struct inputdata
{
   vec2 video_size;
   vec2 texture_size;
   vec2 output_size;
   float frame_count;
   float frame_direction;
   float frame_rotation;
};


attribute vec4 a_position;
attribute vec2 a_texCoord;
varying vec4 TexCoord[8];
varying vec2 v_texCoord;
uniform inputdata IN;

void main()
{
   gl_Position = a_position;

   vec2 ps = vec2(1.0/IN.texture_size.x, 1.0/IN.texture_size.y);
   float dx = ps.x;
   float dy = ps.y;

   v_texCoord = a_texCoord;
   TexCoord[0].xy = a_texCoord + vec2(-dx,-dy);
   TexCoord[0].zw = a_texCoord + vec2(-dx,  0);
   TexCoord[1].xy = a_texCoord + vec2(+dx,-dy);
   TexCoord[1].zw = a_texCoord + vec2(+dx+dx,-dy);
   TexCoord[2].xy = a_texCoord + vec2(-dx,  0);
   TexCoord[2].zw = a_texCoord + vec2(+dx,  0);
   TexCoord[3].xy = a_texCoord + vec2(+dx+dx,  0);
   TexCoord[3].zw = a_texCoord + vec2(-dx,+dy);
   TexCoord[4].xy = a_texCoord + vec2(  0,+dy);
   TexCoord[4].zw = a_texCoord + vec2(+dx,+dy);
   TexCoord[5].xy = a_texCoord + vec2(+dx+dx,+dy);
   TexCoord[5].zw = a_texCoord + vec2(-dx,+dy+dy);
   TexCoord[6].xy = a_texCoord + vec2(  0,+dy+dy);
   TexCoord[6].zw = a_texCoord + vec2(+dx,+dy+dy);
   TexCoord[7].xy = a_texCoord + vec2(+dx+dx,+dy+dy);
}