Function ViewportAddString

src/viewport.cpp:1330–1349

* Add a string to draw in the current viewport. * @param dpi current viewport area * @param sign sign position and dimension * @param flags ViewportStringFlags to control the string's appearance. * @param colour colour of the sign background; or INVALID_COLOUR if transparent * @returns Pointer to std::string to filled with sign, or nullptr if string would be outside the viewport bounds. */

 * @returns Pointer to std::string to filled with sign, or nullptr if string would be outside the viewport bounds.
 */
std::string *ViewportAddString(const DrawPixelInfo *dpi, const ViewportSign *sign, ViewportStringFlags flags, Colours colour)
{
	int left   = dpi->left;
	int top    = dpi->top;
	int right  = left + dpi->width;
	int bottom = top + dpi->height;

	bool small = flags.Test(ViewportStringFlag::Small);
	int sign_height     = ScaleByZoom(WidgetDimensions::scaled.fullbevel.top + GetCharacterHeight(small ? FS_SMALL : FS_NORMAL) + WidgetDimensions::scaled.fullbevel.bottom, dpi->zoom);
	int sign_half_width = ScaleByZoom((small ? sign->width_small : sign->width_normal) / 2, dpi->zoom);

	if (bottom < sign->top ||
			top   > sign->top + sign_height ||
			right < sign->center - sign_half_width ||
			left  > sign->center + sign_half_width) {
		return nullptr;
	}

	return &AddStringToDraw(sign->center - sign_half_width, sign->top, colour, flags, small ? sign->width_small : sign->width_normal);
}

static Rect ExpandRectWithViewportSignMargins(Rect r, ZoomLevel zoom)
{