add timings copier

for copying song timings, so eng+romaji+moonrunes all line up

macros/garret.timings_copier.lua

@@ -0,0 +1,54 @@
+script_name = "Timings copier"
+script_description = "for copying song timings"
+script_version = "1.0.0"
+script_author = "garret"
+script_namespace = "garret.timings_copier"
+
+local haveDepCtrl, DependencyControl, depctrl = pcall(require, "l0.DependencyControl")
+if haveDepCtrl then
+    depctrl = DependencyControl {}
+end
+
+local function get_blocks(sub, sel)
+    local src_style = sub[sel[1]].style
+    local src_len = 1
+    for i = 2, #sel do
+        if sub[sel[i]].style == src_style then
+            src_len = src_len + 1
+        else
+            break
+        end
+    end
+    local blocks = #sel / src_len
+    if blocks % 1 ~= 0 then
+        aegisub.log(0, "FATAL: Block lengths are not equal!\n")
+        aegisub.log(3, "HINT: Each \"block\" of lines must be the same length, e.g. you can't have less romaji than english, or vice versa. a block is a group of consecutive lines with the same style.")
+        aegisub.cancel()
+    else
+        return src_len, blocks
+    end
+end
+
+local function copy(sub, sel, offset, blocks)
+    for index = 1, offset do
+        line = sub[sel[index]]
+        for mul = 1, blocks - 1 do
+            block_line = sub[sel[offset * mul + index]]
+            block_line.start_time = line.start_time
+            block_line.end_time = line.end_time
+            sub[sel[offset * mul + index]] = block_line
+        end
+    end
+end
+
+local function main(sub, sel)
+    offset, blocks = get_blocks(sub, sel)
+    copy(sub, sel, offset, blocks)
+    aegisub.set_undo_point(script_name)
+end
+
+if haveDepCtrl then
+    depctrl:registerMacro(main)
+else
+    aegisub.register_macro(script_name, script_description, main)
+end