source/core/batch.cpp

   1 #include "batch.h"
   2 #include "error.h"
   3
   4 using namespace std;
   5
   6 namespace {
   7
   8 template<typename T>
   9 void append(vector<uint8_t> &data, T i)
  10 {
  11         data.insert(data.end(), sizeof(T), 0);
  12         *(T *)(&data[data.size()-sizeof(T)]) = i;
  13 }
  14
  15 template<typename T, typename U>
  16 U convert(T n)
  17 {
  18         if(!static_cast<T>(~n))
  19                 return ~0;
  20         else
  21                 return n;
  22 }
  23
  24 template<typename T, typename U>
  25 void expand(vector<uint8_t> &data)
  26 {
  27         unsigned count = data.size()/sizeof(T);
  28         data.resize(count*sizeof(U));
  29         for(unsigned i=count; i--;)
  30                 *(U *)(&data[i*sizeof(U)]) = convert<T, U>(*(T *)(&data[i*sizeof(T)]));
  31 }
  32
  33 template<typename T, typename U>
  34 void shrink(vector<uint8_t> &data)
  35 {
  36         unsigned count = data.size()/sizeof(T);
  37         for(unsigned i=0; i<count; ++i)
  38                 *(U *)(&data[i*sizeof(U)]) = convert<T, U>(*(T *)(&data[i*sizeof(T)]));
  39         data.resize(count*sizeof(U));
  40 }
  41
  42 }
  43
  44 namespace Msp {
  45 namespace GL {
  46
  47 Batch::Batch(PrimitiveType t):
  48         BatchBackend(t),
  49         prim_type(t),
  50         index_type(VOID),
  51         max_index(0)
  52 {
  53         set_index_type(UNSIGNED_SHORT);
  54 }
  55
  56 void Batch::set_index_type(DataType t)
  57 {
  58         if(t==index_type)
  59                 return;
  60         if(t!=UNSIGNED_SHORT && t!=UNSIGNED_INT)
  61                 throw invalid_argument("Batch::set_data_type");
  62         if(t==UNSIGNED_SHORT && max_index>0xFFFE)
  63                 throw invalid_operation("Batch::set_data_type");
  64
  65         if(index_type==UNSIGNED_SHORT && t==UNSIGNED_INT)
  66                 expand<uint16_t, uint32_t>(data);
  67         else if(index_type==UNSIGNED_INT && t==UNSIGNED_SHORT)
  68                 shrink<uint32_t, uint16_t>(data);
  69
  70         index_type = t;
  71         BatchBackend::set_index_type(t);
  72         update_offset();
  73         dirty = true;
  74 }
  75
  76 Batch &Batch::append(unsigned i)
  77 {
  78         append_index(i);
  79
  80         update_offset();
  81         dirty = true;
  82
  83         return *this;
  84 }
  85
  86 Batch &Batch::append(const vector<unsigned> &ind)
  87 {
  88         if(ind.empty())
  89                 return *this;
  90
  91         data.reserve(data.size()+ind.size()*get_index_size());
  92         for(unsigned i: ind)
  93                 append_index(i);
  94
  95         update_offset();
  96         dirty = true;
  97
  98         return *this;
  99 }
 100
 101 bool Batch::can_append(PrimitiveType other_type)
 102 {
 103         if(other_type!=prim_type)
 104                 return false;
 105         else if(prim_type==LINE_STRIP || prim_type==TRIANGLE_FAN)
 106                 return check_restart(false);
 107         else
 108                 return true;
 109 }
 110
 111 Batch &Batch::append(const Batch &other)
 112 {
 113         if(other.prim_type!=prim_type)
 114                 throw invalid_argument("Batch::append");
 115         if(prim_type==LINE_STRIP || prim_type==TRIANGLE_FAN)
 116                 check_restart(true);
 117
 118         if(other.data.empty())
 119                 return *this;
 120
 121         // TODO allow appending triangles to a triangle strip
 122
 123         if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES)
 124                 ;
 125         else if(check_restart(false))
 126         {
 127                 if(index_type==UNSIGNED_INT)
 128                         ::append<uint32_t>(data, 0xFFFFFFFF);
 129                 else
 130                         ::append<uint16_t>(data, 0xFFFF);
 131         }
 132         else if(prim_type==TRIANGLE_STRIP)
 133         {
 134                 append(get_index(size()-1));
 135                 append(other.get_index(0));
 136                 if(size()&1)
 137                         append(other.get_index(0));
 138         }
 139
 140         unsigned count = other.size();
 141         for(unsigned i=0; i<count; ++i)
 142                 append_index(other.get_index(i));
 143
 144         update_offset();
 145         dirty = true;
 146
 147         return *this;
 148 }
 149
 150 void Batch::append_index(unsigned i)
 151 {
 152         if(data.empty())
 153                 max_index = i;
 154         else
 155                 max_index = max(max_index, i);
 156
 157         if(index_type==UNSIGNED_SHORT && max_index>0xFFFE)
 158                 set_index_type(UNSIGNED_INT);
 159
 160         if(index_type==UNSIGNED_INT)
 161                 ::append<uint32_t>(data, i);
 162         else
 163                 ::append<uint16_t>(data, i);
 164 }
 165
 166 unsigned Batch::get_index(size_t i) const
 167 {
 168         if(index_type==UNSIGNED_INT)
 169                 return *(uint32_t *)&data[i*sizeof(uint32_t)];
 170         else
 171                 return *(uint16_t *)&data[i*sizeof(uint16_t)];
 172 }
 173
 174
 175 Batch::Loader::Loader(Batch &b):
 176         DataFile::ObjectLoader<Batch>(b)
 177 {
 178         add("indices", &Loader::indices);
 179 }
 180
 181 void Batch::Loader::indices(const vector<unsigned> &ind)
 182 {
 183         obj.append(ind);
 184 }
 185
 186 } // namespace GL
 187 } // namespace Msp