Add comments for the logic used when drawing voice buttons

Source/control.cpp

@@ -1342,15 +1342,22 @@ void DrawTalkPan(const Surface &out)
 		UiFlags color = player.friendlyMode ? UiFlags::ColorWhitegold : UiFlags::ColorRed;
 		const Point talkPanPosition = mainPanelPosition + Displacement { 172, 84 + 18 * talkBtn };
 		if (WhisperList[i]) {
-			if (TalkButtonsDown[talkBtn]) {
-				ClxDraw(out, talkPanPosition, (*talkButtons)[talkBtn != 0 ? 3 : 2]);
+			if (TalkButtonsDown[talkBtn]) { // the normal (unpressed) voice button is pre-rendered on the panel, only need to draw over it when the button is held
+				unsigned spriteIndex = talkBtn == 0 ? 2 : 3; // the first button sprite includes a tip from the devils wing so is different to the rest.
+				ClxDraw(out, talkPanPosition, (*talkButtons)[spriteIndex]);
+
+				// Draw the translated string over the top of the default (english) button. This graphic is inset to avoid overlapping the wingtip, letting
+				// the first button be treated the same as the other two further down the panel.
 				RenderClxSprite(out, (*TalkButton)[2], talkPanPosition + Displacement { 4, -15 });
 			}
 		} else {
-			int nCel = talkBtn != 0 ? 1 : 0;
+			unsigned spriteIndex = talkBtn == 0 ? 0 : 1; // the first button sprite includes a tip from the devils wing so is different to the rest.
 			if (TalkButtonsDown[talkBtn])
-				nCel += 4;
-			ClxDraw(out, talkPanPosition, (*talkButtons)[nCel]);
+				spriteIndex += 4; // held button sprites are at index 4 and 5 (with and without wingtip respectively)
+			ClxDraw(out, talkPanPosition, (*talkButtons)[spriteIndex]);
+
+			// Draw the translated string over the top of the default (english) button. This graphic is inset to avoid overlapping the wingtip, letting
+			// the first button be treated the same as the other two further down the panel.
 			RenderClxSprite(out, (*TalkButton)[TalkButtonsDown[talkBtn] ? 1 : 0], talkPanPosition + Displacement { 4, -15 });
 		}
 		if (player.plractive) {