source/mesh.cpp

   1 #include <msp/gl/extensions/arb_vertex_array_object.h>
   2 #include <msp/gl/extensions/arb_vertex_shader.h>
   3 #include "buffer.h"
   4 #include "error.h"
   5 #include "mesh.h"
   6 #include "renderer.h"
   7
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 Mesh::Mesh():
  14         vertices(VERTEX3),
  15         vbuf(0),
  16         ibuf(0),
  17         vao_id(0),
  18         defer_buffers(true),
  19         dirty(true),
  20         winding(0)
  21 { }
  22
  23 Mesh::Mesh(const VertexFormat &f):
  24         vertices(f),
  25         vbuf(0),
  26         ibuf(0),
  27         vao_id(0),
  28         defer_buffers(true),
  29         dirty(true),
  30         winding(0)
  31 { }
  32
  33 Mesh::~Mesh()
  34 {
  35         delete vbuf;
  36         delete ibuf;
  37         if(vao_id)
  38                 glDeleteVertexArrays(1, &vao_id);
  39 }
  40
  41 void Mesh::clear()
  42 {
  43         vertices.clear();
  44         batches.clear();
  45 }
  46
  47 void Mesh::use_buffers(bool b)
  48 {
  49         defer_buffers = false;
  50         if(b)
  51                 create_buffers();
  52         else
  53         {
  54                 vertices.use_buffer(0);
  55                 delete vbuf;
  56                 vbuf = 0;
  57                 delete ibuf;
  58                 ibuf = 0;
  59         }
  60 }
  61
  62 void Mesh::create_buffers()
  63 {
  64         defer_buffers = false;
  65
  66         if(!vbuf)
  67                 vbuf = new Buffer(ARRAY_BUFFER);
  68         vertices.use_buffer(vbuf);
  69
  70         if(!ibuf)
  71                 ibuf = new Buffer(ELEMENT_ARRAY_BUFFER);
  72
  73         if(ARB_vertex_array_object && !vao_id)
  74                 glGenVertexArrays(1, &vao_id);
  75 }
  76
  77 void Mesh::setup_vao() const
  78 {
  79         Bind bind_vbuf(vbuf, ARRAY_BUFFER);
  80
  81         const VertexFormat &fmt = vertices.get_format();
  82         unsigned stride = get_stride(fmt)*sizeof(float);
  83         float *ptr = 0;
  84         for(const unsigned char *c=fmt.begin(); c!=fmt.end(); ++c)
  85         {
  86                 unsigned t = get_component_type(*c);
  87                 if(t>=get_component_type(ATTRIB1))
  88                         t -= get_component_type(ATTRIB1);
  89                 unsigned sz = get_component_size(*c);
  90                 if(*c==COLOR4_UBYTE)
  91                         glVertexAttribPointer(t, 4, GL_UNSIGNED_BYTE, true, stride, ptr);
  92                 else
  93                         glVertexAttribPointer(t, sz, GL_FLOAT, false, stride, ptr);
  94                 glEnableVertexAttribArray(t);
  95                 ptr += sz;
  96         }
  97         glBindBuffer(ELEMENT_ARRAY_BUFFER, ibuf->get_id());
  98
  99         dirty = false;
 100 }
 101
 102 unsigned Mesh::get_n_vertices() const
 103 {
 104         return vertices.size();
 105 }
 106
 107 float *Mesh::modify_vertex(unsigned i)
 108 {
 109         return vertices.modify(i);
 110 }
 111
 112 void Mesh::add_batch(const Batch &b)
 113 {
 114         if(defer_buffers)
 115                 create_buffers();
 116
 117         if(!batches.empty() && batches.back().can_append(b.get_type()))
 118                 batches.back().append(b);
 119         else
 120         {
 121                 Batch *prev = (batches.empty() ? 0 : &batches.back());
 122                 batches.push_back(b);
 123                 if(ibuf)
 124                         batches.back().use_buffer(ibuf, prev);
 125         }
 126 }
 127
 128 void Mesh::set_winding(const WindingTest *w)
 129 {
 130         winding = w;
 131 }
 132
 133 void Mesh::draw() const
 134 {
 135         const Mesh *cur = current();
 136         if(cur && cur!=this)
 137                 throw invalid_operation("Mesh::draw");
 138
 139         if(!current())
 140                 vertices.apply();
 141         Bind bind_ibuf(ibuf, ELEMENT_ARRAY_BUFFER);
 142         Bind bind_winding(winding);
 143
 144         for(list<Batch>::const_iterator i=batches.begin(); i!=batches.end(); ++i)
 145                 i->draw();
 146 }
 147
 148 void Mesh::draw(Renderer &renderer) const
 149 {
 150         renderer.set_mesh(this);
 151         renderer.set_element_buffer(ibuf);
 152         renderer.set_winding_test(winding);
 153
 154         for(list<Batch>::const_iterator i=batches.begin(); i!=batches.end(); ++i)
 155                 renderer.draw(*i);
 156 }
 157
 158 void Mesh::bind() const
 159 {
 160         /* If VAOs are not supported, vao_id is zero and set_current won't get
 161         called.  Thus unbind won't try to call a null function either. */
 162         if(!vao_id)
 163         {
 164                 unbind();
 165                 vertices.apply();
 166         }
 167         else if(set_current(this))
 168         {
 169                 glBindVertexArray(vao_id);
 170                 vertices.refresh();
 171                 if(dirty)
 172                         setup_vao();
 173         }
 174 }
 175
 176 void Mesh::unbind()
 177 {
 178         if(set_current(0))
 179                 glBindVertexArray(0);
 180 }
 181
 182
 183 Mesh::Loader::Loader(Mesh &m):
 184         DataFile::ObjectLoader<Mesh>(m)
 185 {
 186         add("batch",    &Loader::batch);
 187         add("vertices", &Loader::vertices);
 188         add("winding",  &Loader::winding);
 189 }
 190
 191 void Mesh::Loader::vertices(const vector<VertexComponent> &c)
 192 {
 193         if(c.empty())
 194                 throw invalid_argument("No vertex components");
 195
 196         VertexFormat fmt;
 197         for(vector<VertexComponent>::const_iterator i=c.begin(); i!=c.end(); ++i)
 198                 fmt = (fmt, *i);
 199         obj.vertices.reset(fmt);
 200         obj.dirty = true;
 201         load_sub(obj.vertices);
 202 }
 203
 204 void Mesh::Loader::batch(PrimitiveType p)
 205 {
 206         Batch btc(p);
 207         load_sub(btc);
 208         obj.add_batch(btc);
 209 }
 210
 211 void Mesh::Loader::winding(FaceWinding w)
 212 {
 213         if(w==CLOCKWISE)
 214                 obj.winding = &WindingTest::clockwise();
 215         else if(w==COUNTERCLOCKWISE)
 216                 obj.winding = &WindingTest::counterclockwise();
 217 }
 218
 219 } // namespace GL
 220 } // namespace Msp