#version 450

#include "compiled.inc"
#include "std/gbuffer.glsl"

uniform sampler2D tex;
uniform sampler2D gbuffer0;
uniform sampler2D gbufferD;

uniform vec2 dirInv; // texStep

in vec2 texCoord;
out vec3 fragColor;

const int KERNEL_SIZE = 13;
const float blurWeights[13] = float[](0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.025, 0.02, 0.015, 0.01, 0.005);

void main() {
	vec3 centerNor = getNor(textureLod(gbuffer0, texCoord, 0.0).rg);
	float centerDepth = textureLod(gbufferD, texCoord, 0.0).r;
	
	// skip sky pixels
	if (centerDepth == 1.0) {
		fragColor = vec3(0.0);
		return;
	}
	
	fragColor = textureLod(tex, texCoord, 0.0).rgb * blurWeights[0];
	float totalWeight = blurWeights[0];

	for (int i = 1; i < KERNEL_SIZE; i++) {
		vec2 offset = float(i) * dirInv;

		vec2 uvPos = texCoord + offset;
		vec3 norPos = getNor(textureLod(gbuffer0, uvPos, 0.0).rg);
		float depthPos = textureLod(gbufferD, uvPos, 0.0).r;
		
		float normalWeight = max(0.0, dot(norPos, centerNor));
		normalWeight = pow(normalWeight, 8.0); // Softer normal falloff for better blending
		float depthWeight = 1.0 - smoothstep(0.0, 0.02, abs(depthPos - centerDepth));
		float w = blurWeights[i] * normalWeight * depthWeight;
		
		fragColor += textureLod(tex, uvPos, 0.0).rgb * w;
		totalWeight += w;
		
		vec2 uvNeg = texCoord - offset;
		vec3 norNeg = getNor(textureLod(gbuffer0, uvNeg, 0.0).rg);
		float depthNeg = textureLod(gbufferD, uvNeg, 0.0).r;
		
		normalWeight = max(0.0, dot(norNeg, centerNor));
		normalWeight = pow(normalWeight, 8.0);
		depthWeight = 1.0 - smoothstep(0.0, 0.02, abs(depthNeg - centerDepth));
		w = blurWeights[i] * normalWeight * depthWeight;
		
		fragColor += textureLod(tex, uvNeg, 0.0).rgb * w;
		totalWeight += w;
	}

	fragColor /= totalWeight;
}