source/render/instancearray.cpp

   1 #include <msp/core/algorithm.h>
   2 #include <msp/core/maputils.h>
   3 #include "buffer.h"
   4 #include "instancearray.h"
   5 #include "mesh.h"
   6 #include "object.h"
   7 #include "objectinstance.h"
   8 #include "program.h"
   9 #include "renderer.h"
  10 #include "technique.h"
  11
  12 using namespace std;
  13
  14 namespace Msp {
  15 namespace GL {
  16
  17 InstanceArray::InstanceArray(const Object &o):
  18         object(o)
  19 {
  20         const Technique *tech = object.get_technique();
  21         for(const auto &kvp: tech->get_methods())
  22         {
  23                 const Program *shprog = kvp.second.get_shader_program();
  24                 if(!shprog)
  25                         throw invalid_argument("InstanceArray::InstanceArray");
  26
  27                 int loc = shprog->get_attribute_location("instance_transform");
  28                 if(matrix_location<0)
  29                         matrix_location = loc;
  30                 else if(loc!=matrix_location)
  31                         throw invalid_argument("InstanceArray::InstanceArray");
  32         }
  33
  34         instance_data.set_format((RAW_ATTRIB4,matrix_location, RAW_ATTRIB4,matrix_location+1, RAW_ATTRIB4,matrix_location+2));
  35         const VertexFormat &fmt = instance_data.get_format();
  36         matrix_offset = fmt.offset((RAW_ATTRIB4,matrix_location));
  37
  38         instance_buffer = new Buffer;
  39         instance_data.use_buffer(instance_buffer);
  40
  41         const Mesh *mesh = object.get_mesh();
  42
  43         vtx_setup.set_format_instanced(mesh->get_vertices().get_format(), fmt);
  44         vtx_setup.set_vertex_array(mesh->get_vertices());
  45         vtx_setup.set_index_buffer(*mesh->get_index_buffer(), mesh->get_batches().front().get_index_type());
  46         vtx_setup.set_instance_array(instance_data);
  47 }
  48
  49 InstanceArray::~InstanceArray()
  50 {
  51         for(ObjectInstance *i: instances)
  52                 delete i;
  53         delete instance_buffer;
  54 }
  55
  56 void InstanceArray::append(ObjectInstance *inst)
  57 {
  58         instances.push_back(inst);
  59         if(instance_data.size()<instances.size())
  60         {
  61                 instance_data.append();
  62                 unsigned req_size = instance_data.get_required_buffer_size();
  63                 if(instance_buffer->get_size()>0 && instance_buffer->get_size()<req_size)
  64                 {
  65                         delete instance_buffer;
  66                         instance_buffer = new Buffer;
  67                         instance_data.use_buffer(instance_buffer);
  68                 }
  69         }
  70         update_instance_matrix(instances.size()-1);
  71 }
  72
  73 void InstanceArray::remove(ObjectInstance &inst)
  74 {
  75         auto i = find(instances, &inst);
  76         if(i==instances.end())
  77                 throw key_error(&inst);
  78
  79         delete *i;
  80         *i = instances.back();
  81         instances.pop_back();
  82 }
  83
  84 void InstanceArray::update_instance_matrix(unsigned index)
  85 {
  86         const Matrix &m = *instances[index]->get_matrix();
  87
  88         float *d = reinterpret_cast<float *>(instance_data.modify(instances.size()-1)+matrix_offset);
  89         for(unsigned i=0; i<12; ++i)
  90                 d[i] = m(i/4, i%4);
  91 }
  92
  93 void InstanceArray::render(Renderer &renderer, Tag tag) const
  94 {
  95         if(instances.empty())
  96                 return;
  97
  98         const Technique *tech = object.get_technique();
  99         if(!tech)
 100                 throw logic_error("no technique");
 101         const RenderMethod *method = tech->find_method(tag);
 102         if(!method)
 103                 return;
 104
 105         const Mesh *mesh = object.get_mesh();
 106         mesh->get_vertices().refresh();
 107         if(instance_buffer->get_size()==0)
 108                 instance_buffer->storage(instance_data.get_required_buffer_size(), STREAMING);
 109         instance_data.refresh();
 110
 111         Renderer::Push push(renderer);
 112         method->apply(renderer);
 113         mesh->draw_instanced(renderer, vtx_setup, instances.size());
 114 }
 115
 116 } // namespace GL
 117 } // namespace Msp