From 143c271f231ee4547a0266c9951da586645cf3b1 Mon Sep 17 00:00:00 2001
From: "Raoul v. R" <vanruesc@users.noreply.github.com>
Date: Wed, 14 Nov 2018 22:56:46 +0100
Subject: [PATCH] Always divide by sample count.

This prevents incorrect shadows in some cases.
---
 src/effects/SSAOEffect.js         | 14 ++++++++------
 src/effects/glsl/ssao/shader.frag | 10 ++++------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/effects/SSAOEffect.js b/src/effects/SSAOEffect.js
index ed29b37f3..5f0bed4f9 100644
--- a/src/effects/SSAOEffect.js
+++ b/src/effects/SSAOEffect.js
@@ -59,8 +59,9 @@ export class SSAOEffect extends Effect {
 			blendFunction: settings.blendFunction,
 
 			defines: new Map([
-				["RINGS", "0"],
-				["SAMPLES", "0"]
+				["RINGS_INT", "0"],
+				["SAMPLES_INT", "0"],
+				["SAMPLES_FLOAT", "0.0"]
 			]),
 
 			uniforms: new Map([
@@ -149,7 +150,7 @@ export class SSAOEffect extends Effect {
 
 	get samples() {
 
-		return Number.parseInt(this.defines.get("SAMPLES"));
+		return Number.parseInt(this.defines.get("SAMPLES_INT"));
 
 	}
 
@@ -165,7 +166,8 @@ export class SSAOEffect extends Effect {
 
 		value = Math.floor(value);
 
-		this.defines.set("SAMPLES", value.toFixed(0));
+		this.defines.set("SAMPLES_INT", value.toFixed(0));
+		this.defines.set("SAMPLES_FLOAT", value.toFixed(1));
 		this.updateAngleStep();
 		this.updateRadiusStep();
 
@@ -179,7 +181,7 @@ export class SSAOEffect extends Effect {
 
 	get rings() {
 
-		return Number.parseInt(this.defines.get("RINGS"));
+		return Number.parseInt(this.defines.get("RINGS_INT"));
 
 	}
 
@@ -195,7 +197,7 @@ export class SSAOEffect extends Effect {
 
 		value = Math.floor(value);
 
-		this.defines.set("RINGS", value.toFixed(0));
+		this.defines.set("RINGS_INT", value.toFixed(0));
 		this.updateAngleStep();
 
 	}
diff --git a/src/effects/glsl/ssao/shader.frag b/src/effects/glsl/ssao/shader.frag
index 14a14cd77..08b1fc5ba 100644
--- a/src/effects/glsl/ssao/shader.frag
+++ b/src/effects/glsl/ssao/shader.frag
@@ -49,30 +49,28 @@ float getAmbientOcclusion(const in vec3 p, const in vec3 n, const in float depth
 	vec2 radius = radiusStep;
 	float angle = rand(uv + seed) * PI2;
 	float occlusionSum = 0.0;
-	int sampleCount = 0;
 
 	// Collect samples along a discrete spiral pattern.
-	for(int i = 0; i < SAMPLES; ++i) {
+	for(int i = 0; i < SAMPLES_INT; ++i) {
 
 		vec2 coord = uv + vec2(cos(angle), sin(angle)) * radius;
 		radius += radiusStep;
 		angle += ANGLE_STEP;
 
 		float sampleDepth = readDepth(coord);
+		float proximity = abs(depth - sampleDepth);
 
 		if(sampleDepth <= distanceCutoff.y) {
 
-			float falloff = 1.0 - smoothstep(proximityCutoff.x, proximityCutoff.y, abs(depth - sampleDepth));
+			float falloff = 1.0 - smoothstep(proximityCutoff.x, proximityCutoff.y, proximity);
 			vec3 sampleViewPosition = getViewPosition(coord, sampleDepth, getViewZ(sampleDepth));
 			occlusionSum += getOcclusion(p, n, sampleViewPosition) * falloff;
 
-			++sampleCount;
-
 		}
 
 	}
 
-	return (sampleCount == 0) ? 0.0 : occlusionSum / float(sampleCount);
+	return occlusionSum / SAMPLES_FLOAT;
 
 }