RLE for greyscale lcd (gives more firmware space!) (#1142)

* use RLE encodes bitmaps on 212x64 pixel radios

* fix model image display
fix icon display

* implement RLE bitmaps in companion for splash image on 212x64 radios
reserve 3kB for RLE bitmaps in firmware

* fix size check

* use defines instead of magic numbers

* fix display of splash screens on 212x64 radios

* add warning message if compressed image is larger than the reserved space

radio/src/gui/212x64/lcd.cpp

@@ -976,4 +976,39 @@ void lcdDrawBitmap(coord_t x, coord_t y, const uint8_t * img, coord_t offset, co
     }
   }
 }
+
+void lcdDrawRleBitmap(coord_t x, coord_t y, const uint8_t * img, coord_t offset, coord_t width)
+{
+  RleBitmap pic(img, offset);
+
+  uint8_t w = pic.getWidth();
+  if (!width || width > w) {
+    width = w;
+  }
+  if (x+width > LCD_W) {
+    if (x >= LCD_W ) return;
+    width = LCD_W-x;
+  }
+  uint8_t rows = pic.getRows();
+
+  for (uint8_t row=0; row<rows; row++) {
+    uint8_t *p = &displayBuf[(row + (y/2)) * LCD_W + x];
+    for (coord_t i=0; i<width; i++) {
+      if (p >= DISPLAY_END) return;
+      uint8_t b = pic.getNext();
+      if (y & 1) {
+        *p = (*p & 0x0f) + ((b & 0x0f) << 4);
+        if ((p+LCD_W) < DISPLAY_END) {
+          *(p+LCD_W) = (*(p+LCD_W) & 0xf0) + ((b & 0xf0) >> 4);
+        }
+      }
+      else {
+        *p = b;
+      }
+      p++;
+    }
+    pic.goToNextRow();
+    pic.skip(offset);
+  }
+}
 #endif