Implement display mirroring in StereoCombiner

It's up to individual combiners to use it.  Currently OpenVRCombiner
is the only one to support it, since the others render directly to the
application window.

diff --git a/source/openvr/openvrcombiner.cpp b/source/openvr/openvrcombiner.cpp
index 2272a1a3509dad7b4667b49fb4a6c348d2026078..9bdf4b01a8151755a7f1ca3fa715c6dd96de9045 100644 (file)
--- a/source/openvr/openvrcombiner.cpp
+++ b/source/openvr/openvrcombiner.cpp
@@ -11,8 +11,9 @@ struct OpenVRCombiner::Private
 };
 
 
-OpenVRCombiner::OpenVRCombiner(OpenVRDevice &d):
-       device(d)
+OpenVRCombiner::OpenVRCombiner(OpenVRDevice &d, GL::View &v):
+       device(d),
+       view(v)
 {
        vr::IVRSystem *vr_sys = vr::VRSystem();
        uint32_t w, h;
@@ -23,6 +24,8 @@ OpenVRCombiner::OpenVRCombiner(OpenVRDevice &d):
        Frustum left_frustum = Private::get_projection(vr::Eye_Left);
        Frustum right_frustum = Private::get_projection(vr::Eye_Right);
        configure_eye_frustums(left_frustum, right_frustum);
+
+       set_mirroring(true);
 }
 
 void OpenVRCombiner::prepare() const
@@ -41,6 +44,13 @@ void OpenVRCombiner::render(const GL::Texture2D &left, const GL::Texture2D &righ
        compositor->Submit(vr::Eye_Left, &tex);
        tex.handle = reinterpret_cast<void *>(right.get_id());
        compositor->Submit(vr::Eye_Right, &tex);
+
+       if(mirror)
+       {
+               mirror->shdata.uniform("scale", view.get_aspect()/render_aspect/2, 0.5f);
+               render_mirror(left);
+               view.get_context().swap_buffers();
+       }
 }
 
 

diff --git a/source/openvr/openvrcombiner.h b/source/openvr/openvrcombiner.h
index ad4a37d8a99758ee8f65e4e120bf282ff613ce75..58a24c9c9f2708eebac8c2f048e7e762ec4dada7 100644 (file)
--- a/source/openvr/openvrcombiner.h
+++ b/source/openvr/openvrcombiner.h
@@ -1,6 +1,7 @@
 #ifndef MSP_VR_OPENVRCOMBINER_H_
 #define MSP_VR_OPENVRCOMBINER_H_
 
+#include <msp/gl/view.h>
 #include <msp/vr/stereocombiner.h>
 
 namespace Msp {
@@ -14,9 +15,10 @@ private:
        struct Private;
 
        OpenVRDevice &device;
+       GL::View &view;
 
 public:
-       OpenVRCombiner(OpenVRDevice &);
+       OpenVRCombiner(OpenVRDevice &, GL::View &);
 
        virtual void prepare() const;
        virtual void render(const GL::Texture2D &, const GL::Texture2D &) const;

diff --git a/source/openvr/openvrdevice.cpp b/source/openvr/openvrdevice.cpp
index f6f0bf1cf796cd18c1781e26100c9d68bfe601ba..b4ff20b83fb0944b35ed8b5c769d989fb0ee9368 100644 (file)
--- a/source/openvr/openvrdevice.cpp
+++ b/source/openvr/openvrdevice.cpp
@@ -74,9 +74,9 @@ OpenVRCamera *OpenVRDevice::create_camera(const GL::Camera &bc)
        return new OpenVRCamera(*this, bc);
 }
 
-OpenVRCombiner *OpenVRDevice::create_combiner(GL::View &)
+OpenVRCombiner *OpenVRDevice::create_combiner(GL::View &v)
 {
-       return new OpenVRCombiner(*this);
+       return new OpenVRCombiner(*this, v);
 }
 
 void OpenVRDevice::update_pose_matrices()

diff --git a/source/stereocombiner.cpp b/source/stereocombiner.cpp
index 75c788997e770fa0f1a7340d03b578e969062d51..ebb888ee6fe59ec6bd39446ebff00008b21380e4 100644 (file)
--- a/source/stereocombiner.cpp
+++ b/source/stereocombiner.cpp
@@ -1,8 +1,31 @@
 #include <algorithm>
+#include <msp/gl/meshbuilder.h>
 #include "stereocombiner.h"
 
 using namespace std;
 
+namespace {
+
+const char mirror_vs_source[] =
+       "uniform vec2 scale;\n"
+       "varying vec2 texcoord;\n"
+       "void main()\n"
+       "{\n"
+       "       gl_Position = vec4(gl_Vertex.xy, 0.0, 1.0);\n"
+       "       texcoord = gl_Vertex.xy*scale*0.5+0.5;\n"
+       "}";
+
+const char mirror_fs_source[] =
+       "uniform sampler2D texture;\n"
+       "varying vec2 texcoord;\n"
+       "void main()\n"
+       "{\n"
+       "       gl_FragColor = texture2D(texture, texcoord);\n"
+       "}";
+
+}
+
+
 namespace Msp {
 namespace VR {
 
@@ -10,7 +33,8 @@ StereoCombiner::StereoCombiner():
        target_width(0),
        target_height(0),
        render_aspect(1.0f),
-       frustum_skew(0.0f)
+       frustum_skew(0.0f),
+       mirror(0)
 { }
 
 void StereoCombiner::configure_eye_frustums(const Frustum &left_frustum, const Frustum &right_frustum)
@@ -25,6 +49,28 @@ void StereoCombiner::configure_eye_frustums(const Frustum &left_frustum, const F
        render_aspect = (inner+outer)/(vertical*2);
 }
 
+void StereoCombiner::set_mirroring(bool m)
+{
+       if(m && !mirror)
+               mirror = new MirrorView;
+       else if(!m && mirror)
+       {
+               delete mirror;
+               mirror = 0;
+       }
+}
+
+void StereoCombiner::render_mirror(const GL::Texture2D &tex) const
+{
+       if(!mirror)
+               return;
+
+       GL::Bind bind_tex(tex);
+       GL::Bind bind_shprog(mirror->shader);
+       mirror->shdata.apply();
+       mirror->mesh.draw();
+}
+
 
 StereoCombiner::Frustum::Frustum():
        left(-1),
@@ -40,5 +86,21 @@ StereoCombiner::Frustum::Frustum(float l, float r, float b, float t):
        top(t)
 { }
 
+
+StereoCombiner::MirrorView::MirrorView():
+       mesh(GL::VERTEX2),
+       shader(mirror_vs_source, mirror_fs_source)
+{
+       GL::MeshBuilder bld(mesh);
+       bld.begin(GL::TRIANGLE_STRIP);
+       bld.vertex(-1, 1);
+       bld.vertex(-1, -1);
+       bld.vertex(1, 1);
+       bld.vertex(1, -1);
+       bld.end();
+
+       shdata.uniform("scale", 0.5f, 0.5f);
+}
+
 } // namespace VR
 } // namespace Msp

diff --git a/source/stereocombiner.h b/source/stereocombiner.h
index bef0849b39ee4a460d8c8c838957286f70dc4fa9..2cfe3eb1f5255f30d6104aacd6c1d734700488da 100644 (file)
--- a/source/stereocombiner.h
+++ b/source/stereocombiner.h
@@ -2,6 +2,9 @@
 #define MSP_VR_STEREOCOMBINER_H_
 
 #include <msp/geometry/angle.h>
+#include <msp/gl/mesh.h>
+#include <msp/gl/program.h>
+#include <msp/gl/programdata.h>
 #include <msp/gl/texture2d.h>
 
 namespace Msp {
@@ -21,11 +24,21 @@ protected:
                Frustum(float, float, float, float);
        };
 
+       struct MirrorView
+       {
+               GL::Mesh mesh;
+               GL::Program shader;
+               GL::ProgramData shdata;
+
+               MirrorView();
+       };
+
        unsigned target_width;
        unsigned target_height;
        float render_aspect;
        Geometry::Angle<float> fov;
        float frustum_skew;
+       MirrorView *mirror;
 
        StereoCombiner();
 public:
@@ -40,8 +53,12 @@ public:
        const Geometry::Angle<float> &get_field_of_view() const { return fov; }
        float get_frustum_skew() const { return frustum_skew; }
 
+       void set_mirroring(bool);
+
        virtual void prepare() const { }
        virtual void render(const GL::Texture2D &, const GL::Texture2D &) const = 0;
+protected:
+       void render_mirror(const GL::Texture2D &) const;
 };
 
 } // namespace VR