source/instancearray.cpp

   1 #include <msp/core/algorithm.h>
   2 #include <msp/core/maputils.h>
   3 #include <msp/gl/extensions/arb_draw_instanced.h>
   4 #include <msp/gl/extensions/arb_instanced_arrays.h>
   5 #include <msp/gl/extensions/arb_vertex_array_object.h>
   6 #include <msp/gl/extensions/arb_vertex_shader.h>
   7 #include "buffer.h"
   8 #include "camera.h"
   9 #include "instancearray.h"
  10 #include "mesh.h"
  11 #include "object.h"
  12 #include "objectinstance.h"
  13 #include "renderer.h"
  14 #include "technique.h"
  15 #include "vertexsetup.h"
  16
  17 using namespace std;
  18
  19 namespace Msp {
  20 namespace GL {
  21
  22 InstanceArray::InstanceArray(const Object &o):
  23         object(o),
  24         instance_data(0),
  25         instance_buffer(0),
  26         vtx_setup(0),
  27         matrix_location(-1),
  28         matrix_offset(0)
  29 {
  30         const Technique *tech = object.get_technique();
  31         const Technique::PassMap &passes = tech->get_passes();
  32         for(Technique::PassMap::const_iterator i=passes.begin(); i!=passes.end(); ++i)
  33         {
  34                 const Program *shprog = i->second.get_shader_program();
  35                 if(!shprog)
  36                         throw invalid_argument("InstanceArray::InstanceArray");
  37
  38                 int loc = shprog->get_attribute_location("instance_transform");
  39                 if(matrix_location<0)
  40                         matrix_location = loc;
  41                 else if(loc!=matrix_location)
  42                         throw invalid_argument("InstanceArray::InstanceArray");
  43         }
  44
  45         if(ARB_vertex_array_object && ARB_instanced_arrays && ARB_draw_instanced)
  46         {
  47                 instance_data = new VertexArray((ATTRIB4,matrix_location, ATTRIB4,matrix_location+1, ATTRIB4,matrix_location+2));
  48                 const VertexFormat &fmt = instance_data->get_format();
  49                 matrix_offset = fmt.offset(make_indexed_component(ATTRIB4, matrix_location));
  50
  51                 instance_buffer = new Buffer(ARRAY_BUFFER);
  52                 instance_data->use_buffer(instance_buffer);
  53
  54                 vtx_setup = new VertexSetup;
  55                 vtx_setup->set_vertex_array(object.get_mesh()->get_vertices());
  56                 vtx_setup->set_index_buffer(*object.get_mesh()->get_index_buffer());
  57                 vtx_setup->set_instance_array(instance_data);
  58         }
  59         else
  60                 static Require req(ARB_vertex_shader);
  61 }
  62
  63 InstanceArray::~InstanceArray()
  64 {
  65         for(std::vector<ObjectInstance *>::iterator i=instances.begin(); i!=instances.end(); ++i)
  66                 delete *i;
  67         delete vtx_setup;
  68         delete instance_data;
  69         delete instance_buffer;
  70 }
  71
  72 void InstanceArray::append(ObjectInstance *inst)
  73 {
  74         instances.push_back(inst);
  75         if(instance_data)
  76         {
  77                 if(instance_data->size()<instances.size())
  78                         instance_data->append();
  79                 update_instance_matrix(instances.size()-1);
  80         }
  81 }
  82
  83 void InstanceArray::remove(ObjectInstance &inst)
  84 {
  85         vector<ObjectInstance *>::iterator i = find(instances, &inst);
  86         if(i==instances.end())
  87                 throw key_error(&inst);
  88
  89         delete *i;
  90         *i = instances.back();
  91         instances.pop_back();
  92 }
  93
  94 void InstanceArray::update_instance_matrix(unsigned index)
  95 {
  96         if(!instance_data)
  97                 return;
  98
  99         const Matrix &m = *instances[index]->get_matrix();
 100
 101         float *d = instance_data->modify(instances.size()-1);
 102         for(unsigned i=0; i<12; ++i)
 103                 d[matrix_offset+i] = m(i/4, i%4);
 104 }
 105
 106 void InstanceArray::render(Renderer &renderer, const Tag &tag) const
 107 {
 108         if(instances.empty())
 109                 return;
 110
 111         if(instance_data)
 112         {
 113                 const Technique *tech = object.get_technique();
 114                 if(!tech)
 115                         throw logic_error("no technique");
 116                 if(!tech->has_pass(tag))
 117                         return;
 118                 const RenderPass &pass = tech->get_pass(tag);
 119
 120                 const Mesh *mesh = object.get_mesh();
 121                 mesh->get_vertices().refresh();
 122                 instance_data->refresh();
 123
 124                 Renderer::Push push(renderer);
 125                 pass.apply(renderer);
 126                 mesh->draw_instanced(renderer, *vtx_setup, instances.size());
 127         }
 128         else
 129         {
 130                 for(vector<ObjectInstance *>::const_iterator i=instances.begin(); i!=instances.end(); ++i)
 131                 {
 132                         const Matrix &m = *(*i)->get_matrix();
 133                         for(unsigned j=0; j<3; ++j)
 134                                 glVertexAttrib4f(matrix_location+j, m(j, 0), m(j, 1), m(j, 2), m(j, 3));
 135                         (*i)->render(renderer, tag);
 136                 }
 137         }
 138 }
 139
 140 } // namespace GL
 141 } // namespace Msp