8 bit art

angros47 · Post by **angros47** » Jul 29, 2010 6:51

http://www.effectgames.com/demos/canvascycle/?sound=0

(Mozilla or Chrome required)

The animation effect is gained by color cycling (like in many old games)

I believe that should not be difficult to port this to FreeBasic.

HD_ · Post by **HD_** » Jul 29, 2010 8:04

Wow, that is just plain amazing.

Mentat · Post by **Mentat** » Jul 29, 2010 13:59

Quite neat.

agamemnus · Post by **agamemnus** » Jul 29, 2010 14:31

Nice.

rdc · Post by **rdc** » Jul 29, 2010 14:42

Impressive.

Skyler · Post by **Skyler** » Jul 29, 2010 14:56

Fascinating.

antarman · Post by **antarman** » Jul 30, 2010 2:45

Very, very cool !!!

Post by **counting_pine** » Jul 30, 2010 15:28

Here's some code that will shift a section of the palette. Call it multiple times to shift multiple sections. It features the blending feature that I think the accompanying blog talks about. Now if anyone can actually find a good BMP to try it on...

(One of the old win9x logo.sys files should work, if you can find the right palette section to cycle.)

Code: Select all

function rangemod(i as single, start as integer, period as integer) as single
    
    dim as single j = i - start
    return j - int(j / period) * period + start
    
end function

function shiftindex( _
        i as integer, _
        start as integer, _
        period as integer, _
        cycle as single _
    ) as single
    
    if i < start orelse i >= start + period then return i
    
    return rangemod(i + cycle, start, period)
    
end function

function getcol(pal() as integer, i as single, start as integer, end_ as integer) as integer
    
    dim as integer j1 = int(i), j2 = int(i+1): if j2 = end_ then j2 = start
    dim as integer c1 = pal(j1), c2 = pal(j2)
    
    dim as single r1 = c1 shr 16 and 255, r2 = c2 shr 16 and 255
    dim as single g1 = c1 shr  8 and 255, g2 = c2 shr  8 and 255
    dim as single b1 = c1        and 255, b2 = c2        and 255
    
    dim as single m = (i - int(i))
    r1 += m * (r2 - r1)
    g1 += m * (g2 - g1)
    b1 += m * (b2 - b1)
    
    return (r1 and 255) shl 16 or (g1 and 255) shl 8 or (b1 and 255)
    
end function

sub shiftpalette(oldpal() as integer, newpal() as integer, start as integer, period as integer, cycle as single)
    #if 1
    '' make copy of oldpal so oldpal and newpal can be same array
    dim as integer oldpal_(0 to 255)
    for i as integer = 0 to 255: oldpal_(i) = oldpal(i): next i
    #else
    #define oldpal_ oldpal
    #endif
    
    dim as integer end_ = start + period
    for i as integer = 0 to 255
        'dim j as single = iif(i < 10, (i + cycle) mod 10, i)
        dim j as single = shiftindex(i, start, period, cycle)
        newpal(i) = getcol(oldpal_(), j, start, end_)
    next i
    
end sub



screenres 256, 256, 8
dim as integer pal1(0 to 255), pal2(0 to 255)

bload "C:\Windows\Prairie Wind.bmp", 0, @pal1(0)

dim as single i = 0
do
    shiftpalette(pal1(), pal2(), 0, 10, i)
    palette using pal2
    sleep 1
    i += 0.0625
loop until len(inkey)

angros47 · Post by **angros47** » Jul 30, 2010 19:40

Mysoft · Post by **Mysoft** » Jul 31, 2010 1:37

yeah very nice usage of palette... who needs 32bits anyway? :P

angros47 · Post by **angros47** » Jul 31, 2010 23:15

Ok, I did it!

Here is the viewer:

Code: Select all

open command(1) for input as #1

dim as string a,b

line input #1, a

type cycle
	min as integer
	max as integer
	reverse as integer
	rate as integer
end type




screenres 640,480,8

screenlock
dim pixel as byte

dim dest as byte ptr=screenptr()

for y as integer=1 to 480
	for x as integer=1 to 639
		input #1,pixel
		*dest=pixel
		dest+=1
	next
	input #1,pixel
next
screenunlock

close #1

dim shared as integer p(255,2)
a=mid(a,instr(a,"[[")+2)

for i as integer=0 to 255
	b=left(a,instr(a,"]")-1)
	a=mid(a,instr(a,"[")+1)

	p(i,0)=val(left(b,instr(b,",")-1))
	b=mid(b,instr(b,",")+1)
	p(i,1)=val(left(b,instr(b,",")-1))
	b=mid(b,instr(b,",")+1)
	p(i,2)=val(b)
	palette i,p(i,0),p(i,1),p(i,2)
next

dim as cycle cycles (16)

for i as integer=0 to 15
	a=mid(a,instr(a,"reverse:")+8)
	b=left(a,instr(a,",")-1)
	cycles(i).reverse=val(b)

	a=mid(a,instr(a,"rate:")+5)
	b=left(a,instr(a,",")-1)
	cycles(i).rate=val(b)

	a=mid(a,instr(a,"low:")+4)
	b=left(a,instr(a,",")-1)
	cycles(i).min=val(b)


	a=mid(a,instr(a,"high:")+5)
	b=left(a,instr(a,",")-1)
	cycles(i).max=val(b)

next

sub Cycle (lowest as integer, highest as integer)
	dim as integer a,b,c
	a=p(highest,0)
	b=p(highest,1)
	c=p(highest,2)
	for i as integer= highest to lowest+1 step -1
		p(i,0)=p(i-1,0)
		p(i,1)=p(i-1,1)
		p(i,2)=p(i-1,2)
		palette i,p(i,0),p(i,1),p(i,2)
	next
	p(lowest,0)=a
	p(lowest,1)=b
	p(lowest,2)=c
	palette lowest,a,b,c

end sub

sub CycleRev (lowest as integer, highest as integer)
	dim as integer a,b,c
	a=p(lowest,0)
	b=p(lowest,1)
	c=p(lowest,2)
	for i as integer= lowest to highest-1
		p(i,0)=p(i+1,0)
		p(i,1)=p(i+1,1)
		p(i,2)=p(i+1,2)
		palette i,p(i,0),p(i,1),p(i,2)
	next
	p(highest,0)=a
	p(highest,1)=b
	p(highest,2)=c
	palette highest,a,b,c

end sub



dim t(15) as double

do
	for i as integer=0 to 15
		t(i)=t(i)+Cycles(i).rate/10000

		if t(i) >10 then
			if Cycles(i).reverse=0 then
				Cycle(Cycles(i).min,Cycles(i).max)
			else
				CycleRev(Cycles(i).min,Cycles(i).max)
			end if
			t(i)=t(i)-10
		end if

	next
	sleep 1

loop until inkey<>""

Download a file from links above, and with this program you will be able to view it.

I'd like to put online a file with all the animated pictures, but I don't know if I need permission from the author. So, for now, get the images from the official site.

robert8192 · Post by **robert8192** » Aug 06, 2010 19:58

No Freeking Way.

How cool.

How did you figure this out.

Totally Freeking cool. Everyone should run this.

This is so ultimately Freeking Cool.

Like Absolute Zero Cool - -470Kelvin type stuff.

Rob.

rdc · Post by **rdc** » Aug 06, 2010 21:42

Cool indeed.

Post by **counting_pine** » Aug 07, 2010 15:14

Note: the reverse attribute (despite its name) isn't a boolean. There are several colour-cylcing modes - according to the Javascript code, there's a sine-wave mode and a "ping-pong" mode as well.

EDIT: here are some more images that don't appear in the list:
http://www.effectgames.com/demos/canvas ... ocessImage (the test image that comes with the source code)
http://www.effectgames.com/demos/canvas ... ocessImage (Henge)
http://www.effectgames.com/demos/canvas ... ocessImage (Alpine Ruin)
http://www.effectgames.com/demos/canvas ... ocessImage (Elvin City)
http://www.effectgames.com/demos/canvas ... ocessImage (Dark Castle)
http://www.effectgames.com/demos/canvas ... ocessImage (Desert Twilight)
http://www.effectgames.com/demos/canvas ... ocessImage (Red Canyon)

Apart from the test image, they don't have colour cycling though.
For some reason, TESTRAMP and V12 are missing the callback, but the others can all be made to work in the demo if you hack the scene list.

Thorham · Post by **Thorham** » Aug 18, 2010 22:20

Fantastic! I've seen some color cycle images before, and they were all crap, but this is just astounding :)

I'm going to download all of these with a script, and convert them from crappy java script to binary.