Function getVolumeFragmentShader

source/MRViewer/MRVolumeShader.cpp:103–301

}

std::string getVolumeFragmentShader()
{
    return MR_GLSL_VERSION_LINE R"(
  precision highp float;
  precision highp int;

  uniform mat4 model;
  uniform mat4 view;
  uniform mat4 proj;
  uniform mat4 normal_matrix;

  uniform int shadingMode; // 0-none,1-dense grad,2-alpha grad
  uniform float specExp;   // (in from base) lighting parameter
  uniform vec3 ligthPosEye;   // (in from base) light position transformed by view only (not proj)                            
  uniform float ambientStrength;    // (in from base) non-directional lighting
  uniform float specularStrength;   // (in from base) reflection intensity

  uniform vec4 viewport;
  uniform vec3 voxelSize;
  uniform vec3 minCorner;
  uniform float minValue;
  uniform float maxValue;
  uniform float step;

  uniform highp sampler3D volume;
  uniform highp sampler2D denseMap;
  uniform highp usampler2D activeVoxels;      // (in from base) selection BitSet

  uniform bool useClippingPlane;     // (in from base) clip primitive by plane if true
  uniform vec4 clippingPlane;        // (in from base) clipping plane

  out vec4 outColor;
)"
+ getVolumeShaderCommonFunctions() +
R"(
  vec3 normalEye( in vec3 textCoord, in vec3 dimStepVoxel, in bool alphaGrad )
  {
    float minXVal = getVal( texture( volume, textCoord - vec3(dimStepVoxel.x,0,0)).r );
    float maxXVal = getVal( texture( volume, textCoord + vec3(dimStepVoxel.x,0,0)).r );
    float minYVal = getVal( texture( volume, textCoord - vec3(0,dimStepVoxel.y,0)).r );
    float maxYVal = getVal( texture( volume, textCoord + vec3(0,dimStepVoxel.y,0)).r );
    float minZVal = getVal( texture( volume, textCoord - vec3(0,0,dimStepVoxel.z)).r );
    float maxZVal = getVal( texture( volume, textCoord + vec3(0,0,dimStepVoxel.z)).r );
    if ( alphaGrad )
    {
        minXVal = getGradAlphaVal( minXVal );
        maxXVal = getGradAlphaVal( maxXVal );
        minYVal = getGradAlphaVal( minYVal );
        maxYVal = getGradAlphaVal( maxYVal );
        minZVal = getGradAlphaVal( minZVal );
        maxZVal = getGradAlphaVal( maxZVal );
    }
    vec3 grad = -vec3( maxXVal - minXVal, maxYVal - minYVal, maxZVal - minZVal );
    if ( dot( grad, grad ) < 1.0e-5 )
        return vec3(0,0,0);
    grad = vec3( normal_matrix *vec4( normalize(grad),0.0 ) );
    grad = normalize( grad );
    return grad;