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1 #include <msp/gl/extensions/arb_draw_instanced.h>
2 #include <msp/gl/extensions/msp_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<Msp::UInt8> &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<Msp::UInt8> &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<Msp::UInt8> &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         index_type(UNSIGNED_SHORT),
58         max_index(0),
59         restart(false)
60 { }
61
62 Batch::~Batch()
63 {
64 }
65
66 void Batch::set_index_type(DataType t)
67 {
68         if(t!=UNSIGNED_SHORT && t!=UNSIGNED_INT)
69                 throw invalid_argument("Batch::set_data_type");
70         if(t==UNSIGNED_SHORT && max_index>0xFFFE)
71                 throw invalid_operation("Batch::set_data_type");
72
73         if(index_type==UNSIGNED_SHORT && t==UNSIGNED_INT)
74                 expand<UInt16, UInt32>(data);
75         else if(index_type==UNSIGNED_INT && t==UNSIGNED_SHORT)
76                 shrink<UInt32, UInt16>(data);
77
78         index_type = t;
79         update_offset();
80         dirty = true;
81 }
82
83 Batch &Batch::append(unsigned i)
84 {
85         append_index(i);
86
87         update_offset();
88         dirty = true;
89
90         return *this;
91 }
92
93 Batch &Batch::append(const vector<unsigned> &ind)
94 {
95         if(ind.empty())
96                 return *this;
97
98         data.reserve(data.size()+ind.size()*get_index_size());
99         for(vector<unsigned>::const_iterator i=ind.begin(); i!=ind.end(); ++i)
100                 append_index(*i);
101
102         update_offset();
103         dirty = true;
104
105         return *this;
106 }
107
108 bool Batch::can_append(PrimitiveType other_type)
109 {
110         if(other_type!=prim_type)
111                 return false;
112         else if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
113                 return MSP_primitive_restart;
114         else
115                 return true;
116 }
117
118 Batch &Batch::append(const Batch &other)
119 {
120         if(other.prim_type!=prim_type)
121                 throw invalid_argument("Batch::append");
122         if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
123                 static Require _req(MSP_primitive_restart);
124
125         if(other.data.empty())
126                 return *this;
127
128         // TODO allow appending triangles to a triangle strip
129
130         if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES)
131                 ;
132         else if(MSP_primitive_restart)
133         {
134                 restart = true;
135                 if(index_type==UNSIGNED_INT)
136                         ::append<UInt32>(data, 0xFFFFFFFF);
137                 else
138                         ::append<UInt16>(data, 0xFFFF);
139         }
140         else if(prim_type==TRIANGLE_STRIP)
141         {
142                 append(get_index(size()-1));
143                 append(other.get_index(0));
144                 if(size()&1)
145                         append(other.get_index(0));
146         }
147
148         unsigned count = other.size();
149         for(unsigned i=0; i<count; ++i)
150                 append_index(other.get_index(i));
151
152         update_offset();
153         dirty = true;
154
155         return *this;
156 }
157
158 void Batch::append_index(unsigned i)
159 {
160         if(data.empty())
161                 max_index = i;
162         else
163                 max_index = max(max_index, i);
164
165         if(index_type==UNSIGNED_SHORT && max_index>0xFFFE)
166                 set_index_type(UNSIGNED_INT);
167
168         if(index_type==UNSIGNED_INT)
169                 ::append<UInt32>(data, i);
170         else
171                 ::append<UInt16>(data, i);
172 }
173
174 unsigned Batch::get_index_size() const
175 {
176         return (index_type==UNSIGNED_INT ? sizeof(UInt32) : sizeof(UInt16));
177 }
178
179 unsigned Batch::get_index(unsigned i) const
180 {
181         if(index_type==UNSIGNED_INT)
182                 return *(UInt32 *)&data[i*sizeof(UInt32)];
183         else
184                 return *(UInt16 *)&data[i*sizeof(UInt16)];
185 }
186
187 void Batch::draw() const
188 {
189         BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
190         const void *data_ptr = setup_draw();
191
192         glDrawElements(prim_type, size(), index_type, data_ptr);
193 }
194
195 void Batch::draw_instanced(unsigned count) const
196 {
197         static Require req(ARB_draw_instanced);
198
199         BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
200         const void *data_ptr = setup_draw();
201
202         glDrawElementsInstanced(prim_type, size(), index_type, data_ptr, count);
203 }
204
205 const void *Batch::setup_draw() const
206 {
207         if(restart)
208         {
209                 unsigned index = (index_type==UNSIGNED_INT ? 0xFFFFFFFF : 0xFFFF);
210
211                 if(index!=restart_index)
212                         set_restart_index(index);
213         }
214         else if(restart_index && restart_index<=max_index)
215                 set_restart_index(0);
216
217         if(get_buffer())
218         {
219                 refresh();
220
221                 return reinterpret_cast<const void *>(get_offset());
222         }
223         else
224                 return &data[0];
225 }
226
227 void Batch::set_restart_index(unsigned index)
228 {
229         if(index>0)
230         {
231                 if(!restart_index)
232                         glEnable(GL_PRIMITIVE_RESTART);
233                 glPrimitiveRestartIndex(index);
234         }
235         else
236                 glDisable(GL_PRIMITIVE_RESTART);
237
238         restart_index = index;
239 }
240
241
242 Batch::Loader::Loader(Batch &b):
243         DataFile::ObjectLoader<Batch>(b)
244 {
245         add("indices", &Loader::indices);
246 }
247
248 void Batch::Loader::indices(const vector<unsigned> &ind)
249 {
250         obj.append(ind);
251 }
252
253 } // namespace GL
254 } // namespace Msp