source/batch.cpp

   1 #include <msp/gl/extensions/ext_draw_range_elements.h>
   2 #include <msp/gl/extensions/nv_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         min_index(0),
  59         max_index(0),
  60         restart(false)
  61 {
  62         /* XXX Should probably provide a fallback to glDrawElements since this class
  63         is pretty much required to render anything. */
  64         static Require _req(EXT_draw_range_elements);
  65 }
  66
  67 Batch::~Batch()
  68 {
  69 }
  70
  71 void Batch::set_data_type(DataType t)
  72 {
  73         if(t!=UNSIGNED_BYTE && t!=UNSIGNED_SHORT && t!=UNSIGNED_INT)
  74                 throw invalid_argument("Batch::set_data_type");
  75         if(t==UNSIGNED_BYTE && max_index>0xFE)
  76                 throw invalid_operation("Batch::set_data_type");
  77         else if(t==UNSIGNED_SHORT && max_index>0xFFFE)
  78                 throw invalid_operation("Batch::set_data_type");
  79
  80         if(data_type==UNSIGNED_BYTE && t==UNSIGNED_SHORT)
  81                 expand<unsigned char, unsigned short>(data);
  82         else if(data_type==UNSIGNED_BYTE && t==UNSIGNED_INT)
  83                 expand<unsigned char, unsigned>(data);
  84         else if(data_type==UNSIGNED_SHORT && t==UNSIGNED_INT)
  85                 expand<unsigned short, unsigned>(data);
  86         else if(data_type==UNSIGNED_INT && t==UNSIGNED_BYTE)
  87                 shrink<unsigned, unsigned char>(data);
  88         else if(data_type==UNSIGNED_INT && t==UNSIGNED_SHORT)
  89                 shrink<unsigned, unsigned short>(data);
  90         else if(data_type==UNSIGNED_SHORT && t==UNSIGNED_BYTE)
  91                 shrink<unsigned short, unsigned char>(data);
  92
  93         data_type = t;
  94         update_offset();
  95         dirty = true;
  96 }
  97
  98 Batch &Batch::append(unsigned i)
  99 {
 100         append_index(i);
 101
 102         update_offset();
 103         dirty = true;
 104
 105         return *this;
 106 }
 107
 108 void Batch::append(const vector<unsigned> &ind)
 109 {
 110         if(ind.empty())
 111                 return;
 112
 113         data.reserve(data.size()+ind.size()*get_index_size());
 114         for(vector<unsigned>::const_iterator i=ind.begin(); i!=ind.end(); ++i)
 115                 append_index(*i);
 116
 117         update_offset();
 118         dirty = true;
 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 NV_primitive_restart;
 127         else
 128                 return true;
 129 }
 130
 131 void 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                 static Require _req(NV_primitive_restart);
 137
 138         if(other.data.empty())
 139                 return;
 140
 141         if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES || prim_type==QUADS)
 142                 ;
 143         else if(NV_primitive_restart)
 144         {
 145                 restart = true;
 146                 if(data_type==UNSIGNED_SHORT)
 147                         ::append<unsigned short>(data, 0xFFFF);
 148                 else if(data_type==UNSIGNED_INT)
 149                         ::append<unsigned>(data, 0xFFFFFFFF);
 150                 else
 151                         data.push_back(0xFF);
 152         }
 153         else if(prim_type==TRIANGLE_STRIP)
 154         {
 155                 append(get_index(size()-1));
 156                 append(other.get_index(0));
 157                 if(size()&1)
 158                         append(other.get_index(0));
 159         }
 160         else if(prim_type==QUAD_STRIP)
 161         {
 162                 append(get_index(size()-1));
 163                 append(get_index(size()-1));
 164                 append(other.get_index(0));
 165                 append(other.get_index(0));
 166         }
 167
 168         unsigned count = other.size();
 169         for(unsigned i=0; i<count; ++i)
 170                 append_index(other.get_index(i));
 171
 172         update_offset();
 173         dirty = true;
 174 }
 175
 176 void Batch::append_index(unsigned i)
 177 {
 178         if(data.empty())
 179                 min_index = max_index = i;
 180         else
 181         {
 182                 min_index = min(min_index, i);
 183                 max_index = max(max_index, i);
 184         }
 185
 186         if((data_type==UNSIGNED_BYTE || data_type==UNSIGNED_SHORT) && max_index>0xFFFE)
 187                 set_data_type(UNSIGNED_INT);
 188         else if(data_type==UNSIGNED_BYTE && max_index>0xFE)
 189                 set_data_type(UNSIGNED_SHORT);
 190
 191         if(data_type==UNSIGNED_SHORT)
 192                 ::append<unsigned short>(data, i);
 193         else if(data_type==UNSIGNED_INT)
 194                 ::append<unsigned>(data, i);
 195         else
 196                 data.push_back(i);
 197 }
 198
 199 unsigned Batch::get_index_size() const
 200 {
 201         if(data_type==UNSIGNED_SHORT)
 202                 return sizeof(unsigned short);
 203         else if(data_type==UNSIGNED_INT)
 204                 return sizeof(unsigned);
 205         return sizeof(unsigned char);
 206 }
 207
 208 unsigned Batch::get_index(unsigned i) const
 209 {
 210         if(data_type==UNSIGNED_SHORT)
 211                 return *(unsigned short *)&data[i*sizeof(unsigned short)];
 212         else if(data_type==UNSIGNED_INT)
 213                 return *(unsigned *)&data[i*sizeof(unsigned )];
 214         else
 215                 return data[i];
 216 }
 217
 218 void Batch::draw() const
 219 {
 220         if(restart)
 221         {
 222                 unsigned index;
 223                 if(data_type==UNSIGNED_SHORT)
 224                         index = 0xFFFF;
 225                 else if(data_type==UNSIGNED_INT)
 226                         index = 0xFFFFFFFF;
 227                 else
 228                         index = 0xFF;
 229
 230                 if(index!=restart_index)
 231                 {
 232                         if(!restart_index)
 233                                 glEnableClientState(GL_PRIMITIVE_RESTART_NV);
 234                         glPrimitiveRestartIndexNV(index);
 235                         restart_index = index;
 236                 }
 237         }
 238         else if(restart_index && restart_index<=max_index)
 239         {
 240                 glDisableClientState(GL_PRIMITIVE_RESTART_NV);
 241                 restart_index = 0;
 242         }
 243
 244         Buffer *ibuf = get_buffer();
 245         BindRestore _bind_ibuf(ibuf, ELEMENT_ARRAY_BUFFER);
 246         if(ibuf)
 247         {
 248                 if(dirty)
 249                         update_buffer();
 250
 251                 glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, reinterpret_cast<void *>(get_offset()));
 252         }
 253         else
 254                 glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, &data[0]);
 255 }
 256
 257
 258 Batch::Loader::Loader(Batch &b):
 259         DataFile::ObjectLoader<Batch>(b)
 260 {
 261         add("indices", &Loader::indices);
 262 }
 263
 264 void Batch::Loader::indices(const vector<unsigned> &ind)
 265 {
 266         obj.append(ind);
 267 }
 268
 269 } // namespace GL
 270 } // namespace Msp