svghmi/geometry.ysl2
author Edouard Tisserant
Tue, 13 Jul 2021 16:16:58 +0200
branchsvghmi
changeset 3278 2bcfbea6a2a8
parent 3199 1582753e409b
child 3625 bb1eff4091ab
permissions -rw-r--r--
SVGHMI: Fixed typo on session manager unregister, leading to wrong count of sessions and then exceptions when creating more session than allowed in protocol options. Also added more safety check in protocol in case session would be missing.
// geometry.ysl2
//
// Geometry (bounding box intersection) definitions

// This retrieves geometry obtained through "inkscape -S"
// already parsed by python and presented as a list of
// <bbox x="0" y="0" w="42" h="42">
const "all_geometry", "ns:GetSVGGeometry()";
const "defs", "//svg:defs/descendant-or-self::svg:*";
const "geometry", "$all_geometry[not(@Id = $defs/@id)]";

// Debug data
emit "debug:geometry" {
    | ID, x, y, w, h
    foreach "$geometry"
        |  «@Id» «@x» «@y» «@w» «@h»
}

// Rates 1D intersection of 2 segments A and B
// described respectively with a0,a1 and b0,b1
def "func:intersect_1d" {
    // it is assumed that a1 > a0 and b1 > b0
    param "a0";
    param "a1";
    param "b0";
    param "b1";

    const "d0", "$a0 >= $b0";
    const "d1", "$a1 >= $b1";
    choose {
        when "not($d0) and $d1"
            // b contained in a
            //   a0<b0 b1<a1
            // a +--------+
            // b    +--+
            result "3";
        when "$d0 and not($d1)"
            // a contained in b
            //   b0<a0 a1<b1
            // a    +--+
            // b +--------+
            result "2";
        when "$d0 and $d1 and $a0 < $b1"
            // a and b are overlapped 
            //   b0<a0<b1<a1
            // a    +-----+
            // b +-----+
            result "1";
        when "not($d0) and not($d1) and $b0 < $a1"
            // a and b are overlapped
            //   a0<b0<a1<b1
            // a +-----+
            // b    +-----+
            result "1";
            // since orientation doesn't matter,
            // rated same as previous symetrical overlapping
        otherwise
            result "0"; /* no intersection*/
    }
}


// Rates intersection A and B areas described with x,y,w and h 
// attributes passed as $a and $b parameters.
// 
// returns :
// 0 - no intersection
//            .-----.
//    .-----. |    b|
//    |     | |     |
//    |     | '-----'
//    |a    |
//    '-----'
//
// 1 - overlapping
//        .-----.
//    .---|--. b|
//    |   |  |  |
//    |   '-----'
//    |a     |
//    '------'
//
// 2 - overlapping
//        .-----.
//        |  a  |
//    .---|-----|---.
//    |   '-----'   |
//    | b           |
//    '-------------'
//
// 3 - overlapping
//        .-----.
//        |  b  |
//    .---|-----|---.
//    |   '-----'   |
//    | a           |
//    '-------------'
//
// 4 - a contained in b
//    .-------------.
//    |   .-----.   |
//    |   |  a  |   |
//    |b  '-----'   |
//    '-------------'
//
// 6 - overlapping
//        .----.
//        |   b|
//    .---|----|---.
//    |a  |    |   |
//    '---|----|---'
//        '----'
//
// 9 - b contained in a
//    .-------------.
//    |   .-----.   |
//    |   |  b  |   |
//    |a  '-----'   |
//    '-------------'
//
def "func:intersect" {
    param "a";
    param "b";

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

    choose{
        when "$x_intersect != 0"{
            const "y_intersect", "func:intersect_1d($a/@y, $a/@y+$a/@h, $b/@y, $b/@y+$b/@h)";
            result "$x_intersect * $y_intersect";
        }
        otherwise result "0";
    }
}

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

// return overlapping geometry for a given element
// all intersercting element are returned
// except groups, that must be contained to be counted in
def "func:overlapping_geometry" {
    param "elt";
    const "g", "$geometry[@Id = $elt/@id]"; 
    const "candidates", "$geometry[@Id != $elt/@id]";
    result """$candidates[(@Id = $groups/@id and (func:intersect($g, .) = 9)) or 
                          (not(@Id = $groups/@id) and (func:intersect($g, .) > 0 ))]""";
}