     float iso = 0.0;
     switch (format) {
     case FieldFormat::UInt8:
-      iso = 0.5f*255.f*(iso + 1.f);
+      iso = 0.5f * 255.f * (iso + 1.f);
       break;
     case FieldFormat::UInt16:
-      iso = 0.5f*65535.f*(iso + 1.f);
+      iso = 0.5f * 65535.f * (iso + 1.f);
     default: break;
     }
 


  const std::string simpleFS_src = R"(#version 430

in vec3 normal;

out layout(location=0) vec4 outColor;

void main() {
  outColor = vec4(abs(normal), 1);
  //outColor = vec4(1,0,0,1);
}


  for (int i = 0; i < deviceCount; i++) {
    cudaDeviceProp dev_prop;
    cudaGetDeviceProperties(&dev_prop, i);
    fprintf(stderr, "%c[%i] %s cap=%d.%d\n", i == deviceIndex ? '*' : ' ', i, dev_prop.name, dev_prop.major, dev_prop.minor);
  }
  if (deviceIndex < 0 || deviceCount <= deviceIndex) {
    fprintf(stderr, "Illegal CUDA device index %d\n", deviceIndex);
