transbg.lua

--[[Background originally by londonali1010 (2009)
    ability to set any size for background mrpeachy 2011
    ability to set variables for bg in conkyrc dk75

the change is that if you set width and/or height to 0
then it assumes the width and/or height of the conky window

so:

Above and After TEXT  (requires a composite manager or it blinks!)

 lua_load ~/wea_conky/draw_bg.lua
 TEXT
 ${lua conky_draw_bg 10 0 0 0 0 0x000000 0.4}

OR Both above TEXT (no composite manager required - no blinking!)

 lua_load ~/wea_conky/draw_bg.lua
 lua_draw_hook_pre draw_bg 10 0 0 0 0 0x000000 0.5
 TEXT

Note
${lua conky_draw_bg 20 0 0 0 0 0x000000 0.4}
  See below:        1  2 3 4 5 6        7

${lua conky_draw_bg corner_radius x_position y_position width height color alpha}

covers the whole window and will change if you change the minimum_size setting

1 = 20             corner_radius
2 = 0             x_position
3 = 0             y_position
3 = 0             width
5 = 0             height
6 = 0x000000      color
7 = 0.4           alpha

]]

require 'cairo'
local    cs, cr = nil
function rgb_to_r_g_b(colour,alpha)
return ((colour / 0x10000) % 0x100) / 255., ((colour / 0x100) % 0x100) / 255., (colour % 0x100) / 255., alpha
end
function conky_draw_bg(r,x,y,w,h,color,alpha)
if conky_window == nil then return end
if cs == nil then cairo_surface_destroy(cs) end
if cr == nil then cairo_destroy(cr) end
local cs = cairo_xlib_surface_create(conky_window.display, conky_window.drawable, conky_window.visual, conky_window.width, conky_window.height)
local cr = cairo_create(cs)
w=w
h=h
if w=="0" then w=tonumber(conky_window.width) end
if h=="0" then h=tonumber(conky_window.height) end
cairo_set_source_rgba (cr,rgb_to_r_g_b(color,alpha))
--top left mid circle
local xtl=x+r
local ytl=y+r
--top right mid circle
local xtr=(x+r)+((w)-(2*r))
local ytr=y+r
--bottom right mid circle
local xbr=(x+r)+((w)-(2*r))
local ybr=(y+r)+((h)-(2*r))
--bottom right mid circle
local xbl=(x+r)
local ybl=(y+r)+((h)-(2*r))
-----------------------------
cairo_move_to (cr,xtl,ytl-r)
cairo_line_to (cr,xtr,ytr-r)
cairo_arc(cr,xtr,ytr,r,((2*math.pi/4)*3),((2*math.pi/4)*4))
cairo_line_to (cr,xbr+r,ybr)
cairo_arc(cr,xbr,ybr,r,((2*math.pi/4)*4),((2*math.pi/4)*1))
cairo_line_to (cr,xbl,ybl+r)
cairo_arc(cr,xbl,ybl,r,((2*math.pi/4)*1),((2*math.pi/4)*2))
cairo_line_to (cr,xtl-r,ytl)
cairo_arc(cr,xtl,ytl,r,((2*math.pi/4)*2),((2*math.pi/4)*3))
cairo_close_path(cr)
cairo_fill (cr)
------------------------------------------------------------
cairo_surface_destroy(cs)
cairo_destroy(cr)
return ""
end