C64-ize graphics

[Kitty Hello]

This function uses the current back buffer's contents and re-renders it with the C64 color palette. Unfortunately it's too slow for real-time updates . I'll try to find a way for that.

Code (glbasic) Select Expand

// --------------------------------- //
// Project: C64izer
// Start: Tuesday, March 25, 2008
// IDE Version: 5.212


LOADBMP "test.png"
C64ize()
SHOWSCREEN
MOUSEWAIT




FUNCTION C64ize:
// weighting of color components
LOCAL x,y,c, r,g,b, dr,dg,db
LOCAL mindist, dist, ibest, i
LOCAL c64_pal[]
DIMDATA c64_pal[], _
0x00 , 0x00 , 0x00, 0, _
0xff , 0xff , 0xff, 0, _
0x88 , 0x00 , 0x00, 0, _
0xaa , 0xff , 0xee, 0, _
0xcc , 0x44 , 0xcc, 0, _
0x00 , 0xcc , 0x55, 0, _
0x00 , 0x00 , 0xaa, 0, _
0xee , 0xee , 0x77, 0, _
0xdd , 0x88 , 0x55, 0, _
0x66 , 0x44 , 0x00, 0, _
0xff , 0x77 , 0x77, 0, _
0x33 , 0x33 , 0x33, 0, _
0x77 , 0x77 , 0x77, 0, _
0xaa , 0xff , 0x66, 0, _
0x00 , 0x88 , 0xff, 0, _
0xbb , 0xbb , 0xbb, 0

FOR i=0 TO 15
c64_pal[i*4+3] = RGB(c64_pal[i*4], c64_pal[i*4+1], c64_pal[i*4+2])
NEXT

FOR x=0 TO 319 STEP 2
FOR y=0 TO 239
c = GETPIXEL(x,y)
b=bAND(c/0x10000, 0xff)/2
g=bAND(c/0x100  , 0xff)/2
r=bAND(c        , 0xff)/2
mindist=0
c = GETPIXEL(x+1,y)
INC b,bAND(c/0x10000, 0xff)/2
INC g,bAND(c/0x100  , 0xff)/2
INC r,bAND(c        , 0xff)/2



ibest=0
FOR i=0 TO 15
db=ABS(bAND(c/0x10000, 0xff) - c64_pal[i*4+2])
dg=ABS(bAND(c/0x100  , 0xff) - c64_pal[i*4+1])
dr=ABS(bAND(c        , 0xff) - c64_pal[i*4  ])
dist=dr*dr+dg*dg+db*db
IF i=0 OR dist mindist=dist
ibest=i
ENDIF
NEXT
DRAWRECT x,y,2,1,c64_pal[ibest*4+3]
NEXT
NEXT
ENDFUNCTION

[Schranz0r]

Cool, but very slow

[AndyH]

Wow!

[Achim]

Sweet Gernot ! Nice piece of code ... reminds me to the good old days ... once upon, a long ago

CYA !

[Kitty Hello]

So, now in realtime:
http://www.glbasic.com/showroom.php?game=C64colorshader
Forgive me, for this is my first fragment shader, ever. It's not very optimized, but it works REALTIME.

[Simon Parzer]

Yeah, C64-like graphics REALTIME... but with DX9 capable graphics cards only. That's quite ironic
Anyway, great work!

[AndyH]

It doesn't seem to work on my 7900 GS Go.

[PeeJay]

You're not alone, Andy. All I get is the image displayed as normal, not C64ized.

[Kitty Hello]

What GFX card, PJ?

[Ian Price]

On my machine, the image does turn blocky a la C64, but it's still true colour and doesn't use only C64 palette

ATI Radeon 9800+ 256Mb (old, but gold).

[PeeJay]

NVidia GeForce FX 5500 here (old, but, er, crap )

[Hatonastick]

Works fine for me.  NVidia GeForce 8600M GT here.  Sounds like it's more a problem for older cards maybe?

[Kitty Hello]

Might be. It needs Shader Language 2.0

[AndyH]

Mine has shader 2 and is not that old.  I've some shader's (reportedly v2) in MMF that work ok.

[Hatonastick]

Yeah I noticed that when I went and did a bit of research on each of the cards mentioned.  Unfortunately in the case of Ian and PJ I'm not surprised theirs are having problems with Open GL Shader 2.  BTW Andy, not that it might be the problem, but are you running XP or Vista and are your drivers up to date?