source/stereocombiner.cpp

   1 #include <algorithm>
   2 #include <msp/gl/meshbuilder.h>
   3 #include "stereocombiner.h"
   4
   5 using namespace std;
   6
   7 namespace {
   8
   9 const char mirror_vs_source[] =
  10         "uniform vec2 scale;\n"
  11         "varying vec2 texcoord;\n"
  12         "void main()\n"
  13         "{\n"
  14         "       gl_Position = vec4(gl_Vertex.xy, 0.0, 1.0);\n"
  15         "       texcoord = gl_Vertex.xy*scale*0.5+0.5;\n"
  16         "}";
  17
  18 const char mirror_fs_source[] =
  19         "uniform sampler2D texture;\n"
  20         "varying vec2 texcoord;\n"
  21         "void main()\n"
  22         "{\n"
  23         "       gl_FragColor = texture2D(texture, texcoord);\n"
  24         "}";
  25
  26 }
  27
  28
  29 namespace Msp {
  30 namespace VR {
  31
  32 StereoCombiner::StereoCombiner():
  33         target_width(0),
  34         target_height(0),
  35         render_aspect(1.0f),
  36         frustum_skew(0.0f),
  37         mirror(0)
  38 { }
  39
  40 void StereoCombiner::configure_eye_frustums(const Frustum &left_frustum, const Frustum &right_frustum)
  41 {
  42         float vertical = max(max(left_frustum.top, -left_frustum.bottom), max(right_frustum.top, -right_frustum.bottom));
  43         fov = Geometry::atan<float>(vertical)*2.0f;
  44
  45         float inner = max(left_frustum.right, -right_frustum.left);
  46         float outer = max(-left_frustum.left, right_frustum.right);
  47         frustum_skew = (inner-outer)/(inner+outer);
  48
  49         render_aspect = (inner+outer)/(vertical*2);
  50 }
  51
  52 void StereoCombiner::set_mirroring(bool m)
  53 {
  54         if(m && !is_mirroring_supported())
  55                 throw runtime_error("mirroring not supported");
  56
  57         if(m && !mirror)
  58                 mirror = new MirrorView;
  59         else if(!m && mirror)
  60         {
  61                 delete mirror;
  62                 mirror = 0;
  63         }
  64 }
  65
  66 void StereoCombiner::render_mirror(const GL::Texture2D &tex) const
  67 {
  68         if(!mirror)
  69                 return;
  70
  71         GL::Bind bind_tex(tex);
  72         GL::Bind bind_shprog(mirror->shader);
  73         mirror->shdata.apply();
  74         mirror->mesh.draw();
  75 }
  76
  77
  78 StereoCombiner::Frustum::Frustum():
  79         left(-1),
  80         right(1),
  81         bottom(-1),
  82         top(1)
  83 { }
  84
  85 StereoCombiner::Frustum::Frustum(float l, float r, float b, float t):
  86         left(l),
  87         right(r),
  88         bottom(b),
  89         top(t)
  90 { }
  91
  92
  93 StereoCombiner::MirrorView::MirrorView():
  94         mesh(GL::VERTEX2),
  95         shader(mirror_vs_source, mirror_fs_source)
  96 {
  97         GL::MeshBuilder bld(mesh);
  98         bld.begin(GL::TRIANGLE_STRIP);
  99         bld.vertex(-1, 1);
 100         bld.vertex(-1, -1);
 101         bld.vertex(1, 1);
 102         bld.vertex(1, -1);
 103         bld.end();
 104
 105         shdata.uniform("scale", 0.5f, 0.5f);
 106 }
 107
 108 } // namespace VR
 109 } // namespace Msp