1 #version 330 core

     2 

     3 uniform  sampler2D  uTexture;

     4 in       vec2       vTextureXY;

     5 out      vec4       fColor;

     6 

     7 void main(){

     8 	fColor = texture(uTexture, vTextureXY).rgba;

     9 

    10 	float width = 0.01;

    11 	fColor.a *= smoothstep(0., 0.+width, vTextureXY.x);

    12 	fColor.a *= smoothstep(1., 1.-width, vTextureXY.x);

    13 	fColor.a *= smoothstep(0., 0.+width, vTextureXY.y);

    14 	fColor.a *= smoothstep(1., 1.-width, vTextureXY.y);

    15 }