use view/OffsetArrays instead of ranges

Author: rafaqz

src/UnicodeGraphics.jl

@@ -5,16 +5,18 @@ module UnicodeGraphics
 
 export blockize, brailize
 
-blockize(a, cutoff=0) = blockize(a, cutoff, 1:size(a, 1), 1:size(a, 2))
-blockize(a, cutoff, yrange, xrange) = begin
+blockize(a, cutoff=0) = blockize(a, cutoff)
+blockize(a, cutoff) = begin
+    yrange, xrange = axes(a)
     out = Array{Char,2}(undef, length(xrange) + 1, (length(yrange) - 1) ÷ 2 + 1)
-    blockize!(out, a, cutoff, yrange, xrange) 
+    blockize!(out, a, cutoff) 
 end
 
-blockize!(out, a, cutoff, yrange, xrange) = join(block_array!(out, a, cutoff, yrange, xrange))
+blockize!(out, a, cutoff) = join(block_array!(out, a, cutoff))
 
-function block_array!(out, a, cutoff, yrange, xrange)
-    for y in yrange.start:2:yrange.stop
+function block_array!(out, a, cutoff)
+    yrange, xrange = axes(a)
+    for y in first(yrange):2:last(yrange)
         for x in xrange
             top = checkval(a, y, x, yrange, xrange, cutoff)
             bottom = checkval(a, y + 1, x, yrange, xrange, cutoff)
@@ -23,10 +25,10 @@ function block_array!(out, a, cutoff, yrange, xrange)
             else
                 ch = bottom ? '▄' : ' '
             end
-            out[x-xrange.start + 1, (y-yrange.start) ÷ 2 + 1] = Char(ch)
+            out[x-first(xrange) + 1, (y-first(yrange)) ÷ 2 + 1] = Char(ch)
         end
         # Return after every column
-        out[end, (y-yrange.start) ÷ 2 + 1] = Char('\n')
+        out[end, (y-first(yrange)) ÷ 2 + 1] = Char('\n')
     end
     # The last character is null
     out[end, end] = 0x00
@@ -35,35 +37,37 @@ end
 
 const braile_hex = ((0x01, 0x08), (0x02, 0x10), (0x04, 0x20), (0x40, 0x80))
 
-brailize(a, cutoff=0) = brailize(a, cutoff, 1:size(a, 1), 1:size(a, 2))
-brailize(a, cutoff, yrange, xrange) = begin 
+brailize(a) = brailize(a, 0)
+brailize(a, cutoff) = begin 
+    yrange, xrange = axes(a)
     out = Array{Char,2}(undef, (length(xrange) - 1) ÷ 2 + 2, (length(yrange) - 1) ÷ 4 + 1)
-    brailize!(out, a, cutoff, yrange, xrange) 
+    brailize!(out, a, cutoff) 
 end
 
-brailize!(out, a, cutoff, yrange, xrange) = join(braile_array!(out, a, cutoff, yrange, xrange))
+brailize!(out, a, cutoff) = join(braile_array!(out, a, cutoff))
 
-function braile_array!(out, a, cutoff, yrange, xrange)
-    for y = yrange.start:4:yrange.stop
-        for x = xrange.start:2:xrange.stop
+function braile_array!(out, a, cutoff)
+    yrange, xrange = axes(a)
+    for y in first(yrange):4:last(yrange)
+        for x in first(xrange):2:last(xrange)
             ch = 0x2800
             for j = 0:3, i = 0:1
                 if checkval(a, y+j, x+i, yrange, xrange, cutoff)
                     ch += braile_hex[j % 4 + 1][i % 2 + 1]
                 end
             end
-            out[(x - xrange.start) ÷ 2 + 1, (y-yrange.start) ÷ 4 + 1] = ch
+            out[(x - first(xrange)) ÷ 2 + 1, (y-first(yrange)) ÷ 4 + 1] = ch
         end
         # Return after every column
-        out[end, (y-yrange.start) ÷ 4 + 1] = Char('\n')
+        out[end, (y-first(yrange)) ÷ 4 + 1] = Char('\n')
     end
     # The last character is null
     out[end, end] = 0x00
     out
 end
 
 checkval(a, y, x, yrange, xrange, cutoff) = begin
-    if x <= xrange.stop && y <= yrange.stop
+    if x <= last(xrange) && y <= last(yrange)
         a[y, x] > cutoff
     else
         false

test/REQUIRE

@@ -0,0 +1 @@
+OffsetArrays

test/runtests.jl

@@ -1,4 +1,5 @@
 using UnicodeGraphics, 
+      OffsetArrays,
       Test
 
 pac = [0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0;
@@ -82,7 +83,7 @@ block_ghost =
 ██▀███▀▀███▀██
 ▀   ▀▀  ▀▀   ▀\0"""
 
-test_ghost = blockize(ghost, 0.5, 3:15, 4:17)
+test_ghost = blockize(OffsetArray(ghost[3:15, 4:17], 3:15, 4:17), 0.5, )
 @test test_ghost == block_ghost
 println(test_ghost, "\n\n", block_ghost, "\n\n")
 
@@ -94,6 +95,6 @@ braile_ghost =
 ⣿⣶⣿⣿⣶⣿⣿
 ⠋⠈⠛⠀⠛⠁⠙\0"""
 
-test_ghost = brailize(ghost, 0.5, 2:15, 4:17)
+test_ghost = brailize(OffsetArray(ghost[2:15, 4:17], 2:15, 4:17), 0.5)
 @test test_ghost == braile_ghost
 println(test_ghost, "\n\n", braile_ghost)