#define HIGHP
#define QUANT 0.3

uniform sampler2D u_texture;

varying vec4 v_color;
varying vec2 v_texCoords;

void main(){
    vec4 color = texture2D(u_texture, v_texCoords.xy);
    gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0 - floor(color.r / QUANT) * QUANT);
}