mxl-multiviewer/NoSignalFeed.cpp

#include "NoSignalFeed.hpp"
#include "PixelFormat.hpp"

namespace
{
constexpr uint32_t TileBorderPixels = 0;

uint32_t glyphRows(char c, uint32_t row)
{
    switch (c)
    {
        case 'A':
        {
            constexpr uint32_t rows[] =
                {0x0E, 0x11, 0x11, 0x1F, 0x11, 0x11, 0x11};
            return rows[row];
        }

        case 'G':
        {
            constexpr uint32_t rows[] =
                {0x0E, 0x11, 0x10, 0x17, 0x11, 0x11, 0x0E};
            return rows[row];
        }

        case 'I':
        {
            constexpr uint32_t rows[] =
                {0x1F, 0x04, 0x04, 0x04, 0x04, 0x04, 0x1F};
            return rows[row];
        }

        case 'L':
        {
            constexpr uint32_t rows[] =
                {0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x1F};
            return rows[row];
        }

        case 'N':
        {
            constexpr uint32_t rows[] =
                {0x11, 0x19, 0x15, 0x13, 0x11, 0x11, 0x11};
            return rows[row];
        }

        case 'O':
        {
            constexpr uint32_t rows[] =
                {0x0E, 0x11, 0x11, 0x11, 0x11, 0x11, 0x0E};
            return rows[row];
        }

        case 'S':
        {
            constexpr uint32_t rows[] =
                {0x0F, 0x10, 0x10, 0x0E, 0x01, 0x01, 0x1E};
            return rows[row];
        }

        default:
            return 0;
    }
}

void drawText(
    VideoFrame& frame,
    const char* text,
    uint32_t originX,
    uint32_t originY,
    uint32_t scale,
    RgbColor color)
{
    for (uint32_t charIndex = 0; text[charIndex] != '\0'; ++charIndex)
    {
        const char c = text[charIndex];

        if (c == ' ')
        {
            continue;
        }

        const uint32_t charX =
            originX + charIndex * 6 * scale;

        for (uint32_t gy = 0; gy < 7; ++gy)
        {
            const uint32_t bits = glyphRows(c, gy);

            for (uint32_t gx = 0; gx < 5; ++gx)
            {
                if ((bits & (1u << (4 - gx))) == 0)
                {
                    continue;
                }

                for (uint32_t sy = 0; sy < scale; ++sy)
                {
                    for (uint32_t sx = 0; sx < scale; ++sx)
                    {
                        const uint32_t x =
                            charX + gx * scale + sx;
                        const uint32_t y =
                            originY + gy * scale + sy;

                        if (x < frame.width && y < frame.height)
                        {
                            frame.pixels[y * frame.width + x] =
                                packRgba8(color);
                        }
                    }
                }
            }
        }
    }
}

void fillNoSignalFrame(VideoFrame& frame)
{
    frame.pixels.resize(frame.width * frame.height);

    for (uint32_t y = 0; y < frame.height; ++y)
    {
        for (uint32_t x = 0; x < frame.width; ++x)
        {
            const bool isBorder =
                x < TileBorderPixels ||
                y < TileBorderPixels ||
                x >= frame.width - TileBorderPixels ||
                y >= frame.height - TileBorderPixels;

            const bool hatch =
                ((x + y) / 18) % 2 == 0;

            const RgbColor color =
                isBorder
                    ? RgbColor{95, 100, 110}
                    : (hatch
                        ? RgbColor{18, 20, 24}
                        : RgbColor{12, 14, 18});

            frame.pixels[y * frame.width + x] =
                packRgba8(color);
        }
    }

    const uint32_t scale =
        frame.width >= 512 ? 5 : 3;
    constexpr uint32_t textChars = 9;
    const uint32_t textWidth =
        (textChars * 6 - 1) * scale;
    const uint32_t textHeight = 7 * scale;
    const uint32_t textX =
        frame.width > textWidth
            ? (frame.width - textWidth) / 2
            : 0;
    const uint32_t textY =
        frame.height > textHeight
            ? (frame.height - textHeight) / 2
            : 0;

    drawText(
        frame,
        "NO SIGNAL",
        textX,
        textY,
        scale,
        {210, 215, 225}
    );
}
}

NoSignalFeed::NoSignalFeed(
    uint32_t feedIndex,
    uint32_t frameWidth,
    uint32_t frameHeight)
{
    configure(
        feedIndex,
        frameWidth,
        frameHeight
    );
}

void NoSignalFeed::configure(
    uint32_t feedIndex,
    uint32_t frameWidth,
    uint32_t frameHeight)
{
    (void)feedIndex;
    generated = false;
    version = 0;
    frame.width = frameWidth;
    frame.height = frameHeight;
    frame.pixels.resize(frame.width * frame.height);
}

const VideoFrame& NoSignalFeed::getFrame(uint32_t frameCounter)
{
    (void)frameCounter;

    if (!generated)
    {
        fillNoSignalFrame(frame);
        generated = true;
        ++version;
    }

    return frame;
}

FeedRuntimeStatus NoSignalFeed::status() const
{
    return FeedRuntimeStatus::NoSignal;
}

std::string NoSignalFeed::displayName() const
{
    return "NO SIGNAL";
}