Distorted Android

in vec2 a_Position;           // Per-vertex position.

out vec2 v_TexCoordinate;     //

out vec2 v_Pixel;             //

uniform float u_Depth;        // distance from the near plane to render plane, in clip coords

uniform vec2  u_TexCorr;      // when we blit from postprocessing buffers, the buffers can be

                              // larger than necessary (there is just one static set being

                              // reused!) so we need to compensate here by adjusting the texture

                              // coords.

uniform vec2 u_Size;         // size of the output surface, in pixels.

  v_TexCoordinate = (a_Position + 0.5) * u_TexCorr;

  v_Pixel         = v_TexCoordinate * u_Size;

  gl_Position     = vec4(2.0*a_Position,u_Depth,1.0);