source/box.cpp

   1 /* $Id$
   2
   3 This file is part of libmspgl
   4 Copyright © 2011  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #include <cmath>
   9 #include "box.h"
  10 #include "primitivebuilder.h"
  11
  12 using namespace std;
  13
  14 namespace Msp {
  15 namespace GL {
  16
  17 BoxBuilder::BoxBuilder(float w, float h, float d):
  18         origin(-w/2, -h/2, -d/2),
  19         span(w, h, d)
  20 { }
  21
  22 BoxBuilder::BoxBuilder(const Vector3 &o, const Vector3 &s):
  23         origin(o),
  24         span(s)
  25 { }
  26
  27 void BoxBuilder::build(PrimitiveBuilder &builder) const
  28 {
  29         builder.normal(1, 0, 0);
  30         build_face(builder, Vector3(origin.x+span.x, origin.y, origin.z), Vector3(0, span.y, 0), Vector3(0, 0, span.z));
  31         builder.normal(0, 1, 0);
  32         build_face(builder, Vector3(origin.x+span.x, origin.y+span.y, origin.z), Vector3(-span.x, 0, 0), Vector3(0, 0, span.z));
  33         builder.normal(-1, 0, 0);
  34         build_face(builder, Vector3(origin.x, origin.y+span.y, origin.z), Vector3(0, -span.y, 0), Vector3(0, 0, span.z));
  35         builder.normal(0, -1, 0);
  36         build_face(builder, origin, Vector3(span.x, 0, 0), Vector3(0, 0, span.z));
  37         builder.normal(0, 0, 1);
  38         build_face(builder, Vector3(origin.x, origin.y, origin.z+span.z), Vector3(span.x, 0, 0), Vector3(0, span.y, 0));
  39         builder.normal(0, 0, -1);
  40         build_face(builder, Vector3(origin.x+span.x, origin.y, origin.z), Vector3(-span.x, 0, 0), Vector3(0, span.y, 0));
  41 }
  42
  43 void BoxBuilder::build_face(PrimitiveBuilder &builder, const Vector3 &o, const Vector3 &s1, const Vector3 &s2) const
  44 {
  45         float l1 = 1, l2 = 1;
  46         if(tangent_attr>=0 || tex_fit!=STRETCH)
  47                 l1 = sqrt(s1.x*s1.x+s1.y*s1.y+s1.z*s1.z);
  48         if(binormal_attr>=0 || tex_fit!=STRETCH)
  49                 l2 = sqrt(s2.x*s2.x+s2.y*s2.y+s2.z*s2.z);
  50
  51         if(tangent_attr>=0)
  52                 builder.attrib(tangent_attr, s1.x/l1, s1.y/l1, s1.z/l1);
  53         if(binormal_attr>=0)
  54                 builder.attrib(binormal_attr, s2.x/l2, s2.y/l2, s2.z/l2);
  55
  56         float u_size = 1;
  57         float v_size = 1;
  58         if(tex_fit!=STRETCH)
  59         {
  60                 if((l1<l2)==(tex_fit==CUT))
  61                         u_size = l1/l2;
  62                 else
  63                         v_size = l2/l1;
  64         }
  65
  66         builder.begin(TRIANGLE_STRIP);
  67         builder.texcoord(0, v_size);
  68         builder.vertex(o.x+s2.x, o.y+s2.y, o.z+s2.z);
  69         builder.texcoord(0, 0);
  70         builder.vertex(o.x, o.y, o.z);
  71         builder.texcoord(u_size, v_size);
  72         builder.vertex(o.x+s1.x+s2.x, o.y+s1.y+s2.y, o.z+s1.z+s2.z);
  73         builder.texcoord(u_size, 0);
  74         builder.vertex(o.x+s1.x, o.y+s1.y, o.z+s1.z);
  75         builder.end();
  76 }
  77
  78 } // namespace GL
  79 } // namespace Msp