gistfile1.txt

#define VR_EPSILON 0.0001
#define DESKTOP_FOV 60.0
#define FOV_EPSILON 0.01
#define ROT_EPSILON 0.0001

                bool isOrthographic()
                {
                    return UNITY_MATRIX_P[3][3] == 1;
                }

                bool isInMirror()
                {
                    return unity_CameraProjection[2][0] != 0.f || unity_CameraProjection[2][1] != 0.f;
                }

                bool isPlayerView() {
                    // VR view?

#if defined(USING_STEREO_MATRICES)
                    return 1;
#endif

#if 1
                    if (isOrthographic()) {
                        return 0;
                    }

                    // Check desktop FOV
                    float t = unity_CameraProjection._m11;
                    const float Rad2Deg = 180 / UNITY_PI;
                    float fov = atan(1.0f / t) * 2.0 * Rad2Deg;

                    if (abs(fov - DESKTOP_FOV) >= FOV_EPSILON) {
                        return 0;
                    }
                    
                    // Check Y axis rotation
                    float3 y_vec = float3(0, 1, 0) + _WorldSpaceCameraPos;
                    float4 center_vec = UnityWorldToClipPos(_WorldSpaceCameraPos);
                    float4 projected = UnityWorldToClipPos(y_vec);

                    float4 offset = center_vec - projected;

                    if (abs(offset.x) >= ROT_EPSILON) {
                        return 0;
                    }
#endif
                    return 1;
                }