opengl z-sorting transparency

Question

im rendering png\'s on simple squares in opengl es 2.0, but when i try and draw something behind an square i have already drawn the transparent area in my top square are ren

Answer 1

Figured it out. You can discard in the fragment shader

mediump vec4 basecolor = texture2D(sTexture, TexCoord);

if (basecolor.a == 0.0){
    discard;
}

gl_FragColor = basecolor;