source/builders/box.cpp

   1 #include <cmath>
   2 #include "box.h"
   3 #include "primitivebuilder.h"
   4
   5 using namespace std;
   6
   7 namespace Msp {
   8 namespace GL {
   9
  10 BoxBuilder::BoxBuilder(float w, float h, float d):
  11         origin(-w/2, -h/2, -d/2),
  12         span(w, h, d)
  13 { }
  14
  15 BoxBuilder::BoxBuilder(const Vector3 &o, const Vector3 &s):
  16         origin(o),
  17         span(s)
  18 { }
  19
  20 void BoxBuilder::build(PrimitiveBuilder &builder) const
  21 {
  22         builder.normal(1, 0, 0);
  23         build_face(builder, Vector3(origin.x+span.x, origin.y, origin.z), Vector3(0, span.y, 0), Vector3(0, 0, span.z));
  24         builder.normal(0, 1, 0);
  25         build_face(builder, Vector3(origin.x+span.x, origin.y+span.y, origin.z), Vector3(-span.x, 0, 0), Vector3(0, 0, span.z));
  26         builder.normal(-1, 0, 0);
  27         build_face(builder, Vector3(origin.x, origin.y+span.y, origin.z), Vector3(0, -span.y, 0), Vector3(0, 0, span.z));
  28         builder.normal(0, -1, 0);
  29         build_face(builder, origin, Vector3(span.x, 0, 0), Vector3(0, 0, span.z));
  30         builder.normal(0, 0, 1);
  31         build_face(builder, Vector3(origin.x, origin.y, origin.z+span.z), Vector3(span.x, 0, 0), Vector3(0, span.y, 0));
  32         builder.normal(0, 0, -1);
  33         build_face(builder, Vector3(origin.x+span.x, origin.y, origin.z), Vector3(-span.x, 0, 0), Vector3(0, span.y, 0));
  34 }
  35
  36 void BoxBuilder::build_face(PrimitiveBuilder &builder, const Vector3 &o, const Vector3 &s1, const Vector3 &s2) const
  37 {
  38         float l1 = 1, l2 = 1;
  39         if(generate_tan || tex_fit!=STRETCH)
  40         {
  41                 l1 = s1.norm();
  42                 l2 = s2.norm();
  43         }
  44
  45         if(generate_tan)
  46                 builder.tangent(s1/l1);
  47
  48         float u_size = 1;
  49         float v_size = 1;
  50         adjust_texture_scale(u_size, v_size, l1, l2);
  51
  52         builder.begin(TRIANGLE_STRIP);
  53         builder.texcoord(0, v_size);
  54         builder.vertex(o+s2);
  55         builder.texcoord(0, 0);
  56         builder.vertex(o);
  57         builder.texcoord(u_size, v_size);
  58         builder.vertex(o+s1+s2);
  59         builder.texcoord(u_size, 0);
  60         builder.vertex(o+s1);
  61         builder.end();
  62 }
  63
  64 } // namespace GL
  65 } // namespace Msp