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, setting their parameters and then deciding which to show when.
6 -- Themes are written in Lua, which reflects a simplified form of the Movit API
7 -- where all the low-level details (such as texture formats) are handled by the
8 -- C++ side and you generally just build chains.
10 local transition_start = -2.0
11 local transition_end = -1.0
14 local zoom_poi = 0 -- which input to zoom in on
15 local fade_src_signal = 0
16 local fade_dst_signal = 0
18 local neutral_colors = {
19 {0.5, 0.5, 0.5}, -- Input 0.
20 {0.5, 0.5, 0.5} -- Input 1.
23 local live_signal_num = 0
24 local preview_signal_num = 1
26 -- Valid values for live_signal_num and preview_signal_num.
27 local INPUT0_SIGNAL_NUM = 0
28 local INPUT1_SIGNAL_NUM = 1
29 local SBS_SIGNAL_NUM = 2
30 local STATIC_SIGNAL_NUM = 3
32 -- “fake” signal number that signifies that we are fading from one input
34 local FADE_SIGNAL_NUM = 4
36 -- Last width/height/frame rate for each channel, if we have it.
37 -- Note that unlike the values we get from Nageru, the resolution is per
38 -- frame and not per field, since we deinterlace.
39 local last_resolution = {}
41 -- Utility function to help creating many similar chains that can differ
42 -- in a free set of chosen parameters.
43 function make_cartesian_product(parms, callback)
44 return make_cartesian_product_internal(parms, callback, 1, {})
47 function make_cartesian_product_internal(parms, callback, index, args)
48 if index > #parms then
49 return callback(unpack(args))
52 for _, value in ipairs(parms[index]) do
54 ret[value] = make_cartesian_product_internal(parms, callback, index + 1, args)
59 function make_sbs_input(chain, signal, deint, hq)
60 local input = chain:add_live_input(not deint, deint) -- Override bounce only if not deinterlacing.
61 input:connect_signal(signal)
63 local resample_effect = nil
64 local resize_effect = nil
66 resample_effect = chain:add_effect(ResampleEffect.new())
68 resize_effect = chain:add_effect(ResizeEffect.new())
70 local wb_effect = chain:add_effect(WhiteBalanceEffect.new())
72 local padding_effect = chain:add_effect(IntegralPaddingEffect.new())
76 wb_effect = wb_effect,
77 resample_effect = resample_effect,
78 resize_effect = resize_effect,
79 padding_effect = padding_effect
83 -- The main live chain.
84 function make_sbs_chain(input0_deint, input1_deint, hq)
85 local chain = EffectChain.new(16, 9)
87 local input0 = make_sbs_input(chain, INPUT0_SIGNAL_NUM, input0_deint, hq)
88 local input1 = make_sbs_input(chain, INPUT1_SIGNAL_NUM, input1_deint, hq)
90 input0.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
91 input1.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 0.0)
93 chain:add_effect(OverlayEffect.new(), input0.padding_effect, input1.padding_effect)
103 -- Make all possible combinations of side-by-side chains.
104 local sbs_chains = make_cartesian_product({
105 {"live", "livedeint"}, -- input0_type
106 {"live", "livedeint"}, -- input1_type
108 }, function(input0_type, input1_type, hq)
109 local input0_deint = (input0_type == "livedeint")
110 local input1_deint = (input1_type == "livedeint")
111 return make_sbs_chain(input0_deint, input1_deint, hq)
114 function make_fade_input(chain, signal, live, deint, scale)
115 local input, wb_effect, resample_effect, last
117 input = chain:add_live_input(false, deint)
118 input:connect_signal(signal)
121 input = chain:add_effect(ImageInput.new("bg.jpeg"))
125 -- If we cared about this for the non-main inputs, we would have
126 -- checked hq here and invoked ResizeEffect instead.
128 resample_effect = chain:add_effect(ResampleEffect.new())
129 last = resample_effect
132 -- Make sure to put the white balance after the scaling (usually more efficient).
134 wb_effect = chain:add_effect(WhiteBalanceEffect.new())
140 wb_effect = wb_effect,
141 resample_effect = resample_effect,
146 -- A chain to fade between two inputs, of which either can be a picture
147 -- or a live input. In practice only used live, but we still support the
149 function make_fade_chain(input0_live, input0_deint, input0_scale, input1_live, input1_deint, input1_scale, hq)
150 local chain = EffectChain.new(16, 9)
152 local input0 = make_fade_input(chain, INPUT0_SIGNAL_NUM, input0_live, input0_deint, input0_scale)
153 local input1 = make_fade_input(chain, INPUT1_SIGNAL_NUM, input1_live, input1_deint, input1_scale)
155 local mix_effect = chain:add_effect(MixEffect.new(), input0.last, input1.last)
162 mix_effect = mix_effect
166 -- Chains to fade between two inputs, in various configurations.
167 local fade_chains = make_cartesian_product({
168 {"static", "live", "livedeint"}, -- input0_type
169 {true, false}, -- input0_scale
170 {"static", "live", "livedeint"}, -- input1_type
171 {true, false}, -- input1_scale
173 }, function(input0_type, input0_scale, input1_type, input1_scale, hq)
174 local input0_live = (input0_type ~= "static")
175 local input1_live = (input1_type ~= "static")
176 local input0_deint = (input0_type == "livedeint")
177 local input1_deint = (input1_type == "livedeint")
178 return make_fade_chain(input0_live, input0_deint, input0_scale, input1_live, input1_deint, input1_scale, hq)
181 -- A chain to show a single input on screen.
182 function make_simple_chain(input_deint, input_scale, hq)
183 local chain = EffectChain.new(16, 9)
185 local input = chain:add_live_input(false, input_deint)
186 input:connect_signal(0) -- First input card. Can be changed whenever you want.
188 local resample_effect, resize_effect
191 resample_effect = chain:add_effect(ResampleEffect.new())
193 resize_effect = chain:add_effect(ResizeEffect.new())
197 local wb_effect = chain:add_effect(WhiteBalanceEffect.new())
203 wb_effect = wb_effect,
204 resample_effect = resample_effect,
205 resize_effect = resize_effect
209 -- Make all possible combinations of single-input chains.
210 local simple_chains = make_cartesian_product({
211 {"live", "livedeint"}, -- input_type
212 {true, false}, -- input_scale
214 }, function(input_type, input_scale, hq)
215 local input_deint = (input_type == "livedeint")
216 return make_simple_chain(input_deint, input_scale, hq)
219 -- A chain to show a single static picture on screen (HQ version).
220 local static_chain_hq = EffectChain.new(16, 9)
221 local static_chain_hq_input = static_chain_hq:add_effect(ImageInput.new("bg.jpeg"))
222 static_chain_hq:finalize(true)
224 -- A chain to show a single static picture on screen (LQ version).
225 local static_chain_lq = EffectChain.new(16, 9)
226 local static_chain_lq_input = static_chain_lq:add_effect(ImageInput.new("bg.jpeg"))
227 static_chain_lq:finalize(false)
229 -- Used for indexing into the tables of chains.
230 function get_input_type(signals, signal_num)
231 if signal_num == STATIC_SIGNAL_NUM then
233 elseif signals:get_interlaced(signal_num) then
240 function needs_scale(signals, signal_num, width, height)
241 if signal_num == STATIC_SIGNAL_NUM then
242 -- We assume this is already correctly scaled at load time.
245 assert(is_plain_signal(signal_num))
246 return (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height)
249 function set_scale_parameters_if_needed(chain_or_input, width, height)
250 if chain_or_input.resample_effect then
251 chain_or_input.resample_effect:set_int("width", width)
252 chain_or_input.resample_effect:set_int("height", height)
253 elseif chain_or_input.resize_effect then
254 chain_or_input.resize_effect:set_int("width", width)
255 chain_or_input.resize_effect:set_int("height", height)
260 -- Returns the number of outputs in addition to the live (0) and preview (1).
261 -- Called only once, at the start of the program.
262 function num_channels()
266 function is_plain_signal(num)
267 return num == INPUT0_SIGNAL_NUM or num == INPUT1_SIGNAL_NUM
270 -- Helper function to write e.g. “720p60”. The difference between this
271 -- and get_channel_resolution_raw() is that this one also can say that
272 -- there's no signal.
273 function get_channel_resolution(signal_num)
274 res = last_resolution[signal_num]
275 if (not res) or res.height <= 0 then
278 if not res.has_signal then
279 if res.height == 525 then
280 -- Special mode for the USB3 cards.
283 return get_channel_resolution_raw(res) .. ", no signal"
285 return get_channel_resolution_raw(res)
289 -- Helper function to write e.g. “60” or “59.94”.
290 function get_frame_rate(res)
291 local nom = res.frame_rate_nom
292 local den = res.frame_rate_den
293 if nom % den == 0 then
296 return string.format("%.2f", nom / den)
300 -- Helper function to write e.g. “720p60”.
301 function get_channel_resolution_raw(res)
302 if res.interlaced then
303 return res.height .. "i" .. get_frame_rate(res)
305 return res.height .. "p" .. get_frame_rate(res)
310 -- Returns the name for each additional channel (starting from 2).
311 -- Called at the start of the program, and then each frame for live
312 -- channels in case they change resolution.
313 function channel_name(channel)
314 local signal_num = channel - 2
315 if is_plain_signal(signal_num) then
316 return "Input " .. (signal_num + 1) .. " (" .. get_channel_resolution(signal_num) .. ")"
317 elseif signal_num == SBS_SIGNAL_NUM then
318 return "Side-by-side"
319 elseif signal_num == STATIC_SIGNAL_NUM then
320 return "Static picture"
325 -- Returns, given a channel number, which signal it corresponds to (starting from 0).
326 -- Should return -1 if the channel does not correspond to a simple signal.
327 -- (The information is used for whether right-click on the channel should bring up
328 -- an input selector or not.)
329 -- Called once for each channel, at the start of the program.
330 -- Will never be called for live (0) or preview (1).
331 function channel_signal(channel)
334 elseif channel == 3 then
342 -- Called every frame. Returns the color (if any) to paint around the given
343 -- channel. Returns a CSS color (typically to mark live and preview signals);
344 -- "transparent" is allowed.
345 -- Will never be called for live (0) or preview (1).
346 function channel_color(channel)
347 if channel_involved_in(channel, live_signal_num) then
350 if channel_involved_in(channel, preview_signal_num) then
356 function channel_involved_in(channel, signal_num)
357 if is_plain_signal(signal_num) then
358 return channel == (signal_num + 2)
360 if signal_num == SBS_SIGNAL_NUM then
361 return (channel == 2 or channel == 3)
363 if signal_num == STATIC_SIGNAL_NUM then
364 return (channel == 5)
366 if signal_num == FADE_SIGNAL_NUM then
367 return (channel_involved_in(channel, fade_src_signal) or
368 channel_involved_in(channel, fade_dst_signal))
374 -- Returns if a given channel supports setting white balance (starting from 2).
375 -- Called only once for each channel, at the start of the program.
376 function supports_set_wb(channel)
377 return is_plain_signal(channel - 2)
381 -- Gets called with a new gray point when the white balance is changing.
382 -- The color is in linear light (not sRGB gamma).
383 function set_wb(channel, red, green, blue)
384 if is_plain_signal(channel - 2) then
385 neutral_colors[channel - 2 + 1] = { red, green, blue }
389 function finish_transitions(t)
390 -- If live is SBS but de-facto single, make it so.
391 if live_signal_num == SBS_SIGNAL_NUM and t >= transition_end and zoom_dst == 1.0 then
392 live_signal_num = zoom_poi
395 -- If live is fade but de-facto single, make it so.
396 if live_signal_num == FADE_SIGNAL_NUM and t >= transition_end then
397 live_signal_num = fade_dst_signal
402 -- Called every frame.
403 function get_transitions(t)
404 finish_transitions(t)
406 if live_signal_num == preview_signal_num then
407 -- No transitions possible.
411 if live_signal_num == SBS_SIGNAL_NUM and t >= transition_start and t <= transition_end then
416 if (is_plain_signal(live_signal_num) or live_signal_num == STATIC_SIGNAL_NUM) and
417 (is_plain_signal(preview_signal_num) or preview_signal_num == STATIC_SIGNAL_NUM) then
418 return {"Cut", "", "Fade"}
422 if live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(preview_signal_num) then
423 return {"Cut", "Zoom in"}
424 elseif is_plain_signal(live_signal_num) and preview_signal_num == SBS_SIGNAL_NUM then
425 return {"Cut", "Zoom out"}
432 -- Called when the user clicks a transition button.
433 function transition_clicked(num, t)
436 if live_signal_num == FADE_SIGNAL_NUM then
437 -- Ongoing fade; finish it immediately.
438 finish_transitions(transition_end)
441 local temp = live_signal_num
442 live_signal_num = preview_signal_num
443 preview_signal_num = temp
445 if live_signal_num == SBS_SIGNAL_NUM then
446 -- Just cut to SBS, we need to reset any zooms.
449 transition_start = -2.0
450 transition_end = -1.0
455 finish_transitions(t)
457 if live_signal_num == preview_signal_num then
462 if (is_plain_signal(live_signal_num) and is_plain_signal(preview_signal_num)) then
463 -- We can't zoom between these. Just make a cut.
464 io.write("Cutting from " .. live_signal_num .. " to " .. live_signal_num .. "\n")
465 local temp = live_signal_num
466 live_signal_num = preview_signal_num
467 preview_signal_num = temp
471 if live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(preview_signal_num) then
472 -- Zoom in from SBS to single.
474 transition_end = t + 1.0
477 zoom_poi = preview_signal_num
478 preview_signal_num = SBS_SIGNAL_NUM
479 elseif is_plain_signal(live_signal_num) and preview_signal_num == SBS_SIGNAL_NUM then
480 -- Zoom out from single to SBS.
482 transition_end = t + 1.0
485 preview_signal_num = live_signal_num
486 zoom_poi = live_signal_num
487 live_signal_num = SBS_SIGNAL_NUM
490 finish_transitions(t)
493 if (live_signal_num ~= preview_signal_num) and
494 (is_plain_signal(live_signal_num) or
495 live_signal_num == STATIC_SIGNAL_NUM) and
496 (is_plain_signal(preview_signal_num) or
497 preview_signal_num == STATIC_SIGNAL_NUM) then
499 transition_end = t + 1.0
500 fade_src_signal = live_signal_num
501 fade_dst_signal = preview_signal_num
502 preview_signal_num = live_signal_num
503 live_signal_num = FADE_SIGNAL_NUM
505 -- Fades involving SBS are ignored (we have no chain for it).
511 function channel_clicked(num)
512 preview_signal_num = num
516 -- Called every frame. Get the chain for displaying at input <num>,
517 -- where 0 is live, 1 is preview, 2 is the first channel to display
518 -- in the bottom bar, and so on up to num_channels()+1. t is the
519 -- current time in seconds. width and height are the dimensions of
520 -- the output, although you can ignore them if you don't need them
521 -- (they're useful if you want to e.g. know what to resample by).
523 -- <signals> is basically an exposed InputState, which you can use to
524 -- query for information about the signals at the point of the current
525 -- frame. In particular, you can call get_width() and get_height()
526 -- for any signal number, and use that to e.g. assist in chain selection.
528 -- You should return two objects; the chain itself, and then a
529 -- function (taking no parameters) that is run just before rendering.
530 -- The function needs to call connect_signal on any inputs, so that
531 -- it gets updated video data for the given frame. (You are allowed
532 -- to switch which input your input is getting from between frames,
533 -- but not calling connect_signal results in undefined behavior.)
534 -- If you want to change any parameters in the chain, this is also
537 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
538 -- if and only if num==0.
539 function get_chain(num, t, width, height, signals)
540 local input_resolution = {}
541 for signal_num=0,1 do
543 width = signals:get_width(signal_num),
544 height = signals:get_height(signal_num),
545 interlaced = signals:get_interlaced(signal_num),
546 has_signal = signals:get_has_signal(signal_num),
547 frame_rate_nom = signals:get_frame_rate_nom(signal_num),
548 frame_rate_den = signals:get_frame_rate_den(signal_num)
551 if res.interlaced then
552 -- Convert height from frame height to field height.
553 -- (Needed for e.g. place_rectangle.)
554 res.height = res.height * 2
556 -- Show field rate instead of frame rate; really for cosmetics only
557 -- (and actually contrary to EBU recommendations, although in line
558 -- with typical user expectations).
559 res.frame_rate_nom = res.frame_rate_nom * 2
562 input_resolution[signal_num] = res
564 last_resolution = input_resolution
566 if num == 0 then -- Live.
567 if is_plain_signal(live_signal_num) then -- Plain inputs.
568 local input_type = get_input_type(signals, live_signal_num)
569 local input_scale = needs_scale(signals, live_signal_num, width, height)
570 local chain = simple_chains[input_type][input_scale][true]
572 chain.input:connect_signal(live_signal_num)
573 set_scale_parameters_if_needed(chain, width, height)
574 set_neutral_color_from_signal(chain.wb_effect, live_signal_num)
576 return chain.chain, prepare
577 elseif live_signal_num == STATIC_SIGNAL_NUM then -- Static picture.
580 return static_chain_hq, prepare
581 elseif live_signal_num == FADE_SIGNAL_NUM then -- Fade.
582 local input0_type = get_input_type(signals, fade_src_signal)
583 local input0_scale = needs_scale(signals, fade_src_signal, width, height)
584 local input1_type = get_input_type(signals, fade_dst_signal)
585 local input1_scale = needs_scale(signals, fade_dst_signal, width, height)
586 local chain = fade_chains[input0_type][input0_scale][input1_type][input1_scale][true]
588 if input0_type == "live" or input0_type == "livedeint" then
589 chain.input0.input:connect_signal(fade_src_signal)
590 set_neutral_color_from_signal(chain.input0.wb_effect, fade_src_signal)
592 set_scale_parameters_if_needed(chain.input0, width, height)
593 if input1_type == "live" or input1_type == "livedeint" then
594 chain.input1.input:connect_signal(fade_dst_signal)
595 set_neutral_color_from_signal(chain.input1.wb_effect, fade_dst_signal)
597 set_scale_parameters_if_needed(chain.input1, width, height)
598 local tt = calc_fade_progress(t, transition_start, transition_end)
600 chain.mix_effect:set_float("strength_first", 1.0 - tt)
601 chain.mix_effect:set_float("strength_second", tt)
603 return chain.chain, prepare
606 -- SBS code (live_signal_num == SBS_SIGNAL_NUM).
607 local input0_type = get_input_type(signals, INPUT0_SIGNAL_NUM)
608 local input1_type = get_input_type(signals, INPUT1_SIGNAL_NUM)
609 if t > transition_end and zoom_dst == 1.0 then
610 -- Special case: Show only the single image on screen.
611 local input0_scale = needs_scale(signals, fade_src_signal, width, height)
612 local chain = simple_chains[input0_type][input0_scale][true]
614 chain.input:connect_signal(INPUT0_SIGNAL_NUM)
615 set_scale_parameters_if_needed(chain, width, height)
616 set_neutral_color(chain.wb_effect, neutral_colors[1])
618 return chain.chain, prepare
620 local chain = sbs_chains[input0_type][input1_type][true]
622 if t < transition_start then
623 prepare_sbs_chain(chain, zoom_src, width, height, input_resolution)
624 elseif t > transition_end then
625 prepare_sbs_chain(chain, zoom_dst, width, height, input_resolution)
627 local tt = (t - transition_start) / (transition_end - transition_start)
629 tt = math.sin(tt * 3.14159265358 * 0.5)
630 prepare_sbs_chain(chain, zoom_src + (zoom_dst - zoom_src) * tt, width, height, input_resolution)
633 return chain.chain, prepare
635 if num == 1 then -- Preview.
636 num = preview_signal_num + 2
639 -- Individual preview inputs.
640 if is_plain_signal(num - 2) then
641 local signal_num = num - 2
642 local input_type = get_input_type(signals, signal_num)
643 local input_scale = needs_scale(signals, signal_num, width, height)
644 local chain = simple_chains[input_type][input_scale][false]
646 chain.input:connect_signal(signal_num)
647 set_scale_parameters_if_needed(chain, width, height)
648 set_neutral_color(chain.wb_effect, neutral_colors[signal_num + 1])
650 return chain.chain, prepare
652 if num == SBS_SIGNAL_NUM + 2 then
653 local input0_type = get_input_type(signals, INPUT0_SIGNAL_NUM)
654 local input1_type = get_input_type(signals, INPUT1_SIGNAL_NUM)
655 local chain = sbs_chains[input0_type][input1_type][false]
657 prepare_sbs_chain(chain, 0.0, width, height, input_resolution)
659 return chain.chain, prepare
661 if num == STATIC_SIGNAL_NUM + 2 then
664 return static_chain_lq, prepare
668 function place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height)
674 padding_effect:set_int("width", screen_width)
675 padding_effect:set_int("height", screen_height)
678 if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
679 if resample_effect ~= nil then
680 resample_effect:set_int("width", 1)
681 resample_effect:set_int("height", 1)
682 resample_effect:set_float("zoom_x", screen_width)
683 resample_effect:set_float("zoom_y", screen_height)
685 resize_effect:set_int("width", 1)
686 resize_effect:set_int("height", 1)
688 padding_effect:set_int("left", screen_width + 100)
689 padding_effect:set_int("top", screen_height + 100)
695 srcx0 = -x0 / (x1 - x0)
699 srcy0 = -y0 / (y1 - y0)
702 if x1 > screen_width then
703 srcx1 = (screen_width - x0) / (x1 - x0)
706 if y1 > screen_height then
707 srcy1 = (screen_height - y0) / (y1 - y0)
711 if resample_effect ~= nil then
712 -- High-quality resampling.
713 local x_subpixel_offset = x0 - math.floor(x0)
714 local y_subpixel_offset = y0 - math.floor(y0)
716 -- Resampling must be to an integral number of pixels. Round up,
717 -- and then add an extra pixel so we have some leeway for the border.
718 local width = math.ceil(x1 - x0) + 1
719 local height = math.ceil(y1 - y0) + 1
720 resample_effect:set_int("width", width)
721 resample_effect:set_int("height", height)
723 -- Correct the discrepancy with zoom. (This will leave a small
724 -- excess edge of pixels and subpixels, which we'll correct for soon.)
725 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
726 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
727 resample_effect:set_float("zoom_x", zoom_x)
728 resample_effect:set_float("zoom_y", zoom_y)
729 resample_effect:set_float("zoom_center_x", 0.0)
730 resample_effect:set_float("zoom_center_y", 0.0)
732 -- Padding must also be to a whole-pixel offset.
733 padding_effect:set_int("left", math.floor(x0))
734 padding_effect:set_int("top", math.floor(y0))
736 -- Correct _that_ discrepancy by subpixel offset in the resampling.
737 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
738 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
740 -- Finally, adjust the border so it is exactly where we want it.
741 padding_effect:set_float("border_offset_left", x_subpixel_offset)
742 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
743 padding_effect:set_float("border_offset_top", y_subpixel_offset)
744 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
746 -- Lower-quality simple resizing.
747 local width = round(x1 - x0)
748 local height = round(y1 - y0)
749 resize_effect:set_int("width", width)
750 resize_effect:set_int("height", height)
752 -- Padding must also be to a whole-pixel offset.
753 padding_effect:set_int("left", math.floor(x0))
754 padding_effect:set_int("top", math.floor(y0))
758 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
760 return math.floor(x + 0.5)
763 function lerp(a, b, t)
764 return a + (b - a) * t
767 function lerp_pos(a, b, t)
769 x0 = lerp(a.x0, b.x0, t),
770 y0 = lerp(a.y0, b.y0, t),
771 x1 = lerp(a.x1, b.x1, t),
772 y1 = lerp(a.y1, b.y1, t)
776 function pos_from_top_left(x, y, width, height, screen_width, screen_height)
777 local xs = screen_width / 1280.0
778 local ys = screen_height / 720.0
782 x1 = round(xs * (x + width)),
783 y1 = round(ys * (y + height))
787 function prepare_sbs_chain(chain, t, screen_width, screen_height, input_resolution)
788 chain.input0.input:connect_signal(0)
789 chain.input1.input:connect_signal(1)
790 set_neutral_color(chain.input0.wb_effect, neutral_colors[1])
791 set_neutral_color(chain.input1.wb_effect, neutral_colors[2])
793 -- First input is positioned (16,48) from top-left.
794 -- Second input is positioned (16,48) from the bottom-right.
795 local pos0 = pos_from_top_left(16, 48, 848, 477, screen_width, screen_height)
796 local pos1 = pos_from_top_left(1280 - 384 - 16, 720 - 216 - 48, 384, 216, screen_width, screen_height)
798 local pos_fs = { x0 = 0, y0 = 0, x1 = screen_width, y1 = screen_height }
800 if zoom_poi == INPUT0_SIGNAL_NUM then
801 affine_param = find_affine_param(pos0, lerp_pos(pos0, pos_fs, t))
803 affine_param = find_affine_param(pos1, lerp_pos(pos1, pos_fs, t))
806 -- NOTE: input_resolution is not 1-indexed, unlike usual Lua arrays.
807 place_rectangle_with_affine(chain.input0.resample_effect, chain.input0.resize_effect, chain.input0.padding_effect, pos0, affine_param, screen_width, screen_height, input_resolution[0].width, input_resolution[0].height)
808 place_rectangle_with_affine(chain.input1.resample_effect, chain.input1.resize_effect, chain.input1.padding_effect, pos1, affine_param, screen_width, screen_height, input_resolution[1].width, input_resolution[1].height)
811 -- Find the transformation that changes the first rectangle to the second one.
812 function find_affine_param(a, b)
813 local sx = (b.x1 - b.x0) / (a.x1 - a.x0)
814 local sy = (b.y1 - b.y0) / (a.y1 - a.y0)
818 tx = b.x0 - a.x0 * sx,
819 ty = b.y0 - a.y0 * sy
823 function place_rectangle_with_affine(resample_effect, resize_effect, padding_effect, pos, aff, screen_width, screen_height, input_width, input_height)
824 local x0 = pos.x0 * aff.sx + aff.tx
825 local x1 = pos.x1 * aff.sx + aff.tx
826 local y0 = pos.y0 * aff.sy + aff.ty
827 local y1 = pos.y1 * aff.sy + aff.ty
829 place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height)
832 function set_neutral_color(effect, color)
833 effect:set_vec3("neutral_color", color[1], color[2], color[3])
836 function set_neutral_color_from_signal(effect, signal)
837 if is_plain_signal(signal) then
838 set_neutral_color(effect, neutral_colors[signal - INPUT0_SIGNAL_NUM + 1])
842 function calc_fade_progress(t, transition_start, transition_end)
843 local tt = (t - transition_start) / (transition_end - transition_start)
850 -- Make the fade look maybe a tad more natural, by pumping it
851 -- through a sigmoid function.
853 tt = 1.0 / (1.0 + math.exp(-tt))