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         delete vtx_setup;
  66         delete instance_data;
  67         delete instance_buffer;
  68 }
  69
  70 void InstanceArray::append(ObjectInstance *inst)
  71 {
  72         instances.push_back(inst);
  73         if(instance_data)
  74         {
  75                 if(instance_data->size()<instances.size())
  76                         instance_data->append();
  77                 update_instance_matrix(instances.size()-1);
  78         }
  79 }
  80
  81 void InstanceArray::remove(ObjectInstance &inst)
  82 {
  83         vector<ObjectInstance *>::iterator i = find(instances, &inst);
  84         if(i==instances.end())
  85                 throw key_error(&inst);
  86
  87         delete *i;
  88         *i = instances.back();
  89         instances.pop_back();
  90 }
  91
  92 void InstanceArray::update_instance_matrix(unsigned index)
  93 {
  94         if(!instance_data)
  95                 return;
  96
  97         const Matrix &m = *instances[index]->get_matrix();
  98
  99         float *d = instance_data->modify(instances.size()-1);
 100         for(unsigned i=0; i<12; ++i)
 101                 d[matrix_offset+i] = m(i/4, i%4);
 102 }
 103
 104 void InstanceArray::render(Renderer &renderer, const Tag &tag) const
 105 {
 106         if(instances.empty())
 107                 return;
 108
 109         if(instance_data)
 110         {
 111                 const Technique *tech = object.get_technique();
 112                 if(!tech)
 113                         throw logic_error("no technique");
 114                 if(!tech->has_pass(tag))
 115                         return;
 116                 const RenderPass &pass = tech->get_pass(tag);
 117
 118                 const Mesh *mesh = object.get_mesh();
 119                 mesh->get_vertices().refresh();
 120                 instance_data->refresh();
 121
 122                 Renderer::Push push(renderer);
 123                 pass.apply(renderer);
 124                 mesh->draw_instanced(renderer, *vtx_setup, instances.size());
 125         }
 126         else
 127         {
 128                 for(vector<ObjectInstance *>::const_iterator i=instances.begin(); i!=instances.end(); ++i)
 129                 {
 130                         const Matrix &m = *(*i)->get_matrix();
 131                         for(unsigned j=0; j<3; ++j)
 132                                 glVertexAttrib4f(matrix_location+j, m(j, 0), m(j, 1), m(j, 2), m(j, 3));
 133                         (*i)->render(renderer, tag);
 134                 }
 135         }
 136 }
 137
 138 } // namespace GL
 139 } // namespace Msp