Package org.tinfour.edge

Class QuadEdgeConstants

  • public final class QuadEdgeConstants
extends Object
    Defines constants for use in QuadEdge related operations. At this time, the following constants are defined 
    
 CONSTRAINT_FLAG_MASK              0xf8000000
 CONSTRAINT_EDGE_FLAG              0x80000000
 CONSTRAINT_REGION_BORDER_FLAG     0x40000000
 CONSTRAINT_REGION_INTERIOR_FLAG   0x20000000
 CONSTRAINT_LINE_MEMBER_FLAG       0x10000000
 SYNTHETIC_EDGE_FLAG               0x08000000
 EDGE_FLAG_RESERVED_BIT            0x04000000
 CONSTRAINT_REGION_MEMBER_FLAGS    0x60000000

 CONSTRAINT_INDEX_BIT_SIZE                 13
 CONSTRAINT_INDEX_VALUE_MAX              8190

 CONSTRAINT_LOWER_INDEX_MASK       0x00001fff
 CONSTRAINT_LOWER_INDEX_ZERO       0xffffe000
 CONSTRAINT_UPPER_INDEX_MASK       0x03ffe000
 CONSTRAINT_UPPER_INDEX_ZERO       0xfc001fff

    • Field Detail

      • CONSTRAINT_FLAG_MASK

        public static final int CONSTRAINT_FLAG_MASK
        A mask for preserving the bits allocated for edge-related flags At this time, there are definitions for 5 flags with one bit reserved for future use.
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        Constant Field Values

      • EDGE_FLAG_RESERVED_BIT

        public static final int EDGE_FLAG_RESERVED_BIT
        Defines the bit that is not yet committed for representing edge status. This value is equivalent to bit 26.
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      • CONSTRAINT_INDEX_BIT_SIZE

        public static final int CONSTRAINT_INDEX_BIT_SIZE
        The number of bits committed to the storage of a constraint index. Tinfour reserves space to store the constraint index values for the left and right side of a border constraint. Constraint indices are stored in the "index" element of the QuadEdgePartner class. The high order 5 bits are committed to various flags. So that leaves 27 bits available for constraint information. Since storage is required for two potential indices (left and right), thirteen bits are available for each.
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        Constant Field Values

      • CONSTRAINT_INDEX_VALUE_MAX

        public static final int CONSTRAINT_INDEX_VALUE_MAX
        The maximum value of a constraint index based on the 13 bits allocated for its storage. This would be a value of 8191, or 2^13-1. But QuadEdge reserves the value -1, bit state 0, to represent a null specification. For valid constraint indices, the QuadEdge implementation stores the constraint value plus one. That makes the maximum value 2^13-2
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        Constant Field Values

      • CONSTRAINT_EDGE_FLAG

        public static final int CONSTRAINT_EDGE_FLAG
        A bit indicating that an edge is constrained. This bit just happens to be the sign bit, a feature that is exploited by the isConstrained() method.
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      • CONSTRAINT_REGION_BORDER_FLAG

        public static final int CONSTRAINT_REGION_BORDER_FLAG
        A bit indicating that the edge is the border of a constrained region
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        Constant Field Values

      • CONSTRAINT_REGION_INTERIOR_FLAG

        public static final int CONSTRAINT_REGION_INTERIOR_FLAG
        A bit indicating that an edge is in the interior of a constrained region.
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      • CONSTRAINT_LINE_MEMBER_FLAG

        public static final int CONSTRAINT_LINE_MEMBER_FLAG
        A bit indicating that an edge is part of a non-region constraint line. Edges are allowed to be both an interior and a line, so a separate flag bit is required for both cases.
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      • CONSTRAINT_REGION_MEMBER_FLAGS

        public static final int CONSTRAINT_REGION_MEMBER_FLAGS
        A set of bits combining the constraint region interior and border flags.
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      • SYNTHETIC_EDGE_FLAG

        public static final int SYNTHETIC_EDGE_FLAG
        A bit indicating that an edge has been marked as synthetic.
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      • CONSTRAINT_LOWER_INDEX_ZERO

        public static final int CONSTRAINT_LOWER_INDEX_ZERO
        A specification for using an AND operation to zero out the lower field of bits that contain a constraint index. Used in preparation for storing a new value.
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        Constant Field Values

      • CONSTRAINT_LOWER_INDEX_MASK

        public static final int CONSTRAINT_LOWER_INDEX_MASK
        A specification for using an AND operation to extract the lower field of bits that contain a constraint index.
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      • CONSTRAINT_UPPER_INDEX_MASK

        public static final int CONSTRAINT_UPPER_INDEX_MASK
        A specification for using an AND operation to extract the upper field of bits that contain a constraint index.
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        Constant Field Values

      • CONSTRAINT_UPPER_INDEX_ZERO

        public static final int CONSTRAINT_UPPER_INDEX_ZERO
        A specification for using an AND operation to zero out the upper-field of bits that contain a constraint index. Used in preparation for storing a new value.
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        Constant Field Values