1 -- The theme is what decides what's actually shown on screen, what kind of
2 -- transitions are available (if any), and what kind of inputs there are,
3 -- if any. In general, it drives the entire display logic by creating Movit
4 -- chains (called “scenes”), setting their parameters and then deciding which
7 -- Themes are written in Lua, which reflects a simplified form of the Movit API
8 -- where all the low-level details (such as texture formats) and alternatives
9 -- (e.g. turning scaling on or off) are handled by the C++ side and you
10 -- generally just build scenes.
12 -- This is a much simpler theme than the default theme; it only allows you to
13 -- switch between inputs and set white balance, no transitions or the likes.
14 -- Thus, it should be simpler to understand.
16 local input_neutral_color = {{0.5, 0.5, 0.5}, {0.5, 0.5, 0.5}}
18 local live_signal_num = 0
19 local preview_signal_num = 1
21 local img = ImageInput.new("bg.jpeg")
23 local scene = Scene.new(16, 9)
24 local input = scene:add_input()
25 local wb_effect = scene:add_effect(WhiteBalanceEffect.new())
28 -- Set some global state.
29 Nageru.set_num_channels(2) -- Can only be called at the start of the program.
30 Nageru.set_channel_name(2, "First input")
31 Nageru.set_channel_name(3, "Second input")
34 -- Returns, given a channel number, which signal it corresponds to (starting from 0).
35 -- Should return -1 if the channel does not correspond to a simple signal.
36 -- (The information is used for whether right-click on the channel should bring up
37 -- an input selector or not.)
38 -- Called once for each channel, at the start of the program.
39 -- Will never be called for live (0) or preview (1).
40 function channel_signal(channel)
43 elseif channel == 3 then
51 -- Called every frame. Returns the color (if any) to paint around the given
52 -- channel. Returns a CSS color (typically to mark live and preview signals);
53 -- "transparent" is allowed.
54 -- Will never be called for live (0) or preview (1).
55 function channel_color(channel)
60 -- Returns if a given channel supports setting white balance (starting from 2).
61 -- Called only once for each channel, at the start of the program.
62 function supports_set_wb(channel)
63 return channel == 2 or channel == 3
67 -- Gets called with a new gray point when the white balance is changing.
68 -- The color is in linear light (not sRGB gamma).
69 function set_wb(channel, red, green, blue)
71 input_neutral_color[1] = { red, green, blue }
72 elseif channel == 3 then
73 input_neutral_color[2] = { red, green, blue }
78 -- Called every frame.
79 function get_transitions(t)
80 if live_signal_num == preview_signal_num then
81 -- No transitions possible.
89 -- Called when the user clicks a transition button. For our case,
90 -- we only do cuts, so we ignore the parameters; just switch live and preview.
91 function transition_clicked(num, t)
92 local temp = live_signal_num
93 live_signal_num = preview_signal_num
94 preview_signal_num = temp
98 function channel_clicked(num)
99 preview_signal_num = num
103 -- Called every frame. Get the scene for displaying at input <num>,
104 -- where 0 is live, 1 is preview, 2 is the first channel to display
105 -- in the bottom bar, and so on up to num_channels()+1. t is the
106 -- current time in seconds. width and height are the dimensions of
107 -- the output, although you can ignore them if you don't need them
108 -- (they're useful if you want to e.g. know what to resample by).
110 -- <signals> is basically an exposed InputState, which you can use to
111 -- query for information about the signals at the point of the current
112 -- frame. In particular, you can call get_width() and get_height()
113 -- for any signal number, and use that to e.g. assist in scene selection.
115 -- You should return the scene to use, after having set any parameters you
116 -- want to set (through set_int() etc.). The parameters will be snapshot
117 -- at return time and used during rendering.
118 function get_scene(num, t, width, height, signals)
120 if num == 0 then -- Live (right pane).
121 signal_num = live_signal_num
122 elseif num == 1 then -- Preview (left pane).
123 signal_num = preview_signal_num
124 else -- One of the two previews (bottom panes).
131 input:display(signal_num)
134 local color = input_neutral_color[signal_num + 1]
135 wb_effect:set_vec3("neutral_color", color[1], color[2], color[3])