added slanted sequences

gallery/example2.typ

@@ -84,3 +84,27 @@
 
   _evt("bob", "disable")
 })
+
+#chronos.diagram({
+  import chronos: *
+  _par("alice", display-name: "Alice")
+  _par("bob", display-name: "Bob")
+  _par("craig", display-name: "Craig")
+
+  _seq("alice", "bob")
+  _seq("bob", "craig", slant: auto)
+  _seq("alice", "craig", slant: 20)
+
+  _sync({
+    _seq("alice", "bob", slant: 10)
+    _seq("craig", "bob", slant: 20)
+  })
+
+  _sync({
+    _seq("alice", "bob", slant: auto)
+    _seq("bob", "alice", slant: auto)
+  })
+
+  _gap()
+  _evt("bob", "disable")
+})

src/consts.typ

@@ -3,6 +3,7 @@
 #let COMMENT-PAD = 8
 #let LIFELINE-W = 10
 #let CREATE-OFFSET = 15
+#let DEFAULT-SLANT = 10
 
 #let SYM-GAP = 5
 #let PAR-PAD = (5pt, 3pt)

src/sequence.typ

@@ -35,7 +35,8 @@
   destroy-dst: false,
   disable-src: false,
   destroy-src: false,
-  lifeline-style: auto
+  lifeline-style: auto,
+  slant: none
 ) = {
   return ((
     type: "seq",
@@ -54,6 +55,7 @@
     disable-src: disable-src,
     destroy-src: destroy-src,
     lifeline-style: lifeline-style,
+    slant: slant
   ),)
 }
 
@@ -87,27 +89,38 @@
     y: y,
     ll-lvl: lifelines.at(i2).level * LIFELINE-W / 2
   )
+  let slant = if elmt.slant == auto {
+    DEFAULT-SLANT
+  } else if elmt.slant != none {
+    elmt.slant
+  } else {
+    0
+  }
+  end-info.y -= slant
+  if elmt.p1 == elmt.p2 {
+    end-info.y -= 10
+  }
 
   if elmt.disable-src {
     let src-line = lifelines.at(i1)
     src-line.level -= 1
-    src-line.lines.push(("disable", y))
+    src-line.lines.push(("disable", start-info.y))
     lifelines.at(i1) = src-line
   }
   if elmt.destroy-src {
     let src-line = lifelines.at(i1)
-    src-line.lines.push(("destroy", y))
+    src-line.lines.push(("destroy", start-info.y))
     lifelines.at(i1) = src-line
   }
   if elmt.disable-dst {
     let dst-line = lifelines.at(i2)
     dst-line.level -= 1
-    dst-line.lines.push(("disable", y))
+    dst-line.lines.push(("disable", end-info.y))
     lifelines.at(i2) = dst-line
   }
   if elmt.destroy-dst {
     let dst-line = lifelines.at(i2)
-    dst-line.lines.push(("destroy", y))
+    dst-line.lines.push(("destroy", end-info.y))
     lifelines.at(i2) = dst-line
   }
   if elmt.enable-dst {
@@ -120,7 +133,7 @@
     let m = measure(box(par.display-name))
     let f = if i1 > i2 {-1} else {1}
     end-info.x -= (m.width + PAR-PAD.last() * 2) / 2pt * f
-    shapes += participant.render(x-pos, par, y: y - CREATE-OFFSET)
+    shapes += participant.render(x-pos, par, y: end-info.y - CREATE-OFFSET)
   }
 
   end-info.ll-lvl = lifelines.at(i2).level * LIFELINE-W / 2
@@ -156,9 +169,9 @@
     )
   )
 
-  let y0 = y
+  let y0 = start-info.y
   if "linked-note" in elmt {
-    let shps = note.render(pars-i, x-pos, elmt.linked-note, y, lifelines).last()
+    let shps = note.render(pars-i, x-pos, elmt.linked-note, start-info.y, lifelines).last()
     shapes += shps
   }
 
@@ -177,7 +190,7 @@
 
     if elmt.comment != none {
       shapes += draw.content(
-        (x1, y),
+        (x1, start-info.y),
         elmt.comment,
         anchor: if elmt.flip {"south-east"} else {"south-west"},
         padding: 3pt
@@ -185,13 +198,12 @@
     }
 
     shapes += draw.line(
-      (x1, y),
+      (x1, start-info.y),
-      (x-mid, y),
+      (x-mid, start-info.y),
-      (x-mid, y - 10),
+      (x-mid, end-info.y),
-      (x2, y - 10),
+      (x2, end-info.y),
       ..style
     )
-    y -= 10
 
   } else {
     if elmt.comment != none {
@@ -200,7 +212,7 @@
         x += COMMENT-PAD
       }
       shapes += draw.content(
-        (x, y),
+        (x, start-info.y),
         elmt.comment,
         anchor: "south-west",
         padding: 3pt
@@ -208,28 +220,28 @@
     }
 
     shapes += draw.line(
-      (x1, y),
+      (x1, start-info.y),
-      (x2, y),
+      (x2, end-info.y),
       ..style
     )
   }
   if elmt.enable-dst {
     let dst-line = lifelines.at(i2)
-    dst-line.lines.push(("enable", y, elmt.lifeline-style))
+    dst-line.lines.push(("enable", end-info.y, elmt.lifeline-style))
     lifelines.at(i2) = dst-line
   }
   if elmt.create-dst {
-    y -= CREATE-OFFSET
+    end-info.y -= CREATE-OFFSET
     let dst-line = lifelines.at(i2)
-    dst-line.lines.push(("create", y))
+    dst-line.lines.push(("create", end-info.y))
     lifelines.at(i2) = dst-line
   }
 
   if "linked-note" in elmt {
     let m = note.get-size(elmt.linked-note)
-    y = calc.min(y, y0 - m.height / 2)
+    end-info.y = calc.min(end-info.y, y0 - m.height / 2)
   }
 
-  let r = (y, lifelines, shapes)
+  let r = (end-info.y, lifelines, shapes)
   return r
 }