portapack-mayhem/firmware/application/ui/ui_tv.cpp

/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2020 Shao
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "ui_tv.hpp"

#include "spectrum_color_lut.hpp"

#include "portapack.hpp"
using namespace portapack;

#include "baseband_api.hpp"

#include "string_format.hpp"

#include <cmath>
#include <array>

namespace ui {
namespace tv {

/* TimeScopeView******************************************************/

TimeScopeView::TimeScopeView(
    const Rect parent_rect)
    : View{parent_rect} {
    set_focusable(true);

    add_children({//&labels,
                  //&field_frequency,
                  &waveform});

    /*field_frequency.on_change = [this](int32_t) {
                set_dirty();
        };
        field_frequency.set_value(10);*/
}

void TimeScopeView::paint(Painter& painter) {
    const auto r = screen_rect();

    painter.fill_rectangle(r, Color::black());

    // Cursor
    /*
        const Rect r_cursor {
                field_frequency.value() / (48000 / 240), r.bottom() - 32 - cursor_band_height,
                1, cursor_band_height
        };
        painter.fill_rectangle(
                r_cursor,
                Color::red()
        );*/
}

void TimeScopeView::on_audio_spectrum(const AudioSpectrum* spectrum) {
    for (size_t i = 0; i < spectrum->db.size(); i++)
        audio_spectrum[i] = ((int16_t)spectrum->db[i] - 127) * 256;
    waveform.set_dirty();
}

/* TVView *********************************************************/

void TVView::on_show() {
    clear();

    const auto screen_r = screen_rect();
    display.scroll_set_area(screen_r.top(), screen_r.bottom());
}

void TVView::on_hide() {
    /* TODO: Clear region to eliminate brief flash of content at un-shifted
     * position?
     */
    display.scroll_disable();
}

void TVView::paint(Painter& painter) {
    // Do nothing.
    (void)painter;
}

void TVView::on_adjust_xcorr(uint8_t xcorr) {
    x_correction = xcorr;
}

void TVView::on_channel_spectrum(
    const ChannelSpectrum& spectrum) {
    // portapack has limitations
    //  1.screen resolution (less than 240x320) 2.samples each call back (128 or 256)
    //  3.memory size (for ui::Color, the buffer size
    // spectrum.db[i] is 256 long
    // 768x625 ->128x625 ->128x312 -> 128x104
    // originally @6MHz sample rate, the PAL should be 768x625
    // I reduced sample rate to 2MHz(3 times less samples), then calculate mag (effectively decimate by 2)
    // the resolution is now changed to 128x625. The total decimation factor is 6, which changes how many samples in a line
    // However 625 is too large for the screen, also interlaced scanning is harder to realize in portapack than normal computer.
    // So I decided to simply drop half of the lines, once y is larger than 625/2=312.5 or 312, I recognize it as a new frame.
    // then the resolution is changed to 128x312
    // 128x312 is now able to put into a 240x320 screen, but the buffer for a whole frame is 128x312=39936, which is too large
    // according to my test, I can only make a buffer with a length of 13312 of type ui::Color. which is 1/3 of what I wanted.
    // So now the resolution is changed to 128x104, the height is shrinked to 1/3 of the original height.
    // I was expecting to see 1/3 height of original video.

    // Look how nice is that! I am now able to meet the requirements of 1 and 3 for portapack. Also the length of a line is 128
    // Each call back gives me 256 samples which is exactly 2 lines. What a coincidence!

    // After some experiment, I did some improvements.
    // 1.I found that instead of 1/3 of the frame is shown, I got 3 whole frames shrinked into one window.
    // So I made the height twice simply by painting 2 identical lines in the place of original lines
    // 2.I found sometimes there is an horizontal offset, so I added x_correction to move the frame back to center manually
    // 3.I changed video_buffer's type, from ui::Color to uint_8, since I don't need 3 digit to represent a grey scale value.
    // I was hoping that by doing this, I can have a longer buffer like 39936, then the frame will looks better vertically
    // however this is useless until now.

    for (size_t i = 0; i < 256; i++) {
        // video_buffer[i+count*256] = spectrum_rgb4_lut[spectrum.db[i]];
        video_buffer_int[i + count * 256] = 255 - spectrum.db[i];
    }
    count = count + 1;
    if (count == 52 - 1) {
        ui::Color line_buffer[128];
        Coord line;
        uint32_t bmp_px;

        /*for (line = 0; line < 104; line++)
                {
                        for (bmp_px = 0; bmp_px < 128; bmp_px++)
                        {
                                //line_buffer[bmp_px] = video_buffer[bmp_px+line*128];
                                line_buffer[bmp_px] = spectrum_rgb4_lut[video_buffer_int[bmp_px+line*128 + x_correction]];
                        }

                        display.render_line({ 0, line + 100 }, 128, line_buffer);
                }*/
        for (line = 0; line < 208; line = line + 2) {
            for (bmp_px = 0; bmp_px < 128; bmp_px++) {
                // line_buffer[bmp_px] = video_buffer[bmp_px+line*128];
                line_buffer[bmp_px] = spectrum_rgb4_lut[video_buffer_int[bmp_px + line / 2 * 128 + x_correction]];
            }

            display.render_line({0, line + 100}, 128, line_buffer);
            display.render_line({0, line + 101}, 128, line_buffer);
        }
        count = 0;
    }
}

void TVView::clear() {
    display.fill_rectangle(
        screen_rect(),
        Color::black());
}

/* TVWidget *******************************************************/

TVWidget::TVWidget() {
    add_children({&tv_view,
                  &field_xcorr});
    field_xcorr.set_value(10);
}

void TVWidget::on_show() {
    baseband::spectrum_streaming_start();
}

void TVWidget::on_hide() {
    baseband::spectrum_streaming_stop();
}

void TVWidget::show_audio_spectrum_view(const bool show) {
    if ((audio_spectrum_view && show) || (!audio_spectrum_view && !show)) return;

    if (show) {
        audio_spectrum_view = std::make_unique<TimeScopeView>(audio_spectrum_view_rect);
        add_child(audio_spectrum_view.get());
        update_widgets_rect();
    } else {
        audio_spectrum_update = false;
        remove_child(audio_spectrum_view.get());
        audio_spectrum_view.reset();
        update_widgets_rect();
    }
}

void TVWidget::update_widgets_rect() {
    if (audio_spectrum_view) {
        tv_view.set_parent_rect(tv_reduced_rect);
    } else {
        tv_view.set_parent_rect(tv_normal_rect);
    }
    tv_view.on_show();
}

void TVWidget::set_parent_rect(const Rect new_parent_rect) {
    View::set_parent_rect(new_parent_rect);

    tv_normal_rect = {0, scale_height, new_parent_rect.width(), new_parent_rect.height() - scale_height};
    tv_reduced_rect = {0, audio_spectrum_height + scale_height, new_parent_rect.width(), new_parent_rect.height() - scale_height - audio_spectrum_height};

    update_widgets_rect();
}

void TVWidget::paint(Painter& painter) {
    // TODO:
    (void)painter;
}

void TVWidget::on_channel_spectrum(const ChannelSpectrum& spectrum) {
    tv_view.on_channel_spectrum(spectrum);
    tv_view.on_adjust_xcorr(field_xcorr.value());
    sampling_rate = spectrum.sampling_rate;
}

void TVWidget::on_audio_spectrum() {
    audio_spectrum_view->on_audio_spectrum(audio_spectrum_data);
}

} /* namespace tv */
} /* namespace ui */