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 void Batch::append(const vector<unsigned> &ind)
 107 {
 108         if(ind.empty())
 109                 return;
 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
 119 bool Batch::can_append(PrimitiveType other_type)
 120 {
 121         if(other_type!=prim_type)
 122                 return false;
 123         else if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
 124                 return MSP_primitive_restart || NV_primitive_restart;
 125         else
 126                 return true;
 127 }
 128
 129 void Batch::append(const Batch &other)
 130 {
 131         if(other.prim_type!=prim_type)
 132                 throw invalid_argument("Batch::append");
 133         if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
 134         {
 135                 if(!MSP_primitive_restart)
 136                 {
 137                         static Require _req(NV_primitive_restart);
 138                         // Make sure we have glEnable/DisableClientState as well
 139                         static Require _req2(MSP_legacy_features);
 140                 }
 141         }
 142
 143         if(other.data.empty())
 144                 return;
 145
 146         if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES || prim_type==QUADS)
 147                 ;
 148         else if(MSP_primitive_restart || NV_primitive_restart)
 149         {
 150                 restart = true;
 151                 if(data_type==UNSIGNED_SHORT)
 152                         ::append<unsigned short>(data, 0xFFFF);
 153                 else if(data_type==UNSIGNED_INT)
 154                         ::append<unsigned>(data, 0xFFFFFFFF);
 155                 else
 156                         data.push_back(0xFF);
 157         }
 158         else if(prim_type==TRIANGLE_STRIP)
 159         {
 160                 append(get_index(size()-1));
 161                 append(other.get_index(0));
 162                 if(size()&1)
 163                         append(other.get_index(0));
 164         }
 165         else if(prim_type==QUAD_STRIP)
 166         {
 167                 append(get_index(size()-1));
 168                 append(get_index(size()-1));
 169                 append(other.get_index(0));
 170                 append(other.get_index(0));
 171         }
 172
 173         unsigned count = other.size();
 174         for(unsigned i=0; i<count; ++i)
 175                 append_index(other.get_index(i));
 176
 177         update_offset();
 178         dirty = true;
 179 }
 180
 181 void Batch::append_index(unsigned i)
 182 {
 183         if(data.empty())
 184                 min_index = max_index = i;
 185         else
 186         {
 187                 min_index = min(min_index, i);
 188                 max_index = max(max_index, i);
 189         }
 190
 191         if((data_type==UNSIGNED_BYTE || data_type==UNSIGNED_SHORT) && max_index>0xFFFE)
 192                 set_data_type(UNSIGNED_INT);
 193         else if(data_type==UNSIGNED_BYTE && max_index>0xFE)
 194                 set_data_type(UNSIGNED_SHORT);
 195
 196         if(data_type==UNSIGNED_SHORT)
 197                 ::append<unsigned short>(data, i);
 198         else if(data_type==UNSIGNED_INT)
 199                 ::append<unsigned>(data, i);
 200         else
 201                 data.push_back(i);
 202 }
 203
 204 unsigned Batch::get_index_size() const
 205 {
 206         if(data_type==UNSIGNED_SHORT)
 207                 return sizeof(unsigned short);
 208         else if(data_type==UNSIGNED_INT)
 209                 return sizeof(unsigned);
 210         return sizeof(unsigned char);
 211 }
 212
 213 unsigned Batch::get_index(unsigned i) const
 214 {
 215         if(data_type==UNSIGNED_SHORT)
 216                 return *(unsigned short *)&data[i*sizeof(unsigned short)];
 217         else if(data_type==UNSIGNED_INT)
 218                 return *(unsigned *)&data[i*sizeof(unsigned )];
 219         else
 220                 return data[i];
 221 }
 222
 223 void Batch::draw() const
 224 {
 225         if(restart)
 226         {
 227                 unsigned index;
 228                 if(data_type==UNSIGNED_SHORT)
 229                         index = 0xFFFF;
 230                 else if(data_type==UNSIGNED_INT)
 231                         index = 0xFFFFFFFF;
 232                 else
 233                         index = 0xFF;
 234
 235                 if(index!=restart_index)
 236                         set_restart_index(index);
 237         }
 238         else if(restart_index && restart_index<=max_index)
 239                 set_restart_index(0);
 240
 241         Buffer *ibuf = get_buffer();
 242         const void *data_ptr;
 243         BindRestore _bind_ibuf(ibuf, ELEMENT_ARRAY_BUFFER);
 244         if(ibuf)
 245         {
 246                 if(dirty)
 247                         update_buffer();
 248
 249                 data_ptr = reinterpret_cast<const void *>(get_offset());
 250         }
 251         else
 252                 data_ptr = &data[0];
 253
 254         if(EXT_draw_range_elements)
 255                 glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, data_ptr);
 256         else
 257                 glDrawElements(prim_type, size(), data_type, data_ptr);
 258 }
 259
 260 void Batch::set_restart_index(unsigned index)
 261 {
 262         if(MSP_primitive_restart)
 263         {
 264                 if(index>0)
 265                 {
 266                         if(!restart_index)
 267                                 glEnable(GL_PRIMITIVE_RESTART);
 268                         glPrimitiveRestartIndex(index);
 269                 }
 270                 else
 271                         glDisable(GL_PRIMITIVE_RESTART);
 272         }
 273         else
 274         {
 275                 if(index>0)
 276                 {
 277                         if(!restart_index)
 278                                 glEnableClientState(GL_PRIMITIVE_RESTART_NV);
 279                         glPrimitiveRestartIndexNV(index);
 280                 }
 281                 else
 282                         glDisableClientState(GL_PRIMITIVE_RESTART_NV);
 283         }
 284
 285         restart_index = index;
 286 }
 287
 288
 289 Batch::Loader::Loader(Batch &b):
 290         DataFile::ObjectLoader<Batch>(b)
 291 {
 292         add("indices", &Loader::indices);
 293 }
 294
 295 void Batch::Loader::indices(const vector<unsigned> &ind)
 296 {
 297         obj.append(ind);
 298 }
 299
 300 } // namespace GL
 301 } // namespace Msp