Pete's QBASIC Site

My spiffy screen 13 palette fader...

2007-12-01T00:49:31-05:00

Umm, added another feature which fades to and from any color.
So pretty much, with just a couple more lines of code, this routine
could be used for palette to palette fades also.
Anyways, here's the final fading routine that I'll be using in my gfx lib...

Code:

'DEFINT A-Z'TYPE PALdata Red AS INTEGER Grn AS INTEGER Blu AS INTEGEREND TYPE'DIM SHARED PAL(255) AS PALdata'SCREEN 13'OUT &H3C7, 0'FOR x = 0 TO 255 PAL(x).Red = INP(&H3C9) PAL(x).Grn = INP(&H3C9) PAL(x).Blu = INP(&H3C9)NEXT'FOR y = 0 TO 199 FOR x = 0 TO 319  PSET (x, y), INT(RND(1) * 254 + 1) NEXTNEXT'COLOR 15: LOCATE 13, 12: PRINT "...Press a key..."'DO: LOOP UNTIL INKEY$ <> INKEY$'c = 1 'Color of fade.'OUT &H3C8, 0'FOR y = 1 TO 64 FOR x = 0 TO 255  r = PAL(x).Red - (y * ((PAL(x).Red - PAL(c).Red) / 64))  g = PAL(x).Grn - (y * ((PAL(x).Grn - PAL(c).Grn) / 64))  b = PAL(x).Blu - (y * ((PAL(x).Blu - PAL(c).Blu) / 64))  OUT &H3C9, r  OUT &H3C9, g  OUT &H3C9, b NEXT t! = TIMER: DO: LOOP UNTIL TIMER <> t!NEXT'DO: LOOP UNTIL INKEY$ <> INKEY$'FOR y = 1 TO 64 FOR x = 0 TO 255  r = PAL(c).Red + (y * ((PAL(x).Red - PAL(c).Red) / 64))  g = PAL(c).Grn + (y * ((PAL(x).Grn - PAL(c).Grn) / 64))  b = PAL(c).Blu + (y * ((PAL(x).Blu - PAL(c).Blu) / 64))  OUT &H3C9, r  OUT &H3C9, g  OUT &H3C9, b NEXT t! = TIMER: DO: LOOP UNTIL TIMER <> t!NEXT'SYSTEM'

(Change the variable c for different colors of fade.)

Cya, Nemesis

Statistics: Posted by Nemesis — Sat Dec 01, 2007 12:49 am

My spiffy screen 13 palette fader...

2007-11-30T10:22:15-05:00

That's funny. I have one that I wrote that's very similar to that. I was disatisfied with the ones I found in tutorials that looked very fakey.

Mine also pregenerates each inner loop (x in your case) to a temporary array, then puts that out to the video card in a separate inner loop. The result: a flickerless fade. (Your code would probably cause some flicker in the top quarter of the screen on my PIII 500mhz.)

Statistics: Posted by BDZ — Fri Nov 30, 2007 10:22 am

My spiffy screen 13 palette fader...

2007-11-30T05:47:30-05:00

Hi, just got back into doing some programming in QB. It's been almost 2 yrs. since I last coded. Anyways, what I was wanting to do first was to improve the quality of my palette fade in/out routines.
What I did was instead of decreasing a colors rgb intensity every cycle,
like most other fading routines, I decreased the colors rgb intensity more
gradually. (This fading effect looks much cleaner!)

Code:

'DEFINT A-Z'TYPE PALdata Red AS INTEGER Grn AS INTEGER Blu AS INTEGEREND TYPE'DIM SHARED PAL(255) AS PALdata'SCREEN 13'OUT &H3C7, 0'FOR x = 0 TO 255 PAL(x).Red = INP(&H3C9) PAL(x).Grn = INP(&H3C9) PAL(x).Blu = INP(&H3C9)NEXT'FOR y = 0 TO 199 FOR x = 0 TO 319  PSET (x, y), INT(RND(1) * 254 + 1) NEXTNEXT'COLOR 15: LOCATE 13, 12: PRINT "...Press a key..."'DO: LOOP UNTIL INKEY$ <> INKEY$'OUT &H3C8, 0'FOR y = 1 TO 64 FOR x = 0 TO 255  r = PAL(x).Red - (y * (PAL(x).Red / 64))  g = PAL(x).Grn - (y * (PAL(x).Grn / 64))  b = PAL(x).Blu - (y * (PAL(x).Blu / 64))  OUT &H3C9, r  OUT &H3C9, g  OUT &H3C9, b NEXT WAIT &H3DA, 8NEXT'FOR y = 1 TO 64 FOR x = 0 TO 255  r = y * (PAL(x).Red / 64)  g = y * (PAL(x).Grn / 64)  b = y * (PAL(x).Blu / 64)  OUT &H3C9, r  OUT &H3C9, g  OUT &H3C9, b NEXT WAIT &H3DA, 8NEXT'SYSTEM'

Cya, Nemesis.

p.s..I was thinking maybe writing a tutorial or something to explain the code in detail, step by step. What do you guys think?

Statistics: Posted by Nemesis — Fri Nov 30, 2007 5:47 am