#ifdef GL_EXT_frag_depth
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#extension GL_EXT_frag_depth : enable
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#endif
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varying vec4 v_startPlaneEC;
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varying vec4 v_endPlaneEC;
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varying vec4 v_rightPlaneEC;
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varying float v_halfWidth;
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varying vec3 v_volumeUpEC;
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uniform vec4 u_highlightColor;
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void main()
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{
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float logDepthOrDepth = czm_branchFreeTernary(czm_sceneMode == czm_sceneMode2D, gl_FragCoord.z, czm_unpackDepth(texture2D(czm_globeDepthTexture, gl_FragCoord.xy / czm_viewport.zw)));
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// Discard for sky
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if (logDepthOrDepth == 0.0) {
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#ifdef DEBUG_SHOW_VOLUME
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gl_FragColor = vec4(0.0, 0.0, 1.0, 0.5);
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return;
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#else // DEBUG_SHOW_VOLUME
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discard;
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#endif // DEBUG_SHOW_VOLUME
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}
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vec4 eyeCoordinate = czm_windowToEyeCoordinates(gl_FragCoord.xy, logDepthOrDepth);
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eyeCoordinate /= eyeCoordinate.w;
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float halfMaxWidth = v_halfWidth * czm_metersPerPixel(eyeCoordinate);
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// Expand halfMaxWidth if direction to camera is almost perpendicular with the volume's up direction
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halfMaxWidth += halfMaxWidth * (1.0 - dot(-normalize(eyeCoordinate.xyz), v_volumeUpEC));
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// Check distance of the eye coordinate against the right-facing plane
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float widthwiseDistance = czm_planeDistance(v_rightPlaneEC, eyeCoordinate.xyz);
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// Check eye coordinate against the mitering planes
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float distanceFromStart = czm_planeDistance(v_startPlaneEC, eyeCoordinate.xyz);
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float distanceFromEnd = czm_planeDistance(v_endPlaneEC, eyeCoordinate.xyz);
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if (abs(widthwiseDistance) > halfMaxWidth || distanceFromStart < 0.0 || distanceFromEnd < 0.0) {
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#ifdef DEBUG_SHOW_VOLUME
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gl_FragColor = vec4(logDepthOrDepth, 0.0, 0.0, 0.5);
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return;
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#else // DEBUG_SHOW_VOLUME
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discard;
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#endif // DEBUG_SHOW_VOLUME
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}
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gl_FragColor = u_highlightColor;
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czm_writeDepthClamp();
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}
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