Include heightmap index in tooltip

src/main.cpp

@@ -127,15 +127,18 @@ int main(int argc, char** argv) {
 
 		/*Check if we want to get the height*/
 		float height_measured = NOT_ON_SURFACE;
+		size_t hmap_hovered_index = 99999;
 		if (InputState::lmb_pressed && !(ImGui::GetIO().WantCaptureMouse)) {
 			for (size_t i = 0; i < heightmaps.size(); ++i) {
 				height_measured = heightmaps[i]->getSurfaceHeight(InputState::umpos_x, HEIGHT - InputState::umpos_y, projection, view, models[i]);
 				if (height_measured != NOT_ON_SURFACE) {
+					hmap_hovered_index = i;
 					break;
 				}
 			}
 			ImGui::BeginTooltip();
-			std::string tool_tip_str = "Height: ";
+			std::string tool_tip_str = "Height (";
+			tool_tip_str += (height_measured != NOT_ON_SURFACE) ? std::to_string(hmap_hovered_index) + "): " : "-1";
 			tool_tip_str += (height_measured != NOT_ON_SURFACE) ? std::to_string(height_measured) + " um" : "N/A";
 			ImGui::Text(tool_tip_str.c_str());
 			ImGui::EndTooltip();