Set gui controls alpha (global state), alpha goes from 0.0f to 1.0f.
See also
Other gui functions:
gui_button(),
gui_check_box(),
gui_color_bar_alpha(),
gui_color_bar_hue(),
gui_color_panel(),
gui_color_panel_hsv(),
gui_color_picker(),
gui_color_picker_hsv(),
gui_combo_box(),
gui_disable(),
gui_disable_tooltip(),
gui_draw_icon(),
gui_dropdown_box(),
gui_dummy_rec(),
gui_enable(),
gui_enable_tooltip(),
gui_get_font(),
gui_get_state(),
gui_get_style(),
gui_get_text_width(),
gui_grid(),
gui_group_box(),
gui_is_locked(),
gui_label(),
gui_label_button(),
gui_line(),
gui_list_view(),
gui_load_style(),
gui_load_style_default(),
gui_lock(),
gui_message_box(),
gui_panel(),
gui_progress_bar(),
gui_scroll_panel(),
gui_set_font(),
gui_set_icon_scale(),
gui_set_state(),
gui_set_style(),
gui_set_tooltip(),
gui_slider(),
gui_slider_bar(),
gui_spinner(),
gui_status_bar(),
gui_tab_bar(),
gui_text_box(),
gui_text_input_box(),
gui_toggle(),
gui_toggle_group(),
gui_toggle_slider(),
gui_unlock(),
gui_value_box(),
gui_value_box_float(),
gui_window_box()