sm-26/Source/LcdDisplay.cpp

#include "LcdDisplay.h"

LcdDisplay::LcdDisplay()
{
    clear();
    startTimerHz (30);
}

juce::Font LcdDisplay::getMonoFont() const
{
    return juce::Font (juce::FontOptions { juce::Font::getDefaultMonospacedFontName(),
                                           (float) kCharH - 1.0f, juce::Font::plain });
}

void LcdDisplay::rasterize (juce::uint32 c)
{
    if (c >= 256 || glyphCache[c].cached) return;

    juce::Image img (juce::Image::ARGB, kCharW * 2, kCharH * 2, true);
    {
        juce::Graphics g (img);
        g.setColour (juce::Colours::white);
        g.setFont (getMonoFont());
        juce::String s;
        s << (juce_wchar) c;
        g.drawText (s, img.getBounds().removeFromBottom (kCharH * 2 - 2),
                    juce::Justification::centredBottom, false);
    }

    const float sx = (float) img.getWidth()  / (float) kCharW;
    const float sy = (float) img.getHeight() / (float) kCharH;

    for (int row = 0; row < 8; ++row)
        glyphCache[c].rows[row] = 0;

    for (int row = 0; row < 8; ++row)
    {
        uint8_t bits = 0;
        for (int col = 0; col < 5; ++col)
        {
            int count = 0, total = 0;
            int px0 = (int) (col * sx);
            int py0 = (int) (row * sy);
            int px1 = juce::jmin ((int) ((col + 1) * sx), img.getWidth() - 1);
            int py1 = juce::jmin ((int) ((row + 1) * sy), img.getHeight() - 1);
            for (int y = py0; y <= py1; ++y)
                for (int x = px0; x <= px1; ++x)
                {
                    total++;
                    if (img.getPixelAt (x, y).getAlpha() > 127)
                        count++;
                }
            if (total > 0 && count > total / 3)
                bits |= (uint8_t) (1u << (4 - col));
        }
        glyphCache[c].rows[row] = bits;
    }
    glyphCache[c].cached = true;
}

uint8_t* LcdDisplay::getGlyph (juce::uint32 c)
{
    if (c >= 256) c = '?';
    if (! glyphCache[c].cached)
        rasterize (c);
    return glyphCache[c].rows;
}

void LcdDisplay::setLine (int row, const juce::String& s)
{
    if (row >= 0 && row < kRows)
        lines[row] = s;
}

void LcdDisplay::showCursor (bool show) { cursorVisible = show; }

void LcdDisplay::clear()
{
    for (int r = 0; r < kRows; ++r)
        lines[r] = "";
    cursorCol = 0;
    cursorRow = 0;
    cursorVisible = false;
}

void LcdDisplay::paint (juce::Graphics& g)
{
    const float cw = (float) kCharW;
    const float ch = (float) kCharH;
    const float w = (float) getWidth();
    const float h = (float) getHeight();

    const juce::Colour bgCol    (0xFF0D1A05);
    const juce::Colour gridCol  (0xFF15260A);
    const juce::Colour pixOn    (0xFF4AE038);
    const juce::Colour pixOnDim (0xFF1E3A12);
    const juce::Colour pixOff   (0xFF0F1C07);

    g.fillAll (bgCol);

    g.setColour (gridCol);
    float totalW = (float) kCols * cw;
    float totalH = (float) kRows * ch;
    float ox = (w - totalW) / 2.0f;
    float oy = (h - totalH) / 2.0f;
    g.fillRect (ox - 1.0f, oy - 1.0f, totalW + 2.0f, totalH + 2.0f);

    bool blinkOn = cursorVisible &&
        ((int) (juce::Time::getMillisecondCounterHiRes() / 400.0) % 2 == 0);

    for (int row = 0; row < kRows; ++row)
    {
        const juce::String& line = lines[row];
        for (int col = 0; col < kCols; ++col)
        {
            juce_wchar ch2 = col < line.length() ? line [(size_t) col] : (juce_wchar) ' ';
            uint8_t* glyph = getGlyph ((juce::uint32) ch2);

            float cx = ox + (float) col * cw;
            float cy = oy + (float) row * ch;

            g.setColour (pixOff);
            g.fillRect (cx + 0.5f, cy + 0.5f, cw - 1.0f, ch - 1.0f);

            for (int gRow = 0; gRow < 8; ++gRow)
            {
                uint8_t bits = glyph[gRow];
                if (bits == 0) continue;
                for (int gCol = 0; gCol < 5; ++gCol)
                {
                    if (bits & (1u << (4 - gCol)))
                    {
                        float px = cx + 1.0f + (float) gCol * (cw - 2.0f) / 5.0f;
                        float py = cy + 1.0f + (float) gRow * (ch - 2.0f) / 9.0f;
                        float pw = (cw - 2.0f) / 5.0f - 0.5f;
                        float ph = (ch - 2.0f) / 9.0f - 0.3f;

                        g.setColour (pixOnDim);
                        g.fillRect (px - 0.4f, py - 0.3f, pw + 0.8f, ph + 0.6f);
                        g.setColour (pixOn);
                        g.fillRect (px, py, pw, ph);
                    }
                }
            }

            if (blinkOn && col == cursorCol && row == cursorRow)
            {
                g.setColour (pixOn);
                g.fillRect (cx + 1.0f, cy + ch - 3.0f, cw - 2.0f, 2.0f);
            }
        }
    }
}

void LcdDisplay::timerCallback() { repaint(); }