#version 150

in vec2 vertTexCoord;
in vec4 vertColor;
in float vertTextureIndex;

uniform sampler2D textures[8];
uniform float threshold;
uniform float smoothRange;

out vec4 fragColor;

void main() {
	float sample = 0.0;
	float smoothMin = threshold - smoothRange * 0.5;
	float smoothMax = smoothMin + smoothRange;
	sample += smoothstep(smoothMin, smoothMax, texture(textures[0], vertTexCoord).r) * int(vertTextureIndex == 0);
	sample += smoothstep(smoothMin, smoothMax, texture(textures[1], vertTexCoord).r) * int(vertTextureIndex == 1);
	sample += smoothstep(smoothMin, smoothMax, texture(textures[2], vertTexCoord).r) * int(vertTextureIndex == 2);
	sample += smoothstep(smoothMin, smoothMax, texture(textures[3], vertTexCoord).r) * int(vertTextureIndex == 3);
	sample += smoothstep(smoothMin, smoothMax, texture(textures[4], vertTexCoord).r) * int(vertTextureIndex == 4);
	sample += smoothstep(smoothMin, smoothMax, texture(textures[5], vertTexCoord).r) * int(vertTextureIndex == 5);
	sample += smoothstep(smoothMin, smoothMax, texture(textures[6], vertTexCoord).r) * int(vertTextureIndex == 6);
	sample += smoothstep(smoothMin, smoothMax, texture(textures[7], vertTexCoord).r) * int(vertTextureIndex == 7);
	fragColor = vec4(min(1.0, sample));
	fragColor *= vertColor;
}