Merge pull request #7431 from AnalyticalGraphicsInc/fix-bg-alpha

Fix transparent background colors with HDR.

Author: lilleyse

CHANGES.md

@@ -13,6 +13,7 @@ Change Log
 ##### Fixes :wrench:
 * Fixed 3D Tiles visibility checking when running multiple passes within the same frame. [#7289](https://github.com/AnalyticalGraphicsInc/cesium/pull/7289)
 * Fixed contrast on imagery layers. [#7382](https://github.com/AnalyticalGraphicsInc/cesium/issues/7382)
+* Fixed rendering transparent background color when `highDynamicRange` is enabled. [#7427](https://github.com/AnalyticalGraphicsInc/cesium/issues/7427)
 
 ### 1.52 - 2018-12-03
 

Source/Shaders/PostProcessStages/AcesTonemapping.glsl

@@ -11,7 +11,8 @@ uniform sampler2D autoExposure;
 
 void main()
 {
-    vec3 color = texture2D(colorTexture, v_textureCoordinates).rgb;
+    vec4 fragmentColor = texture2D(colorTexture, v_textureCoordinates);
+    vec3 color = fragmentColor.rgb;
 
 #ifdef AUTO_EXPOSURE
     color /= texture2D(autoExposure, vec2(0.5)).r;
@@ -27,5 +28,5 @@ void main()
 
     color = clamp(color, 0.0, 1.0);
     color = czm_inverseGamma(color);
-    gl_FragColor = vec4(color, 1.0);
+    gl_FragColor = vec4(color, fragmentColor.a);
 }

Source/Shaders/PostProcessStages/FilmicTonemapping.glsl

@@ -11,7 +11,8 @@ uniform sampler2D autoExposure;
 
 void main()
 {
-    vec3 color = texture2D(colorTexture, v_textureCoordinates).rgb;
+    vec4 fragmentColor = texture2D(colorTexture, v_textureCoordinates);
+    vec3 color = fragmentColor.rgb;
 
 #ifdef AUTO_EXPOSURE
     float exposure = texture2D(autoExposure, vec2(0.5)).r;
@@ -31,5 +32,5 @@ void main()
 	float w = ((white * (A * white + C * B) + D * E) / (white * ( A * white + B) + D * F)) - E / F;
 
 	c = czm_inverseGamma(c / w);
-	gl_FragColor = vec4(c, 1.0);
+	gl_FragColor = vec4(c, fragmentColor.a);
 }

Source/Shaders/PostProcessStages/ModifiedReinhardTonemapping.glsl

@@ -12,12 +12,13 @@ uniform sampler2D autoExposure;
 
 void main()
 {
-    vec3 color = texture2D(colorTexture, v_textureCoordinates).rgb;
+    vec4 fragmentColor = texture2D(colorTexture, v_textureCoordinates);
+    vec3 color = fragmentColor.rgb;
 #ifdef AUTO_EXPOSURE
     float exposure = texture2D(autoExposure, vec2(0.5)).r;
     color /= exposure;
 #endif
     color = (color * (1.0 + color / white)) / (1.0 + color);
     color = czm_inverseGamma(color);
-    gl_FragColor = vec4(color, 1.0);
+    gl_FragColor = vec4(color, fragmentColor.a);
 }

Source/Shaders/PostProcessStages/ReinhardTonemapping.glsl

@@ -11,12 +11,13 @@ uniform sampler2D autoExposure;
 
 void main()
 {
-    vec3 color = texture2D(colorTexture, v_textureCoordinates).rgb;
+    vec4 fragmentColor = texture2D(colorTexture, v_textureCoordinates);
+    vec3 color = fragmentColor.rgb;
 #ifdef AUTO_EXPOSURE
     float exposure = texture2D(autoExposure, vec2(0.5)).r;
     color /= exposure;
 #endif
     color = color / (1.0 + color);
     color = czm_inverseGamma(color);
-    gl_FragColor = vec4(color, 1.0);
+    gl_FragColor = vec4(color, fragmentColor.a);
 }