/*
    Copyright (C) 2021  hiimgoodpack

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
#version 330 core

in vec2 vTexCoord;

uniform sampler2D aTexture0;

void main() {
	/*
		dot(vTexCoord, vTexCoord)
		essentially does pow(length(gl_FragCoord.xy),2), but
		(probably) more optimized

		We're doing this since we don't want fragments outside a circle
	*/
	float alpha = dot(vTexCoord, vTexCoord) > 1 ? 1 : 0;

	gl_FragColor = vec4(0, 0, 0, alpha);
}