--[[ RINGS with SECTORS widget
    v1.0 by wlourf (08.08.2010)
    this widget draws a ring with differents effects     
http://u-scripts.blogspot.com/2010/08/r ... dgets.html    To call the script in a conky, use, before TEXT
    lua_load /path/to/the/script/rings.lua
    lua_draw_hook_pre main_rings
and add one line (blank or not) after TEXT
Parameters are :
3 parameters are mandatory
name        - the name of the conky variable to display,
              for example for {$cpu cpu0}, just write name="cpu"
arg            - the argument of the above variable,
              for example for {$cpu cpu0}, just write arg="cpu0"
                arg can be a numerical value if name=""
max            - the maximum value the above variable can reach,
              for example for {$cpu cpu0}, just write max=100    
Optional parameters:
xc,yc        - coordinates of the center of the ring,
              default = middle of the conky window
radius        - external radius of the ring, in pixels,
              default = quarter of the width of the conky window
thickness    - thickness of the ring, in pixels, default = 10 pixels
start_angle    - starting angle of the ring, in degrees, value can be negative,
              default = 0 degree
end_angle    - ending angle of the ring, in degrees,
              value must be greater than start_angle, default = 360 degrees
sectors        - number of sectors in the ring, default = 10
gap_sectors - gap between two sectors, in pixels, default = 1 pixel
cap            - the way to close a sector, available values are
                "p" for parallel , default value 
                "r" for radial (follow the radius)
inverse_arc    - if set to true, arc will be anticlockwise, default=false
border_size    - size of the border, in pixels, default = 0 pixel i.e. no border
fill_sector    - if set to true, each sector will be completely filled,
              default=false, this parameter is inoperate if sectors=1
background    - if set to false, background will not be drawn, default=true
foreground    - if set to false, foreground will not be drawn, default=true
Colours tables below are defined into braces :
{position in the gradient (0 to 1), colour in hexadecimal, alpha (0 to 1)}
example for a single colour table : 
{{0,0xFFAA00,1}} position parameter doesn't matter
example for a two-colours table : 
{{0,0xFFAA00,1},{1,0x00AA00,1}} or {{0.5,0xFFAA00,1},{1,0x00AA00,1}}
example for a three-colours table : 
{{0,0xFFAA00,1},{0.5,0xFF0000,1},{1,0x00AA00,1}}
bg_colour1    - colour table for background,
              default = {{0,0x00ffff,0.1},{0.5,0x00FFFF,0.5},{1,0x00FFFF,0.1}}
fg_colour1    - colour table for foreground,
              default = {{0,0x00FF00,0.1},{0.5,0x00FF00,1},{1,0x00FF00,0.1}}
bd_colour1    - colour table for border,
              default = {{0,0xFFFF00,0.5},{0.5,0xFFFF00,1},{1,0xFFFF00,0.5}}              
Seconds tables for radials gradients :
bg_colour2    - second colour table for background, default = no second colour
fg_colour2    - second colour table for foreground, default = no second colour
bd_colour2    - second colour table for border, default = no second colour
v1.0 (08 Aug. 2010) original release
]]
require 'cairo'
function conky_main_rings()
-- START PARAMETERS HERE
rings_settings={
    {
    name="time",
    arg="%S",
    max=60,
    xc=118,
    yc=676,
    start_angle=0,
    end_angle=360,
    thickness=5,
    radius=30,
    sectors=30,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0x00FF00,0.6}},
    },
    {
    name="time",
    arg="%M.%S",
    max=60,
    xc=118,
    yc=676,
    start_angle=0,
    end_angle=360,
    thickness=5,
    radius=24,
    sectors=30,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0xFFFF00,0.6}},
    },
    {
    name="time",
    arg="%I.%M",
    max=12,
    xc=118,
    yc=676,
    start_angle=0,
    end_angle=360,
    thickness=5,
    radius=18,
    sectors=6,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0xFF0000,0.6}},
    },
    {
    --ring 1-1 :cpu
    name="cpu",
    arg="cpu1",
    max=100,
    xc=82,
    yc=145,
    start_angle=180,
    end_angle=-180,
    thickness=5,
    radius=30,
    sectors=30,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0xD7DB3,0.6}},
    fg_colour2={{0.5,0xFF0000,0.6}},
    },
    {
    --ring 1-2 :cpu
    name="cpu",
    arg="cpu2",
    max=100,
    xc=82,
    yc=145,
    start_angle=180,
    end_angle=-180,
    thickness=5,
    radius=25,
    sectors=30,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0x49A835,0.6}},
    fg_colour2={{0.5,0xFF0000,0.6}},
    },
    {
    name="memperc",
    arg="",
    max=100,
    xc=175,
    yc=297,
    start_angle=180,
    end_angle=-180,
    thickness=7,
    radius=30,
    sectors=10,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0x00FF00,0.6}},
    fg_colour2={{0.5,0xFF0000,0.6}},
    },
    {
    --ring 4-1 : download speed
    name="downspeedf",
    arg="eth0",
    max=700,
    xc=187,
    yc=548,
    start_angle=180,
    end_angle=-180,
    thickness=17,
    radius=30,
    sectors=30,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0x0000ff,0.6}},
    fg_colour2={{0.5,0xFFFF00,0.6}},
    --ring 4-2 : upload speed
    },
    {
    name="upspeedf",
    arg="eth0",
    max=150,
    xc=95,
    yc=433,
    start_angle=180,
    end_angle=-180,
    thickness=17,
    radius=30,
    sectors=30,
    gap_sectors=1,
    bg_colour1={{0.5,0xFFFFFF,0.2}},
    fg_colour1={{0.5,0xFFFF00,0.6}},
    fg_colour2={{0.5,0x0000FF,0.6}},
    },
}
--END OF PARAMETERS HERE
--main function
    if conky_window==nil then return end
    local cs=cairo_xlib_surface_create(conky_window.display,
        conky_window.drawable, 
        conky_window.visual, conky_window.width, conky_window.height)
    cr=cairo_create(cs)
    if tonumber(conky_parse('${updates}'))>3 then
        for i in pairs(rings_settings) do
            draw_ring(rings_settings[i])
        end
    end
    cairo_destroy(cr)
end
function draw_ring(t)
    local function rgba_to_r_g_b_a(tcolour)
        colour,alpha=tcolour[2],tcolour[3]
        return ((colour / 0x10000) % 0x100) / 255., 
            ((colour / 0x100) % 0x100) / 255., (colour % 0x100) / 255., alpha
    end                        
    local function calc_delta(tcol1,tcol2)
        --calculate deltas P R G B A to table_colour 1
        for x = 1, #tcol1 do
            tcol1[x].dA    = 0
            tcol1[x].dP = 0
             tcol1[x].dR = 0
            tcol1[x].dG = 0
            tcol1[x].dB = 0
            if tcol2~=nil and #tcol1 == #tcol2 then
                local r1,g1,b1,a1 = rgba_to_r_g_b_a(tcol1[x])
                local r2,g2,b2,a2 = rgba_to_r_g_b_a(tcol2[x])
                tcol1[x].dP = (tcol2[x][1]-tcol1[x][1])/t.sectors
                 tcol1[x].dR = (r2-r1)/t.sectors
                tcol1[x].dG = (g2-g1)/t.sectors
                tcol1[x].dB = (b2-b1)/t.sectors
                tcol1[x].dA = (a2-a1)/t.sectors                        
            end
        end        
        return tcol1
    end
    --check values
    local function setup(t)
        if t.name==nil and t.arg==nil then 
            print ("No input values ... use parameters 'name'" +
                " with 'arg' or only parameter 'arg' ") 
            return
        end
        if t.max==nil then
            print ("No maximum value defined, use 'max'")
            print ("for name=" .. t.name)
            print ("with arg=" .. t.arg)
            return
        end
        if t.name==nil then t.name="" end
        if t.arg==nil then t.arg="" end
        if t.xc==nil then t.xc=conky_window.width/2 end
        if t.yc==nil then t.yc=conky_window.height/2 end
        if t.thickness ==nil then t.thickness = 10 end
        if t.radius ==nil then t.radius =conky_window.width/4 end
        if t.start_angle==nil then t.start_angle =0 end
        if t.end_angle==nil then t.end_angle=360 end
        if t.bg_colour1==nil then 
            t.bg_colour1={{0,0x00ffff,0.1},{0.5,0x00FFFF,0.5},{1,0x00FFFF,0.1}}
        end
        if t.fg_colour1==nil then
            t.fg_colour1={{0,0x00FF00,0.1},{0.5,0x00FF00,1},{1,0x00FF00,0.1}}
        end
        if t.bd_colour1==nil then
            t.bd_colour1={{0,0xFFFF00,0.5},{0.5,0xFFFF00,1},{1,0xFFFF00,0.5}}
        end
        if t.sectors==nil then t.sectors=10 end
        if t.gap_sectors==nil then t.gap_sectors=1 end 
        if t.fill_sector==nil then t.fill_sector=false end
        if t.sectors==1 then t.fill_sector=false end
        if t.border_size==nil then t.border_size=0 end
        if t.cap==nil then t.cap="p" end
        --some checks
        if t.thickness>t.radius then t.thickness=t.radius*0.1 end
        t.int_radius = t.radius-t.thickness
        --check colors tables 
        for i=1, #t.bg_colour1 do 
            if #t.bg_colour1[i]~=3 then t.bg_colour1[i]={1,0xFFFFFF,0.5} end
        end
        for i=1, #t.fg_colour1 do 
            if #t.fg_colour1[i]~=3 then t.fg_colour1[i]={1,0xFF0000,1} end
        end
        for i=1, #t.bd_colour1 do 
            if #t.bd_colour1[i]~=3 then t.bd_colour1[i]={1,0xFFFF00,1} end
        end    
        if t.bg_colour2~=nil then
            for i=1, #t.bg_colour2 do 
                if #t.bg_colour2[i]~=3 then t.bg_colour2[i]={1,0xFFFFFF,0.5} end
            end
        end
        if t.fg_colour2~=nil then
            for i=1, #t.fg_colour2 do 
                if #t.fg_colour2[i]~=3 then t.fg_colour2[i]={1,0xFF0000,1} end
            end
        end
        if t.bd_colour2~=nil then
            for i=1, #t.bd_colour2 do 
                if #t.bd_colour2[i]~=3 then t.bd_colour2[i]={1,0xFFFF00,1} end
            end
        end             
        if t.start_angle>=t.end_angle then
         local tmp_angle=t.end_angle
         t.end_angle= t.start_angle
         t.start_angle = tmp_angle
         -- print ("inversed angles")
            if t.end_angle-t.start_angle>360 and t.start_angle>0 then
                t.end_angle=360+t.start_angle
                print ("reduce angles")
            end        
            if t.end_angle+t.start_angle>360 and t.start_angle<=0 then
                t.end_angle=360+t.start_angle
                print ("reduce angles")
            end        
            if t.int_radius<0 then t.int_radius =0 end
            if t.int_radius>t.radius then
                local tmp_radius=t.radius
                t.radius=t.int_radius
                t.int_radius=tmp_radius
                print ("inversed radius")
            end
            if t.int_radius==t.radius then
                t.int_radius=0
                print ("int radius set to 0")
            end 
        end        
        t.fg_colour1 = calc_delta(t.fg_colour1,t.fg_colour2)
        t.bg_colour1 = calc_delta(t.bg_colour1,t.bg_colour2)
        t.bd_colour1 = calc_delta(t.bd_colour1,t.bd_colour2)
    end    
    --initialize table
    setup(t)
    --[[grid
    h=conky_window.height
    w=conky_window.width
    cairo_set_source_rgba(cr,1,1,1,1)
    cairo_set_line_width(cr,0.5)
    cairo_move_to(cr,0,t.yc)
    cairo_line_to(cr,w,t.yc)
    cairo_stroke(cr)
    cairo_move_to(cr,t.xc,0)
    cairo_line_to(cr,t.xc,h)
    cairo_stroke(cr)
    cairo_move_to(cr,t.xc,t.yc)
    cairo_line_to(cr,t.xc+200*math.sin(math.pi/4),t.yc-200*math.cos(math.pi/4))
    cairo_stroke(cr)
    cairo_move_to(cr,0,t.yc-t.radius)
    cairo_line_to(cr,w,t.yc-t.radius)
    cairo_stroke(cr)
    cairo_move_to(cr,0,t.yc-t.int_radius)
    cairo_line_to(cr,w,t.yc-t.int_radius)
    cairo_stroke(cr)
    cairo_move_to(cr,0,t.yc-t.gap_sectors)
    cairo_line_to(cr,w,t.yc-t.gap_sectors)
    cairo_stroke(cr)
    cairo_set_source_rgba(cr,1,0,0,0.5)
    cairo_arc(cr,t.xc,t.yc,t.radius,0,2*math.pi)
    cairo_stroke(cr)
    cairo_arc(cr,t.xc,t.yc,t.int_radius,0,2*math.pi)    
    cairo_stroke(cr)    
    cairo_set_source_rgba(cr,0,1,0,1)    
    cairo_move_to(cr,t.xc+t.gap_sectors,t.yc-t.gap_sectors)
    cairo_line_to(cr,t.xc+400*math.sin(math.pi/4),t.yc-400*math.cos(math.pi/4))
    cairo_stroke(cr)
    --END GRID
    ]]    
    --initialize cairo context
    cairo_save(cr)
    cairo_translate(cr,t.xc,t.yc)
    cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND)
    cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND)
    --get value
    local value = 0
    if t.name ~="" then
        value = tonumber(conky_parse(string.format('${%s %s}', t.name, t.arg)))
    else
        value = tonumber(t.arg)
    end
    if value==nil then value =0 end
    --initialize sectors
    --angle of a sector :
    angleA = ((t.end_angle-t.start_angle)/t.sectors)*math.pi/180
    --value of a sector : 
    valueA = t.max/t.sectors
    --first angle of a sector : 
    lastAngle = t.start_angle*math.pi/180
    local function draw_sector(type_arc,angle0,angle,valpc, idx)     
        --this function draws a portion of arc
         --type of arc, angle0 = strating angle, angle= angle of sector,
         --valpc = percentage inside the sector, idx = sctor number #
         if type_arc=="bg" then         --background
             if valpc==1 then return end
             tcolor=t.bg_colour1
         elseif type_arc=="fg" then    --foreground
             if valpc==0 then return end
             tcolor=t.fg_colour1
         elseif type_arc=="bd" then    --border
             tcolor=t.bd_colour1
         end 
        --angles equivalents to gap_sector
        local ext_delta=math.atan(t.gap_sectors/(2*t.radius))
        local int_delta=math.atan(t.gap_sectors/(2*t.int_radius))
        --angles of arcs
        local ext_angle=(angle-ext_delta*2)*valpc
        local int_angle=(angle-int_delta*2)*valpc
        --define colours to use for this sector
        if #tcolor==1 then 
            --plain color
            local vR,vG,vB,vA = rgba_to_r_g_b_a(tcolor[1])
            cairo_set_source_rgba(cr,vR+tcolor[1].dR*idx,
                                    vG+tcolor[1].dG*idx,
                                    vB+tcolor[1].dB*idx,
                                    vA+tcolor[1].dA*idx    )
        else
            --radient color
            local pat=cairo_pattern_create_radial(0,0,t.int_radius,0,0,t.radius)
            for i=1, #tcolor do
                local vP,vR,vG,vB,vA = tcolor[i][1], rgba_to_r_g_b_a(tcolor[i])
                cairo_pattern_add_color_stop_rgba (pat, 
                                    vP+tcolor[i].dP*idx,
                                    vR+tcolor[i].dR*idx,
                                    vG+tcolor[i].dG*idx,
                                    vB+tcolor[i].dB*idx,
                                    vA+tcolor[i].dA*idx    )
            end
            cairo_set_source (cr, pat)
            cairo_pattern_destroy(pat)
        end
        --start drawing
         cairo_save(cr)
        --x axis is parrallel to start of sector
        cairo_rotate(cr,angle0-math.pi/2)
        local ri,re = t.int_radius ,t.radius
        --point A 
        local angle_a    
        if t.cap == "p" then 
            angle_a = int_delta
            if t.inverse_arc and type_arc ~="bg" then
                angle_a = angle-int_angle-int_delta
            end
            if not(t.inverse_arc) and type_arc =="bg" then
                angle_a = int_delta+int_angle
            end
        else --t.cap=="r"
            angle_a = ext_delta
            if t.inverse_arc and type_arc~="bg" then
                angle_a = angle-ext_angle-ext_delta
            end
            if not(t.inverse_arc) and type_arc=="bg" then
                angle_a = ext_delta+ext_angle
            end
        end
        local ax,ay = ri*math.cos(angle_a),ri*math.sin(angle_a)
        --point B
        local angle_b = ext_delta
        if t.cap == "p" then 
            if t.inverse_arc and type_arc ~="bg" then
                angle_b = angle-ext_angle-ext_delta
            end
            if not(t.inverse_arc) and type_arc=="bg" then
                angle_b = ext_delta+ext_angle
            end
        else
            if t.inverse_arc and type_arc ~="bg" then
                angle_b = angle-ext_angle-ext_delta
            end
            if not(t.inverse_arc) and type_arc=="bg" then
                angle_b = ext_delta+ext_angle
            end
        end
        local bx,by = re*math.cos(angle_b),re*math.sin(angle_b)
        -- EXTERNAL ARC B --> C
        if t.inverse_arc then
            if type_arc=="bg" then
                b0,b1= ext_delta, angle-ext_delta-ext_angle
            else
                b0,b1= angle-ext_angle-ext_delta, angle-ext_delta
            end
        else
            if type_arc=="bg" then
                b0,b1= ext_delta+ext_angle, angle-ext_delta
            else
                b0,b1= ext_delta, ext_angle+ext_delta
            end
        end        
        ---POINT D
        local angle_c 
        if t.cap == "p" then 
            angle_d = angle-int_delta
            if t.inverse_arc and type_arc=="bg" then
                angle_d = angle-int_delta-int_angle    
            end
            if not(t.inverse_arc) and type_arc~="bg" then
                angle_d=int_delta+int_angle
            end
        else
            angle_d = angle-ext_delta
            if t.inverse_arc and type_arc=="bg" then
                angle_d =angle-ext_delta-ext_angle
            end
            if not(t.inverse_arc) and type_arc~="bg" then
                angle_d = ext_angle+ext_delta
            end
        end
        local dx,dy = ri*math.cos(angle_d),ri*math.sin(angle_d)        
        -- INTERNAL ARC D --> A
        if t.cap=="p" then    
            if t.inverse_arc then    
                if type_arc=="bg" then
                    d0,d1= angle-int_delta-int_angle,int_delta
                else
                    d0,d1= angle-int_delta, angle- int_angle-int_delta
                end
            else
                if type_arc=="bg" then
                    d0,d1= angle-int_delta, int_delta+int_angle
                else
                    d0,d1= int_delta+int_angle, int_delta
                end
            end
        else
            if t.inverse_arc then    
                if type_arc=="bg" then    
                    d0,d1= angle-ext_delta-ext_angle,ext_delta
                else
                    d0,d1= angle-ext_delta, angle- ext_angle-ext_delta
                end
            else
                if type_arc=="bg" then    
                    d0,d1= angle-ext_delta,ext_delta+ext_angle
                else    
                    d0,d1= ext_angle+ext_delta, ext_delta
                end
            end            
        end            
        --draw sector
        cairo_move_to(cr,ax,ay)
        cairo_line_to(cr,bx,by)
        cairo_arc(cr,0,0,re,b0,b1)
        cairo_line_to(cr,dx,dy) 
        cairo_arc_negative(cr,0,0,ri,d0,d1)
         cairo_close_path (cr);
        --stroke or fill sector
         if type_arc=="bd" then
             cairo_set_line_width(cr,t.border_size)
             cairo_stroke(cr)
         else
             cairo_fill(cr)
         end
         cairo_restore(cr)
     end
    --draw sectors
    local n0,n1,n2 = 1,t.sectors,1
    if t.inverse_arc then n0,n1,n2 = t.sectors,1,-1 end
    local index = 0
    for i = n0,n1,n2 do 
        index = index +1
        local valueZ=1
        local cstA, cstB = (i-1),i
        if t.inverse_arc then cstA,cstB = (t.sectors-i), (t.sectors-i+1) end        
        if value>valueA *cstA and value<valueA*cstB then
            if not t.fill_sector then
                valueZ = (value-valueA*cstA)/valueA
            end
        else
            if value<valueA*cstB then valueZ=0 end
        end        
        local start_angle= lastAngle+(i-1)*angleA
        if t.foreground ~= false then 
            draw_sector("fg",start_angle,angleA,valueZ, index)
        end
        if t.background ~= false then 
            draw_sector("bg",start_angle,angleA,valueZ, i)
        end
        if t.border_size>0 then draw_sector("bd",start_angle,angleA,1, i) end
    end
    cairo_restore(cr)
end
--[[END OF RING-SECTORS WIDGET]]
function axis(ctx,alpha)
    cairo_set_line_width(ctx,1)
    cairo_set_source_rgba(ctx,1,0,0,alpha)
    cairo_move_to(ctx,0,0)
    cairo_line_to(ctx,150,0)
    cairo_stroke(ctx)
    cairo_set_source_rgba(ctx,0,1,0,alpha)
    cairo_move_to(ctx,0,0)
    cairo_line_to(ctx,0,150)
    cairo_stroke(ctx)
end