Sim GUI: Add support for LED displays (#2138)

LED displays connect the LEDs in various ways (column major vs row major,
different starting locations, serpentine connection order), so add
configuration parameters for these options.

simulation/halsim_gui/src/main/native/include/ExtraGuiWidgets.h

@@ -11,6 +11,33 @@
 
 namespace halsimgui {
 
+/**
+ * DrawLEDs() configuration for 2D arrays.
+ */
+struct LEDConfig {
+  /**
+   * Whether the major order is serpentined (e.g. the first row goes left to
+   * right, the second row right to left, the third row left to right, and so
+   * on).
+   */
+  bool serpentine = false;
+
+  /**
+   * The input array order (row-major or column-major).
+   */
+  enum Order { RowMajor = 0, ColumnMajor } order = RowMajor;
+
+  /**
+   * The starting location of the array (0 location).
+   */
+  enum Start {
+    UpperLeft = 0,
+    LowerLeft,
+    UpperRight,
+    LowerRight
+  } start = UpperLeft;
+};
+
 /**
  * Draw a 2D array of LEDs.
  *
@@ -27,8 +54,10 @@ namespace halsimgui {
  *             if 0, defaults to 1/2 of font size
  * @param spacing spacing between each LED (both horizontal and vertical);
  *                if 0, defaults to 1/3 of font size
+ * @param config 2D array configuration
  */
 void DrawLEDs(const int* values, int numValues, int cols, const ImU32* colors,
-              float size = 0.0f, float spacing = 0.0f);
+              float size = 0.0f, float spacing = 0.0f,
+              const LEDConfig& config = LEDConfig{});
 
 }  // namespace halsimgui