made eye dome lighting support different resolution scales

Source/Scene/PointCloudEyeDomeLighting.js

@@ -1,4 +1,4 @@
-import Cartesian3 from '../Core/Cartesian3.js';
+import Cartesian2 from '../Core/Cartesian2.js';
 import Color from '../Core/Color.js';
 import defined from '../Core/defined.js';
 import destroyObject from '../Core/destroyObject.js';
@@ -111,7 +111,7 @@ import PointCloudEyeDomeLightingShader from '../Shaders/PostProcessStages/PointC
         processor._depthTexture = depthTexture;
     }
 
-    var distancesAndEdlStrengthScratch = new Cartesian3();
+    var distanceAndEdlStrengthScratch = new Cartesian2();
 
     function createCommands(processor, context) {
         var blendFS = PointCloudEyeDomeLightingShader;
@@ -123,11 +123,10 @@ import PointCloudEyeDomeLightingShader from '../Shaders/PostProcessStages/PointC
             u_pointCloud_depthGBuffer : function() {
                 return processor._depthGBuffer;
             },
-            u_distancesAndEdlStrength : function() {
-                distancesAndEdlStrengthScratch.x = processor._radius / context.drawingBufferWidth;
-                distancesAndEdlStrengthScratch.y = processor._radius / context.drawingBufferHeight;
-                distancesAndEdlStrengthScratch.z = processor._strength;
-                return distancesAndEdlStrengthScratch;
+            u_distanceAndEdlStrength : function() {
+                distanceAndEdlStrengthScratch.x = processor._radius;
+                distanceAndEdlStrengthScratch.y = processor._strength;
+                return distanceAndEdlStrengthScratch;
             }
         };
 

Source/Shaders/PostProcessStages/PointCloudEyeDomeLighting.glsl

@@ -2,16 +2,27 @@
 
 uniform sampler2D u_pointCloud_colorGBuffer;
 uniform sampler2D u_pointCloud_depthGBuffer;
-uniform vec3 u_distancesAndEdlStrength;
+uniform vec2 u_distanceAndEdlStrength;
 varying vec2 v_textureCoordinates;
 
-vec2 neighborContribution(float log2Depth, vec2 padding)
+vec2 neighborContribution(float log2Depth, vec2 offset)
 {
-    float depthOrLogDepth = czm_unpackDepth(texture2D(u_pointCloud_depthGBuffer, v_textureCoordinates + padding));
-    if (depthOrLogDepth == 0.0) { // 0.0 is the clear value for the gbuffer
+    float dist = u_distanceAndEdlStrength.x;
+    vec2 texCoordOrig = v_textureCoordinates + offset * dist;
+    vec2 texCoord0 = v_textureCoordinates + offset * floor(dist);
+    vec2 texCoord1 = v_textureCoordinates + offset * ceil(dist);
+
+    float depthOrLogDepth0 = czm_unpackDepth(texture2D(u_pointCloud_depthGBuffer, texCoord0));
+    float depthOrLogDepth1= czm_unpackDepth(texture2D(u_pointCloud_depthGBuffer, texCoord1));
+
+    // ignore depth values that are the clear depth
+    if (depthOrLogDepth0 == 0.0 || depthOrLogDepth1 == 0.0) {
         return vec2(0.0);
     }
-    vec4 eyeCoordinate = czm_windowToEyeCoordinates(v_textureCoordinates + padding, depthOrLogDepth);
+
+    // interpolate the two adjacent depth values
+    float depthMix = mix(depthOrLogDepth0, depthOrLogDepth1, fract(dist));
+    vec4 eyeCoordinate = czm_windowToEyeCoordinates(texCoordOrig, depthMix);
     return vec2(max(0.0, log2Depth - log2(-eyeCoordinate.z / eyeCoordinate.w)), 1.0);
 }
 
@@ -31,19 +42,19 @@ void main()
 
     vec4 color = texture2D(u_pointCloud_colorGBuffer, v_textureCoordinates);
 
-    // sample from neighbors up, down, left, right
-    float distX = u_distancesAndEdlStrength.x;
-    float distY = u_distancesAndEdlStrength.y;
+    // sample from neighbors left, right, down, up
+    vec2 texelSize = 1.0 / czm_viewport.zw;
 
     vec2 responseAndCount = vec2(0.0);
 
-    responseAndCount += neighborContribution(log2Depth, vec2(0, distY));
-    responseAndCount += neighborContribution(log2Depth, vec2(distX, 0));
-    responseAndCount += neighborContribution(log2Depth, vec2(0, -distY));
-    responseAndCount += neighborContribution(log2Depth, vec2(-distX, 0));
+    responseAndCount += neighborContribution(log2Depth, vec2(-texelSize.x, 0.0));
+    responseAndCount += neighborContribution(log2Depth, vec2(+texelSize.x, 0.0));
+    responseAndCount += neighborContribution(log2Depth, vec2(0.0, -texelSize.y));
+    responseAndCount += neighborContribution(log2Depth, vec2(0.0, +texelSize.y));
 
     float response = responseAndCount.x / responseAndCount.y;
-    float shade = exp(-response * 300.0 * u_distancesAndEdlStrength.z);
+    float strength = u_distanceAndEdlStrength.y;
+    float shade = exp(-response * 300.0 * strength);
     color.rgb *= shade;
     gl_FragColor = vec4(color);