precision highp float;
precision highp sampler3D;

#include "parameters"

#define saturate(x) clamp(x, 0.0, 1.0)

uniform mat4 projectionMatrix;
uniform mat4 modelViewMatrix;
uniform mat4 viewMatrix;
uniform mat4 matrixWorld;
uniform vec3 cameraPosition;
uniform float cameraFar;
uniform vec3 ellipsoidCenter;
uniform mat4 inverseEllipsoidMatrix;
uniform vec3 altitudeCorrection;
uniform float pointSize;
uniform vec2 magnitudeRange;
uniform float radianceScale;

layout(location = 0) in vec3 position;
layout(location = 1) in float magnitude;
layout(location = 2) in vec3 color;

out vec3 vCameraPosition;
out vec3 vRayDirection;
out vec3 vEllipsoidCenter;
out vec3 vColor;

void main() {
  // Magnitude is stored between 0 to 1 within the given range.
  float m = mix(magnitudeRange.x, magnitudeRange.y, magnitude);
  vec3 v = pow(vec3(10.0), -vec3(magnitudeRange, m) / 2.5);
  vColor = vec3(radianceScale * color);
  vColor *= saturate((v.z - v.y) / (v.x - v.y));

  #ifdef BACKGROUND
  vec3 worldDirection = normalize(matrixWorld * vec4(position, 1.0)).xyz;
  mat3 rotation = mat3(inverseEllipsoidMatrix);
  vCameraPosition = rotation * cameraPosition * METER_TO_LENGTH_UNIT;
  vRayDirection = rotation * worldDirection;
  vEllipsoidCenter = (ellipsoidCenter + altitudeCorrection) * METER_TO_LENGTH_UNIT;
  gl_Position =
    projectionMatrix * viewMatrix * vec4(cameraPosition + worldDirection * cameraFar, 1.0);
  #else // BACKGROUND
  gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
  #endif // BACKGROUND

  gl_PointSize = pointSize;
}