add ui module

src/lua/pxl8.lua

@@ -329,5 +329,37 @@ end
 
 pxl8.gfx = gfx
 pxl8.input = input
+pxl8.ui = _pxl8_ui
+
+function pxl8.bounds(x, y, w, h)
+    return ffi.new("pxl8_bounds", {x = x, y = y, w = w, h = h})
+end
+
+function pxl8.ui_window_begin(title, x, y, w, h, options)
+    local rect = ffi.new("pxl8_bounds", {x = x, y = y, w = w, h = h})
+    return C.pxl8_ui_window_begin(_pxl8_ui, title, rect, options or 0)
+end
+
+function pxl8.ui_window_end()
+    C.pxl8_ui_window_end(_pxl8_ui)
+end
+
+function pxl8.ui_button(label)
+    return C.pxl8_ui_button(_pxl8_ui, label)
+end
+
+function pxl8.ui_label(text)
+    C.pxl8_ui_label(_pxl8_ui, text)
+end
+
+function pxl8.ui_layout_row(item_count, widths, height)
+    local widths_array = widths
+    if type(widths) == "table" then
+        widths_array = ffi.new("int[?]", #widths, widths)
+    elseif type(widths) == "number" then
+        widths_array = ffi.new("int[1]", widths)
+    end
+    C.pxl8_ui_layout_row(_pxl8_ui, item_count, widths_array, height)
+end
 
 return pxl8