// Exclusive to SSR for now
#version 450

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

uniform sampler2D tex;
uniform sampler2D gbuffer0; // Roughness
uniform sampler2D gbufferD; // Depth

uniform vec2 dirInv;

in vec2 texCoord;
out vec4 fragColor;

void main() {
	float roughness = textureLod(gbuffer0, texCoord, 0.0).b;
	if (roughness >= 0.8) {
		fragColor.rgb = textureLod(tex, texCoord, 0.0).rgb;
		return;
	}
	if (roughness < 0.01) {
		fragColor.rgb = textureLod(tex, texCoord, 0.0).rgb;
		return;
	}

	float blurRadius = 1.0 + roughness * 4.0;
	vec3 center = textureLod(tex, texCoord, 0.0).rgb;

	float centerDepth = textureLod(gbufferD, texCoord, 0.0).r;

	float w0 = 1.0 / (1.0 + roughness * 2.0);
	float w1 = 1.0 / (1.0 + roughness);
	float w2 = 1.0 / (1.0 + roughness * 0.5);
	float totalW = w0;

	fragColor.rgb = center * w0;

	vec2 offsets[4];
	offsets[0] = dirInv * blurRadius * 2.5;
	offsets[1] = dirInv * blurRadius * 1.5;
	offsets[2] = -dirInv * blurRadius * 1.5;
	offsets[3] = -dirInv * blurRadius * 2.5;
	float weights[4];
	weights[0] = w2;
	weights[1] = w1;
	weights[2] = w1;
	weights[3] = w2;

	for (int i = 0; i < 4; i++) {
		vec2 sampleTC = texCoord + offsets[i];
		float sampleDepth = textureLod(gbufferD, sampleTC, 0.0).r;
		float depthWeight = exp(-abs(centerDepth - sampleDepth) * 100.0);
		float w = weights[i] * depthWeight;
		fragColor.rgb += textureLod(tex, sampleTC, 0.0).rgb * w;
		totalW += w;
	}

	fragColor.rgb /= vec3(totalW);
}