add edgegap func

CHANGELOG.md

@@ -1,9 +1,11 @@
 # Changelog
 
-## current master
+## [v1.1.0] current master
 
 ### Added
 
+- edgegap can be function
+
 ## Changed
 
 ### Removed

Project.toml

@@ -1,7 +1,7 @@
 name = "Karnak"
 uuid = "cd156443-31ad-4f6f-850f-a93ee5f75905"
 authors = ["cormullion <[email protected]> and contributors"]
-version = "1.0.0"
+version = "1.1.0"
 
 [deps]
 Colors = "5ae59095-9a9b-59fe-a467-6f913c188581"

docs/src/syntax.md

@@ -949,9 +949,13 @@ This example draws the graph more than once; once with all the edges, once with
 end 600 600
 ```
 
-### `edgecurvature` and `edgecaps`
+### `edgecurvature` and `edgegaps`
 
-`edgecurvature` determines the curvature of the edges, and `edgegaps` sets the distance between the tip of the arrowhead and the vertex position. Units, as everywhere in Karnak, are points/pixels (1 point is 0.3527mm).
+The `edgecurvature` keyword determines the curvature of the edges. 
+
+The `edgegaps` keyword sets the distances between the ends of the edges and the vertex positions. 
+
+Units, as everywhere in Karnak, are points/pixels (1 point is 0.3527mm).
 
 ```@example graphsection
 g = grid((3, 3))
@@ -978,6 +982,49 @@ end
 end 600 500
 ```
 
+The value for the edge gap (either as supplied in vector, range, or scalar form, or calculated and returned by a function) applies to both ends of an edge. This is a minor issue for cases where, for example, the vertex shapes are different sizes, and the gaps need to be calculated independently for each end of a single edge. You'll have to calculate and draw the edges yourself, as shown in this unnecessarily animated example:
+
+```julia
+using Karnak, Graphs, Colors
+function frame(scene, framenumber, g, vertexsizes)
+    background("black")
+    eased_n = scene.easingfunction(framenumber - scene.framerange.start,
+        0, 1, (scene.framerange.stop + 1) - scene.framerange.start)
+    a = 10 + vertexsizes[1] * abs(sin(0 + rescale(eased_n, 0, 1, 0, π)))
+    b = 10 + vertexsizes[2] * abs(sin(π / 4 + rescale(eased_n, 0, 1, 0, π)))
+    c = 10 + vertexsizes[3] * abs(sin(π / 3 + rescale(eased_n, 0, 1, 0, π)))
+    d = 10 + vertexsizes[4] * abs(sin(rescale(eased_n, 0, 1, 0, π)))
+    newvertexsizes = [a, b, c, d]
+    sethue("gold")
+    drawgraph(g,
+        margin=80,
+        vertexshapesizes=newvertexsizes,
+        vertexfillcolors=[c for c in Colors.JULIA_LOGO_COLORS |> values],
+        edgefunction=(args...) -> begin
+            edgenumber, edgesrc, edgedest, from, to = args
+            d = distance(from, to)
+            startpoint = between(from, to, newvertexsizes[edgesrc] / d)
+            endpoint = between(from, to, 1 - newvertexsizes[edgedest] / d)
+            arrow(startpoint, endpoint)
+        end)
+end
+
+function main()
+    g = complete_digraph(4)
+    vertexsizes = [20, 35, 50, 60]
+    amovie = Movie(800, 600, "gap animation")
+    animate(amovie,
+        Scene(amovie, (s, f) -> frame(s, f, g, vertexsizes), 1:40),
+        framerate=15,
+        creategif=true,
+        pathname=joinpath(dirname(dirname(pathof(Karnak))) * "/docs/src/assets/figures/edgegapanimation.gif"))
+end
+
+main()
+```
+
+![edge gap animation](assets/figures/edgegapanimation.gif)
+
 ### `edgestrokecolors` and `edgestrokeweights`
 
 ```@example graphsection

src/drawgraph.jl

@@ -132,6 +132,8 @@ function _drawedgelines(from, to, edgesrc, edgedest;
         edgegap = edgegaps[mod1(edgenumber, end)]
     elseif edgegaps isa AbstractRange
         edgegap = edgegaps[mod1(edgenumber, end)]
+    elseif edgegaps isa Function 
+        edgegap = edgegaps(edgenumber, edgesrc, edgedest, from, to)
     elseif edgegaps isa Real
         edgegap = edgegaps
     end
@@ -911,14 +913,15 @@ All keywords:
  layout                      Vector{Point}                                            
                              function from NetworkLayout.jl                           
                              f(g::Graph)                                              
- edgefunction                f(edgenumber::Int, edgesrc::Int, edgedest::Int, from::Poi
+ edgefunction                f(edgenumber::Int, edgesrc::Int, edgedest::Int, from::Point)
  vertexfunction              f(vtx::Int, coordinates::Vector{Point})                  
  edgecurvature               Float64                                                  
  edgedashpatterns            Vector{Vector}[number]                                   
                              Vector{Number}                                           
  edgegaps                    Vector                                                   
                              Range                                                    
-                             Real                                                     
+                             Real
+                             f(edgenumber::Int, edgesrc::Int, edgedest::Int, from::Point)                                                     
  edgelabelcolors             Vector{Colorant}                                         
                              Colorant                                                 
  edgelabelfontfaces          Vector{Strings}[edgenumber]                              
@@ -933,7 +936,7 @@ All keywords:
                              range                                                    
                              Dict{Int, Int}                                           
                              f(edgenumber, edgesrc, edgedest, from::Point, to::Point)
-                               - this function should draw the required text 
+                               - this function must draw the required text 
                              :none                                                    
  edgelines                   Vector{Int}                                              
                              range                                                    
@@ -958,7 +961,7 @@ All keywords:
                              Real                                                     
                              :none
                              f(vtx::Int, coord::Point[])
-                               function should return a numeric value for fontsize
+                              - function must return a numeric value for fontsize
  vertexlabeloffsetangles     Vector                                                   
                              Range                                                    
                              Real                                                     
@@ -974,7 +977,7 @@ All keywords:
                              range[vtx::Int]                                          
                              :none                                                    
                              f(vtx::Int)
-                              this function should return a string                                              
+                             - this function must return a string                                              
  vertexlabeltextcolors       Vector{Colorant}                                         
                              Colorant
                              f(vtx::Int)