Listing 2. Necessary structure for storing position data input and output.

15          CGPROGRAM

16          #pragma vertex vert

17          #pragma fragment frag

18

19          #include  "UnityCG.cginc"

20

21          struct appdata

22          {

23              float4 vertex : POSITION;

24              UNITY_VERTEX_INPUT_INSTANCE_ID

25          };

26

27          struct v2f

28          {

29              float4 position : SV_POSITION;

30              UNITY_VERTEX_OUTPUT_STEREO

31          };