OpenSpace/modules/fieldlinessequence/shaders/fieldlinessequence_vs.glsl

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 * OpenSpace                                                                             *
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 * Copyright (c) 2014-2024                                                               *
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#version __CONTEXT__

// Inputs
layout(location = 0) in vec3 in_position;        // Should be provided in meters
layout(location = 1) in float in_color_scalar;   // The extra value used to color lines.
layout(location = 2) in float in_masking_scalar; // The extra value used to mask out parts of lines.

out vec4 vs_color;
out float vs_depth;
//out vec4 vs_gPosition;

// General Uniforms that's always needed
uniform vec4 lineColor;
uniform mat4 modelViewProjection;

// Uniforms needed to color by quantity
uniform int colorMethod;
uniform sampler1D colorTable;
uniform vec2 colorTableRange;

// Uniforms needed for Particle Flow
uniform vec4 flowColor;
uniform int particleSize;
uniform int particleSpeed;
uniform int particleSpacing;
uniform double time;
uniform bool usingParticles;

// Masking Uniforms
uniform bool usingMasking;
uniform vec2 maskingRange;

// Domain Uniforms
uniform bool usingDomain;
uniform vec2 domainLimX;
uniform vec2 domainLimY;
uniform vec2 domainLimZ;
uniform vec2 domainLimR;

// These should correspond to the enum 'ColorMethod' in renderablefieldlinesequence.cpp
const int uniformColor = 0;
const int colorByQuantity = 1;


vec4 getTransferFunctionColor() {
  // Remap the color scalar to a [0,1] range
  float lookUpVal =
    (in_color_scalar - colorTableRange.x) / (colorTableRange.y - colorTableRange.x);
  return texture(colorTable, lookUpVal);
}

bool isPartOfParticle(double time, int vertexId, int particleSize, int particleSpeed,
                      int particleSpacing)
{
  int modulusResult = int(double(particleSpeed) * time + vertexId) % particleSpacing;
  return modulusResult > 0 && modulusResult <= particleSize;
}


void main() {
  bool hasColor = true;

  if (usingMasking && (in_masking_scalar < maskingRange.x ||
                        in_masking_scalar > maskingRange.y))
  {
    hasColor = false;
  }

  if (usingDomain && hasColor) {
    float radius = length(in_position);

    if (in_position.x < domainLimX.x || in_position.x > domainLimX.y ||
        in_position.y < domainLimY.x || in_position.y > domainLimY.y ||
        in_position.z < domainLimZ.x || in_position.z > domainLimZ.y ||
        radius        < domainLimR.x || radius        > domainLimR.y)
    {
      hasColor = false;
    }
  }

  if (hasColor) {
    bool isParticle = usingParticles &&
      isPartOfParticle(time, gl_VertexID, particleSize, particleSpeed, particleSpacing);

    if (isParticle) {
      vs_color = flowColor;
    }
    else {
      vs_color = lineColor;
    }

    if (colorMethod == colorByQuantity) {
      vec4 quantityColor = getTransferFunctionColor();
      vs_color = vec4(quantityColor.xyz, vs_color.a * quantityColor.a);
    }
  }
  else {
    vs_color = vec4(0);
  }

  vec4 position_in_meters = vec4(in_position, 1);
  vec4 positionClipSpace = modelViewProjection * position_in_meters;
  //vs_gPosition = vec4(modelViewTransform * dvec4(in_point_position, 1));
  gl_Position = vec4(positionClipSpace.xy, 0, positionClipSpace.w);

  vs_depth = gl_Position.w;
}