source/render/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((RAW_ATTRIB4,matrix_location, RAW_ATTRIB4,matrix_location+1, RAW_ATTRIB4,matrix_location+2));
  48                 const VertexFormat &fmt = instance_data->get_format();
  49                 matrix_offset = fmt.offset(make_indexed_attribute(RAW_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_format_instanced(object.get_mesh()->get_vertices().get_format(), fmt);
  56                 vtx_setup->set_vertex_array(object.get_mesh()->get_vertices());
  57                 vtx_setup->set_index_buffer(*object.get_mesh()->get_index_buffer());
  58                 vtx_setup->set_instance_array(*instance_data);
  59         }
  60         else
  61                 static Require req(ARB_vertex_shader);
  62 }
  63
  64 InstanceArray::~InstanceArray()
  65 {
  66         for(vector<ObjectInstance *>::iterator i=instances.begin(); i!=instances.end(); ++i)
  67                 delete *i;
  68         delete vtx_setup;
  69         delete instance_data;
  70         delete instance_buffer;
  71 }
  72
  73 void InstanceArray::append(ObjectInstance *inst)
  74 {
  75         instances.push_back(inst);
  76         if(instance_data)
  77         {
  78                 if(instance_data->size()<instances.size())
  79                 {
  80                         instance_data->append();
  81                         unsigned req_size = instance_data->get_required_buffer_size();
  82                         if(instance_buffer->get_size()>0 && instance_buffer->get_size()<req_size)
  83                         {
  84                                 delete instance_buffer;
  85                                 instance_buffer = new Buffer(ARRAY_BUFFER);
  86                                 instance_data->use_buffer(instance_buffer);
  87                         }
  88                 }
  89                 update_instance_matrix(instances.size()-1);
  90         }
  91 }
  92
  93 void InstanceArray::remove(ObjectInstance &inst)
  94 {
  95         vector<ObjectInstance *>::iterator i = find(instances, &inst);
  96         if(i==instances.end())
  97                 throw key_error(&inst);
  98
  99         delete *i;
 100         *i = instances.back();
 101         instances.pop_back();
 102 }
 103
 104 void InstanceArray::update_instance_matrix(unsigned index)
 105 {
 106         if(!instance_data)
 107                 return;
 108
 109         const Matrix &m = *instances[index]->get_matrix();
 110
 111         float *d = instance_data->modify(instances.size()-1);
 112         for(unsigned i=0; i<12; ++i)
 113                 d[matrix_offset+i] = m(i/4, i%4);
 114 }
 115
 116 void InstanceArray::render(Renderer &renderer, Tag tag) const
 117 {
 118         if(instances.empty())
 119                 return;
 120
 121         if(instance_data)
 122         {
 123                 const Technique *tech = object.get_technique();
 124                 if(!tech)
 125                         throw logic_error("no technique");
 126                 const RenderPass *pass = tech->find_pass(tag);
 127                 if(!pass)
 128                         return;
 129
 130                 const Mesh *mesh = object.get_mesh();
 131                 mesh->get_vertices().refresh();
 132                 if(instance_buffer->get_size()==0)
 133                         instance_buffer->storage(instance_data->get_required_buffer_size());
 134                 instance_data->refresh();
 135
 136                 Renderer::Push push(renderer);
 137                 pass->apply(renderer);
 138                 mesh->draw_instanced(renderer, *vtx_setup, instances.size());
 139         }
 140         else
 141         {
 142                 for(vector<ObjectInstance *>::const_iterator i=instances.begin(); i!=instances.end(); ++i)
 143                 {
 144                         const Matrix &m = *(*i)->get_matrix();
 145                         for(unsigned j=0; j<3; ++j)
 146                                 glVertexAttrib4f(matrix_location+j, m(j, 0), m(j, 1), m(j, 2), m(j, 3));
 147                         (*i)->render(renderer, tag);
 148                 }
 149         }
 150 }
 151
 152 } // namespace GL
 153 } // namespace Msp