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 Batch::~Batch()
  57 {
  58 }
  59
  60 void Batch::set_index_type(DataType t)
  61 {
  62         if(t==index_type)
  63                 return;
  64         if(t!=UNSIGNED_SHORT && t!=UNSIGNED_INT)
  65                 throw invalid_argument("Batch::set_data_type");
  66         if(t==UNSIGNED_SHORT && max_index>0xFFFE)
  67                 throw invalid_operation("Batch::set_data_type");
  68
  69         if(index_type==UNSIGNED_SHORT && t==UNSIGNED_INT)
  70                 expand<uint16_t, uint32_t>(data);
  71         else if(index_type==UNSIGNED_INT && t==UNSIGNED_SHORT)
  72                 shrink<uint32_t, uint16_t>(data);
  73
  74         index_type = t;
  75         BatchBackend::set_index_type(t);
  76         update_offset();
  77         dirty = true;
  78 }
  79
  80 Batch &Batch::append(unsigned i)
  81 {
  82         append_index(i);
  83
  84         update_offset();
  85         dirty = true;
  86
  87         return *this;
  88 }
  89
  90 Batch &Batch::append(const vector<unsigned> &ind)
  91 {
  92         if(ind.empty())
  93                 return *this;
  94
  95         data.reserve(data.size()+ind.size()*get_index_size());
  96         for(unsigned i: ind)
  97                 append_index(i);
  98
  99         update_offset();
 100         dirty = true;
 101
 102         return *this;
 103 }
 104
 105 bool Batch::can_append(PrimitiveType other_type)
 106 {
 107         if(other_type!=prim_type)
 108                 return false;
 109         else if(prim_type==LINE_STRIP || prim_type==TRIANGLE_FAN)
 110                 return check_restart(false);
 111         else
 112                 return true;
 113 }
 114
 115 Batch &Batch::append(const Batch &other)
 116 {
 117         if(other.prim_type!=prim_type)
 118                 throw invalid_argument("Batch::append");
 119         if(prim_type==LINE_STRIP || prim_type==TRIANGLE_FAN)
 120                 check_restart(true);
 121
 122         if(other.data.empty())
 123                 return *this;
 124
 125         // TODO allow appending triangles to a triangle strip
 126
 127         if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES)
 128                 ;
 129         else if(check_restart(false))
 130         {
 131                 if(index_type==UNSIGNED_INT)
 132                         ::append<uint32_t>(data, 0xFFFFFFFF);
 133                 else
 134                         ::append<uint16_t>(data, 0xFFFF);
 135         }
 136         else if(prim_type==TRIANGLE_STRIP)
 137         {
 138                 append(get_index(size()-1));
 139                 append(other.get_index(0));
 140                 if(size()&1)
 141                         append(other.get_index(0));
 142         }
 143
 144         unsigned count = other.size();
 145         for(unsigned i=0; i<count; ++i)
 146                 append_index(other.get_index(i));
 147
 148         update_offset();
 149         dirty = true;
 150
 151         return *this;
 152 }
 153
 154 void Batch::append_index(unsigned i)
 155 {
 156         if(data.empty())
 157                 max_index = i;
 158         else
 159                 max_index = max(max_index, i);
 160
 161         if(index_type==UNSIGNED_SHORT && max_index>0xFFFE)
 162                 set_index_type(UNSIGNED_INT);
 163
 164         if(index_type==UNSIGNED_INT)
 165                 ::append<uint32_t>(data, i);
 166         else
 167                 ::append<uint16_t>(data, i);
 168 }
 169
 170 size_t Batch::get_index_size() const
 171 {
 172         return (index_type==UNSIGNED_INT ? sizeof(uint32_t) : sizeof(uint16_t));
 173 }
 174
 175 unsigned Batch::get_index(size_t i) const
 176 {
 177         if(index_type==UNSIGNED_INT)
 178                 return *(uint32_t *)&data[i*sizeof(uint32_t)];
 179         else
 180                 return *(uint16_t *)&data[i*sizeof(uint16_t)];
 181 }
 182
 183
 184 Batch::Loader::Loader(Batch &b):
 185         DataFile::ObjectLoader<Batch>(b)
 186 {
 187         add("indices", &Loader::indices);
 188 }
 189
 190 void Batch::Loader::indices(const vector<unsigned> &ind)
 191 {
 192         obj.append(ind);
 193 }
 194
 195 } // namespace GL
 196 } // namespace Msp