232
 233         if(EXT_draw_range_elements)
 234                 glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, data_ptr);
 235         else
 236                 glDrawElements(prim_type, size(), data_type, data_ptr);
 237 }
 238
 239 void Batch::draw_instanced(unsigned count) const
 240 {
 241         static Require req(ARB_draw_instanced);
 242
 243         BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
 244         const void *data_ptr = setup_draw();
 245
 246         glDrawElementsInstanced(prim_type, size(), data_type, data_ptr, count);
 247 }
 248
 249 const void *Batch::setup_draw() const
 250 {
 251         if(restart)
 252         {
 253                 unsigned index;
 254                 if(data_type==UNSIGNED_SHORT)
 255                         index = 0xFFFF;
 256                 else if(data_type==UNSIGNED_INT)
 257                         index = 0xFFFFFFFF;
 258                 else
 259                         index = 0xFF;
 260
 261                 if(index!=restart_index)
 262                         set_restart_index(index);
 263         }
 264         else if(restart_index && restart_index<=max_index)
 265                 set_restart_index(0);
 266
 267         if(get_buffer())
 268         {
 269                 if(dirty)
 270                         update_buffer();
 271
 272                 return reinterpret_cast<const void *>(get_offset());
 273         }
 274         else
 275                 return &data[0];
 276 }
 277
 278 void Batch::set_restart_index(unsigned index)
 279 {
 280         if(MSP_primitive_restart)
 281         {
 282                 if(index>0)
 283                 {
 284                         if(!restart_index)
 285                                 glEnable(GL_PRIMITIVE_RESTART);
 286                         glPrimitiveRestartIndex(index);
 287                 }
 288                 else
 289                         glDisable(GL_PRIMITIVE_RESTART);
 290         }
 291         else
 292         {
 293                 if(index>0)
 294                 {
 295                         if(!restart_index)
 296                                 glEnableClientState(GL_PRIMITIVE_RESTART_NV);
 297                         glPrimitiveRestartIndexNV(index);
 298                 }
 299                 else
 300                         glDisableClientState(GL_PRIMITIVE_RESTART_NV);
 301         }
 302
 303         restart_index = index;
 304 }
 305
 306
 307 Batch::Loader::Loader(Batch &b):
 308         DataFile::ObjectLoader<Batch>(b)
 309 {
 310         add("indices", &Loader::indices);
 311 }
 312
 313 void Batch::Loader::indices(const vector<unsigned> &ind)
 314 {
 315         obj.append(ind);
 316 }
 317
 318 } // namespace GL
 319 } // namespace Msp