From 4a86c112ddd54e7e469d33ca223177f0cf9d3c68 Mon Sep 17 00:00:00 2001
From: Jozufozu <jozsefaug@gmail.com>
Date: Sat, 11 Dec 2021 17:31:09 -0800
Subject: [PATCH] Cylindrical fog

 - having the world position is very nice
 - mojang manages to do multiple matrix multiplications
---
 .../jozufozu/flywheel/light/GPULightVolume.java    | 11 ++++++-----
 .../flywheel/shaders/context/crumbling.glsl        |  2 +-
 .../flywheel/flywheel/shaders/context/fog.glsl     | 14 ++++++++++++--
 .../flywheel/flywheel/shaders/context/world.glsl   |  6 +-----
 4 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/src/main/java/com/jozufozu/flywheel/light/GPULightVolume.java b/src/main/java/com/jozufozu/flywheel/light/GPULightVolume.java
index d463a54d7..cb7d3727e 100644
--- a/src/main/java/com/jozufozu/flywheel/light/GPULightVolume.java
+++ b/src/main/java/com/jozufozu/flywheel/light/GPULightVolume.java
@@ -55,6 +55,12 @@ public class GPULightVolume extends LightVolume {
 		int sizeZ = box.sizeZ();
 		glTexImage3D(GL_TEXTURE_3D, 0, GL30.GL_RG8, sizeX, sizeY, sizeZ, 0, GL30.GL_RG, GL_UNSIGNED_BYTE, 0);
 
+		glTexture.setParameteri(GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexture.setParameteri(GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+		glTexture.setParameteri(GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
+		glTexture.setParameteri(GL_TEXTURE_WRAP_R, GL_MIRRORED_REPEAT);
+		glTexture.setParameteri(GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);
+
 		glTexture.unbind();
 		oldState.makeActive();
 	}
@@ -73,11 +79,6 @@ public class GPULightVolume extends LightVolume {
 
 		textureUnit.makeActive();
 		glTexture.bind();
-		glTexture.setParameteri(GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-		glTexture.setParameteri(GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-		glTexture.setParameteri(GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
-		glTexture.setParameteri(GL_TEXTURE_WRAP_R, GL_MIRRORED_REPEAT);
-		glTexture.setParameteri(GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);
 
 		uploadTexture();
 	}
diff --git a/src/main/resources/assets/flywheel/flywheel/shaders/context/crumbling.glsl b/src/main/resources/assets/flywheel/flywheel/shaders/context/crumbling.glsl
index d55e86289..c9ab41cbe 100644
--- a/src/main/resources/assets/flywheel/flywheel/shaders/context/crumbling.glsl
+++ b/src/main/resources/assets/flywheel/flywheel/shaders/context/crumbling.glsl
@@ -18,7 +18,7 @@ void FLWFinalizeNormal(inout vec3 normal) {
 #if defined(VERTEX_SHADER)
 void FLWFinalizeWorldPos(inout vec4 worldPos) {
     #if defined(USE_FOG)
-    FragDistance = length(worldPos.xyz - uCameraPos);
+    FragDistance = cylindrical_distance(worldPos.xyz, uCameraPos);
     #endif
 
     gl_Position = uViewProjection * worldPos;
diff --git a/src/main/resources/assets/flywheel/flywheel/shaders/context/fog.glsl b/src/main/resources/assets/flywheel/flywheel/shaders/context/fog.glsl
index 49380b14f..ada0be19e 100644
--- a/src/main/resources/assets/flywheel/flywheel/shaders/context/fog.glsl
+++ b/src/main/resources/assets/flywheel/flywheel/shaders/context/fog.glsl
@@ -1,5 +1,3 @@
-#define USE_FOG
-
 #if defined(VERTEX_SHADER)
 out float FragDistance;
 #elif defined(FRAGMENT_SHADER)
@@ -8,6 +6,18 @@ in float FragDistance;
 uniform vec4 uFogColor;
 uniform vec2 uFogRange;
 
+float cylindrical_distance(vec3 worldPos, vec3 cameraPos) {
+    float distXZ = length(worldPos.xz - cameraPos.xz);
+    float distY = abs(worldPos.y - cameraPos.y);
+    return max(distXZ, distY);
+}
+
+float cylindrical_distance(vec3 worldPos) {
+    float distXZ = length(worldPos.xz);
+    float distY = abs(worldPos.y);
+    return max(distXZ, distY);
+}
+
 float FLWFogFactor() {
     return (uFogRange.y - FragDistance) / (uFogRange.y - uFogRange.x);
 }
diff --git a/src/main/resources/assets/flywheel/flywheel/shaders/context/world.glsl b/src/main/resources/assets/flywheel/flywheel/shaders/context/world.glsl
index f6f94ebf2..138c5aca9 100644
--- a/src/main/resources/assets/flywheel/flywheel/shaders/context/world.glsl
+++ b/src/main/resources/assets/flywheel/flywheel/shaders/context/world.glsl
@@ -16,9 +16,7 @@ void FLWFinalizeNormal(inout vec3 normal) {
 
 #if defined(VERTEX_SHADER)
 void FLWFinalizeWorldPos(inout vec4 worldPos) {
-    #if defined(USE_FOG)
-    FragDistance = length(worldPos.xyz - uCameraPos);
-    #endif
+    FragDistance = cylindrical_distance(worldPos.xyz, uCameraPos);
 
     gl_Position = uViewProjection * worldPos;
 }
@@ -41,13 +39,11 @@ vec4 FLWBlockTexture(vec2 texCoords) {
 }
 
 void FLWFinalizeColor(vec4 color) {
-    #if defined(USE_FOG)
     float a = color.a;
     float fog = clamp(FLWFogFactor(), 0., 1.);
 
     color = mix(uFogColor, color, fog);
     color.a = a;
-    #endif
 
     #if defined(ALPHA_DISCARD)
     if (color.a < ALPHA_DISCARD) {