vshader.glsl Example File

 #ifdef GL_ES
 // Set default precision to medium
 precision mediump int;
 precision mediump float;
 #endif

 uniform mat4 mvp_matrix;

 attribute vec4 a_position;
 attribute vec2 a_texcoord;

 varying vec2 v_texcoord;

 void main()
 {
     // Calculate vertex position in screen space
     gl_Position = mvp_matrix * a_position;

     // Pass texture coordinate to fragment shader
     // Value will be automatically interpolated to fragments inside polygon faces
     v_texcoord = a_texcoord;
 }