SPACE 2

home *** CD-ROM | disk | FTP | other *** search

/ SPACE 2 / SPACE - Library 2 - Volume 1.iso / utility / 681 / scrnsavr / faze.s < prev next >

Wrap

Text File | 1992-05-11 | 16.8 KB | 546 lines

*-------------------------------------* * -F-A-Z-E- Screen Saver * * by Damien M. Jones * * Version 1.00 * *-------------------------------------* * This screen saver is built around a generic screen saver * frame. The frame hooks into the VBL and KBD/MIDI interrupts, * displays a successful installation message, and then terminates * with ptermres. * * I've gone through (May 12, 1992) and added extra comments to * clear up some confusion. The separate parts of the program * have been more clearly labeled. If you don't like the way * I format my assembly, tough; I write it for me, not for you. * Code begins. * Generic Screen Saver * by Damien M. Jones * Copyright 1992 Damien M. Jones, All Rights Reserved. * * Just change the "saver" routine to change the screen saver. * Please include a note in your documentation that you used * the "Generic Screen Saver Frame by dmj"; I place no other * restrictions on the use of this code. So you could release * a Shareware screen saver using this code, and you wouldn't * have to send me a penny. A copy of the screensaver would * be nice, but not mandatory. * If you leave the "id" string as it is, you can use the BoinkCfg * program to set the time delay for the screen saver, as well * as disable it. Otherwise, you'll have to write your own * config program. * You'll need to change the amount of memory to save, around line * 182. Faze uses a 32K screen, plus space for the program. jmp install ; Install program. * Variables (for the config program). id dc.b 'dmjScreenSaver' ; Fourteen-byte ID string. ssave dc.w 0 ; Old screen address. screen dc.w 0 ; Address of screen saver screen. timeout dc.w 300 ; Default is two minutes. count dc.w 300 ; Number of cycles left to wait. flag dc.w 0 ; Set if screen saver active. palsave dc.w 0,0,0,0,0,0,0,0 ; Place to store system palette. dc.w 0,0,0,0,0,0,0,0 rezsave dc.w 0 ; Place to store system resolution. pal dc.w $000,$722,$631,$540,$450,$361,$272,$163 ; Screensaver palette. dc.w $054,$045,$136,$227,$316,$405,$504,$613 rez dc.w 0 ; Resolution of screen saver. rndseed dc.l $31415926 ; Random number generator seed. * The VBL. Decrements timer, then checks to see if screen saver * needs to be activated. It then jumps to the OS VBL. vbl tst.w flag ; Is the screen saver active? beq vskip ; No, need to check counter. jsr saver ; Call the screen save subroutine. bra jmp1 ; All done. vskip move.l a0,-(a7) ; Save this register. move.l #count,a0 ; Address of count variable. subq.w #1,(a0) ; Decrement counter. tst.w (a0)+ ; Is it zero? bne vblend ; Nope, exit now. st (a0) ; Set in-use flag. movem.l d0/a1,-(a7) ; Save these register too. lea $FFFF8240.w,a1 ; Address of palette registers. move.l #palsave,a0 ; Address to save into. move.l (a1)+,(a0)+ ; Save palette. move.l (a1)+,(a0)+ move.l (a1)+,(a0)+ move.l (a1)+,(a0)+ move.l (a1)+,(a0)+ move.l (a1)+,(a0)+ move.l (a1)+,(a0)+ move.l (a1)+,(a0)+ move.w (a1)+,(a0)+ ; Resolution. lea $FFFF8240.w,a1 ; Address of palette registers. move.l (a0)+,(a1)+ ; Move in saver palette. move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.b (a0),(a1) ; And saver resolution. lea $FFFF8201.w,a1 ; Screen address vars in Shifter. move.l #ssave,a0 ; Address of variable. movep.w 0(a1),d0 ; Read old value. move.w d0,(a0)+ ; And save it. move.w (a0),d0 ; Get saver screen address. movep.w d0,0(a1) ; Copy over address. movem.l (a7)+,d0/a1 ; Restore registers. vblend move.l (a7)+,a0 ; Restore register. jmp1 jmp $11111111 ; Jump to old VBL. * The keyboard interrupt. Resets VBL timer, and shuts off screen * saver if it's active. kbd move.l a0,-(a7) ; Save this register. move.l #timeout,a0 ; Address of variable. move.w (a0)+,(a0)+ ; Copy over word. tst.w (a0)+ ; Was the screen saver active? beq kbdend ; No, exit now. movem.l d0/a1,-(a7) ; Save these registers too. lea $FFFF8240.w,a1 ; Address of palette registers. move.l (a0)+,(a1)+ ; Restore palette. move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.l (a0)+,(a1)+ move.b (a0),(a1) ; Restore resolution. lea $FFFF8201.w,a1 ; Screen address vars in Shifter. move.l #ssave,a0 ; Address of variable. move.w (a0),d0 ; Get contents. movep.w d0,0(a1) ; Copy over address. clr.w flag ; Clear this flag. movem.l (a7)+,d0/a1 ; Restore these registers. kbdend move.l (a7)+,a0 ; Restore register. jmp2 jmp $11111111 ; Jump to old KBD. * The installation routine. Displays install message, hooks into * KBD/MIDI and VBL, and exits with ptermres. install pea initmsg ; Address of text. move.w #9,-(a7) ; cconws trap #1 ; GEMDOS(9) addq.l #6,a7 ; Adjust stack. move.w #4,-(a7) ; getrez trap #14 ; XBIOS(4) addq.l #2,a7 ; Adjust stack. cmp.b #2,d0 ; High resolution? bne color ; No, install and exit. pea errmsg ; Address of text. move.w #9,-(a7) ; cconws trap #1 ; GEMDOS(9) addq.l #6,a7 ; Adjust stack. clr.w -(a7) ; pterm0 trap #1 ; GEMDOS(0) - No return. color pea init ; Address of init routine. move.w #38,-(a7) ; supexec trap #14 ; XBIOS(38) addq.l #6,-(a7) ; Adjust stack. bsr sinit ; Init Screen Saver. pea okmsg ; Address of text. move.w #9,-(a7) ; cconws trap #1 ; GEMDOS(9) addq.l #6,a7 ; Adjust stack. move.l #34080,-(a7) ; Save 33K for program & screen. move.w #49,-(a7) ; ptermres trap #1 ; GEMDOS(49) - No return. * This actually hooks the interrupts. init movem.l d0/a0,-(a7) ; Save this register. move.w sr,-(a7) ; Save status register. move.w #$2700,sr ; No interruptions. move.l #jmp2+2,a0 ; Address of jump instruction. move.l $118.w,(a0) ; Copy over old keyboard vector. move.l #kbd,a0 ; Address of KBD routine. move.l a0,$118.w ; Store it. move.l #jmp1+2,a0 ; Address of jump instruction. move.l $70.w,(a0) ; Copy over old VBL vector. move.l #vbl,a0 ; Address of VBL routine. move.l a0,$70.w ; Store it. move.l #svscrn,d0 ; Address of screen area. add.l #255,d0 ; Round up if necessary. lsr.l #8,d0 ; Shift that address down. move.w d0,screen ; Save screen address. move.w (a7)+,sr ; Restore status register. movem.l (a7)+,d0/a0 ; Restore this register. rts ; Return. * Init custom to FAZE. Different screen savers will require * different init code here. sinit clr.l d0 ; Make sure all of this is clear. move.w screen,d0 ; Get screen address. lsl.l #8,d0 ; Shift it to get real address. move.l d0,a0 ; Copy to address register. move.w #7679,d1 ; Number of words. move.l #-1,d2 ; Word to move. siloop move.l d2,(a0)+ ; Store word. dbra d1,siloop ; Next long. rts ; All done. * The actual saver routine; it makes the screen saver what it is. * This routine, the one above it, and the amount of memory to * save on line 182 are all you need to change to make a different * screen saver. * -F-A-Z-E- Screen Save Routine * by Damien M. Jones * Copyright 1992 Damien M. Jones, All Rights Reserved. * Basically, this program picks a random point from 0,0 to 31,31. * It then checks the adjacent four points. If any of these are * in the next lower color, nothing is done. Otherwise, if two * of the connecting points are of the next higher color, then * the point is plotted in that next higher color. Otherwise it * has a 20% chance of being plotted in that next higher color. * Colors wrap, so 1 is the next higher color after 15. * Only one point is tested per VBL. This routine takes about * 11% of processor time. saver movem.l d0-d7/a0-a2,-(a7) ; Save registers. bsr rnd ; Randomize. clr.l d0 ; Make sure all of this is clear. move.w screen,d0 ; Get screen address. lsl.l #8,d0 ; Shift it to get real address. move.l d0,a0 ; Copy to address register. Faze bsr rnd ; Get a random number. move.w d0,d3 ; Save it... and.w #$1F,d3 ; 0-31, please. bsr rnd ; Another random number. move.w d0,d4 ; Save it... and.w #$1F,d4 ; 0-31, please. move.w d4,-(a7) ; Y coordinate. move.w d3,-(a7) ; X coordinate. bsr A_ptst ; Determine color of point. addq.l #4,a7 ; Adjust stack. move.w d0,d5 ; Copy over the color. clr.w d6 ; Points in lower color (0) clr.w d7 ; Points in higher color (0) move.w d3,-(a7) ; Save this. subq.w #1,d3 ; Check point to the left. tst.w d3 ; Less than zero? bpl FSkip1 ; No. beq FSkip1 ; No. add.w #32,d3 ; Wrap. FSkip1 bsr FPoint ; Check the point. move.w (a7)+,d3 ; Restore value. move.w d4,-(a7) ; Save this. subq.w #1,d4 ; Check point above. tst.w d4 ; Less than zero? bpl FSkip2 ; No. beq FSkip2 ; No. add.w #32,d4 ; Wrap. FSkip2 bsr FPoint ; Check the point. move.w (a7)+,d4 ; Restore value. move.w d3,-(a7) ; Save this. addq.w #1,d3 ; Check point to the right. bsr FPoint ; Check the point. move.w (a7)+,d3 ; Restore value. move.w d4,-(a7) ; Save this. addq.w #1,d4 ; Check point below. bsr FPoint ; Check the point. move.w (a7)+,d4 ; Restore value. tst.w d6 ; Any lower color points here? beq FSkip5 ; Nope, so far, so good. bra send ; Else return now. FSkip5 cmp.w #1,d7 ; 2 or more higher points? bgt FPlot ; Yes, plot away! bsr rnd ; Get a random number. and.w #$FF,d0 ; Just the low byte. cmp.w #204,d0 ; In the top 80%? bgt FPlot ; Yes, okay to plot the point. bra send ; Else return now. FPlot move.w d3,d6 ; Copy the X coordinate. addq.w #1,d5 ; Next color up. cmp.w #16,d5 ; Is it color 16? bne FPLoop ; Nope. moveq.w #1,d5 ; Reset this to 1. FPLoop move.w d5,-(a7) ; Point color. move.w d4,-(a7) ; Y Coordinate. move.w d3,-(a7) ; X Coordinate. bsr A_plot ; Plot the point. addq.l #6,a7 ; Adjust stack. add.w #32,d3 ; Next column. cmp.w #320,d3 ; Off the right edge? blt FPLoop ; No, do next point. move.w d6,d3 ; Move back to left edge. add.w #32,d4 ; Next line. cmp.w #192,d4 ; Off the bottom? blt FPLoop ; No, do the next point. send movem.l (a7)+,d0-d7/a0-a2 ; Restore registers. rts ; We're done now! * Test the color of a neighbor point, tally up. FPoint move.w d4,-(a7) ; Y coordinate. move.w d3,-(a7) ; X coordinate. bsr A_ptst ; Determine color of point. addq.l #4,a7 ; Adjust stack. sub.w d5,d0 ; Subtract out the original color. cmp.w #14,d0 ; The edge. bne FSkip3 ; Not here. move.w #-1,d0 FSkip3 cmp.w #-14,d0 ; The other edge. bne FSkip4 ; Not here. move.w #1,d0 FSkip4 tst.w d0 ; Show me a sign! bpl FHigh ; Next higher color. bmi FLow ; Next lower color. rts ; Same color. FHigh addq.w #1,d7 ; One more high point. rts FLow addq.w #1,d6 ; One more low point. rts * Assembler Line-A Replacement Plotter (low res _only_!) * a0 contains address of screen. ~C:A_plot(X&,Y&,C&) A_plot move.l a7,a1 ; Copy over stack pointer. lea vtable(pc),a2 ; Address of vertical table. clr.l d1 move.w 4(a1),d0 ; X coordinate. move.w 6(a1),d1 ; Y coordinate. move.w 8(a1),d2 ; Color. lsl.w #1,d1 ; Double Y-coord for lookup. move.l a0,a1 ; Copy over the address. move.w 0(a2,d1.w),d1 ; Move in the Y-offset. add.l d1,a1 ; Add in the vertical offset. move.w d0,d1 ; Copy the X-coord. lsr.w #4,d1 ; Shift down. lsl.w #3,d1 ; Shift up. add.l d1,a1 ; Add in the horizontal offset. and.w #$F,d0 ; Take just the low nibble. eor.w #$F,d0 ; Invert it. btst #3,d0 ; In the higher byte? bne flowb ; Yes. addq.l #1,a1 ; Increment address. flowb btst #0,d2 ; Check out the bit. beq aclr1 ; It's clear, clear the bit. bset d0,(a1) ; Set the bit. bra askip1 ; Next plane. aclr1 bclr d0,(a1) ; Clear the bit. askip1 addq.l #2,a1 ; Increment address. btst #1,d2 ; Check out the bit. beq aclr2 ; It's clear, clear the bit. bset d0,(a1) ; Set the bit. bra askip2 ; Next plane. aclr2 bclr d0,(a1) ; Clear the bit. askip2 addq.l #2,a1 ; Increment address. btst #2,d2 ; Check out the bit. beq aclr3 ; It's clear, clear the bit. bset d0,(a1) ; Set the bit. bra askip3 ; Next plane. aclr3 bclr d0,(a1) ; Clear the bit. askip3 addq.l #2,a1 ; Increment address. btst #3,d2 ; Check out the bit. beq aclr4 ; It's clear, clear the bit. bset d0,(a1) ; Set the bit. bra askip4 ; Next plane. aclr4 bclr d0,(a1) ; Clear the bit. askip4 rts ; All done, return. * Assembler Line-A Replacement Point Tester (low res _only_!) * a0 contains address of screen. ~C:A_ptst(X&,Y&) A_ptst move.l a7,a1 ; Copy over stack pointer. lea vtable(pc),a2 ; Address of vertical table. clr.l d0 ; Make sure all of this is clear. clr.l d1 ; Make sure all of this is clear. clr.w d2 ; This is the return color. move.w 4(a1),d0 ; X coordinate. move.w 6(a1),d1 ; Y coordinate. lsl.w #1,d1 ; Double Y-coord for lookup. move.l a0,a1 ; Copy over the address. move.w 0(a2,d1.w),d1 ; Move in the Y-offset. add.l d1,a1 ; Add in the vertical offset. move.w d0,d1 ; Copy the X-coord. lsr.w #4,d1 ; Shift down. lsl.w #3,d1 ; Shift up. add.l d1,a1 ; Add in the horizontal offset. and.w #$F,d0 ; Take just the low nibble. eor.w #$F,d0 ; Invert it. btst #3,d0 ; In the higher byte? bne flowb2 ; Yes. addq.l #1,a1 ; Increment address. flowb2 btst d0,(a1) ; Check out the bit. beq bclr1 ; It's clear, clear the bit. bset #0,d2 ; Set the bit. bra bskip1 ; Next plane. bclr1 bclr #0,d2 ; Clear the bit. bskip1 addq.l #2,a1 ; Increment address. btst d0,(a1) ; Check out the bit. beq bclr2 ; It's clear, clear the bit. bset #1,d2 ; Set the bit. bra bskip2 ; Next plane. bclr2 bclr #1,d2 ; Clear the bit. bskip2 addq.l #2,a1 ; Increment address. btst d0,(a1) ; Check out the bit. beq bclr3 ; It's clear, clear the bit. bset #2,d2 ; Set the bit. bra bskip3 ; Next plane. bclr3 bclr #2,d2 ; Clear the bit. bskip3 addq.l #2,a1 ; Increment address. btst d0,(a1) ; Check out the bit. beq bclr4 ; It's clear, clear the bit. bset #3,d2 ; Set the bit. bra bskip4 ; Next plane. bclr4 bclr #3,d2 ; Clear the bit. bskip4 move.w d2,d0 ; Return value. rts ; All done. * The random number generator. rnd move.l rndseed,d1 ; Get random number seed. move.l d1,d0 ; Make a copy. lsl.l #4,d0 ; Shift this over. lsr.l #3,d1 ; Shift this the other way. eor.l d1,d0 ; XOR them together. move.l $4BC.w,d1 ; Get system timer. eor.l d1,d0 ; XOR the system timer. move.l d0,rndseed ; Save it for next time. lsr #8,d0 ; Shift this down, please. rts ; Done. * Other variables. initmsg dc.b $1B,'p -F-A-Z-E- ',$1B,'q',$D,$A dc.b ' v1.0 by dmj',$D,$A,$D,$A,0 errmsg dc.b 7,'Not usable in high rez!',$D,$A,$D,$A,0 okmsg dc.b '** Installed **',$D,$A,$D,$A,0 even * The Vertical Offset Table - faster than muls. vtable dc.b $00,$00,$00,$A0,$01,'@',$01,$E0,$02,$80,$03,' ',$03,$C0,$04,'`' dc.b $05,$00,$05,$A0,$06,'@',$06,$E0,$07,$80,$08,' ',$08,$C0,$09,'`' dc.b $0A,$00,$0A,$A0,$0B,'@',$0B,$E0,$0C,$80,$0D,' ',$0D,$C0,$0E,'`' dc.b $0F,$00,$0F,$A0,$10,'@',$10,$E0,$11,$80,$12,' ',$12,$C0,$13,'`' dc.b $14,$00,$14,$A0,$15,'@',$15,$E0,$16,$80,$17,' ',$17,$C0,$18,'`' dc.b $19,$00,$19,$A0,$1A,'@',$1A,$E0,$1B,$80,$1C,' ',$1C,$C0,$1D,'`' dc.b $1E,$00,$1E,$A0,$1F,'@',$1F,$E0,' ',$80,'! !',$C0,'"`#',$00,'#' dc.b $A0,'$@$',$E0,'%',$80,'& &',$C0,$27,'`(',$00,'(',$A0,')@)',$E0,'*' dc.b $80,'+ +',$C0,',`-',$00,'-',$A0,'.@.',$E0,'/',$80,'0 0',$C0,'1`' dc.b '2',$00,'2',$A0,'3@3',$E0,'4',$80,'5 5',$C0,'6`7',$00,'7',$A0 dc.b '8@8',$E0,'9',$80,': :',$C0,';`<',$00,'<',$A0,'=@=',$E0,'>',$80 dc.b '? ?',$C0,'@`A',$00,'A',$A0,'B@B',$E0,'C',$80,'D D',$C0,'E`F' dc.b $00,'F',$A0,'G@G',$E0,'H',$80,'I I',$C0,'J`K',$00,'K',$A0,'L@L' dc.b $E0,'M',$80,'N N',$C0,'O`P',$00,'P',$A0,'Q@Q',$E0,'R',$80,'S S' dc.b $C0,'T`U',$00,'U',$A0,'V@V',$E0,'W',$80,'X X',$C0,'Y`Z',$00,'Z' dc.b $A0,'[@[',$E0,'\',$80,'] ]',$C0,'^`_',$00,'_',$A0,'`@`',$E0,'a' dc.b $80,'b b',$C0,'c`d',$00,'d',$A0,'e@e',$E0,'f',$80,'g g',$C0,'h`' dc.b 'i',$00,'i',$A0,'j@j',$E0,'k',$80,'l l',$C0,'m`n',$00,'n',$A0 dc.b 'o@o',$E0,'p',$80,'q q',$C0,'r`s',$00,'s',$A0,'t@t',$E0,'u',$80 dc.b 'v v',$C0,'w`x',$00,'x',$A0,'y@y',$E0,'z',$80,'{ {',$C0,'|`' svscrn * Well, you made it to the end. I realize this probably isn't the * most efficient assembly code around, but I don't normally write * self-contained assembly programs. The only reason I started was * to write TSRs. If you have any suggestions for improving the * code, I'd be glad to hear it. * * Damien M. Jones * PSC 8 Box 657 * APO AE 09109 * * Be sure to check out BoinkSave, available on GEnie; you can * probably find it on the other networks as well. * * -dmj