Fixed negative chunks invisible

Shaders/shader.frag

@@ -10,16 +10,23 @@ uniform vec3 cameraPosition;
 
 void main()
 {
-    float fogEnd = 512;
-    float fogStart = 32;
-
-    float dist = length(cameraPosition - fragPos);
-    float fogFactor = (fogEnd - dist) / (fogEnd - fogStart);
-    fogFactor = clamp(fogFactor, 0, 1);
-
-    vec4 fogColor = vec4(0.8,0.8,0.8,1);
-    vec4 texColor = texture(uTexture, fragUV) * lighting;
-    vec4 color = mix(fogColor, texColor, fogFactor);
-
-    FragColor = vec4(color.rgb, texColor.a);
+    // Use squared distance
+    vec3 delta = cameraPosition - fragPos;
+    float distSq = dot(delta, delta);
+    
+    // Precomputed fog parameters
+    const float fogEndSq = 16384.0; // 128^2
+    const float fogStartSq = 1024.0; // 32^2
+    const float fogRangeInv = 1.0 / (fogEndSq - fogStartSq);
+    
+    float fogFactor = (fogEndSq - distSq) * fogRangeInv;
+    fogFactor = clamp(fogFactor, 0.0, 1.0);
+    
+    // Texture and lighting
+    vec4 texColor = texture(uTexture, fragUV);
+    texColor.rgb *= lighting;
+    
+    // Fog blend
+    const vec3 fogColor = vec3(0.8, 0.8, 0.8);
+    FragColor = vec4(mix(fogColor, texColor.rgb, fogFactor), texColor.a);
 }