OpenEuphoria

palette animation experiments

• Posted by Jacques Deschenes <desja at QUEBECTEL.COM> Dec 21, 1996
• 1805 views

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Whoops, forgot to attach pal_anim.ex


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-- some experiments in palette animation.
-- December 21th, 1996
include graphics.e

-- check library ref. and didn't find it.
function get_palette()
sequence Pal
object junk
  Pal = repeat({0,0,0},64)
  junk = Pal[1]
  for i = 1 to  64 do
      junk = palette(i-1,junk)
      if atom(junk) then
        all_palette(Pal[1..i-1])
        return Pal[1..i-1]
      else
        Pal[i] = junk
      end if
  end for
  all_palette(Pal)  -- restore it.
  return Pal
end function -- get_palette()

procedure delay(atom t)
atom s
    s = time()
    while time()-s < t do
    end while
end procedure

-- draw a thick line ellipse
procedure ThickEllipse(integer color, -- color of ellipse
                      integer ThickNess,  -- thickness of the line
                      sequence ul, -- up left corner
                      sequence dr   -- down right corner
                      )
    for i = 0 to ThickNess - 1  do
        ellipse(color,0,{ul[1]+i,ul[2]+i},{dr[1]-i,dr[2]-i})
    end for
end procedure

sequence SavePalette, RotatePal

object junk
junk = graphics_mode(256) -- 640X480, 256 colors

SavePalette = get_palette()

-- TEST 1   range scanning
-- affecting same palette to many entries and scanning a second color in
-- that range

sequence tmp,wave

  RotatePal = SavePalette

  RotatePal[4] = RotatePal[8]
  junk = palette(3,RotatePal[8])
  wave = RotatePal[16]
  RotatePal[5] = RotatePal[8]
  junk = palette(4,RotatePal[8])
  tmp = RotatePal[8]

for i = 1 to length(SavePalette) do -- draw palette
    polygon(i,1,{{10*i,0},{10+10*i,0},{10+10*i,10},{10*i,10}})
end for

position(3,1)
puts(1,"TEST 1: animation by range scanning.\n")
puts(1,"Press a key for next experiment.")

for i = 0 to 15  do
    ThickEllipse(2+remainder(i,3),8,{319-8*i,239-8*i},{321+8*i,241+8*i})
end for

while get_key() = -1 do
    for i = 3 to 5  do
      junk = palette(i-1,wave)
      delay(.2)
      junk = palette(i-1,tmp)
    end for
end while

-- TEST 2  rotating a range
-- rotating a range of entries in a loop
-- rotating colors 16 to 31 (gray scale)
-- twinning palette entries so that same colors can be fixed and animated at the
-- same time.  ( windows 95 opening banner trick)

clear_screen()
position(2,1)
puts(1,"   fixed twin           animated twin\n")
puts(1,"Animation by palette rotation.\n")
puts(1,"Press a key to end.")

RotatePal = SavePalette
RotatePal[1..16] = RotatePal[17..32]
all_palette(RotatePal)
for i = 0 to 15  do
  polygon(i,1,{{10*i,0},{10+10*i,0},{10+10*i,10},{10*i,10}})--fixed colors bar
  polygon(16+i,1,{{10*(16+i),0},{10+10*(16+i),0},  -- animated colors bar
                  {10+10*(16+i),10},{10*(16+i),10}})
  ThickEllipse(16+i,8,{319-8*i,239-8*i},{321+8*i,241+8*i}) -- animated circles
end for

while get_key() = -1 do
  for l = 1 to  16 do -- rotate one way thrue
    tmp = RotatePal[17]
    for i = 17 to 31 do
        RotatePal[i] = RotatePal[i+1]
    end for
    RotatePal[32] = tmp
    all_palette(RotatePal)
    delay(.06)
  end for
  for l  = 1 to  16 do  -- rotate the other way thrue
    tmp = RotatePal[32]
    for i = 32 to 18 by -1 do
        RotatePal[i] = RotatePal[i-1]
    end for
    RotatePal[17] = tmp
    all_palette(RotatePal)
    delay(.06)
  end for
end while

---------------------
all_palette(SavePalette)
junk = graphics_mode(-1)



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Jacques Deschenes
Baie-Comeau, Quebec
Canada
desja at quebectel.com

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