message: The gaussian blur running sum must be in highp
  This is to acomodate hdr and evsm blurring.
diff: @@ -50,12 +50,12 @@ vertex {
  }
  fragment {
  - void tap(inout vec3 sum, float weight, highp vec2 position) {
  + void tap(inout highp vec3 sum, const float weight, const highp vec2 position) {
  vec3 s = textureLod(materialParams_source, position, materialParams.level).rgb;
  sum += s * weight;
  }
  - void tapReinhard(inout vec3 sum, inout float totalWeight, float weight, highp vec2 position) {
  + void tapReinhard(inout highp vec3 sum, inout float totalWeight, const float weight, const highp vec2 position) {
  vec3 s = textureLod(materialParams_source, position, materialParams.level).rgb;
  float w = weight / (1.0 + max3(s));
  totalWeight += w;
  @@ -66,7 +66,7 @@ fragment {
  highp vec2 uv = variable_vertex.xy;
  // we handle the center pixel separately
  - vec3 sum = vec3(0);
  + highp vec3 sum = vec3(0);
  if (materialParams.reinhard != 0) {
  float totalWeight = 0.0;
  