+-- API ENTRY POINT
+-- Called every frame. Returns the color (if any) to paint around the given
+-- channel. Returns a CSS color (typically to mark live and preview signals);
+-- "transparent" is allowed.
+-- Will never be called for live (0) or preview (1).
+function channel_color(channel)
+ if channel_involved_in(channel, live_signal_num) then
+ return "#f00"
+ end
+ if channel_involved_in(channel, preview_signal_num) then
+ return "#0f0"
+ end
+ return "transparent"
+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
+ end
+ if signal_num == SBS_SIGNAL_NUM then
+ return (channel == 2 or channel == 3)
+ end
+ if signal_num == STATIC_SIGNAL_NUM then
+ return (channel == 5)
+ end
+ if signal_num == FADE_SIGNAL_NUM then
+ return (channel_involved_in(channel, fade_src_signal) or
+ channel_involved_in(channel, fade_dst_signal))
+ end
+ return false
+end
+