1

// geometry.ysl2

     2

//

     3

// Geometry (bounding box intersection) definitions

     4

     5

// This retrieves geometry obtained through "inkscape -S"

     6

// already parsed by python and presented as a list of

     7

// <bbox x="0" y="0" w="42" h="42">

     8

const "all_geometry", "ns:GetSVGGeometry()";

     9

const "defs", "//svg:defs/descendant-or-self::svg:*";

    10

const "geometry", "$all_geometry[not(@Id = $defs/@id)]";

    11

    12

// Debug data

    13

emit "debug:geometry" {

    14

    | ID, x, y, w, h

    15

    foreach "$geometry"

    16

        |  «@Id» «@x» «@y» «@w» «@h»

    17

}

    18

    19

// Rates 1D intersection of 2 segments A and B

    20

// described respectively with a0,a1 and b0,b1

    21

def "func:intersect_1d" {

    22

    // it is assumed that a1 > a0 and b1 > b0

    23

    param "a0";

    24

    param "a1";

    25

    param "b0";

    26

    param "b1";

    27

    28

    const "d0", "$a0 >= $b0";

    29

    const "d1", "$a1 >= $b1";

    30

    choose {

    31

        when "not($d0) and $d1"

    32

            // b contained in a

    33

            //   a0<b0 b1<a1

    34

            // a +--------+

    35

            // b    +--+

    36

            result "3";

    37

        when "$d0 and not($d1)"

    38

            // a contained in b

    39

            //   b0<a0 a1<b1

    40

            // a    +--+

    41

            // b +--------+

    42

            result "2";

    43

        when "$d0 and $d1 and $a0 < $b1"

    44

            // a and b are overlapped 

    45

            //   b0<a0<b1<a1

    46

            // a    +-----+

    47

            // b +-----+

    48

            result "1";

    49

        when "not($d0) and not($d1) and $b0 < $a1"

    50

            // a and b are overlapped

    51

            //   a0<b0<a1<b1

    52

            // a +-----+

    53

            // b    +-----+

    54

            result "1";

    55

            // since orientation doesn't matter,

    56

            // rated same as previous symetrical overlapping

    57

        otherwise

    58

            result "0"; /* no intersection*/

    59

    }

    60

}

    61

    62

    63

// Rates intersection A and B areas described with x,y,w and h 

    64

// attributes passed as $a and $b parameters.

    65

// 

    66

// returns :

    67

// 0 - no intersection

    68

//            .-----.

    69

//    .-----. |    b|

    70

//    |     | |     |

    71

//    |     | '-----'

    72

//    |a    |

    73

//    '-----'

    74

//

    75

// 1 - overlapping

    76

//        .-----.

    77

//    .---|--. b|

    78

//    |   |  |  |

    79

//    |   '-----'

    80

//    |a     |

    81

//    '------'

    82

//

    83

// 2 - overlapping

    84

//        .-----.

    85

//        |  a  |

    86

//    .---|-----|---.

    87

//    |   '-----'   |

    88

//    | b           |

    89

//    '-------------'

    90

//

    91

// 3 - overlapping

    92

//        .-----.

    93

//        |  b  |

    94

//    .---|-----|---.

    95

//    |   '-----'   |

    96

//    | a           |

    97

//    '-------------'

    98

//

    99

// 4 - a contained in b

   100

//    .-------------.

   101

//    |   .-----.   |

   102

//    |   |  a  |   |

   103

//    |b  '-----'   |

   104

//    '-------------'

   105

//

   106

// 6 - overlapping

   107

//        .----.

   108

//        |   b|

   109

//    .---|----|---.

   110

//    |a  |    |   |

   111

//    '---|----|---'

   112

//        '----'

   113

//

   114

// 9 - b contained in a

   115

//    .-------------.

   116

//    |   .-----.   |

   117

//    |   |  b  |   |

   118

//    |a  '-----'   |

   119

//    '-------------'

   120

//

   121

def "func:intersect" {

   122

    param "a";

   123

    param "b";

   124

   125

    const "x_intersect", "func:intersect_1d($a/@x, $a/@x+$a/@w, $b/@x, $b/@x+$b/@w)";

   126

   127

    choose{

   128

        when "$x_intersect != 0"{

   129

            const "y_intersect", "func:intersect_1d($a/@y, $a/@y+$a/@h, $b/@y, $b/@y+$b/@h)";

   130

            result "$x_intersect * $y_intersect";

   131

        }

   132

        otherwise result "0";

   133

    }

   134

}

   135

   136

const "groups", "/svg:svg | //svg:g";

   137

   138

// return overlapping geometry for a given element

   139

// all intersercting element are returned

   140

// except groups, that must be contained to be counted in

   141

def "func:overlapping_geometry" {

   142

    param "elt";

   143

    const "g", "$geometry[@Id = $elt/@id]"; 

   144

    const "candidates", "$geometry[@Id != $elt/@id]";

   145

    result """$candidates[(@Id = $groups/@id and (func:intersect($g, .) = 9)) or 

   146

                          (not(@Id = $groups/@id) and (func:intersect($g, .) > 0 ))]""";

   147

}