Fixed text alignment to be visible based rather than surface based

Widgets/WidgetText.cpp

@@ -15,6 +15,72 @@ static SDL_Surface* render_text(bool should_wrap, TTF_Font* font, const string&
 	return txt_surface;
 }
 
+static SDL_Rect find_visible_area(const SDL_Surface* txt_surface)
+{
+	int x_start = -1;
+	int x_end = -1;
+	int y_start = -1;
+	int y_end = -1;
+
+	for (int y = 0; y < txt_surface->h; ++y)
+	{
+		bool found = false;
+		for (int x = 0; x < txt_surface->w; ++x)
+		{
+			if (1 == (static_cast<Uint8*>(txt_surface->pixels)[y * txt_surface->pitch + x]))
+			{
+				if (-1 == x_start)
+				{
+					x_start = x;
+				}
+				else
+				{
+					if (x < x_start)
+					{
+						x_start = x;
+					}
+				}
+
+				if (-1 == x_end)
+				{
+					x_end = x;
+				}
+				else
+				{
+					if (x > x_end)
+					{
+						x_end = x;
+					}
+				}
+				found = true;
+			}
+		}
+
+		if (found)
+		{
+			if (-1 == y_start)
+			{
+				y_start = y;
+			}
+			y_end = y;
+		}
+	}
+	SDL_Rect result = {.x = 0, .y = 0, .w = 0, .h = 0};
+	if ((-1 != x_start) && (-1 != x_end))
+	{
+		result.x = x_start;
+		result.w = x_end - x_start + 1;
+	}
+
+	if ((-1 != y_start) && (-1 != y_end))
+	{
+		result.y = y_start;
+		result.h = y_end - y_start + 1;
+	}
+
+	return result;
+}
+
 WidgetText::WidgetText(int x, int y, int width, int height, string text,
 	TextFit fit, bool should_wrap,
 	HorizontalAlign halign, VerticalAlign valign,
@@ -171,7 +237,8 @@ void WidgetText::draw()
 	}
 
 	// Now we have the final rendered text surface
-	SDL_Rect align = surface_align(m_surface, txt_surface, m_halign, m_valign);
+	SDL_Rect hint = find_visible_area(txt_surface);
+	SDL_Rect align = surface_align(m_surface, txt_surface, m_halign, m_valign, &hint);
 	SDL_BlitSurface(txt_surface, NULL, m_surface, &align);
 	SDL_FreeSurface(txt_surface);
 }