/// <summary> Shows the tower menu (see <see cref="towerMenuPrefab"/>) at the same
/// screen position as the parameter LymphNode <paramref name="lymphNode"/>. Called
/// by a LymphNode object when it is clicked with a tower on it. </summary>
internal GameObject ShowTowerMenu(Transform lymphNode, Tower tower)
{
GameObject towerMenu = Instantiate(towerMenuPrefab, new Vector3(0f, 0f, -1.2f), activeGameUIPanel.rotation);
towerMenu.transform.SetParent(activeGameUIPanel, false);
// if this tower is not upgradeable (i.e. the current tower...
// ...level is the last one), don't show the "upgrade" button
int currLevel = tower.GetCurrentLevel();
//int maxLevel = tower.numberOfLevels;
int maxLevel = tower.GetNumberOfLevels();
bool upgradeable = currLevel < maxLevel;
if (!upgradeable)
{
Transform buttonUpgradeTower = towerMenu.transform.Find(Constants.ButtonUpgradeTower);
buttonUpgradeTower.gameObject.SetActive(false);
}
// if this is a melee tower, show the "set rally point" button
if (tower as MeleeTower != null)
{
Transform buttonSetRallyPoint = towerMenu.transform.Find(Constants.ButtonSetRallyPoint);
buttonSetRallyPoint.gameObject.SetActive(true);
}
/////////////////////////////////////
// gather the cost data
int sellValue = -1;
int upgradeCost = -1;
sellValue = tower.GetCurrentSellValue();
upgradeCost = tower.GetNextLevelCost();
ShopMenu shopMenu = towerMenu.GetComponent <ShopMenu>();
shopMenu.SetValueSell(sellValue);
shopMenu.SetCostUpgrade(upgradeCost);
/////////////////////////////////////
// UI elements and other scene objects use different coordinate systems;
// in order to position the menu where the lymph node is (on the screen)...
// ...we have to do some conversions between World and Viewport
RectTransform towerMenuRT = towerMenu.GetComponent <RectTransform>();
RectTransform canvasRT = activeGameUIPanel.parent.GetComponent <RectTransform>(); // this assumes that this panel is the child of the top-level UI panel
Vector2 viewportPosition = Camera.main.WorldToViewportPoint(lymphNode.position);
Vector2 uiOffset = new Vector2((float)canvasRT.sizeDelta.x / 2f, (float)canvasRT.sizeDelta.y / 2f); // screen offset for the canvas
Vector2 proportionalPosition = new Vector2(viewportPosition.x * canvasRT.sizeDelta.x, viewportPosition.y * canvasRT.sizeDelta.y); // position on the canvas
// set the position and remove the screen offset
towerMenuRT.localPosition = proportionalPosition - uiOffset;
return(towerMenu);
}