[DBP] - ARGB() function. Set rgb with alpha.

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zeroSlave

15

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Joined: 13th Jun 2009

Location: Springfield

Posted: 4th Jun 2012 23:02 Edited at: 8th Jun 2012 01:29

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Was trying to change change the alpha when setting a color to text and didnt see an option in the internal commands. Came up with a quick and easy function. Works with objects also. Unfortunately, it doesn't work with 2D shape commands.

Here is a quick method for doing it from Mr Kohlenstoff that uses bitwise operators:

+ Code Snippet

`Just call argb() like you would rgb(), but send an extra variable for alpha.
function argb2(r, g, b, a)
    col = a<<24 || r<<16 || g<<8 || b
endfunction col

Here is the original using multipication:

+ Code Snippet

`Just call argb() like you would rgb(), but send an extra variable for alpha.
function argb(r, g, b, a)
    col as dword: col = ((a * 256 + r) * 256 + g) * 256 + b
endfunction col

Here it is in action:

+ Code Snippet


`Set up screen and camera
sync on
sync rate 60
autocam off
position camera 0,10,-20
point camera 0,0,0

`Set up objects
make object cube 1, 10
make object cube 2, 8
make object cube 3, 6
color object 1, argb(255,0,0,150)
color object 2, argb(255,255,0,150)
color object 3, argb(255,0,255,150)
set object transparency 1, 3
set object transparency 2, 3
set object transparency 3, 3
position object 1, 0, 0, 0
position object 2, 5, 0, 5
position object 3, 10, 0, 10

`Set up text
set text font "impact"
set text size 50
set text to bold
ink argb(255,255,255,50)

do
    text screen width() / 2 - 315, screen height() / 2, "Hello World! This is transparent text!"
    sync
loop
end

function argb2(r, g, b, a)
    col = a<<24 || r<<16 || g<<8 || b
endfunction col

Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.

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Mr Kohlenstoff

18

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Joined: 7th Jun 2006

Location: Germany

Posted: 7th Jun 2012 20:38 Edited at: 7th Jun 2012 20:47

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I thought using bitshift-operations instead of multiplications should run faster, but seemingly there is no significant difference:

set display mode 800, 600, 32
set window on
sync on
sync rate 0
sync

iterations = 5
times = 1000000
r as byte
b as byte
g as byte

set text font "Tahoma"
set text size 16

cls

sum1 = 0
sum2 = 0

for j = 1 to iterations

print
   print "Test ", j, "/", iterations
   print "  Iterations: ", times : sync

t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb1(r,g,b,255)
   next i
   t = timer()-t
   inc sum1, t
   print "  argb1: ", t, " ms" : sync

t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb2(r,g,b,255)
   next i
   t = timer()-t
   inc sum2, t
   print "  argb2: ", t, " ms" : sync

times = times*2

if escapekey() then end

next j

fac# = sum1/(1.0*sum2)
print "___________________________"
print
print "Result:"
print "  argb1: ", sum1, " ms"
print "  argb2: ", sum2, " ms"
print
print "  Factor: ", str$(fac#,3)
if fac# < 1.0 then print "  - argb1 wins!" else print "  - argb2 wins!"

repeat
   sync
until escapekey()
end

function argb1(r, g, b, a)
    col as dword : col = ((a * 256 + r) * 256 + g) * 256 + b
endfunction col

function argb2(r, g, b, a)
    col = a<<24 || r<<16 || g<<8 || b
endfunction col

+ Code Snippet


set display mode 800, 600, 32
set window on
sync on
sync rate 0
sync

iterations = 5
times = 1000000
r as byte
b as byte
g as byte


set text font "Tahoma"
set text size 16


cls


sum1 = 0
sum2 = 0

for j = 1 to iterations

   print
   print "Test ", j, "/", iterations
   print "  Iterations: ", times : sync

   t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb1(r,g,b,255)
   next i
   t = timer()-t
   inc sum1, t
   print "  argb1: ", t, " ms" : sync


   t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb2(r,g,b,255)
   next i
   t = timer()-t
   inc sum2, t
   print "  argb2: ", t, " ms" : sync

   times = times*2

   if escapekey() then end

next j



fac# = sum1/(1.0*sum2)
print "___________________________"
print
print "Result:"
print "  argb1: ", sum1, " ms"
print "  argb2: ", sum2, " ms"
print
print "  Factor: ", str$(fac#,3)
if fac# < 1.0 then print "  - argb1 wins!" else print "  - argb2 wins!"

repeat
   sync
until escapekey()
end


function argb1(r, g, b, a)
    col as dword : col = ((a * 256 + r) * 256 + g) * 256 + b
endfunction col

function argb2(r, g, b, a)
    col = a<<24 || r<<16 || g<<8 || b
endfunction col

Anyway. Given the fact that the argb-function won't be used too often probably and it should already be fast enough, I highly doubt that optimizations on this level have any noticable effect on a game or application at all. I did this test just out of curiousity, you know.

Edit:

Actually there is quite a difference. When reducing the overhead generated by the for-loop and variable-assignments, the difference gets more obvious and the function using bitwise-operators gets around ~30% faster (on my computer at least).

set display mode 800, 600, 32
set window on
sync on
sync rate 0
sync

iterations = 5
times = 100000
r as byte
b as byte
g as byte

set text font "Tahoma"
set text size 16

cls

sum1 = 0
sum2 = 0

for j = 1 to iterations

print
   print "Test ", j, "/", iterations
   print "  Iterations: ", times : sync

t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255)
      temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255)
      temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255)
   next i
   t = timer()-t
   inc sum1, t
   print "  argb1: ", t, " ms" : sync

if escapekey() then end

t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255)
      temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255)
      temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255)
   next i
   t = timer()-t
   inc sum2, t
   print "  argb2: ", t, " ms" : sync

times = times*2

if escapekey() then end

next j

fac# = sum1/(1.0*sum2)
print "___________________________"
print
print "Result:"
print "  argb1: ", sum1, " ms"
print "  argb2: ", sum2, " ms"
print
print "  Factor: ", str$(fac#,3)
if fac# < 1.0 then print "  - argb1 wins!" else print "  - argb2 wins!"

repeat
   sync
until escapekey()
end

function argb1(r, g, b, a)
    col as dword : col = ((a * 256 + r) * 256 + g) * 256 + b
endfunction col

function argb2(r, g, b, a)
    col = a<<24 || r<<16 || g<<8 || b
endfunction col

+ Code Snippet


set display mode 800, 600, 32
set window on
sync on
sync rate 0
sync

iterations = 5
times = 100000
r as byte
b as byte
g as byte


set text font "Tahoma"
set text size 16


cls


sum1 = 0
sum2 = 0

for j = 1 to iterations

   print
   print "Test ", j, "/", iterations
   print "  Iterations: ", times : sync

   t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255)
      temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255)
      temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255) : temp = argb1(r,g,b,255)
   next i
   t = timer()-t
   inc sum1, t
   print "  argb1: ", t, " ms" : sync


   if escapekey() then end

   t = timer()
   for i = 1 to times
      r = i : g = 255-r : b = r+128
      temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255)
      temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255)
      temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255) : temp = argb2(r,g,b,255)
   next i
   t = timer()-t
   inc sum2, t
   print "  argb2: ", t, " ms" : sync

   times = times*2

   if escapekey() then end

next j



fac# = sum1/(1.0*sum2)
print "___________________________"
print
print "Result:"
print "  argb1: ", sum1, " ms"
print "  argb2: ", sum2, " ms"
print
print "  Factor: ", str$(fac#,3)
if fac# < 1.0 then print "  - argb1 wins!" else print "  - argb2 wins!"

repeat
   sync
until escapekey()
end


function argb1(r, g, b, a)
    col as dword : col = ((a * 256 + r) * 256 + g) * 256 + b
endfunction col

function argb2(r, g, b, a)
    col = a<<24 || r<<16 || g<<8 || b
endfunction col

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zeroSlave

15

Years of Service

User Offline

Joined: 13th Jun 2009

Location: Springfield

Posted: 8th Jun 2012 01:28

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That's cool! I didn't even think about using bitwise operators in darkbasic like that. Thanks for testing it out. I went ahead and updated the first post with the function you wrote. Hope that's okay!