feat: draw icons with transparent background

lib/GfxRenderer/GfxRenderer.cpp

@@ -821,6 +821,67 @@ void GfxRenderer::drawBitmap1Bit(const Bitmap &bitmap, const int x, const int y,
   free(rowBytes);
 }
 
+void GfxRenderer::drawTransparentBitmap(const Bitmap& bitmap, const int x, const int y, const int w, const int h) const {
+  // Similar to drawBitmap1Bit but strictly skips 1s (white) in the source 1-bit data
+  // The Bitmap reader returns 2-bit packed data where 0-2=Black and 3=White for 1-bit sources
+
+  float scale = 1.0f;
+  bool isScaled = false;
+  if (w > 0 && bitmap.getWidth() > w) {
+    scale = static_cast<float>(w) / static_cast<float>(bitmap.getWidth());
+    isScaled = true;
+  }
+  if (h > 0 && bitmap.getHeight() > h) {
+    scale = std::min(scale, static_cast<float>(h) / static_cast<float>(bitmap.getHeight()));
+    isScaled = true;
+  }
+
+  const int outputRowSize = (bitmap.getWidth() + 3) / 4;
+  auto* outputRow = static_cast<uint8_t*>(malloc(outputRowSize));
+  auto* rowBytes = static_cast<uint8_t*>(malloc(bitmap.getRowBytes()));
+
+  if (!outputRow || !rowBytes) {
+    Serial.printf("[%lu] [GFX] !! Failed to allocate BMP row buffers\n", millis());
+    free(outputRow);
+    free(rowBytes);
+    return;
+  }
+
+  for (int bmpY = 0; bmpY < bitmap.getHeight(); bmpY++) {
+    if (bitmap.readNextRow(outputRow, rowBytes) != BmpReaderError::Ok) {
+      free(outputRow);
+      free(rowBytes);
+      return;
+    }
+
+    const int bmpYOffset = bitmap.isTopDown() ? bmpY : bitmap.getHeight() - 1 - bmpY;
+    int screenY = y + (isScaled ? static_cast<int>(std::floor(bmpYOffset * scale)) : bmpYOffset);
+
+    if (screenY >= getScreenHeight()) continue;
+    if (screenY < 0) continue;
+
+    for (int bmpX = 0; bmpX < bitmap.getWidth(); bmpX++) {
+      int screenX = x + (isScaled ? static_cast<int>(std::floor(bmpX * scale)) : bmpX);
+
+      if (screenX >= getScreenWidth()) break;
+      if (screenX < 0) continue;
+
+      // Get 2-bit value. For 1-bit BMPs from BmpReader:
+      // Black in BMP -> 0 (Black)
+      // White in BMP -> 3 (White)
+      const uint8_t val = outputRow[bmpX / 4] >> (6 - ((bmpX * 2) % 8)) & 0x3;
+
+      // Only draw if NOT white (val < 3)
+      if (val < 3) {
+         drawPixel(screenX, screenY, true); // True = Black
+      }
+    }
+  }
+
+  free(outputRow);
+  free(rowBytes);
+}
+
 void GfxRenderer::fillPolygon(const int *xPoints, const int *yPoints,
                               int numPoints, bool state) const {
   if (numPoints < 3)

lib/GfxRenderer/GfxRenderer.h

@@ -80,6 +80,7 @@ public:
                   int maxHeight, float cropX = 0, float cropY = 0) const;
   void drawBitmap1Bit(const Bitmap &bitmap, int x, int y, int maxWidth,
                       int maxHeight) const;
+  void drawTransparentBitmap(const Bitmap& bitmap, int x, int y, int w, int h) const;
   void draw2BitImage(const uint8_t data[], int x, int y, int w, int h) const;
   void fillPolygon(const int *xPoints, const int *yPoints, int numPoints,
                    bool state = true) const;

lib/ThemeEngine/src/LayoutElements.cpp

@@ -45,7 +45,7 @@ void Icon::draw(const GfxRenderer& renderer, const ThemeContext& context) {
   if (data && !data->empty()) {
     Bitmap bmp(data->data(), data->size());
     if (bmp.parseHeaders() == BmpReaderError::Ok) {
-      renderer.drawBitmap(bmp, absX, absY, w, h);
+      renderer.drawTransparentBitmap(bmp, absX, absY, w, h);
       markClean();
       return;
     }