*********************************************************** * © 1992, Dancing Fool of Epsilon * * Using AsmOne, to make into executable: * 1. Make sure that BOOT_BLOCK is EQU'ed to 0. * 2. >a * 3. >wo miniplasma * * Using AsmOne, to put on boot block: * 1. Make sure that BOOT_BLOCK is EQU'ed to 1. * 2. >a * 3. >ws * 4. RAM_PTR> Start * 5. DISK_PTR> 0 * 6. LENGTH> 2 * 7. >cc * *********************************************************** * Why did I write this? * * Well, after spending several months trying to figure rgb plasma out (and * finally getting it!), I got some source to an old Masters demo that had * some zero bit plane plasma in it that looked a lot like this, only not * as good, so I decided to make a boot block out of it. After that, I * decided to put the source out for the world to see, learn from, and laugh * at. * * How does it work? * * This code is pretty much the same a any other plasma that uses bit planes. * Zero bit plane plasma is a little bit different (and a lot faster), but looks * crappy, so who cares? :^) Anyway, I set up four bit planes of the same bit * map just a different offsets and scroll values. Bit plane one is +4 into * the bit map and has a scroll of 4, bit plane two is +6 and scroll of $c, * bit plane 3 is +6 and scroll $c, and bit plane three is +8 and scroll of 4. * Each frame you bit in a sine wave on the bit map "stripes". Looking * at this data shows that on any given scan line you will end up with the * following bit patterns: * * bpl1 $00ff00ffff00ff0000ff00ffff00ff0000ff00ffff00ff0000ff00ffff00ff00 * bpl2 $ 00ffff00ff0000ff00ffff00ff0000ff00ffff00ff0000ff00ffff00ff0000ff * bpl3 $00ffff00ff0000ff00ffff00ff0000ff00ffff00ff0000ff00ffff00ff0000ff * bpl4 $ ff00ff0000ff00ffff00ff0000ff00ffff00ff0000ff00ffff00ff0000ff00ff * * Across the scan line the color pattern is: * * color 13 6 11 5 2 9 4 10 13 6 11 5 2 9 4 10 13 6 11 5 2 9 4 10 ... * * So, even with four bitplanes only eight colors ever occour. With this * in mind, and knowing the maximum number of copper cycles per scan line, * we know that these colors will repeat six times per raster. * * In standard plasma, which this is not, you would take the next value * from your sine table and use that as an offset into your color bar. Then, * you blit your color bar into the first "column" of your copper list, and * repeat for the other fourty-seven (a column is a color entry). To do rgb * plasma you would use all three blitter sources, one for each color component, * and or them all together to obtain the correct values for your copper list. * * This plasma is a little bit different. Instead of using a horizontal sine * wave on my copper bars, I use a vertical sine wave. This allows me to blit * an entire raster at a time. This is a little different approach from * normal plasma, but it also takes less static space, which allows it to * easily fit on a boot block. * * Do what ever you want with this source, just don't take credit for it! * Contact me at (on InterNet): * idr@rigel.cs.pdx.edu * Contact Epsilon at: * Epsilon * P.O.B. 1914 * Beaverton, OR 97075-1914 * U.S.A. *********************************************************** * Equates *********************************************************** BOOT_BLOCK EQU 0 ; 0 = normal executable, 1 = boot block CUSTOM EQU $dff000 ; custom chip base CIA_A EQU $bfe001 ; cia chip for left mouse button S_SPEED EQU (2<<1) ; speed to 'scroll' copper(must be a mult of 2) S_SIZE EQU 72 ; max scroll. if you change the color data, ; then you may need to change this too. ROWS EQU 180 ; number of plasma rasters (changeable) COLS EQU 6 ; number of columns. should be 6, but could ; be less. COLORS EQU 8 ; number of color combinations that occour. MOD EQU 2 ; size of 'move' instruction in copper list AMP EQU $20 ; amplitude of sine data. if you change the ; sine data, you should change this. MD2 EQU (4*((COLS*COLORS)+1)) ; size of one raster of ; clist data SIZE EQU ((64*COLS*COLORS)+1) ; blit size for copper list *********************************************************** * Macros *********************************************************** WaitBlit MACRO tst.b (a5) ; ignore first test for old Agnus .\@ btst #6,(a5) ; test blit done bit in high byte of ; DMACON bne.b .\@ ; loop if not done ENDM WaitVblank MACRO .\@ move.l 4-2(a5),d0 ; read full beam position andi.l #$0003ff00,d0 ; mask of hoizontal position cmpi.l #$00002c00,d0 ; top of screen? bne.b .\@ ; not yet. ENDM ********************************************************************* IFNE BOOT_BLOCK Start: dc.b "DOS",0 ; boot block id long work dc.l 0 ; checksum dc.l $370 ; root block ELSE section plasma_bb,code_c ENDIF TakeSystem: movem.l d1-d7/a1-a6,-(sp) IFEQ BOOT_BLOCK movea.l 4.w,a6 ; at boot this is already done! ENDIF move.l #(size_of_list),d0 move.l #($10003),d1 ; MEMF_CHIP | MEMF_PUBLIC | MEMF_CLEAR jsr -198(a6) ; AllocMem() tst.l d0 ; did we get the mem? beq.w err_exit ; nope. move.l d0,a6 ; ptr to mem. lea sine(pc),a0 ; sine table move.l a0,sineptr(a6) ; initial sine ptr move.l #CUSTOM+2,a5 ; Custom chip base + 2!!! move.w (a5),d0 ; Save DMACON ori.w #$8000,d0 ; OR in the SET bit for later move.l a6,a0 move.w d0,(a0) ; Keep it move.w #$83c0,$96-2(a5); Turn on only certain DMA channels move.w #$0020,$96-2(a5); kill sprite DMA InstallPlasmaCopper: lea Copper1(a6),a0 ; pointer to our copper list move.l a0,$80-2(a5) ; install it move.w #$00e0,d0 ; bpl1pth moveq #7,d1 ; loop counter .make_bplpt: move.w d0,(a0)+ ; write it to our copper list addq.w #2,a0 ; next in list addq.w #2,d0 ; next value dbra d1,.make_bplpt ; loop sub.w #30,a0 ; a0 points to mapptrs + 2 move.l a6,d0 ; data segment add.l #PBmap+4,d0 ; plasma map plus a bit move.w d0,4(a0) ; bpl1ptl swap d0 ; high word in low half of register move.w d0,(a0) ; bpl1pth swap d0 ; swap back addq.l #2,d0 ; in a bit more move.w d0,12(a0) ; bpl2ptl move.w d0,20(a0) ; bpl3ptl swap d0 ; high word in low word move.w d0,8(a0) ; bpl2pth move.w d0,16(a0) ; bpl3pth swap d0 ; swap back addq.l #2,d0 ; in some more move.w d0,28(a0) ; bpl4ptl swap d0 ; guess why I do this. :^) move.w d0,24(a0) ; bpl4pth lea plasma_copper1(a6),a0 ; raster data move.l #$2d1ffffe,d1 ; starting raster - 1 move.w #ROWS-1,d5 ; number of rasters m_plasma1: add.l #$01000000,d1 ; next raster move.l d1,(a0)+ ; write raster wait to clist moveq #COLS-1,d4 ; number of columns m_plasma2: move.w #$019a,(a0)+ ; write each color out to clist addq.w #2,a0 ; next entry move.w #$018c,(a0)+ addq.w #2,a0 move.w #$0196,(a0)+ addq.w #2,a0 move.w #$018a,(a0)+ addq.w #2,a0 move.w #$0184,(a0)+ addq.w #2,a0 move.w #$0192,(a0)+ addq.w #2,a0 move.w #$0188,(a0)+ addq.w #2,a0 move.w #$0194,(a0)+ addq.w #2,a0 dbra d4,m_plasma2 ; loop for columns dbra d5,m_plasma1 ; loop for rasters moveq #-2,d0 ; end of clist move.l d0,(a0) ; write it out moveq #0,d4 ; the following are not in the clist to save space move.w #$4200,$100-2(a5) ; bplcon0 (4 bit planes) move.w #$00c4,$102-2(a5) ; fine scroll moveq #$0008,d0 ; modulo value move.w d0,$0108-2(a5) ; write to clist move.w d0,$010a-2(a5) ; ... move.w #$2e78,$8e-2(a5) ; window start move.w #$e2c6,$90-2(a5) ; window stop move.w #$0028,$92-2(a5) ; data fetch start move.w #$00d8,$94-2(a5) ; data fetch stop Plasm2: WaitVblank lea PBmap(a6),a0 ; bit map move.l sineptr(a6),a4 ; pointer to sine table lea stripes(pc),a2 ; "stripe data" move.l a6,d2 ; data seg add.l #plasma_copper1+6,d2 ; raster data move.w #ROWS-1,d0 ; loop counter move.l #$09f00000,d3 ; bltcon0 & bltcon1 moveq #$f,d5 ; mask off upper bits moveq #64+26,d6 ; blit window map_top: tst.b (a4) ; is it -1 ($ff)? bpl.b .no_sine_reset ; nope lea sine(pc),a4 ; reset sine pointer .no_sine_reset: WaitBlit ; wait for it... move.l a0,a3 ; ptr to bit map ; you can replace this with a move.b (a4),d1 and see what happens moveq #AMP,d1 ; amplitude of sine wave sub.b (a4),d1 ; less sine value lsr.w #4,d1 ; divide by 16 (nearest word offset) add.w d1,d1 ; word offset add.w d1,a3 ; add to bit map pointer ; if you made above into a move.b (a4),d1 then do it here, too. moveq #AMP,d1 ; amplitude of sine wave sub.b (a4),d1 ; less sine value and.l d5,d1 ; mask off upper bits to make into ; shift value ror.l #4,d1 ; put shift value in high nibble or.l d3,d1 ; or into bplcon ; I'm only doing one line at a time, so the modulos ; are irrelevant. move.l d1,$40-2(a5) ; bltcon0 & bltcon1 move.l #-1,$44-2(a5) ; first word mask movem.l a2/a3,$50-2(a5) ; source move.w d6,$58-2(a5) ; blit window adda.w #54,a0 ; next raster in bit map lea color_list(pc),a1 ; Get start of color lists. move.b (a4)+,d1 ; sine value (again!) add.w d1,d1 ; word align. add.w d4,a1 ; gives copper a cool 'scrolly' effect ; try removing. add.w d1,a1 ; new position in color table (sine) moveq #MOD,d1 ; in the clist, this is how big the ; first part of the 'move' is. WaitBlit move.l d3,$40-2(a5) ; bltcon0 & bltcon1 move.l d1,$64-2(a5) ; dest mod. move.l a1,$50-2(a5) ; source A move.l d2,$54-2(a5) ; dest. move.w #SIZE,$58-2(a5) ; bltsize add.l #MD2,d2 ; Next color in copper list. dbra d0,map_top ; loop end_frame: lea sineptr(a6),a1 ; old sine ptr addq.l #1,(a1) ; next place in sine table move.l (a1),a1 ; new sine ptr tst.b (a1) ; is it -1? bpl.b .no_sine_reset ; no. lea sine(pc),a4 ; reset sine pointer move.l a4,sineptr(a6) ; reset sine prt .no_sine_reset: addq.w #(S_SPEED),d4 ; scroll speed cmpi.w #(S_SIZE),d4 ; past scroll limit? blt.b .no_scroll_reset moveq #0,d4 ; reset copper scrolly value .no_scroll_reset: btst.b #6,CIA_A ; is lmb down? bne.w Plasm2 ; not yet... move.l a6,a4 movea.l 4.w,a6 ; ExecBase lea GraphicsName(pc),a1 ; "graphics.library" jsr -$198(a6) ; OldOpenLibrary() move.l d0,a1 ; Copy ptr to GfxBase move.l $26(a1),$80-2(a5) ; Install old system copperlist jsr -$19e(a6) ; CloseLibrary() move.l a4,a1 move.w #$7fff,$96-2(a5) ; Kill all DMA! move.w (a1),$96-2(a5) ; Activate old DMA channels move.l #(size_of_list),d0 ; size of block jsr -$d2(a6) ; Free() err_exit: lea DosName(pc),a1 ; pointer to lib. name jsr -$60(a6) ; FindResident() tst.l d0 ; error? beq.b .error ; yes. move.l d0,a0 ; ptr to dos base move.l $16(a0),a0 ; pointer to dos lib moveq #0,d0 ; return no error .exit: movem.l (sp)+,d1-d7/a1-a6 rts ; Done .error: moveq #-1,d0 ; error code bra.b .exit *********************************************************** stripes:dc.l $00ff00ff,$ff00ff00,$00ff00ff,$ff00ff00,$00ff00ff,$ff00ff00 dc.l $00ff00ff,$ff00ff00,$00ff00ff,$ff00ff00,$00ff00ff,$ff00ff00 dc.l $00ff00ff color_list: dc.l $ff00ff0,$fe10fd2,$fc30fb4,$fa50f96,$f870f78,$f690f5a dc.l $f4b0f3c,$f2d0f1e,$f0f0f0f,$f0f0f0f,$f1e0f2d,$f3c0f4b dc.l $f5a0f69,$f780f87,$f960fa5,$fb40fc3,$fd20fe1,$ff00ff0 dc.l $ff00ff0,$fe10fd2,$fc30fb4,$fa50f96,$f870f78,$f690f5a dc.l $f4b0f3c,$f2d0f1e,$f0f0f0f,$f0f0f0f,$f1e0f2d,$f3c0f4b dc.l $f5a0f69,$f780f87,$f960fa5,$fb40fc3,$fd20fe1,$ff00ff0 dc.l $ff00ff0,$fe10fd2,$fc30fb4,$fa50f96,$f870f78,$f690f5a dc.l $f4b0f3c,$f2d0f1e,$f0f0f0f,$f0f0f0f,$f1e0f2d,$f3c0f4b dc.l $f5a0f69,$f780f87,$f960fa5,$fb40fc3,$fd20fe1,$ff00ff0 dc.l $ff00ff0,$fe10fd2,$fc30fb4,$fa50f96 ; Sine table MUST end with a $ff! sine: dc.l $10111213,$14161718,$191a1b1c,$1c1d1e1e,$1f1f1f1f,$1f1f1f1f dc.l $1f1e1e1d,$1d1c1b1a,$19181716,$15141311,$10100f0e,$0c0b0a09 dc.l $08070605,$04030302,$02010101,$01010101,$01010202,$03040405 dc.w $0607,$0809,$0a0b,$0d0e,$0fff GraphicsName: dc.b 'graphics.library',0 DosName: dc.b 'dos.library',0 message: dc.b "Not a virus! A plasma bb by the DF of Epsilon!" ********************************************************************* rsreset DMACONSave rs.w 1 ; save DMA bits here sineptr rs.l 1 PBmap rs.b 54*ROWS+100 ; plasma bit map Copper1 rs.b 0 ; start of copper list mapptrs rs.w 16 ; bmap pointer plasma_copper1 rs.b (4*(ROWS*(1+(COLS*COLORS)))) ; raster data pe_1 rs.w 2 ; end of clist size_of_list rs.b 0 ; duh! :^)