***** IFF - ILBM file save subroutine, M.Meany 1992. ; This very crude routine does not take advantage of the finer points of the ;IFF-ILBM format, but it will allow you to save a picture to disk! ; No error checking is done on the data you supply -- get it right;-) ; Entry a0->a completed structure as defined below ; dos.library open and base pointer in _DOSBase ; Exit d0=0 if file saved OK, structure will be cleared!!! ; d0 is non-zero if a file error occurred!!! ; If the ilbms_modes field of the structure is zero, routine will make a ;wild guess at suitable modes to use. Best way to get the modes you really ;want is to define them yourself. ; 452 bytes ( +44 bytes for required structure ) IffSave movem.l d1-d7/a0-a6,-(sp) save 'em bsr GuessIffModes get display modes move.l a0,a5 param into safe reg moveq.l #1,d7 set for error moveq.l #0,d5 move.w ilbms_Modulo(a5),d5 get bpl modulo ext.l d5 sign extend move.l d5,-(sp) onto stack ; Determine byte width of piccy from pixel width moveq.l #0,d5 clear move.w ilbms_Width(a5),d5 get pixel width move.w d5,_ILBMS_Width save in both move.w d5,_ILBMS_PWidth header location divu #8,d5 get byte width swap d5 check remainder to tst.w d5 see if we must bump beq.s .NoAdd nope, so skip! add.l #$10000,d5 bump ; If byte width is odd we must pad out line with an extra byte. Lines must be ;saved in word data multiples! .NoAdd move.l d5,d0 swap d0 btst #0,d0 odd beq.s .NoPad addq.w #1,d0 bump to even ; Calculate the space occupied by bpl data .NoPad move.l d0,-(sp) length onto stack swap d5 mulu ilbms_Depth(a5),d0 WxD mulu ilbms_Height(a5),d0 WxHxD move.l d0,_ILBMS_BSize set chunk length add.l #_ILBMS_SSIZE,d0 add header length subq.l #8,d0 less 2 longs move.l d0,_ILBMS_FSize and save ; Copy other data move.w ilbms_Modes(a5),_ILBMS_Modes+2 move.w ilbms_Height(a5),_ILBMS_Height move.w ilbms_Height(a5),_ILBMS_PHeight move.w ilbms_Depth(a5),d4 move.b d4,_ILBMS_Depth ; Copy colours - must be save as Red, Green and Blue components, one byte ;each! Since the Amiga supports less that 256 colour intensities, value ;must be shifted left ( never realised this at first:-( ) moveq.l #31,d0 always 32 colours move.l ilbms_Colours(a5),a0 a0->CMAP lea _ILBMS_Colours,a1 dest .Cloop move.w (a0)+,d2 Get next RGB move.w d2,d1 and.w #$0f00,d1 isolate RED asr.w #4,d1 into high nibble move.b d1,(a1)+ save RED move.w d2,d1 Get RGB and.w #$00f0,d1 isolate GREEN move.b d1,(a1)+ save GREEN move.w d2,d1 get RGB and.w #$000f,d1 isolate BLUE asl.b #4,d1 into high nibble move.b d1,(a1)+ save BLUE dbra d0,.Cloop for all 32 entries ; Open the file ; move.l ilbms_Fname(a5),d1 filename move.l (a5),d1 filename move.l #MODE_NEWFILE,d2 access mode required CALLDOS Open and open it move.l d0,d6 save handle beq .error exit on failure ; Write the data header move.l d0,d1 handle move.l #_ILBMS_Header,d2 buffer move.l #_ILBMS_SSIZE,d3 size jsr _LVOWrite(a6) and write it ; now write the bitplane data in interleave format moveq.l #0,d4 clear move.w ilbms_Height(a5),d4 get height subq.w #1,d4 dbra adjust lea ilbms_bpl1(a5),a4 a4->bpl pointers move.l #0,ilbms_Colours(a5) clear .OuterLoop move.l a4,a3 .InnerLoop move.l (a3),d0 get next pointer beq .Next skip if no more move.l d0,d2 Address of data add.l d5,d0 bump to next line add.l 4(sp),d1 add modulo move.l d0,(a3)+ and save move.l d6,d1 handle move.l (sp),d3 size jsr _LVOWrite(a6) save bra.s .InnerLoop and loop .Next dbra d4,.OuterLoop for all lines move.l d6,d1 handle jsr _LVOClose(a6) close it moveq.l #0,d7 .error move.l d7,d0 set return code addq.l #8,sp flush stack movem.l (sp)+,d1-d7/a0-a6 restore rts ; file header for IFF - ILBM file. ; first the FORM chunk _ILBMS_Header dc.b 'FORM' _ILBMS_FSize dc.l 0 file length-calculate dc.b 'ILBM' ; the BMHD chunk dc.b 'BMHD' dc.l 20 _ILBMS_Width dc.w 0 pixel width _ILBMS_Height dc.w 0 pixel height dc.w 0 dc.w 0 _ILBMS_Depth dc.b 0 depth dc.b 0 dc.b 0 dc.b 0 dc.w 0 dc.b 10 EA say so (320x200) dc.b 11 _ILBMS_PWidth dc.w 0 _ILBMS_PHeight dc.w 0 ; the CMAP chunk dc.b 'CMAP' dc.l 32*3 size - 32 colours _ILBMS_Colours ds.b 32*3 ; the CAMG chunk dc.b 'CAMG' dc.l 4 _ILBMS_Modes dc.l 0 ; the start of the BODY chunk, data will be added after! ; the BODY chunk dc.b 'BODY' _ILBMS_BSize dc.l 0 size of this chunk _ILBMS_SSIZE equ *-_ILBMS_Header size of header ; Structure used by IffSave. This must be prepared prior to calling. Fields ;marked with an * must be set, others may be initialised to zero. rsreset ilbms_Fname rs.l 1 * address of filename ilbms_bpl1 rs.l 1 * bitplane 1 address ilbms_bpl2 rs.l 1 bitplane 2 address ilbms_bpl3 rs.l 1 bitplane 3 address ilbms_bpl4 rs.l 1 bitplane 4 address ilbms_bpl5 rs.l 1 bitplane 5 address ilbms_bpl6 rs.l 1 bitplane 6 address ilbms_Colours rs.l 1 * address of CMAP ilbms_Width rs.w 1 * pixel width ilbms_Height rs.w 1 * line height ilbms_Depth rs.w 1 * depth ilbms_Modes rs.w 1 view modes or NULL ilbms_Modulo rs.w 1 bpl modulo value ***** Makes a guess at what screen modes to use for file being saved. ; This routine has been supplied seperately as it's prone to get the wrong ;idea. Set the ilbms_Modes field yourself if you can, use this as a last ;resort. ; Entry a0->Structure prior to passing to IffSave ; Exit ilbms_Modes will be set with something??? GuessIffModes tst.l ilbms_Modes(a0) mode set already? bne.s .done yes, exit now ; Check for six bitplanes, set for HAM mode if present. tst.l ilbms_bpl6(a0) plane 6 set? beq.s .NotHam no, skip HAM move.w #$0800,ilbms_Modes(a0) else set HAM mode bra.s .done and exit ; If width > 320, set HiRes .NotHam cmpi.w #320,ilbms_Width(a0) check width ble.s .TryLace not HiRes, skip move.w #$8000,ilbms_Modes(a0) else set HiRes ; if height > 256, set LACE .TryLace cmpi.w #256,ilbms_Height(a0) check height ble.s .done not interlace, skip or.w #$0004,ilbms_Modes(a0) else set interlace .done rts