source/sidebysidecombiner.cpp

   1 #include <msp/gl/meshbuilder.h>
   2 #include <msp/gl/texture2d.h>
   3 #include "sidebysidecombiner.h"
   4
   5 namespace {
   6
   7 const char vs_source[] =
   8         "uniform float offset;\n"
   9         "varying vec2 texcoord;\n"
  10         "void main()\n"
  11         "{\n"
  12         "       gl_Position = vec4(gl_Vertex.x*0.5+offset, gl_Vertex.yzw);\n"
  13         "       texcoord = gl_Vertex.xy*0.5+0.5;\n"
  14         "}\n";
  15
  16 const char fs_source[] =
  17         "uniform sampler2D texture;\n"
  18         "varying vec2 texcoord;\n"
  19         "void main()\n"
  20         "{\n"
  21         "       gl_FragColor = texture2D(texture, texcoord);\n"
  22         "}\n";
  23
  24 }
  25
  26 namespace Msp {
  27 namespace VR {
  28
  29 SideBySideCombiner::SideBySideCombiner(GL::View &v, bool c):
  30         view(v),
  31         mesh(GL::VERTEX2),
  32         shprog(vs_source, fs_source)
  33 {
  34         target_width = view.get_width()/2;
  35         target_height = view.get_height()/2;
  36         render_aspect = static_cast<float>(target_width)/target_height;
  37
  38         left_shdata.uniform("texture", 0);
  39         right_shdata.uniform("texture", 0);
  40
  41         set_cross_eyed(c);
  42
  43         GL::MeshBuilder bld(mesh);
  44         bld.begin(GL::TRIANGLE_STRIP);
  45         bld.vertex(-1, 1);
  46         bld.vertex(-1, -1);
  47         bld.vertex(1, 1);
  48         bld.vertex(1, -1);
  49         bld.end();
  50 }
  51
  52 void SideBySideCombiner::set_cross_eyed(bool c)
  53 {
  54         cross_eyed = c;
  55         float m = (cross_eyed ? -0.5f : 0.5f);
  56         left_shdata.uniform("offset", -m);
  57         right_shdata.uniform("offset", m);
  58 }
  59
  60 void SideBySideCombiner::render(const GL::Texture2D &left, const GL::Texture2D &right) const
  61 {
  62         GL::Bind bind_shprog(shprog);
  63
  64         GL::Bind bind_tex(left);
  65         left_shdata.apply();
  66         mesh.draw();
  67
  68         right.bind();
  69         right_shdata.apply();
  70         mesh.draw();
  71
  72         view.get_context().swap_buffers();
  73 }
  74
  75 } // namespace VR
  76 } // namespace Msp