source/batch.cpp

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