Moved linearDepthMap into Haze.slf

Refactored computation of keylight attenuation - now function in Haze.slh

libraries/render-utils/src/DeferredGlobalLight.slh

@@ -123,6 +123,9 @@ vec3 evalSkyboxGlobalColor(mat4 invViewMat, float shadowAttenuation, float obscu
     color += ambientSpecular;
 
     // Directional
+    // Get directional light (used by both directional light and haze attenuation)
+    Light directionalLight = getLight();
+
     vec3 directionalDiffuse;
     vec3 directionalSpecular;
     evalLightingDirectional(directionalDiffuse, directionalSpecular, lightDirection, lightIrradiance, fragEyeDir, fragNormal, roughness, metallic, fresnel, albedo, shadowAttenuation
@@ -135,52 +138,7 @@ vec3 evalSkyboxGlobalColor(mat4 invViewMat, float shadowAttenuation, float obscu
 
     // Attenuate the light if haze effect selected
     if ((hazeParams.hazeMode & HAZE_MODE_IS_KEYLIGHT_ATTENUATED) == HAZE_MODE_IS_KEYLIGHT_ATTENUATED) {
-        // Directional light attenuation is simulated by assuming the light source is at a fixed height above the
+        color = computeHazeColor(color, directionalLight, invViewMat, position);    
-        // fragment.  This height is where the haze density is reduced by 95% from the haze at the fragment's height
-        //
-        // The distance is computed from the height and the directional light orientation
-        // The distance is limited to height * 1,000, which gives an angle of ~0.057 degrees
-
-        // Get directional light
-        Light light = getLight();
-        vec3 lightDirection = getLightDirection(light);
-
-        // Height at which haze density is reduced by 95% (default set to 2000.0 for safety ,this should never happen)
-        float height_95p = 2000.0;
-        if (hazeParams.hazeKeyLightAltitudeFactor > 0.0f) {
-            height_95p = -log(0.05) / hazeParams.hazeKeyLightAltitudeFactor;
-        }
-
-        // Note that the sine will always be positive
-        float sin_pitch = sqrt(1.0 - lightDirection.y * lightDirection.y);
-            
-        float distance;
-        const float minimumSinPitch = 0.001;
-        if (sin_pitch < minimumSinPitch) {
-            distance = height_95p / minimumSinPitch;
-        } else {
-            distance = height_95p / sin_pitch;
-        }
-
-        // Position of fragment in world coordinates
-        vec4 worldFragPos = invViewMat * vec4(position, 0.0);
-
-        // Integration is from the fragment towards the light source
-        // Note that the haze base reference affects only the haze density as function of altitude
-        float hazeDensityDistribution =  
-            hazeParams.hazeKeyLightRangeFactor * 
-            exp(-hazeParams.hazeKeyLightAltitudeFactor * (worldFragPos.y - hazeParams.hazeBaseReference));
-
-        float hazeIntegral =  hazeDensityDistribution * distance;
-
-        // Note that t is constant and equal to -log(0.05)
-        //      float t = hazeParams.hazeAltitudeFactor * height_95p;
-        //      hazeIntegral *= (1.0 - exp (-t)) / t;
-        hazeIntegral *= 0.3171178;
-
-        float hazeAmount = 1.0 - exp(-hazeIntegral);
-
-        color = mix(color, vec3(0.0, 0.0, 0.0), hazeAmount);
     }
 
     return color;

libraries/render-utils/src/Haze.slf

@@ -23,6 +23,7 @@
 <@include Haze.slh@>
 
 uniform sampler2D colorMap;
+uniform sampler2D linearDepthMap;
 
 vec4 unpackPositionFromZeye(vec2 texcoord) {
     float Zeye = -texture(linearDepthMap, texcoord).x;

libraries/render-utils/src/Haze.slh

@@ -40,7 +40,48 @@ layout(std140) uniform hazeBuffer {
     HazeParams hazeParams;
 };
 
-uniform sampler2D linearDepthMap;
+vec3 computeHazeColor(vec3 color, Light directionalLight, mat4 invViewMat, vec3 worldFragPos) {
+    // Directional light attenuation is simulated by assuming the light source is at a fixed height above the
+    // fragment.  This height is where the haze density is reduced by 95% from the haze at the fragment's height
+    //
+    // The distance is computed from the height and the directional light orientation
+    // The distance is limited to height * 1,000, which gives an angle of ~0.057 degrees
+    vec3 lightDirection = getLightDirection(directionalLight);
 
+    // Height at which haze density is reduced by 95% (default set to 2000.0 for safety ,this should never happen)
+    float height_95p = 2000.0;
+    const float log_p_005 = log(0.05);
+    if (hazeParams.hazeKeyLightAltitudeFactor > 0.0f) {
+        height_95p = -log_p_005 / hazeParams.hazeKeyLightAltitudeFactor;
+    }
+
+    // Note that we need the sine to be positive
+    float sin_pitch = abs(lightDirection.y);
+            
+    float distance;
+    const float minimumSinPitch = 0.001;
+    if (sin_pitch < minimumSinPitch) {
+        distance = height_95p / minimumSinPitch;
+    } else {
+        distance = height_95p / sin_pitch;
+    }
+
+    // Integration is from the fragment towards the light source
+    // Note that the haze base reference affects only the haze density as function of altitude
+    float hazeDensityDistribution =  
+        hazeParams.hazeKeyLightRangeFactor * 
+        exp(-hazeParams.hazeKeyLightAltitudeFactor * (worldFragPos.y - hazeParams.hazeBaseReference));
+
+    float hazeIntegral =  hazeDensityDistribution * distance;
+
+    // Note that t is constant and equal to -log(0.05)
+    //      float t = hazeParams.hazeAltitudeFactor * height_95p;
+    //      hazeIntegral *= (1.0 - exp (-t)) / t;
+    hazeIntegral *= 0.3171178;
+
+    float hazeAmount = 1.0 - exp(-hazeIntegral);
+
+    return mix(color, vec3(0.0, 0.0, 0.0), hazeAmount);
+}
 <@endif@>