source/oculusriftcombiner.cpp

   1 #include <cmath>
   2 #include <msp/gl/meshbuilder.h>
   3 #include <msp/gl/texture2d.h>
   4 #include "oculusriftcombiner.h"
   5 #include "oculusriftdevice.h"
   6 #include "oculusriftdevice_private.h"
   7
   8 using namespace std;
   9
  10
  11 namespace {
  12
  13 const char vs_source[] =
  14         "varying vec2 texcoord_r;\n"
  15         "varying vec2 texcoord_g;\n"
  16         "varying vec2 texcoord_b;\n"
  17         "void main()\n"
  18         "{\n"
  19         "       gl_Position = vec4(gl_Vertex.xy, 0.5, 1.0);\n"
  20         "       texcoord_r = gl_MultiTexCoord0.xy;\n"
  21         "       texcoord_g = gl_MultiTexCoord1.xy;\n"
  22         "       texcoord_b = gl_MultiTexCoord2.xy;\n"
  23         "}\n";
  24
  25 const char fs_source[] =
  26         "uniform sampler2D texture;\n"
  27         "varying vec2 texcoord_r;\n"
  28         "varying vec2 texcoord_g;\n"
  29         "varying vec2 texcoord_b;\n"
  30         "void main()\n"
  31         "{\n"
  32         "       float r = texture2D(texture, texcoord_r).r;\n"
  33         "       float g = texture2D(texture, texcoord_g).g;\n"
  34         "       float b = texture2D(texture, texcoord_b).b;\n"
  35         "       gl_FragColor = vec4(r, g, b, 1.0);\n"
  36         "}\n";
  37
  38 void create_distortion_mesh(Msp::GL::Mesh &mesh, ovrHmd hmd, ovrEyeType eye, const ovrFovPort &fov)
  39 {
  40         ovrDistortionMesh ovr_mesh;
  41         ovrHmd_CreateDistortionMesh(hmd, eye, fov, ovrDistortionCap_Chromatic, &ovr_mesh);
  42
  43         ovrSizei tex_size = ovrHmd_GetFovTextureSize(hmd, eye, fov, 1.0);
  44         ovrRecti view_rect;
  45         view_rect.Pos.x = 0;
  46         view_rect.Pos.y = 0;
  47         view_rect.Size = tex_size;
  48         ovrVector2f uv_scale_offset[2];
  49         ovrHmd_GetRenderScaleAndOffset(fov, tex_size, view_rect, uv_scale_offset);
  50         ovrVector2f &scale = uv_scale_offset[0];
  51         ovrVector2f &offset = uv_scale_offset[1];
  52
  53         Msp::GL::MeshBuilder bld(mesh);
  54         for(unsigned i=0; i<ovr_mesh.VertexCount; ++i)
  55         {
  56                 ovrDistortionVertex &v = ovr_mesh.pVertexData[i];
  57                 bld.multitexcoord(0, v.TanEyeAnglesR.x*scale.x+offset.x, 1.0f-(v.TanEyeAnglesR.y*scale.y+offset.y));
  58                 bld.multitexcoord(1, v.TanEyeAnglesG.x*scale.x+offset.x, 1.0f-(v.TanEyeAnglesG.y*scale.y+offset.y));
  59                 bld.multitexcoord(2, v.TanEyeAnglesB.x*scale.x+offset.x, 1.0f-(v.TanEyeAnglesB.y*scale.y+offset.y));
  60                 bld.vertex(v.ScreenPosNDC.x, v.ScreenPosNDC.y);
  61         }
  62
  63         Msp::GL::Batch batch(Msp::GL::TRIANGLES);
  64         batch.append(vector<unsigned>(ovr_mesh.pIndexData, ovr_mesh.pIndexData+ovr_mesh.IndexCount));
  65         mesh.add_batch(batch);
  66
  67         ovrHmd_DestroyDistortionMesh(&ovr_mesh);
  68 }
  69
  70 }
  71
  72 namespace Msp {
  73 namespace VR {
  74
  75 OculusRiftCombiner::OculusRiftCombiner(const OculusRiftDevice &d):
  76         device(d),
  77         left_mesh((GL::VERTEX2, GL::TEXCOORD2,0, GL::TEXCOORD2,1, GL::TEXCOORD2,2)),
  78         right_mesh((GL::VERTEX2, GL::TEXCOORD2,0, GL::TEXCOORD2,1, GL::TEXCOORD2,2)),
  79         shprog(vs_source, fs_source)
  80 {
  81         const OculusRiftDevice::Private &dev_priv = device.get_private();
  82         ovrHmd hmd = dev_priv.ovr_hmd;
  83
  84         ovrFovPort left_fov = hmd->DefaultEyeFov[ovrEye_Left];
  85         ovrFovPort right_fov = hmd->DefaultEyeFov[ovrEye_Right];
  86         float vertical = max(max(left_fov.UpTan, left_fov.DownTan), max(right_fov.UpTan, right_fov.DownTan));
  87         fov = Geometry::atan<float>(vertical)*2.0f;
  88
  89         float inner = max(left_fov.RightTan, right_fov.LeftTan);
  90         float outer = max(left_fov.LeftTan, right_fov.RightTan);
  91         frustum_skew = (inner-outer)*2/(inner+outer);
  92
  93         left_fov.UpTan = right_fov.UpTan = vertical;
  94         left_fov.DownTan = right_fov.DownTan = vertical;
  95         left_fov.RightTan = right_fov.LeftTan = inner;
  96         left_fov.LeftTan = right_fov.RightTan = outer;
  97
  98         create_distortion_mesh(left_mesh, hmd, ovrEye_Left, left_fov);
  99         create_distortion_mesh(right_mesh, hmd, ovrEye_Right, right_fov);
 100
 101         ovrSizei tex_size = ovrHmd_GetFovTextureSize(hmd, ovrEye_Left, left_fov, 1.0);
 102         width_factor = tex_size.w*1.0f/hmd->Resolution.w;
 103         height_factor = tex_size.h*1.0f/hmd->Resolution.h;
 104         float aspect = (inner+outer)/(vertical*2);
 105         aspect_factor = aspect*hmd->Resolution.h/hmd->Resolution.w;
 106
 107         shdata.uniform("texture", 0);
 108
 109 }
 110
 111 void OculusRiftCombiner::render(const GL::Texture2D &left, const GL::Texture2D &right) const
 112 {
 113         GL::Bind bind_shprog(shprog);
 114         shdata.apply();
 115
 116         GL::Bind bind_tex(left);
 117         left_mesh.draw();
 118
 119         right.bind();
 120         right_mesh.draw();
 121 }
 122
 123 } // namespace VR
 124 } // namespace Msp