;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=; ;=; GIFscale ;=; ;=;===================================================================;=; ;=; A very fast GIF viewer that supports greyscaled viewing ;=; ;=; of GIF images, including larger-than-screen scrolling and Degas ;=; ;=; PI1 screen saves. ;=; ;=;===================================================================;=; ;=; Written in November 1990 by Robert Barnhardt & Robert Steger. ;=; ;=; (C) 1990 Brain~Waves Freeware Group ;=; ;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=;=; text GS_ResizeMemory move.l 4(sp),a2 move.l $c(a2),d0 add.l $14(a2),d0 add.l $1c(a2),d0 add.l #$100,d0 move.l d0,-(sp) move.l a2,-(sp) clr.w -(sp) move.w #$4a,-(sp) trap #1 lea $c(sp),sp GS_ReadTTP move.b #'\',BFS_Pathfudge lea $80(a2),a2 lea BFS_Pathspec,a1 move.b (a2)+,d0 GS_RT_Loop move.b (a2)+,(a1)+ dbra d0,GS_RT_Loop GS_SaveRez move.w #$4,-(sp) trap #14 addq.l #2,sp move.w d0,ST_SaveRez cmpi.b #2,d0 bne.s GS_SavePalette clr.w -(sp) trap #1 GS_SavePalette move.w #15,d7 lea ST_SavePalette+32,a6 GS_SP_1 move.w #-1,-(sp) move.w d7,-(sp) move.w #$7,-(sp) trap #14 addq.l #6,sp move.w d0,-(a6) dbra d7,GS_SP_1 GS_SaveDTA move.w #$2f,-(sp) trap #1 addq.l #2,sp move.l d0,ST_DTASave GS_NewRez clr.w -(sp) pea -1 pea -1 move.w #$5,-(sp) trap #14 lea $c(sp),sp GS_NewPalette pea ST_PureGrey move.w #$6,-(sp) trap #14 addq.l #6,sp GS_NewDTA pea ST_DTA move.w #$1a,-(sp) trap #1 addq.l #6,sp GS_FindScreen move.w #$3,-(sp) trap #14 addq.l #2,sp move.l d0,ST_Screen GS_ShowTitleCheck move.b BFS_Pathspec,d0 sub.b #65,d0 cmpi.b #':',BFS_Pathspec+1 beq.s GS_STC_1 move.w #$19,-(sp) trap #1 addq.l #2,sp GS_STC_1 cmpi.b #1,d0 bgt.s GS_FindFirstFile pea ST_TitleScreen move.w #$9,-(sp) trap #1 addq.l #6,sp move.b #1,ST_TitleFlag GS_FindFirstFile clr.w -(sp) pea BFS_Pathspec move.w #$4e,-(sp) trap #1 lea 8(sp),sp tst.w d0 bmi GS_AllDone lea BFS_Filenames,a6 move.l a6,BFS_FileIndex GS_StoreName lea ST_DTA+30,a5 GS_SN_1 move.b (a5)+,(a6)+ bne.s GS_SN_1 addq.w #1,BFS_FileCount GS_FindNextName move.w #$4f,-(sp) trap #1 addq.l #2,sp tst.w d0 bpl.s GS_StoreName GS_FindPathEnd lea BFS_Pathspec+128,a0 GS_FPE_1 cmpi.b #'\',-(a0) bne.s GS_FPE_1 addq.l #1,a0 move.l a0,BFS_FnamePtr GS_RestoreDTA move.l ST_DTASave,-(sp) move.w #$1a,-(sp) trap #1 addq.l #6,sp GS_OpenNextFile move.l BFS_FileIndex,a0 move.l BFS_FnamePtr,a1 GS_ONF_1 move.b (a0)+,(a1)+ bne.s GS_ONF_1 move.l a0,BFS_FileIndex clr.w -(sp) pea BFS_Pathspec move.w #$3d,-(sp) trap #1 lea 8(sp),sp move.w d0,BFS_FileDescriptor GS_MakeSaveName move.l BFS_FnamePtr,a0 move.w #5,d0 GS_MSN_SS_1 tst.b (a0) beq.s GS_MSN_Overlay cmpi.b #'.',(a0) beq.s GS_MSN_Overlay addq.l #1,a0 dbra d0,GS_MSN_SS_1 GS_MSN_Overlay lea ST_SaveOverlay,a1 GS_MSN_O_1 move.b (a1)+,(a0)+ bne.s GS_MSN_O_1 subq.l #6,a0 move.l a0,ST_SaveNumAddr GS_ReadSDescriptor pea GIF_ScreenDescriptor move.l #13,-(sp) move.w BFS_FileDescriptor,-(sp) move.w #$3f,-(sp) trap #1 lea $c(sp),sp tst.l d0 ble GS_DoneGIF GS_ReadGPalette move.b GIF_ScreenBits,d0 and.b #7,d0 addq.b #1,d0 moveq #1,d1 lsl.w d0,d1 move.w d1,GIF_ColourCount mulu #3,d1 ext.l d1 pea GIF_GlobalPalette move.l d1,-(sp) move.w BFS_FileDescriptor,-(sp) move.w #$3f,-(sp) trap #1 lea $c(sp),sp tst.l d0 ble GS_DoneGIF GS_GreyMap lea GIF_GlobalPalette,a0 lea ST_GlobalMap,a1 move.w GIF_ColourCount,d2 subq.l #1,d2 GS_GM_Loop clr.w d0 clr.l d1 move.b (a0)+,d0 mulu #30,d0 move.w d0,d1 clr.w d0 move.b (a0)+,d0 mulu #59,d0 add.w d0,d1 clr.w d0 move.b (a0)+,d0 mulu #11,d0 add.w d0,d1 divu #1600,d1 move.b d1,(a1)+ dbra d2,GS_GM_Loop GS_ReadIDescriptor pea GIF_ImageDescriptor move.l #11,-(sp) move.w BFS_FileDescriptor,-(sp) move.w #$3f,-(sp) trap #1 lea $c(sp),sp tst.l d0 ble GS_DoneGIF GS_RI_FixHW move.b GIF_ImageHeight+1,d0 lsl.w #8,d0 move.b GIF_ImageHeight,d0 move.w d0,ST_ImageHeight move.b GIF_ImageWidth+1,d0 lsl.w #8,d0 move.b GIF_ImageWidth,d0 move.w d0,ST_ImageWidth move.l d0,d5 swap d5 GS_AllocateMemory lsl.w #4,d0 tst.b d0 beq.s GS_AM_Even clr.b d0 add.w #$100,d0 GS_AM_Even lsr.w #5,d0 move.w d0,d4 clr.l d1 move.w ST_ImageHeight,d1 mulu d0,d1 move.l d1,-(sp) move.w #$48,-(sp) trap #1 addq.l #6,sp tst.l d0 beq GS_DoneGIF move.l d0,ST_ScreenBuffer move.l d0,a4 GS_AllocateBuffer move.l #-$1,-(sp) move.w #$48,-(sp) trap #1 addq.l #6,sp move.l d0,BFS_FileBufferSize move.l d0,-(sp) move.w #$48,-(sp) trap #1 addq.l #6,sp tst.l d0 beq GS_DoneGIF move.l d0,BFS_FileBuffer GS_InterlaceSetup move.w ST_ImageHeight,ST_HeightCount move.w d4,ST_WordWidth btst #6,GIF_ImageBits beq.s GS_LZWSetup move.w d4,d0 clr.w GIF_InterlaceStart move.w d0,GIF_InterlaceStart+6 move.w d0,GIF_InterlaceSkip+6 add.w d0,d0 move.w d0,GIF_InterlaceStart+4 add.w d4,d0 move.w d0,GIF_InterlaceSkip+4 add.w d4,d0 move.w d0,GIF_InterlaceStart+2 add.w d0,d0 sub.w d4,d0 move.w d0,GIF_InterlaceSkip+2 move.w d0,GIF_InterlaceSkip move.l #GIF_InterlaceStart,GIF_IlacePointer GS_LZWSetup sub.l a6,a6 sub.l a5,a5 move.b #16,ST_BitCount move.b LZW_CodeSize,d0 moveq #1,d1 addq.b #1,d0 lsl.w d0,d1 move.w d1,LZW_ClearCode addq.l #2,d1 move.w d1,LZW_EOICode addq.l #2,d1 move.w d1,LZW_FirstCode subq.w #6,d1 lea LZW_Prefices,a0 lea LZW_Suffices,a1 lea LZW_Transform,a2 lea ST_GlobalMap,a3 GS_LS_Loop move.w #-1,(a0,d1.w) move.w d1,(a1,d1.w) subq.w #2,d1 bge.s GS_LS_Loop bsr BFS_ByteRead clr.w d6 move.b d0,d6 clr.l d4 GS_LzwLoop swap d7 move.b LZW_CodeSize,d7 addq.l #1,d7 move.l #$fff00000,d0 rol.l d7,d0 lsl.l #1,d0 swap d6 move.w d0,d6 swap d6 swap d7 move.w LZW_FirstCode,d7 bsr UBR_GetCode clr.l d3 move.w d0,d3 cmp.w LZW_ClearCode,d3 beq.s GS_LzwLoop move.w d3,(a2) swap d3 swap d5 clr.w d1 clr.w d2 subq.l #2,d7 bra GS_Output GS_GIFLoop bsr UBR_GetCode move.w d0,d3 cmp.w LZW_ClearCode,d3 beq.s GS_LZWLoop cmp.w LZW_EOICode,d3 beq GS_DisplayGIF swap d5 cmp.w d7,d3 beq.s GS_Weird GS_Normal move.w d3,d0 bsr GS_TranslateCode move.w #2,d1 swap d3 move.w d3,(a0,d7.w) move.w (a2,d2.w),(a1,d7.w) bra.s GS_Output GS_Weird swap d3 move.w d3,d0 bsr GS_TranslateCode move.w d3,(a0,d7.w) move.w (a2,d2.w),(a1,d7.w) move.w (a2,d2.w),(a2) clr.w d1 GS_Output move.w (a2,d2.w),d0 lsr.w #1,d0 move.b (a3,d0.w),d0 lsr.b #1,d0 roxl (a4) lsr.b #1,d0 roxl 2(a4) lsr.b #1,d0 roxl 4(a4) lsr.b #1,d0 roxl 6(a4) subq.b #1,ST_BitCount bne.s GS_CheckWidth lea 8(a4),a4 move.b #16,ST_BitCount GS_CheckWidth subq.w #1,d5 bne GS_WithinWord move.w ST_ImageWidth,d5 move.b ST_BitCount,d0 and.b #15,d0 tst.b d0 beq.s GS_CheckInterlace xor.b #15,d0 GS_CW_Loop lsl (a4) lsl 2(a4) lsl 4(a4) lsl 6(a4) dbra d0,GS_CW_Loop lea 8(a4),a4 move.b #16,ST_BitCount GS_CheckInterlace btst #6,GIF_ImageBits beq.s GS_WithinWord move.l a7,ST_USPSave move.l GIF_IlacePointer,a7 clr.l d0 move.w 8(a7),d0 add.l d0,a4 move.w 24(a7),d0 sub.w d0,ST_HeightCount bgt.s GS_ResetUSP move.l ST_ScreenBuffer,a4 move.w 2(a7),d0 add.w d0,a4 move.w 18(a7),d0 neg.w d0 add.w ST_ImageHeight,d0 move.w d0,ST_HeightCount addq.l #2,GIF_IlacePointer GS_ResetUSP move.l ST_USPSave,a7 GS_WithinWord subq.w #2,d2 cmp.w d1,d2 bge GS_Output addq.w #2,d7 swap d5 bra GS_GIFLoop GS_TranslateCode move.w #2,d2 move.w (a1,d0.w),(a2,d2.w) GS_TC_Loop cmp.w LZW_FirstCode,d0 blt.s GS_TC_Done move.w (a0,d0.w),d0 addq.w #2,d2 move.w (a1,d0.w),(a2,d2.w) bra.s GS_TC_Loop GS_TC_Done rts ;========================================================================; ;== GIFview3 Display Routines: Splat and ScrollCheck ==; ;========================================================================; GS_DisplayGIF move.w #-1,-(sp) move.w #$b,-(sp) trap #13 addq.l #4,sp btst #3,d0 bne.s GS_DisplayGIF GS_ClearScreen move.l ST_Screen,a0 move.w #3999,d0 GS_ClearLoop clr.l (a0)+ clr.l (a0)+ dbra d0,GS_ClearLoop GS_MovePicture move.w #200,d2 cmp.w ST_ImageHeight,d2 ble.s GS_MP_HeightOK move.w ST_ImageHeight,d2 GS_MP_HeightOK move.w #160,d3 cmp.w ST_WordWidth,d3 ble.s GS_MP_WidthOK move.w ST_WordWidth,d3 GS_MP_WidthOK lsr.w #3,d3 subq.w #1,d3 subq.w #1,d2 clr.w d6 clr.l d7 GS_SplatPicture move.l ST_ScreenBuffer,a0 move.l ST_Screen,a1 clr.b ST_TitleFlag clr.l d0 move.w ST_WordWidth,d0 mulu d7,d0 add.l d0,a0 move.w d2,d0 GS_SP_HLoop move.w d3,d1 clr.w d4 move.w d6,d5 GS_SP_WLoop move.l (a0,d5.w),(a1,d4.w) move.l 4(a0,d5.w),4(a1,d4.w) add.w #8,d4 add.w #8,d5 dbra d1,GS_SP_WLoop add.w ST_WordWidth,a0 add.w #160,a1 dbra d0,GS_SP_HLoop GS_KeyCheck move.w #$2,-(sp) move.w #$2,-(sp) trap #13 addq.l #4,sp GS_CheckPalette cmpi.b #$30,d0 blt.s GS_CheckSave cmpi.b #$36,d0 bgt.s GS_CheckSave and.l #$f,d0 lsl.w #5,d0 add.l #ST_Palettes,d0 move.l d0,ST_PalettePointer move.l d0,-(sp) move.w #$6,-(sp) trap #14 addq.l #6,sp bra GS_KeyCheck GS_CheckSave cmpi.b #115,d0 bne.s GS_CheckExit movem.l d0-d7/a0-a6,-(sp) move.l ST_SaveNumAddr,a0 addq.b #1,(a0) clr.w -(sp) pea BFS_Pathspec move.w #$3c,-(sp) trap #1 lea 8(sp),sp move.w d0,d7 pea ST_DegasRez move.l #2,-(sp) move.w d7,-(sp) move.w #$40,-(sp) trap #1 lea $c(sp),sp move.l ST_PalettePointer,-(sp) move.l #32,-(sp) move.w d7,-(sp) move.w #$40,-(sp) trap #1 lea $c(sp),sp move.l ST_Screen,-(sp) move.l #32000,-(sp) move.w d7,-(sp) move.w #$40,-(sp) trap #1 lea $c(sp),sp move.w d7,-(sp) move.w #$3e,-(sp) trap #1 addq.l #4,sp movem.l (sp)+,d0-d7/a0-a6 bra GS_KeyCheck GS_CheckExit swap d0 cmpi.b #28,d0 beq GS_DoneGIF cmpi.b #57,d0 beq GS_DoneGIF cmpi.b #114,d0 beq GS_DoneGIF cmpi.b #97,d0 bne.s GS_CheckRight move.w #1,BFS_FileCount bra GS_DoneGIF GS_CheckRight cmpi.b #77,d0 bne.s GS_CheckLeft move.w d6,d0 add.w #160,d0 cmp.w ST_WordWidth,d0 bge GS_KeyCheck add.w #8,d6 bra GS_SplatPicture GS_CheckLeft cmpi.b #75,d0 bne.s GS_CheckDown tst.w d6 beq GS_KeyCheck sub.w #8,d6 bra GS_SplatPicture GS_CheckDown cmpi.b #80,d0 bne.s GS_CheckUp move.w d7,d0 add.w #200,d0 sub.w ST_ImageHeight,d0 bge GS_KeyCheck neg.w d0 cmpi.w #16,d0 bge.s GS_CD_1 add.w d0,d7 bra GS_SplatPicture GS_CD_1 add.w #16,d7 bra GS_SplatPicture GS_CheckUp cmpi.b #72,d0 bne GS_KeyCheck tst.w d7 beq GS_KeyCheck sub.w #16,d7 bge.s GS_CU_1 clr.w d7 GS_CU_1 bra GS_SplatPicture GS_DoneGIF move.l ST_ScreenBuffer,-(sp) move.w #$49,-(sp) trap #1 addq.l #6,sp move.l BFS_FileBuffer,-(sp) move.w #$49,-(sp) trap #1 addq.l #6,sp move.w BFS_FileDescriptor,-(sp) move.w #$3e,-(sp) trap #1 addq.l #4,sp subq.w #1,BFS_FileCount bne GS_OpenNextFile GS_AllDone pea ST_SavePalette move.w #$6,-(sp) trap #14 addq.l #6,sp move.w ST_SaveRez,-(sp) pea -1 pea -1 move.w #$5,-(sp) trap #14 lea $c(sp),sp clr.w -(sp) trap #1 ;========================================================================; ;== GIFview2 Subroutines: Buffered Byte-Read Routine ==; ;========================================================================; BFS_ByteRead cmpa.l a5,a6 bne.s BFS_BR_Done movem.l d1-d2/a0-a2,-(sp) move.l BFS_FileBuffer,-(sp) move.l BFS_FileBufferSize,-(sp) move.w BFS_FileDescriptor,-(sp) move.w #$3f,-(sp) trap #1 lea $c(sp),sp movem.l (sp)+,d1-d2/a0-a2 move.l BFS_FileBuffer,a5 move.l a5,a6 add.l d0,a6 tst.l d0 bne.s BFS_BR_Done moveq #-1,d0 rts BFS_BR_Done clr.l d0 move.b (a5)+,d0 rts UBR_GetCode swap d7 UBR_CzechBitCount cmp.b d7,d5 bgt.s UBR_SnatchBits bsr BFS_ByteRead tst.l d0 blt.s FuckingEndOfStream subq.w #1,d6 bge.s UBR_WithinBlock tst.b d0 beq.s FuckingEndOfStream move.w d0,d6 bsr BFS_ByteRead tst.l d0 blt.s FuckingEndOfStream subq.w #1,d6 UBR_WithinBlock lsl.l d5,d0 add.l d0,d4 add.b #8,d5 bra.s UBR_CzechBitCount UBR_SnatchBits swap d6 move.w d4,d0 lsr.l d7,d4 add.w d0,d0 and.w d6,d0 sub.b d7,d5 swap d7 cmp.w d6,d7 bne.s UBR_Done UBR_HouseKeeping swap d7 cmpi.b #12,d7 beq.s UBR_HK_Done addq.b #1,d7 add.w d6,d6 bset #1,d6 UBR_HK_Done swap d7 UBR_Done swap d6 rts FuckingEndOfStream addq.l #4,sp bra GS_DisplayGIF data ;========================================================================; ;== GIFview3 DATA: ST/Subroutines ==; ;========================================================================; ST_TitleScreen dc.b 27,"E",27,"f",27,"b",15,27,"c",2 dc.b "============== GIFscale ==============" dc.b 13,10,"== ",27,"b",10 dc.b 189,"1990 Brain~Waves Freeware Group" dc.b 27,"b",15," ==",13,10,"== ",27,"b",10 dc.b "Robert Barnhardt / Robert Steger" dc.b 27,"b",15," ==",13,10 dc.b "========================================" dc.b 13,10,10,27,"b",10 dc.b " Active Keys... ",13,10 dc.b " ALT Keeps this screen up ",13,10 dc.b " 0 Regular (pure grey) palette ",13,10 dc.b " 1-6 Pseudogrey (tinted) palettes ",13,10 dc.b " S Save screen (Degas format) ",13,10 dc.b " ARROWS Scroll picture (if applicable) ",13,10 dc.b " ",13,10 dc.b " SPACE, ENTER, or RETURN for next GIF. ",13,10 dc.b " UNDO or ESC to exit. ",13,10 dc.b 27,66,15,27,67,0 align ST_Palettes: ST_PureGrey dc.w $000,$000,$111,$111,$222,$222,$333,$333 dc.w $444,$444,$555,$555,$666,$666,$777,$777 ST_Reddish dc.w $000,$100,$111,$211,$222,$322,$333,$433 dc.w $444,$544,$555,$655,$666,$766,$777,$777 ST_Greenish dc.w $000,$010,$111,$121,$222,$232,$333,$343 dc.w $444,$454,$555,$565,$666,$676,$777,$777 ST_Blueish dc.w $000,$001,$111,$112,$222,$223,$333,$334 dc.w $444,$445,$555,$556,$666,$667,$777,$777 ST_Yellowish dc.w $000,$110,$111,$221,$222,$332,$333,$443 dc.w $444,$554,$555,$665,$666,$776,$777,$777 ST_Purplish dc.w $000,$101,$111,$212,$222,$323,$333,$434 dc.w $444,$545,$555,$656,$666,$767,$777,$777 ST_Cyanish dc.w $000,$011,$111,$122,$222,$233,$333,$344 dc.w $444,$455,$555,$566,$666,$677,$777,$777 ST_PalettePointer dc.l ST_PureGrey ST_SaveOverlay dc.b "_0.PI1",0 ST_TitleFlag dc.b 0 ST_DegasRez dc.w 0 GIF_InterlaceStart ds.w 4 GIF_InterlaceSkip ds.w 4 GIF_IStart_2 dc.w 0,4,2,1 GIF_ISkip_2 dc.w 8,8,4,2 bss ;========================================================================; ;== GIFview3 BSS: ST/Subroutines ==; ;========================================================================; ST_GlobalMap ds.b 256 ST_SaveRez ds.w 1 ST_SavePalette ds.w 16 ST_USPSave ds.l 1 ST_Screen ds.l 1 ST_ScreenBuffer ds.l 1 ST_SaveNumAddr ds.l 1 ST_DTASave ds.l 1 ST_DTAnamePtr ds.l 1 ST_ImageWidth ds.w 1 ST_ImageHeight ds.w 1 ST_HeightCount ds.w 1 ST_WordWidth ds.w 1 ST_DTA ds.b 44 ST_BitCount ds.b 1 BFS_Pathfudge ds.b 1 BFS_Pathspec ds.b 128 BFS_Filenames ds.b 2048 BFS_FnamePtr ds.l 1 BFS_FileIndex ds.l 1 BFS_FileCount ds.w 1 BFS_FileDescriptor ds.w 1 BFS_FileBufferSize ds.l 1 BFS_FileBuffer ds.l 1 ;========================================================================; ;== GIFview3 BSS: LZW-Specific ==; ;========================================================================; LZW_Prefices ds.w 4096 LZW_Suffices ds.w 4096 LZW_Transform ds.w 4096 LZW_ClearCode ds.w 1 LZW_EOICode ds.w 1 LZW_FirstCode ds.w 1 ;========================================================================; ;== GIFview3 BSS: GIF-Specific ==; ;========================================================================; GIF_ScreenDescriptor: GIF_Signature ds.b 6 GIF_ScreenWidth ds.w 1 GIF_ScreenHeight ds.w 1 GIF_ScreenBits ds.b 1 GIF_Background ds.b 1 GIF_Blank ds.b 1 GIF_ColourCount ds.w 1 GIF_GlobalPalette ds.b 256*3 GIF_ImageDescriptor: GIF_ImageSignature ds.b 1 GIF_ImageXPos ds.b 2 GIF_ImageYPos ds.b 2 GIF_ImageWidth ds.b 2 GIF_ImageHeight ds.b 2 GIF_ImageBits ds.b 1 LZW_CodeSize ds.b 2 ; It's a long & boring story... GIF_IlacePointer ds.l 1 end