Factor out a repeated if test in the theme to an is_plain_signal() function (backport...

diff --git a/theme.lua b/theme.lua
index 7f47c8491341879c350dd7babe489163ce56a19b..858be1b22dda0204bad6ce8cc64fef2d99f73175 100644 (file)
--- a/theme.lua
+++ b/theme.lua
@@ -240,7 +240,7 @@ function needs_scale(signals, signal_num, width, height)
                -- We assume this is already correctly scaled at load time.
                return false
        end
-       assert(signal_num == INPUT0_SIGNAL_NUM or signal_num == INPUT1_SIGNAL_NUM)
+       assert(is_plain_signal(signal_num))
        return (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height)
 end
 
@@ -261,6 +261,10 @@ function num_channels()
        return 4
 end
 
+function is_plain_signal(num)
+       return num == INPUT0_SIGNAL_NUM or num == INPUT1_SIGNAL_NUM
+end
+
 -- Helper function to write e.g. “720p60”. The difference between this
 -- and get_channel_resolution_raw() is that this one also can say that
 -- there's no signal.
@@ -349,11 +353,8 @@ function channel_color(channel)
 end
 
 function channel_involved_in(channel, signal_num)
-       if signal_num == INPUT0_SIGNAL_NUM then
-               return channel == 2
-       end
-       if signal_num == INPUT1_SIGNAL_NUM then
-               return channel == 3
+       if is_plain_signal(signal_num) then
+               return channel == (signal_num + 2)
        end
        if signal_num == SBS_SIGNAL_NUM then
                return (channel == 2 or channel == 3)
@@ -413,21 +414,15 @@ function get_transitions(t)
                return {"Cut"}
        end
 
-       if (live_signal_num == INPUT0_SIGNAL_NUM or
-           live_signal_num == INPUT1_SIGNAL_NUM or
-           live_signal_num == STATIC_SIGNAL_NUM) and
-          (preview_signal_num == INPUT0_SIGNAL_NUM or
-           preview_signal_num == INPUT1_SIGNAL_NUM or
-           preview_signal_num == STATIC_SIGNAL_NUM) then
+       if (is_plain_signal(live_signal_num) or live_signal_num == STATIC_SIGNAL_NUM) and
+          (is_plain_signal(preview_signal_num) or preview_signal_num == STATIC_SIGNAL_NUM) then
                return {"Cut", "", "Fade"}
        end
 
        -- Various zooms.
-       if live_signal_num == SBS_SIGNAL_NUM and
-          (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
+       if live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(preview_signal_num) then
                return {"Cut", "Zoom in"}
-       elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
-              preview_signal_num == SBS_SIGNAL_NUM then
+       elseif is_plain_signal(live_signal_num) and preview_signal_num == SBS_SIGNAL_NUM then
                return {"Cut", "Zoom out"}
        end
 
@@ -465,8 +460,7 @@ function transition_clicked(num, t)
                        return
                end
 
-               if (live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM) or
-                  (live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM) then
+               if (is_plain_signal(live_signal_num) and is_plain_signal(preview_signal_num)) then
                        -- We can't zoom between these. Just make a cut.
                        io.write("Cutting from " .. live_signal_num .. " to " .. live_signal_num .. "\n")
                        local temp = live_signal_num
@@ -475,8 +469,7 @@ function transition_clicked(num, t)
                        return
                end
 
-               if live_signal_num == SBS_SIGNAL_NUM and
-                  (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
+               if live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(preview_signal_num) then
                        -- Zoom in from SBS to single.
                        transition_start = t
                        transition_end = t + 1.0
@@ -484,8 +477,7 @@ function transition_clicked(num, t)
                        zoom_dst = 1.0
                        zoom_poi = preview_signal_num
                        preview_signal_num = SBS_SIGNAL_NUM
-               elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
-                      preview_signal_num == SBS_SIGNAL_NUM then
+               elseif is_plain_signal(live_signal_num) and preview_signal_num == SBS_SIGNAL_NUM then
                        -- Zoom out from single to SBS.
                        transition_start = t
                        transition_end = t + 1.0
@@ -500,11 +492,9 @@ function transition_clicked(num, t)
 
                -- Fade.
                if (live_signal_num ~= preview_signal_num) and
-                  (live_signal_num == INPUT0_SIGNAL_NUM or
-                   live_signal_num == INPUT1_SIGNAL_NUM or
+                  (is_plain_signal(live_signal_num) or
                    live_signal_num == STATIC_SIGNAL_NUM) and
-                  (preview_signal_num == INPUT0_SIGNAL_NUM or
-                   preview_signal_num == INPUT1_SIGNAL_NUM or
+                  (is_plain_signal(preview_signal_num) or
                    preview_signal_num == STATIC_SIGNAL_NUM) then
                        transition_start = t
                        transition_end = t + 1.0
@@ -575,7 +565,7 @@ function get_chain(num, t, width, height, signals)
        last_resolution = input_resolution
 
        if num == 0 then  -- Live.
-               if live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM then  -- Plain input.
+               if is_plain_signal(live_signal_num) then  -- Plain inputs.
                        local input_type = get_input_type(signals, live_signal_num)
                        local input_scale = needs_scale(signals, live_signal_num, width, height)
                        local chain = simple_chains[input_type][input_scale][true]