//This file is automatically rebuilt by the Cesium build process. export default "void clipLineSegmentToNearPlane(\n\ vec3 p0,\n\ vec3 p1,\n\ out vec4 positionWC,\n\ out bool clipped,\n\ out bool culledByNearPlane,\n\ out vec4 clippedPositionEC)\n\ {\n\ culledByNearPlane = false;\n\ clipped = false;\n\ \n\ vec3 p0ToP1 = p1 - p0;\n\ float magnitude = length(p0ToP1);\n\ vec3 direction = normalize(p0ToP1);\n\ \n\ // Distance that p0 is behind the near plane. Negative means p0 is\n\ // in front of the near plane.\n\ float endPoint0Distance = czm_currentFrustum.x + p0.z;\n\ \n\ // Camera looks down -Z.\n\ // When moving a point along +Z: LESS VISIBLE\n\ // * Points in front of the camera move closer to the camera.\n\ // * Points behind the camrea move farther away from the camera.\n\ // When moving a point along -Z: MORE VISIBLE\n\ // * Points in front of the camera move farther away from the camera.\n\ // * Points behind the camera move closer to the camera.\n\ \n\ // Positive denominator: -Z, becoming more visible\n\ // Negative denominator: +Z, becoming less visible\n\ // Nearly zero: parallel to near plane\n\ float denominator = -direction.z;\n\ \n\ if (endPoint0Distance > 0.0 && abs(denominator) < czm_epsilon7)\n\ {\n\ // p0 is behind the near plane and the line to p1 is nearly parallel to\n\ // the near plane, so cull the segment completely.\n\ culledByNearPlane = true;\n\ }\n\ else if (endPoint0Distance > 0.0)\n\ {\n\ // p0 is behind the near plane, and the line to p1 is moving distinctly\n\ // toward or away from it.\n\ \n\ // t = (-plane distance - dot(plane normal, ray origin)) / dot(plane normal, ray direction)\n\ float t = endPoint0Distance / denominator;\n\ if (t < 0.0 || t > magnitude)\n\ {\n\ // Near plane intersection is not between the two points.\n\ // We already confirmed p0 is behind the naer plane, so now\n\ // we know the entire segment is behind it.\n\ culledByNearPlane = true;\n\ }\n\ else\n\ {\n\ // Segment crosses the near plane, update p0 to lie exactly on it.\n\ p0 = p0 + t * direction;\n\ \n\ // Numerical noise might put us a bit on the wrong side of the near plane.\n\ // Don't let that happen.\n\ p0.z = min(p0.z, -czm_currentFrustum.x);\n\ \n\ clipped = true;\n\ }\n\ }\n\ \n\ clippedPositionEC = vec4(p0, 1.0);\n\ positionWC = czm_eyeToWindowCoordinates(clippedPositionEC);\n\ }\n\ \n\ vec4 getPolylineWindowCoordinatesEC(vec4 positionEC, vec4 prevEC, vec4 nextEC, float expandDirection, float width, bool usePrevious, out float angle)\n\ {\n\ // expandDirection +1 is to the _left_ when looking from positionEC toward nextEC.\n\ \n\ #ifdef POLYLINE_DASH\n\ // Compute the window coordinates of the points.\n\ vec4 positionWindow = czm_eyeToWindowCoordinates(positionEC);\n\ vec4 previousWindow = czm_eyeToWindowCoordinates(prevEC);\n\ vec4 nextWindow = czm_eyeToWindowCoordinates(nextEC);\n\ \n\ // Determine the relative screen space direction of the line.\n\ vec2 lineDir;\n\ if (usePrevious) {\n\ lineDir = normalize(positionWindow.xy - previousWindow.xy);\n\ }\n\ else {\n\ lineDir = normalize(nextWindow.xy - positionWindow.xy);\n\ }\n\ angle = atan(lineDir.x, lineDir.y) - 1.570796327; // precomputed atan(1,0)\n\ \n\ // Quantize the angle so it doesn't change rapidly between segments.\n\ angle = floor(angle / czm_piOverFour + 0.5) * czm_piOverFour;\n\ #endif\n\ \n\ vec4 clippedPrevWC, clippedPrevEC;\n\ bool prevSegmentClipped, prevSegmentCulled;\n\ clipLineSegmentToNearPlane(prevEC.xyz, positionEC.xyz, clippedPrevWC, prevSegmentClipped, prevSegmentCulled, clippedPrevEC);\n\ \n\ vec4 clippedNextWC, clippedNextEC;\n\ bool nextSegmentClipped, nextSegmentCulled;\n\ clipLineSegmentToNearPlane(nextEC.xyz, positionEC.xyz, clippedNextWC, nextSegmentClipped, nextSegmentCulled, clippedNextEC);\n\ \n\ bool segmentClipped, segmentCulled;\n\ vec4 clippedPositionWC, clippedPositionEC;\n\ clipLineSegmentToNearPlane(positionEC.xyz, usePrevious ? prevEC.xyz : nextEC.xyz, clippedPositionWC, segmentClipped, segmentCulled, clippedPositionEC);\n\ \n\ if (segmentCulled)\n\ {\n\ return vec4(0.0, 0.0, 0.0, 1.0);\n\ }\n\ \n\ vec2 directionToPrevWC = normalize(clippedPrevWC.xy - clippedPositionWC.xy);\n\ vec2 directionToNextWC = normalize(clippedNextWC.xy - clippedPositionWC.xy);\n\ \n\ // If a segment was culled, we can't use the corresponding direction\n\ // computed above. We should never see both of these be true without\n\ // `segmentCulled` above also being true.\n\ if (prevSegmentCulled)\n\ {\n\ directionToPrevWC = -directionToNextWC;\n\ }\n\ else if (nextSegmentCulled)\n\ {\n\ directionToNextWC = -directionToPrevWC;\n\ }\n\ \n\ vec2 thisSegmentForwardWC, otherSegmentForwardWC;\n\ if (usePrevious)\n\ {\n\ thisSegmentForwardWC = -directionToPrevWC;\n\ otherSegmentForwardWC = directionToNextWC;\n\ }\n\ else\n\ {\n\ thisSegmentForwardWC = directionToNextWC;\n\ otherSegmentForwardWC = -directionToPrevWC;\n\ }\n\ \n\ vec2 thisSegmentLeftWC = vec2(-thisSegmentForwardWC.y, thisSegmentForwardWC.x);\n\ \n\ vec2 leftWC = thisSegmentLeftWC;\n\ float expandWidth = width * 0.5;\n\ \n\ // When lines are split at the anti-meridian, the position may be at the\n\ // same location as the next or previous position, and we need to handle\n\ // that to avoid producing NaNs.\n\ if (!czm_equalsEpsilon(prevEC.xyz - positionEC.xyz, vec3(0.0), czm_epsilon1) && !czm_equalsEpsilon(nextEC.xyz - positionEC.xyz, vec3(0.0), czm_epsilon1))\n\ {\n\ vec2 otherSegmentLeftWC = vec2(-otherSegmentForwardWC.y, otherSegmentForwardWC.x);\n\ \n\ vec2 leftSumWC = thisSegmentLeftWC + otherSegmentLeftWC;\n\ float leftSumLength = length(leftSumWC);\n\ leftWC = leftSumLength < czm_epsilon6 ? thisSegmentLeftWC : (leftSumWC / leftSumLength);\n\ \n\ // The sine of the angle between the two vectors is given by the formula\n\ // |a x b| = |a||b|sin(theta)\n\ // which is\n\ // float sinAngle = length(cross(vec3(leftWC, 0.0), vec3(-thisSegmentForwardWC, 0.0)));\n\ // Because the z components of both vectors are zero, the x and y coordinate will be zero.\n\ // Therefore, the sine of the angle is just the z component of the cross product.\n\ vec2 u = -thisSegmentForwardWC;\n\ vec2 v = leftWC;\n\ float sinAngle = abs(u.x * v.y - u.y * v.x);\n\ expandWidth = clamp(expandWidth / sinAngle, 0.0, width * 2.0);\n\ }\n\ \n\ vec2 offset = leftWC * expandDirection * expandWidth * czm_pixelRatio;\n\ return vec4(clippedPositionWC.xy + offset, -clippedPositionWC.z, 1.0) * (czm_projection * clippedPositionEC).w;\n\ }\n\ \n\ vec4 getPolylineWindowCoordinates(vec4 position, vec4 previous, vec4 next, float expandDirection, float width, bool usePrevious, out float angle)\n\ {\n\ vec4 positionEC = czm_modelViewRelativeToEye * position;\n\ vec4 prevEC = czm_modelViewRelativeToEye * previous;\n\ vec4 nextEC = czm_modelViewRelativeToEye * next;\n\ return getPolylineWindowCoordinatesEC(positionEC, prevEC, nextEC, expandDirection, width, usePrevious, angle);\n\ }\n\ ";