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 StereoCombiner::~StereoCombiner()
  41 {
  42         delete mirror;
  43 }
  44
  45 void StereoCombiner::configure_eye_frustums(const Frustum &left_frustum, const Frustum &right_frustum)
  46 {
  47         float vertical = max(max(left_frustum.top, -left_frustum.bottom), max(right_frustum.top, -right_frustum.bottom));
  48         fov = Geometry::atan<float>(vertical)*2.0f;
  49
  50         float inner = max(left_frustum.right, -right_frustum.left);
  51         float outer = max(-left_frustum.left, right_frustum.right);
  52         frustum_skew = (inner-outer)/(inner+outer);
  53
  54         render_aspect = (inner+outer)/(vertical*2);
  55 }
  56
  57 void StereoCombiner::set_mirroring(bool m)
  58 {
  59         if(m && !is_mirroring_supported())
  60                 throw runtime_error("mirroring not supported");
  61
  62         if(m && !mirror)
  63                 mirror = new MirrorView;
  64         else if(!m && mirror)
  65         {
  66                 delete mirror;
  67                 mirror = 0;
  68         }
  69 }
  70
  71 void StereoCombiner::render_mirror(const GL::Texture2D &tex) const
  72 {
  73         if(!mirror)
  74                 return;
  75
  76         GL::Bind bind_tex(tex);
  77         GL::Bind bind_shprog(mirror->shader);
  78         mirror->shdata.apply();
  79         mirror->mesh.draw();
  80 }
  81
  82
  83 StereoCombiner::Frustum::Frustum():
  84         left(-1),
  85         right(1),
  86         bottom(-1),
  87         top(1)
  88 { }
  89
  90 StereoCombiner::Frustum::Frustum(float l, float r, float b, float t):
  91         left(l),
  92         right(r),
  93         bottom(b),
  94         top(t)
  95 { }
  96
  97
  98 StereoCombiner::MirrorView::MirrorView():
  99         mesh(GL::VERTEX2),
 100         shader(mirror_vs_source, mirror_fs_source)
 101 {
 102         GL::MeshBuilder bld(mesh);
 103         bld.begin(GL::TRIANGLE_STRIP);
 104         bld.vertex(-1, 1);
 105         bld.vertex(-1, -1);
 106         bld.vertex(1, 1);
 107         bld.vertex(1, -1);
 108         bld.end();
 109
 110         shdata.uniform("scale", 0.5f, 0.5f);
 111 }
 112
 113 } // namespace VR
 114 } // namespace Msp