SM-26 synthesizer: initial implementation

Source/LcdDisplay.cpp

@@ -0,0 +1,155 @@
+#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(); }