// Exclusive to SSAO for now
#version 450

#ifdef GL_ES
precision mediump float;
#endif

#include "../compiled.glsl"

uniform sampler2D tex;
uniform sampler2D gbuffer0;

uniform vec2 dir;
uniform vec2 screenSize;

in vec2 texCoord;
out vec4 fragColor;

const float blurWeights[10] = float[] (0.132572, 0.125472, 0.106373, 0.08078, 0.05495, 0.033482, 0.018275, 0.008934, 0.003912, 0.001535);
const float discardThreshold = 0.95;
// const float discardThreshold = 0.70;

vec3 result = vec3(0.0);

vec2 octahedronWrap(vec2 v) {
	return (1.0 - abs(v.yx)) * (vec2(v.x >= 0.0 ? 1.0 : -1.0, v.y >= 0.0 ? 1.0 : -1.0));
}

vec3 getNor(vec2 enc) {
	vec3 n;
	n.z = 1.0 - abs(enc.x) - abs(enc.y);
	n.xy = n.z >= 0.0 ? enc.xy : octahedronWrap(enc.xy);
	n = normalize(n);
	return n;
}

float doBlur(float blurWeight, int pos, vec3 nor, vec2 texCoord) {
	vec2 texstep = dir / screenSize;
	
	vec3 nor2 = getNor(texture(gbuffer0, texCoord + pos * texstep).rg);
	float influenceFactor = step(discardThreshold, dot(nor2, nor));
	vec3 col = texture(tex, texCoord + (pos + 0.5) * texstep).rgb;
	result += col * blurWeight * influenceFactor;
	float weight = blurWeight * influenceFactor;
	
	nor2 = getNor(texture(gbuffer0, texCoord - pos * texstep).rg);
	influenceFactor = step(discardThreshold, dot(nor2, nor));
	col = texture(tex, texCoord - (pos + 0.5) * texstep).rgb;
	result += col * blurWeight * influenceFactor;
	weight += blurWeight * influenceFactor;
	
	return weight;
}

void main() {
	vec2 tc = texCoord * ssaoTextureScale;

	// vec2 step = dir / screenSize;
	// vec3 result = texture(tex, tc + (step * 4.5)).rgb;
	// result += texture(tex, tc + (step * 3.5)).rgb;
	// result += texture(tex, tc + (step * 2.5)).rgb;
	// result += texture(tex, tc + step * 1.5).rgb;
	// result += texture(tex, tc).rgb;
	// result += texture(tex, tc - step * 1.5).rgb;
	// result += texture(tex, tc - (step * 2.5)).rgb;
	// result += texture(tex, tc - (step * 3.5)).rgb;
	// result += texture(tex, tc - (step * 4.5)).rgb;
	// result /= vec3(9.0);
	// fragColor.rgb = vec3(result);

	vec3 nor = getNor(texture(gbuffer0, texCoord).rg);
	
	// for (int i = 0; i < 9; i++) {
		vec3 col = texture(tex, tc).rgb;
		result += col * blurWeights[0];
		
		float weight = blurWeights[0];
		weight += doBlur(blurWeights[1], 1, nor, tc);
		weight += doBlur(blurWeights[2], 2, nor, tc);
		weight += doBlur(blurWeights[3], 3, nor, tc);
		weight += doBlur(blurWeights[4], 4, nor, tc);
		weight += doBlur(blurWeights[5], 5, nor, tc);
		weight += doBlur(blurWeights[6], 6, nor, tc);
		weight += doBlur(blurWeights[7], 7, nor, tc);
		weight += doBlur(blurWeights[8], 8, nor, tc);
		weight += doBlur(blurWeights[9], 9, nor, tc);
	// }

	result /= weight;
	// fragColor = vec4(result.rgb, 1.0);
	fragColor = vec4(result.rrr, 1.0); // SSAO only
}