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.
13 transition_start = -2.0,
14 transition_end = -1.0,
16 transition_src_signal = 0,
17 transition_dst_signal = 0,
20 {0.5, 0.5, 0.5}, -- Input 0.
21 {0.5, 0.5, 0.5} -- Input 1.
25 preview_signal_num = 1
28 -- Valid values for live_signal_num and preview_signal_num.
29 local INPUT0_SIGNAL_NUM = 0
30 local INPUT1_SIGNAL_NUM = 1
31 local SBS_SIGNAL_NUM = 2
32 local STATIC_SIGNAL_NUM = 3
34 -- Valid values for transition_type. (Cuts are done directly, so they need no entry.)
35 local NO_TRANSITION = 0
36 local ZOOM_TRANSITION = 1 -- Also for slides.
37 local FADE_TRANSITION = 2
39 function make_sbs_input(scene)
41 input = scene:add_input(),
42 resample_effect = scene:add_effect({ResampleEffect.new(), ResizeEffect.new()}),
43 wb_effect = scene:add_effect(WhiteBalanceEffect.new()),
44 padding_effect = scene:add_effect(IntegralPaddingEffect.new())
48 -- The main live scene.
49 function make_sbs_scene()
50 local scene = Scene.new(16, 9)
52 local input0 = make_sbs_input(scene)
53 input0.input:display(0)
54 input0.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
56 local input1 = make_sbs_input(scene)
57 input1.input:display(1)
58 input1.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 0.0)
60 scene:add_effect(OverlayEffect.new(), input0.padding_effect, input1.padding_effect)
69 local sbs_scene = make_sbs_scene()
71 function make_fade_input(scene)
73 input = scene:add_input(),
74 resample_effect = scene:add_optional_effect(ResampleEffect.new()), -- Activated if scaling.
75 wb_effect = scene:add_optional_effect(WhiteBalanceEffect.new()) -- Activated for video inputs.
79 -- A scene to fade between two inputs, of which either can be a picture
80 -- or a live input. Only used live.
81 function make_fade_scene()
82 local scene = Scene.new(16, 9)
83 local input0 = make_fade_input(scene)
84 local input1 = make_fade_input(scene)
85 local mix_effect = scene:add_effect(MixEffect.new(), input0.wb_effect, input1.wb_effect)
86 scene:finalize(true) -- Only used live.
92 mix_effect = mix_effect
95 local fade_scene = make_fade_scene()
97 -- A scene to show a single input on screen.
98 local scene = Scene.new(16, 9)
99 local simple_scene = {
101 input = scene:add_input(),
102 resample_effect = scene:add_effect({ResampleEffect.new(), ResizeEffect.new(), IdentityEffect.new()}),
103 wb_effect = scene:add_effect(WhiteBalanceEffect.new())
107 -- A scene to show a single static picture on screen.
108 local static_image = ImageInput.new("bg.jpeg") -- Also used as input to other scenes.
109 local static_scene = Scene.new(16, 9)
110 static_scene:add_input(static_image) -- Note: Locks this input to images only.
111 static_scene:finalize()
113 -- Set some global state.
114 Nageru.set_num_channels(4) -- Can only be called at the start of the program.
116 -- Set some global state. Unless marked otherwise, these can only be set once,
117 -- at the start of the program.
118 Nageru.set_num_channels(4)
120 -- Sets, for each channel, which signal it corresponds to (starting from 0).
121 -- The information is used for whether right-click on the channel should bring up
122 -- an input selector or not. Only call this for channels that actually correspond
123 -- directly to a signal (ie., live inputs, not live (0) or preview (1)).
124 Nageru.set_channel_signal(2, 0)
125 Nageru.set_channel_signal(3, 1)
127 -- Set whether a given channel supports setting white balance. (Default is false.)
128 Nageru.set_supports_wb(2, true)
129 Nageru.set_supports_wb(3, true)
131 -- These can be set at any time.
132 Nageru.set_channel_name(SBS_SIGNAL_NUM + 2, "Side-by-side")
133 Nageru.set_channel_name(STATIC_SIGNAL_NUM + 2, "Static picture")
136 -- Called every frame. Returns the color (if any) to paint around the given
137 -- channel. Returns a CSS color (typically to mark live and preview signals);
138 -- "transparent" is allowed.
139 -- Will never be called for live (0) or preview (1).
140 function channel_color(channel)
141 if state.transition_type ~= NO_TRANSITION then
142 if channel_involved_in(channel, state.transition_src_signal) or
143 channel_involved_in(channel, state.transition_dst_signal) then
147 if channel_involved_in(channel, state.live_signal_num) then
151 if channel_involved_in(channel, state.preview_signal_num) then
157 function is_plain_signal(num)
158 return num == INPUT0_SIGNAL_NUM or num == INPUT1_SIGNAL_NUM
161 function channel_involved_in(channel, signal_num)
162 if is_plain_signal(signal_num) then
163 return channel == (signal_num + 2)
165 if signal_num == SBS_SIGNAL_NUM then
166 return (channel == 2 or channel == 3)
168 if signal_num == STATIC_SIGNAL_NUM then
169 return (channel == 5)
175 -- Gets called with a new gray point when the white balance is changing.
176 -- The color is in linear light (not sRGB gamma).
177 function set_wb(channel, red, green, blue)
178 if is_plain_signal(channel - 2) then
179 state.neutral_colors[channel - 2 + 1] = { red, green, blue }
183 function finish_transitions(t)
184 if state.transition_type ~= NO_TRANSITION and t >= state.transition_end then
185 state.live_signal_num = state.transition_dst_signal
186 state.transition_type = NO_TRANSITION
190 function in_transition(t)
191 return t >= state.transition_start and t <= state.transition_end
195 -- Called every frame.
196 function get_transitions(t)
197 if in_transition(t) then
198 -- Transition already in progress, the only thing we can do is really
199 -- cut to the preview. (TODO: Make an “abort” and/or “finish”, too?)
203 finish_transitions(t)
205 if state.live_signal_num == state.preview_signal_num then
206 -- No transitions possible.
210 if (is_plain_signal(state.live_signal_num) or state.live_signal_num == STATIC_SIGNAL_NUM) and
211 (is_plain_signal(state.preview_signal_num) or state.preview_signal_num == STATIC_SIGNAL_NUM) then
212 return {"Cut", "", "Fade"}
216 if state.live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(state.preview_signal_num) then
217 return {"Cut", "Zoom in"}
218 elseif is_plain_signal(state.live_signal_num) and state.preview_signal_num == SBS_SIGNAL_NUM then
219 return {"Cut", "Zoom out"}
225 function swap_preview_live()
226 local temp = state.live_signal_num
227 state.live_signal_num = state.preview_signal_num
228 state.preview_signal_num = temp
231 function start_transition(type_, t, duration)
232 state.transition_start = t
233 state.transition_end = t + duration
234 state.transition_type = type_
235 state.transition_src_signal = state.live_signal_num
236 state.transition_dst_signal = state.preview_signal_num
241 -- Called when the user clicks a transition button.
242 function transition_clicked(num, t)
245 if in_transition(t) then
246 -- Ongoing transition; finish it immediately before the cut.
247 finish_transitions(state.transition_end)
253 finish_transitions(t)
255 if state.live_signal_num == state.preview_signal_num then
260 if is_plain_signal(state.live_signal_num) and is_plain_signal(state.preview_signal_num) then
261 -- We can't zoom between these. Just make a cut.
262 io.write("Cutting from " .. state.live_signal_num .. " to " .. state.live_signal_num .. "\n")
267 if (state.live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(state.preview_signal_num)) or
268 (state.preview_signal_num == SBS_SIGNAL_NUM and is_plain_signal(state.live_signal_num)) then
269 start_transition(ZOOM_TRANSITION, t, 1.0)
272 finish_transitions(t)
275 if (state.live_signal_num ~= state.preview_signal_num) and
276 (is_plain_signal(state.live_signal_num) or
277 state.live_signal_num == STATIC_SIGNAL_NUM) and
278 (is_plain_signal(state.preview_signal_num) or
279 state.preview_signal_num == STATIC_SIGNAL_NUM) then
280 start_transition(FADE_TRANSITION, t, 1.0)
282 -- Fades involving SBS are ignored (we have no scene for it).
288 function channel_clicked(num)
289 state.preview_signal_num = num
292 function setup_fade_input(state, input, signals, signal_num, width, height)
293 if signal_num == STATIC_SIGNAL_NUM then
294 input.input:display(static_image)
295 input.wb_effect:disable()
297 -- We assume this is already correctly scaled at load time.
298 input.resample_effect:disable()
300 input.input:display(signal_num)
301 input.wb_effect:enable()
302 set_neutral_color(input.wb_effect, state.neutral_colors[signal_num - INPUT0_SIGNAL_NUM + 1])
304 if (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height) then
305 input.resample_effect:enable()
306 input.resample_effect:set_int("width", width)
307 input.resample_effect:set_int("height", height)
309 input.resample_effect:disable()
314 function needs_scale(signals, signal_num, width, height)
315 if signal_num == STATIC_SIGNAL_NUM then
316 -- We assume this is already correctly scaled at load time.
319 assert(is_plain_signal(signal_num))
320 return (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height)
323 function setup_simple_input(state, signals, signal_num, width, height, hq)
324 simple_scene.input:display(signal_num)
325 if needs_scale(signals, signal_num, width, height) then
327 simple_scene.resample_effect:choose(ResampleEffect) -- High-quality resampling.
329 simple_scene.resample_effect:choose(ResizeEffect) -- Low-quality resampling.
331 simple_scene.resample_effect:set_int("width", width)
332 simple_scene.resample_effect:set_int("height", height)
334 simple_scene.resample_effect:disable() -- No scaling.
336 set_neutral_color_from_signal(state, simple_scene.wb_effect, signal_num)
340 -- Called every frame. Get the scene for displaying at input <num>,
341 -- where 0 is live, 1 is preview, 2 is the first channel to display
342 -- in the bottom bar, and so on up to num_channels()+1. t is the
343 -- current time in seconds. width and height are the dimensions of
344 -- the output, although you can ignore them if you don't need them
345 -- (they're useful if you want to e.g. know what to resample by).
347 -- <signals> is basically an exposed InputState, which you can use to
348 -- query for information about the signals at the point of the current
349 -- frame. In particular, you can call get_width() and get_height()
350 -- for any signal number, and use that to e.g. assist in scene selection.
352 -- You should return scene to use, after having set any parameters you
353 -- want to set (through set_int() etc.). The parameters will be snapshot
354 -- at return time and used during rendering.
355 function get_scene(num, t, width, height, signals)
356 local input_resolution = {}
357 for signal_num=0,1 do
359 width = signals:get_width(signal_num),
360 height = signals:get_height(signal_num),
362 if signals:get_interlaced(signal_num) then
363 -- Convert height from frame height to field height.
364 -- (Needed for e.g. place_rectangle.)
365 res.height = res.height * 2
367 input_resolution[signal_num] = res
369 local text_res = signals:get_human_readable_resolution(signal_num)
370 Nageru.set_channel_name(signal_num + 2, "Input " .. (signal_num + 1) .. " (" .. text_res .. ")")
373 if num == 0 then -- Live.
374 finish_transitions(t)
375 if state.transition_type == ZOOM_TRANSITION then
376 -- Transition in or out of SBS.
377 prepare_sbs_scene(state, calc_zoom_progress(state, t), state.transition_type, state.transition_src_signal, state.transition_dst_signal, width, height, input_resolution, true)
378 return sbs_scene.scene
379 elseif state.transition_type == NO_TRANSITION and state.live_signal_num == SBS_SIGNAL_NUM then
381 prepare_sbs_scene(state, 0.0, NO_TRANSITION, 0, SBS_SIGNAL_NUM, width, height, input_resolution, true)
382 return sbs_scene.scene
383 elseif state.transition_type == FADE_TRANSITION then
384 setup_fade_input(state, fade_scene.input0, signals, state.transition_src_signal, width, height)
385 setup_fade_input(state, fade_scene.input1, signals, state.transition_dst_signal, width, height)
387 local tt = calc_fade_progress(t, state.transition_start, state.transition_end)
388 fade_scene.mix_effect:set_float("strength_first", 1.0 - tt)
389 fade_scene.mix_effect:set_float("strength_second", tt)
391 return fade_scene.scene
392 elseif is_plain_signal(state.live_signal_num) then
393 setup_simple_input(state, signals, state.live_signal_num, width, height, true)
394 return simple_scene.scene
395 elseif state.live_signal_num == STATIC_SIGNAL_NUM then -- Static picture.
401 if num == 1 then -- Preview.
402 num = state.preview_signal_num + 2
405 -- Individual preview inputs.
406 if is_plain_signal(num - 2) then
407 setup_simple_input(state, signals, num - 2, width, height, false)
408 return simple_scene.scene
410 if num == SBS_SIGNAL_NUM + 2 then
411 prepare_sbs_scene(state, 0.0, NO_TRANSITION, 0, SBS_SIGNAL_NUM, width, height, input_resolution, false)
412 return sbs_scene.scene
414 if num == STATIC_SIGNAL_NUM + 2 then
419 function place_rectangle(input, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height, hq)
420 input.padding_effect:set_int("width", screen_width)
421 input.padding_effect:set_int("height", screen_height)
424 if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
425 input.resample_effect:choose(ResizeEffect) -- Low-quality resizing.
426 input.resample_effect:set_int("width", 1)
427 input.resample_effect:set_int("height", 1)
428 input.padding_effect:set_int("left", screen_width + 100)
429 input.padding_effect:set_int("top", screen_height + 100)
440 srcx0 = -x0 / (x1 - x0)
444 srcy0 = -y0 / (y1 - y0)
447 if x1 > screen_width then
448 srcx1 = (screen_width - x0) / (x1 - x0)
451 if y1 > screen_height then
452 srcy1 = (screen_height - y0) / (y1 - y0)
457 -- High-quality resampling. Go for the actual effect (returned by choose())
458 -- since we want to set zoom_*, which will give an error if set on ResizeEffect.
459 local resample_effect = input.resample_effect:choose(ResampleEffect)
461 local x_subpixel_offset = x0 - math.floor(x0)
462 local y_subpixel_offset = y0 - math.floor(y0)
464 -- Resampling must be to an integral number of pixels. Round up,
465 -- and then add an extra pixel so we have some leeway for the border.
466 local width = math.ceil(x1 - x0) + 1
467 local height = math.ceil(y1 - y0) + 1
468 resample_effect:set_int("width", width)
469 resample_effect:set_int("height", height)
471 -- Correct the discrepancy with zoom. (This will leave a small
472 -- excess edge of pixels and subpixels, which we'll correct for soon.)
473 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
474 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
475 resample_effect:set_float("zoom_x", zoom_x)
476 resample_effect:set_float("zoom_y", zoom_y)
477 resample_effect:set_float("zoom_center_x", 0.0)
478 resample_effect:set_float("zoom_center_y", 0.0)
480 -- Padding must also be to a whole-pixel offset.
481 input.padding_effect:set_int("left", math.floor(x0))
482 input.padding_effect:set_int("top", math.floor(y0))
484 -- Correct _that_ discrepancy by subpixel offset in the resampling.
485 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
486 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
488 -- Finally, adjust the border so it is exactly where we want it.
489 input.padding_effect:set_float("border_offset_left", x_subpixel_offset)
490 input.padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
491 input.padding_effect:set_float("border_offset_top", y_subpixel_offset)
492 input.padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
494 -- Lower-quality simple resizing.
495 input.resample_effect:choose(ResizeEffect)
497 local width = round(x1 - x0)
498 local height = round(y1 - y0)
499 input.resample_effect:set_int("width", width)
500 input.resample_effect:set_int("height", height)
502 -- Padding must also be to a whole-pixel offset.
503 input.padding_effect:set_int("left", math.floor(x0))
504 input.padding_effect:set_int("top", math.floor(y0))
506 -- No subpixel stuff.
507 input.padding_effect:set_float("border_offset_left", 0.0)
508 input.padding_effect:set_float("border_offset_right", 0.0)
509 input.padding_effect:set_float("border_offset_top", 0.0)
510 input.padding_effect:set_float("border_offset_bottom", 0.0)
514 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
516 return math.floor(x + 0.5)
519 function lerp(a, b, t)
520 return a + (b - a) * t
523 function lerp_pos(a, b, t)
525 x0 = lerp(a.x0, b.x0, t),
526 y0 = lerp(a.y0, b.y0, t),
527 x1 = lerp(a.x1, b.x1, t),
528 y1 = lerp(a.y1, b.y1, t)
532 function pos_from_top_left(x, y, width, height, screen_width, screen_height)
533 local xs = screen_width / 1280.0
534 local ys = screen_height / 720.0
538 x1 = round(xs * (x + width)),
539 y1 = round(ys * (y + height))
543 function prepare_sbs_scene(state, t, transition_type, src_signal, dst_signal, screen_width, screen_height, input_resolution, hq)
544 set_neutral_color(sbs_scene.input0.wb_effect, state.neutral_colors[1])
545 set_neutral_color(sbs_scene.input1.wb_effect, state.neutral_colors[2])
547 -- First input is positioned (16,48) from top-left.
548 -- Second input is positioned (16,48) from the bottom-right.
549 local pos0 = pos_from_top_left(16, 48, 848, 477, screen_width, screen_height)
550 local pos1 = pos_from_top_left(1280 - 384 - 16, 720 - 216 - 48, 384, 216, screen_width, screen_height)
552 local pos_fs = { x0 = 0, y0 = 0, x1 = screen_width, y1 = screen_height }
554 if transition_type == NO_TRANSITION then
556 affine_param = { sx = 1.0, sy = 1.0, tx = 0.0, ty = 0.0 } -- Identity.
558 -- Zooming to/from SBS view into or out of a single view.
559 assert(transition_type == ZOOM_TRANSITION)
561 if src_signal == SBS_SIGNAL_NUM then
565 assert(dst_signal == SBS_SIGNAL_NUM)
570 if signal == INPUT0_SIGNAL_NUM then
571 affine_param = find_affine_param(pos0, lerp_pos(pos0, pos_fs, real_t))
572 elseif signal == INPUT1_SIGNAL_NUM then
573 affine_param = find_affine_param(pos1, lerp_pos(pos1, pos_fs, real_t))
577 -- NOTE: input_resolution is not 1-indexed, unlike usual Lua arrays.
578 place_rectangle_with_affine(sbs_scene.input0, pos0, affine_param, screen_width, screen_height, input_resolution[0].width, input_resolution[0].height, hq)
579 place_rectangle_with_affine(sbs_scene.input1, pos1, affine_param, screen_width, screen_height, input_resolution[1].width, input_resolution[1].height, hq)
582 -- Find the transformation that changes the first rectangle to the second one.
583 function find_affine_param(a, b)
584 local sx = (b.x1 - b.x0) / (a.x1 - a.x0)
585 local sy = (b.y1 - b.y0) / (a.y1 - a.y0)
589 tx = b.x0 - a.x0 * sx,
590 ty = b.y0 - a.y0 * sy
594 function place_rectangle_with_affine(input, pos, aff, screen_width, screen_height, input_width, input_height, hq)
595 local x0 = pos.x0 * aff.sx + aff.tx
596 local x1 = pos.x1 * aff.sx + aff.tx
597 local y0 = pos.y0 * aff.sy + aff.ty
598 local y1 = pos.y1 * aff.sy + aff.ty
600 place_rectangle(input, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height, hq)
603 function set_neutral_color(effect, color)
604 effect:set_vec3("neutral_color", color[1], color[2], color[3])
607 function set_neutral_color_from_signal(state, effect, signal)
608 if is_plain_signal(signal) then
609 set_neutral_color(effect, state.neutral_colors[signal - INPUT0_SIGNAL_NUM + 1])
613 function calc_zoom_progress(state, t)
614 if t < state.transition_start then
616 elseif t > state.transition_end then
619 local tt = (t - state.transition_start) / (state.transition_end - state.transition_start)
621 return math.sin(tt * 3.14159265358 * 0.5)
625 function calc_fade_progress(t, transition_start, transition_end)
626 local tt = (t - transition_start) / (transition_end - transition_start)
633 -- Make the fade look maybe a tad more natural, by pumping it
634 -- through a sigmoid function.
636 tt = 1.0 / (1.0 + math.exp(-tt))