;-------- Initialisation routines ------------------------------------------ ; Graphics_Init() ; Graphics_Close() ; Open_Screen(d0,d1,d2,d3,a0) width, height, depth, viewmodes, cmap ; Close_Screen(a0) screen ; Init_Mask(d0,d1,d2,d3,d4,d5) x_min,y_min,x_max,y_max,sreen x,screen y ; Free_Mask(a0) maskplane struct ;-------- Drawing routines ------------------------------------------------- ; Fill_Polygon(a0,a1,d0,d1) screen, vertex list, npoints, colour ; Draw_Polygon(a0,a1,d0,d1) screen, vertex list, npoints, colour ; Draw_Line(a0,d0,d1,d2,d3,d4) screen, x1, y1, x2, y2, colour ; Write_Pixel(a0,d0,d1,d2) screen, x1, x2, colour ; Screen_Clear(a0) screen ;-------- Fade Routines------------------------------------------------ ; Fade_To_White(a0,a1) source screen,source colourmap ; Fade_To_Black(a0,a1) source screen,source colourmap ; Fade(a0,a1,a2) screen,source,destination ;-------- IFF Handling routines reading and writing of bitmaps ------------- ; Save_IFF(a0,a1)=filename APTR, screen ADDR ; Load_IFF(a0,a1)=filename APTR, screen ADDR ;-------- File handling Routines ------------------------------------------- ; Load_Data(a0,d0,a1) filename, buffer length, destination ; Save_Data(a0,d0,a1) filename, buffer length, source ;-------- Text handling routines ------------------------------------------- ; Write_Text(a0,a1,d0,d1,d2,d3) screen, text, x, y, colour, length ; Num_To_String(d0) word ;-------- Copper handling routines ------------------------------------- ; Add_Copper(a0,a1) screen,copper list ;-------- Input Handling Routines ------------------------------------------ ; GetKey() ;-------- Initialisation routines ------------------------------------------ ; Graphics_Init() ; Graphics_Close() ; Open_Screen(d0,d1,d2,d3,a0) width, height, depth, viewmodes, cmap ; Close_Screen(a0) screen ; Init_Mask(d0,d1,d2,d3,d4,d5) x_min,y_min,x_max,y_max,sreen x,screen y ; Free_Mask(a0) maskplane struct Graphics_Init ; sets a high taskpri, opens the graphics library ; and loads a null view ; returns 0 if failure ; 1 if success move.l #0,d7 OPENLIB _graphics_lib,0,_GfxBase tst.l d0 beq.s G_Init_Failed move.l 4.w,a6 sub.l a1,a1 Zero - Find current task jsr _LVOFindTask(a6) move.l d0,a1 moveq #127,d0 task priority to very high... jsr _LVOSetTaskPri(a6) move.l _GfxBase,a0 get GfxBase move.l gb_ActiView(a0),a1 get the current view move.l a1,_oldview store the address move.l #0,a1 CALLGRAF LoadView load a null view CALLGRAF WaitTOF moveq.l #SETCHIPREV_AA,d0 set chipset to AGA CALLGRAF SetChipRev call SetChipRev move.l #1,d7 G_Init_Failed move.l d7,d0 rts Graphics_Close ; closes the graphics library and restores the view tst.l _oldview beq.s Graphics_Close_1 move.l _oldview,a1 get the previous address view CALLGRAF LoadView load it into the view CALLGRAF WaitTOF wait a bit Graphics_Close_1 tst.l _GfxBase beq.s Graphics_Close_2 CLOSELIB _GfxBase Graphics_Close_2 rts Open_Screen ; opens a view ; d0.l=pixel width ; d1.l=pixel height ; d2.l=depth ; d3.l=viewmodes ; a0.l=colourmap ; d0.l=returns screen address movem.l d0-d3/a0,-(sp) store inputs moveq.l #0,d7 set d7 to failure move.l #Screen_Store_SIZEOF,d0 the screen storage structure move.l #MEMF_ANY!MEMF_CLEAR,d1 don't care about the memory CALLEXEC AllocMem allocate it tst.l d0 beq Screen_Failed failed to allocate my screen move.l d0,a4 base of storage structure ; moveq.l #0,d7 move.l #18,d0 size of a view structure move.l #MEMF_ANY!MEMF_CLEAR,d1 don't care about the memory CALLEXEC AllocMem allocate memory for view struct move.l d0,SS_View(a4) store the address tst.l d0 beq Screen_Failed failed to open the view structure move.l SS_View(a4),a1 init view structure CALLGRAF InitView move.l #VIEW_EXTRA_TYPE,d0 set up a view extra CALLGRAF GfxNew structure for the view move.l d0,SS_ViewExtra(a4) store the viewextra structure tst.l d0 beq Screen_Failed couldn't allocate one so off we go move.l SS_View(a4),a0 associate view extra move.l SS_ViewExtra(a4),a1 with view CALLGRAF GfxAssociate move.l SS_View(a4),a0 tell the view struct move.l #EXTEND_VSTRUCT,v_Modes(a0) that there is a view extra move.l #0,a1 open the monitor and move.l #DEFAULT_MONITOR_ID,d0 get it's default spec CALLGRAF OpenMonitor move.l d0,SS_MonSpec(a4) tst.l d0 beq Screen_Failed couldn't allocate the monitor move.l SS_ViewExtra(a4),a0 put the monitor spec move.l SS_MonSpec(a4),ve_Monitor(a0) into the view extra move.l #40,d0 size of a bitmap struct move.l #MEMF_ANY!MEMF_CLEAR,d1 don't care about the memory CALLEXEC AllocMem allocate it move.l d0,SS_BitMap(a4) tst.l d0 beq Screen_Failed couldn't allocate a bitmap structure move.l SS_BitMap(a4),a0 set up the bitmap move.l 8(sp),d0 NPLANES move.l (sp),d1 WIDTH move.l 4(sp),d2 HEIGHT CALLGRAF InitBitMap move.l (sp),d0 WIDTH lsr.l #3,d0 /8 muls.l 4(sp),d0 *HEIGHT muls.l 8(sp),d0 *NPLANES move.l #MEMF_CHIP!MEMF_CLEAR,d1 chip mem CALLEXEC AllocMem allocate the memory move.l d0,SS_Screen(a4) tst.l d0 beq Screen_Failed couldn't allocate a screen memory move.l SS_BitMap(a4),a2 get the bitmap struct lea bm_Planes(a2),a2 address of bitplanes move.l SS_Screen(a4),a3 screen 1 :-prev alloc move.l (sp),d0 WIDTH lsr.l #3,d0 /8 muls.l 4(sp),d0 *HEIGHT move.l 8(sp),d7 NPLANES sub.l #1,d7 -1 .bpl_loop move.l a3,(a2)+ put bitplane into struct add.l d0,a3 add plane size dbra d7,.bpl_loop loop round move.l #12,d0 size of rasinfo structure move.l #MEMF_ANY!MEMF_CLEAR,d1 don't care about the memory CALLEXEC AllocMem memory for rasinfo struct move.l d0,SS_RasInfo(a4) tst.l d0 beq Screen_Failed couldn't allocate a rasinfo struct move.l SS_RasInfo(a4),a0 move.l SS_BitMap(a4),a1 move.l a1,ri_BitMap(a0) rasinfo into bitmap move.l #40,d0 size of a viewport structure move.l #MEMF_ANY!MEMF_CLEAR,d1 don't care about the memory CALLEXEC AllocMem memory for viewport struct move.l d0,SS_ViewPort(a4) tst.l d0 beq Screen_Failed couldn't allocate the viewport struct move.l d0,a0 viewport address into a0 CALLGRAF InitVPort initialise the viewport move.l SS_ViewPort(a4),a0 move.w 14(sp),vp_Modes(a0) viewmodes into viewport move.l SS_View(a4),a1 viewport is already in a0 move.l a0,v_ViewPort(a1) associate the view and viewport move.l SS_RasInfo(a4),a1 viewport already in a0 move.l a1,vp_RasInfo(a0) associate the vport & rasinfo move.w 2(sp),vp_DWidth(a0) WIDTH move.w 6(sp),vp_DHeight(a0) HEIGHT move.l #VIEWPORT_EXTRA_TYPE,d0 gfx extra type CALLGRAF GfxNew make a vpextra struct move.l d0,SS_ViewPortExtra(a4) store the vpextra address tst.l d0 beq Screen_Failed couldn't allocate a vpextra lea vctags,a0 the vctag structure ; lea 12(a0),a0 move.l SS_ViewPortExtra(a4),12(a0) vpextra into vctags move.l #88,d0 size of a dim info structure move.l #MEMF_ANY!MEMF_CLEAR,d1 don't care about the memory CALLEXEC AllocMem allocate memory for diminfo struct move.l d0,SS_DimensionInfo(a4) tst.l d0 beq Screen_Failed couldn't allocate the memory move.l #0,a0 move.l SS_DimensionInfo(a4),a1 move.l #88,d0 move.l #DTAG_DIMS,d1 move.l #DEFAULT_MONITOR_ID,d2 CALLGRAF GetDisplayInfoData get the diminfo struct move.l SS_ViewPortExtra(a4),a0 link these bits together lea vpe_DisplayClip(a0),a0 move.l SS_DimensionInfo(a4),a1 lea dim_Nominal(a1),a1 move.l (a1)+,(a0)+ move.l (a1),(a0) move.l #DEFAULT_MONITOR_ID,d0 get the display ID CALLGRAF FindDisplayInfo for this display! lea vctags,a0 lea 20(a0),a0 store this in the tag list move.l d0,(a0) moveq.l #0,d0 clear d0 move.l 8(sp),d1 set bit number for no of colours bset d1,d0 CALLGRAF GetColorMap allocate a colourmap structure move.l d0,SS_ColorMap(a4) tst.l d0 beq Screen_Failed couldn't allocate a colourmap struct lea vctags,a0 lea 4(a0),a0 stick the vieport into move.l SS_ViewPort(a4),a1 the tag list structure move.l a1,(a0) move.l SS_ColorMap(a4),a0 lea vctags,a1 CALLGRAF VideoControl tst.l d0 bne Screen_Failed move.l #100,d0 size of a rastport structure move.l #MEMF_ANY!MEMF_CLEAR,d1 don't care about the memory CALLEXEC AllocMem memory for rastport structure move.l d0,SS_RastPort(a4) tst.l d0 beq.s Screen_Failed couldn't allocate a rastport move.l d0,a1 CALLGRAF InitRastPort init the rastport move.l SS_BitMap(a4),a0 move.l SS_RastPort(a4),a1 move.l a0,rp_BitMap(a1) bitmap struct into rastport move.l SS_ViewPort(a4),a0 move.l 16(sp),a1 colortable into a0 CALLGRAF LoadRGB32 load the colortable into the viewport move.l SS_View(a4),a0 move.l SS_ViewPort(a4),a1 CALLGRAF MakeVPort make the viewport tst.l d0 bne.s Screen_Failed couldn't make the viewport move.l SS_View(a4),a1 CALLGRAF MrgCop build the copperlist tst.l d0 bne.s Screen_Failed couldn't build the copperlist move.l SS_View(a4),a1 all done so CALLGRAF LoadView load the view up :-)<-< movem.l (sp)+,d0-d3/a0 outputs back out. move.l d0,SS_Width(a4) store the width move.l d1,SS_Height(a4) store the height move.l d2,SS_Planes(a4) store the number of planes move.l a0,SS_ColorTable(a4) store the colourtable move.l a4,d7 screen store base address Screen_Failed move.l d7,d0 return value. bne.s Screen_Done not zero so out we go movem.l (sp)+,d0-d3/a0 pull outputs off if we haven't done it Screen_Done rts all done! Close_Screen: ; Closes a view ; in:-a0=screen storage structure move.l a0,a4 move.l SS_UserCopperList(a4),a0 tst.l a0 have we got any user coppers ? beq.s Close_Screen14 move.l SS_ViewPort(a4),a0 CALLGRAF FreeVPortCopLists free the user copperlists Close_Screen14 move.l SS_View(a4),a0 tst.l a0 have we got a view structure ? beq.s Close_Screen12 lea v_LOFCprList(a0),a0 move.l (a0),a0 CALLGRAF FreeCprList free the copper lists move.l SS_RastPort(a4),a1 tst.l a1 have we got a rastport struct ? beq.s Close_Screen12 move.l #100,d0 CALLEXEC FreeMem free the rastport Close_Screen13 move.l SS_View(a4),a1 tst.l a1 have we got a view structure ? beq.s Close_Screen12 move.l #18,d0 CALLEXEC FreeMem free the view structure Close_Screen12 move.l SS_ViewPort(a4),a0 tst.l a0 have we got a viewport struct ? beq.s Close_Screen11 CALLGRAF FreeVPortCopLists free the viewport copper lists Close_Screen11 move.l SS_ColorMap(a4),a0 tst.l a0 colour map structure ? beq.s Close_Screen10 CALLGRAF FreeColorMap free the colourmap structure Close_Screen10 move.l SS_ViewPortExtra(a4),a0 tst.l a0 vpextra structure ? beq.s Close_Screen9 CALLGRAF GfxFree free it Close_Screen9 move.l SS_MonSpec(a4),a0 tst.l a0 have we got a monitor spec ? beq.s Close_Screen8 CALLGRAF CloseMonitor close the monitor spec Close_Screen8 move.l SS_BitMap(a4),a1 tst.l a1 bitmap structure ? beq.s Close_Screen7 move.l #40,d0 CALLEXEC FreeMem free it. Close_Screen7 move.l SS_Screen(a4),a1 tst.l a1 have we got bitplane memory ? beq.s Close_Screen6 move.l SS_Width(a4),d0 WIDTH lsr.l #3,d0 /8 muls.l SS_Height(a4),d0 *HEIGHT muls.l SS_Planes(a4),d0 *NPLANES CALLEXEC FreeMem free the memory Close_Screen6 move.l SS_RasInfo(a4),a1 tst.l a1 have we got a ras info structure ? beq.s Close_Screen5 move.l #12,d0 CALLEXEC FreeMem free it Close_Screen5 move.l SS_ViewPort(a4),a1 tst.l a1 have we got a viewport structure ? beq.s Close_Screen4 move.l #40,d0 CALLEXEC FreeMem free it. Close_Screen4 move.l SS_ViewExtra(a4),a0 tst.l a0 have we got a view extra struct ? beq.s Close_Screen3 CALLGRAF GfxFree free it. Close_Screen3 move.l SS_DimensionInfo(a4),a1 tst.l a1 a dim info struct ? beq.s Close_Screen2 move.l #88,d0 CALLEXEC FreeMem free the memory. Close_Screen2 move.l a4,a1 move.l #Screen_Store_SIZEOF,d0 CALLEXEC FreeMem free the screen store memory. Close_Screen1 moveq.l #0,d0 rts Init_Mask ; allocates a maskplane to be linked into ; a screen for the polygon filling ; operations ; d0.l=x_min ; d1.l=y_min ; d2.l=x_max ; d3.l=y_max ; d4=screen x ; d5-screen y ; returns ; d0=maskplane address ;*** Notes This could do with some better error checking!!! PUSH d0-d3 store the inputs move.l #MaskPlane_SIZEOF,d0 enough space for a maskplane move.l #MEMF_ANY!MEMF_CLEAR,d1 any type of memory CALLEXEC AllocMem allocate it move.l d0,d7 store base address of the mem. move.l d0,a3 get memory address PULL d0-d3 inputs of stack move.w d0,MP_Clip_X_Min(a3) store min clip x move.w d1,MP_Clip_Y_Min(a3) store min clip y move.w d2,MP_Clip_X_Max(a3) store max clip x move.w d3,MP_Clip_Y_Max(a3) store max clip y lsr.l #3,d4 the bit size of the mask memory. muls d5,d4 times the height of the memory move.l d4,(a3)+ store the memory size in the struct move.l d4,d0 move.l #MEMF_CHIP!MEMF_CLEAR,d1 chip memory CALLEXEC AllocMem allocate the mask memory move.l d0,(a3)+ store the memory area move.l d7,d0 return base address of mem. rts Free_Mask: ; Frees a previously allocated maskplane ; a0.l=maskplane address returned by Init_Mask ;*** like above this could use some better error checking!!! move.l a0,a5 move.l MP_MaskPlane(a5),a1 move.l MP_PlaneSize(a5),d0 CALLEXEC FreeMem free the mask memory move.l a5,a1 move.l #MaskPlane_SIZEOF,d0 CALLEXEC FreeMem free the maskplane structure memory rts ;------------------------------------------------------------------------ ;-------- Drawing routines ------------------------------------------------- ; Fill_Polygon(a0,a1,d0,d1) screen, vertex list, npoints, colour ; Draw_Polygon(a0,a1,d0,d1) screen, vertex list, npoints, colour ; Draw_Line(a0,d0,d1,d2,d3,d4) screen, x1, y1, x2, y2, colour ; Write_Pixel(a0,d0,d1,d2) screen, x1, x2, colour Fill_Polygon ; a0=screen to draw onto ; a1=list of vertices ; d0=npoints ; d1=colour PUSH a0/d1 store the screen and number of points exg.l a0,a1 swap the screen and point list. clip: ; clips a polygon ; internal routine called by Fill_Polygon ; DONT CALL THIS PROCUDURE YOURSELF ; d0=number of points coming in ; a0=points coming in ; a1=screen structure move.l SS_MaskPlane(a1),a6 get the maskplane address lea clip_out,a2 temporary variable ; the source buffer is already in a0 lea MP_PointBuffer(a6),a1 initial destination buffer move.l a1,a4 store this address clr.w (a2) clear the clip out variable move.w d0,d7 get the number of points beq clip_end no points so jump out subq.w #1,d7 sub 1 for the loop move.w (a0)+,d5 get the first x point move.w (a0)+,d6 get the first y point move.w MP_Clip_X_Min(a6),d0 get the clip value cmp.w d0,d5 compare the point to the clip value bge.s xmin_save point is in so store it bra.s xmin_update point is out so update the temp var. xmin_next: move.w (a0)+,d3 get the next x point move.w (a0)+,d4 get the next y point move d3,d5 store these values move d4,d6 sub.w d0,d3 subtract the clip value bge.s xmin_x2in the point is in so check the other ; the point must be outside so check the other point sub.w d0,d1 subtract the clip value blt.s xmin_update do this if both points are outside ; if we get to here then the first point is outside but the ; second is inside so we have to clip the line beq.s .yint_out movem d5/d6,-(sp) store d5 and d6 .yint_in move.w d2,d6 store the first y coord add.w d4,d6 add the second y coordinate onto this asr.w #1,d6 divide this by 2 move.w d1,d5 get the x difference into d5 add.w d3,d5 add the first x onto this asr.w #1,d5 divide this by 2 beq.s .yint_end if this is 0 we have the intersect bgt.s .yint_loop greater than 0 so off we go ; less than zero move.w d5,d3 the x value goes into d3 move.w d6,d4 the y value goes into d4 bra.s .yint_in iterate backwards .yint_loop: move.w d5,d1 the x value goes into d1 move.w d6,d2 y into d2 bra.s .yint_in iterate backwards .yint_end: move.w d0,(a1)+ store the x value move.w d6,(a1)+ store the intersect value addq.w #1,(a2) increment the counter. movem (sp)+,d5/d6 pull the contents off the stack. .yint_out: bra.s xmin_update update the temp variables. xmin_x2in: ; the first point is in so check the second sub.w d0,d1 subtract the clip value bge.s xmin_save the point is in so save tst.w d3 check if d3 is 0 beq.s .yint_out it is so jump off. movem d5/d6,-(sp) store d5 and d6 .yint_in move.w d4,d6 store the first y coord add.w d2,d6 add the second y coordinate onto this asr.w #1,d6 divide this by 2 move d3,d5 get the x difference into d5 add.w d1,d5 add the first x onto this asr.w #1,d5 divide this by 2 beq.s .yint_end if this is 0 we have the intersect bgt.s .yint_loop greater than 0 so off we go ; less than zero move d5,d1 the x value goes into d3 move d6,d2 the y value goes into d4 bra.s .yint_in iterate backwards .yint_loop: move d5,d3 the x value goes into d1 move d6,d4 y into d2 bra.s .yint_in iterate backwards .yint_end: move.w d0,(a1)+ store the x value move.w d6,(a1)+ store the intersect value addq.w #1,(a2) increment the counter. movem (sp)+,d5/d6 pull the contents off the stack. .yint_out: xmin_save: move.w d5,(a1)+ store the x coordinate move.w d6,(a1)+ store the y coordinate addq.w #1,(a2) increment the counter xmin_update: move d5,d1 move x into the other x move d6,d2 move the y into the other one dbf d7,xmin_next loop back. tst.w (a2) check if there are no points. beq.s clip_xmax no points so jump off. subq.w #4,a1 check if the first and last cmpm.l (a4)+,(a1)+ points are the same beq.s clip_xmax if they aren't copy the move.l -(a4),(a1) first to the last point and addq.w #1,(a2) increment the counter. clip_xmax: lea MP_PointBuffer(a6),a0 source buffer lea MP_PointBuffer2(a6),a1 destination buffer move.l a1,a4 move.w (a2),d7 beq clip_ymin no points so don't waste time subq.w #1,d7 decrement the counter clr.w (a2) clear the temporary variable move.w (a0)+,d5 get the first x point move.w (a0)+,d6 get the first y point move.w MP_Clip_X_Max(a6),d0 get the clip value cmp.w d5,d0 compare the point to the clip value bge.s xmax_save point is in so store it bra.s xmax_update point is out so update the temp var. xmax_next: move.w (a0)+,d3 get the next x point move.w (a0)+,d4 get the next y point move d3,d5 store these values move d4,d6 sub.w d0,d3 subtract the clip value neg.w d3 negate the distance bge.s xmax_x2in the point is in so check the other ; the point must be outside so check the other point sub.w d0,d1 subtract the clip value neg.w d1 negate the distance blt.s xmax_update do this if both points are outside ; if we get to here then the first point is outside but the ; second is inside so we have to clip the line beq.s .yint_out movem d5/d6,-(sp) store d5 and d6 .yint_in move.w d2,d6 store the first y coord add.w d4,d6 add the second y coordinate onto this asr.w #1,d6 divide this by 2 move d1,d5 get the x difference into d5 add.w d3,d5 add the first x onto this asr.w #1,d5 divide this by 2 beq.s .yint_end if this is 0 we have the intersect bgt.s .yint_loop greater than 0 so off we go ; less than zero move d5,d3 the x value goes into d3 move d6,d4 the y value goes into d4 bra.s .yint_in iterate backwards .yint_loop: move d5,d1 the x value goes into d1 move d6,d2 y into d2 bra.s .yint_in iterate backwards .yint_end: move.w d0,(a1)+ store the x value move.w d6,(a1)+ store the intersect value addq.w #1,(a2) increment the counter. movem (sp)+,d5/d6 pull the contents off the stack. .yint_out: bra.s xmax_update update the temp variables. xmax_x2in: ; the first point is in so check the second sub.w d0,d1 subtract the clip value neg.w d1 negate the distance bge.s xmax_save the point is in so save tst.w d3 check if d3 is 0 beq.s .yint_out it is so jump off. movem d5/d6,-(sp) store d5 and d6 .yint_in move.w d4,d6 store the first y coord add.w d2,d6 add the second y coordinate onto this asr.w #1,d6 divide this by 2 move d3,d5 get the x difference into d5 add.w d1,d5 add the first x onto this asr.w #1,d5 divide this by 2 beq.s .yint_end if this is 0 we have the intersect bgt.s .yint_loop greater than 0 so off we go ; less than zero move d5,d1 the x value goes into d3 move d6,d2 the y value goes into d4 bra.s .yint_in iterate backwards .yint_loop: move d5,d3 the x value goes into d1 move d6,d4 y into d2 bra.s .yint_in iterate backwards .yint_end: move.w d0,(a1)+ store the x value move.w d6,(a1)+ store the intersect value addq.w #1,(a2) increment the counter. movem (sp)+,d5/d6 pull the contents off the stack. .yint_out: xmax_save: move.w d5,(a1)+ store the x coordinate move.w d6,(a1)+ store the y coordinate addq.w #1,(a2) increment the counter xmax_update: move d5,d1 move x into the other x move d6,d2 move the y into the other one dbf d7,xmax_next loop back. tst.w (a2) check if there are no points. beq.s clip_ymin no points so jump off. subq #4,a1 check if the first and las cmpm.l (a4)+,(a1)+ points are the same beq.s clip_ymin if they aren't copy the move.l -(a4),(a1) first to the last point and addq.w #1,(a2) increment the counter. clip_ymin: lea MP_PointBuffer2(a6),a0 source buffer lea MP_PointBuffer(a6),a1 destination buffer move.l a1,a4 move.w (a2),d7 counter into d7 beq clip_ymax no points to do ? so jump off subq.w #1,d7 decrement the counter clr.w (a2) clear the clip out variable move.w (a0)+,d5 get the first x point move.w (a0)+,d6 get the first y point move.w MP_Clip_Y_Min(a6),d0 get the clip value cmp.w d0,d6 compare the point to the clip value bge.s ymin_save point is in so store it bra.s ymin_update point is out so update the temp var. ymin_next: move.w (a0)+,d3 get the next x point move.w (a0)+,d4 get the next y point move d3,d5 store these values move d4,d6 sub.w d0,d4 subtract the clip value bge.s ymin_y2in the point is in so check the other ; the point must be outside so check the other point sub.w d0,d2 subtract the clip value blt.s ymin_update do this if both points are outside ; if we get to here then the first point is outside but the ; second is inside so we have to clip the line beq.s .xint_out movem d5/d6,-(sp) store d5 and d6 .xint_in move.w d1,d5 store the first x coordinate add.w d3,d5 add on the second x coordinate asr.w #1,d5 divide this by 2 move.w d2,d6 get the y difference into d6 add.w d4,d6 add the second y coordinate asr.w #1,d6 divide this by 2 beq.s .xint_end if this is 0 we have the intersect bgt.s .xint_loop greater than 0 so off we go ; less than zero move.w d6,d4 the y value goes into d4 move.w d5,d3 the x value goes into d3 bra.s .xint_in iterate backwards .xint_loop: move.w d5,d1 the y value into d1 move.w d6,d2 x into d2 bra.s .xint_in iterate backwards .xint_end: move.w d5,(a1)+ store the intersect value move.w d0,(a1)+ store the clip value addq.w #1,(a2) increment the counter movem (sp)+,d5/d6 pull the contents off the stack. .xint_out bra.s ymin_update update the temp variables. ymin_y2in: ; the first point is in so check the second sub.w d0,d2 subtract the clip value bge.s ymin_save the point is in so save tst.w d4 check if d3 is 0 beq.s .xint_out it is so jump off. movem d5/d6,-(sp) store d5 and d6 .xint_in move d3,d5 store the second x coord add.w d1,d5 add the first x coordinate onto this asr.w #1,d5 divide this by 2 move d4,d6 get the y difference add.w d2,d6 add on the first y coordinate asr.w #1,d6 divide this by 2 beq.s .xint_end if this is 0 we have the intersect bgt.s .xint_loop greater than 0 so off we go ; less than zero move d6,d2 the y value into d2 move d5,d1 x into d1 bra.s .xint_in iterate backwards .xint_loop: move d5,d3 x into d3 move d6,d4 y into d4 bra.s .xint_in iterate backwards. .xint_end: move.w d5,(a1)+ store the x value move.w d0,(a1)+ store the intersect value addq.w #1,(a2) increment the counter. movem (sp)+,d5/d6 pull the contents off the stack. .xint_out ymin_save: move.w d5,(a1)+ store the x coordinate move.w d6,(a1)+ store the y coordinate addq.w #1,(a2) increment the counter ymin_update: move d5,d1 move x into the other x move d6,d2 move the y into the other one dbf d7,ymin_next loop back. tst.w (a2) check if there are no points. beq.s clip_ymax no points so jump off. subq #4,a1 check if the first and last cmpm.l (a4)+,(a1)+ points are the same beq.s clip_ymax if they aren't copy the move.l -(a4),(a1) first to the last point and addq.w #1,(a2) increment the counter. clip_ymax: lea MP_PointBuffer(a6),a0 source buffer lea MP_PointBuffer2(a6),a1 destination buffer move.l a1,a4 move.w (a2),d7 no points so don't waste time beq clip_end subq.w #1,d7 decrement the counter clr.w (a2) clear the temporary variable move.w (a0)+,d5 get the first x point move.w (a0)+,d6 get the first y point move.w MP_Clip_Y_Max(a6),d0 get the clip value cmp.w d6,d0 compare the point to the clip value bge.s ymax_save point is in so store it bra.s ymax_update point is out so update the temp var. ymax_next: move.w (a0)+,d3 get the next x point move.w (a0)+,d4 get the next y point move d3,d5 store these values move d4,d6 sub.w d0,d4 subtract the clip value neg.w d4 negate the distance bge.s ymax_y2in the point is in so check the other ; the point must be outside so check the other point sub.w d0,d2 subtract the clip value neg.w d2 negate the distance blt.s ymax_update do this if both points are outside ; if we get to here then the first point is outside but the ; second is inside so we have to clip the line beq.s .xint_out movem d5/d6,-(sp) store d5 and d6 .xint_in move d1,d5 store the first x coordinate add.w d3,d5 add the second x onto this asr.w #1,d5 divide this by 2 move d2,d6 get the y distance add.w d4,d6 add on the second y coord asr.w #1,d6 divide this by 2 beq.s .xint_end if this is 0 we have the intersect bgt.s .xint_loop greater than 0 so off we go ; less than zero move d6,d4 the y value goes into d4 move d5,d3 the x value goes into d3 bra.s .xint_in iterate backwards .xint_loop: move d5,d1 the x value goes into d1 move d6,d2 y into d2 bra.s .xint_in iterate backwards .xint_end: move.w d5,(a1)+ store the x value move.w d0,(a1)+ store the intersect value addq.w #1,(a2) increment the counter. movem (sp)+,d5/d6 pull the contents off the stack. .xint_out bra.s ymax_update update the temp variables. ymax_y2in: ; the first point is in so check the second sub.w d0,d2 subtract the clip value neg.w d2 negate the distance bge.s ymax_save the point is in so save ;x_intercept: tst.w d4 check if d3 is 0 beq.s .xint_out it is so jump off. movem d5/d6,-(sp) store d5 and d6 .xint_in move d3,d5 store the second x coord add.w d1,d5 add the first x coordinate onto this asr.w #1,d5 divide this by 2 move d4,d6 get the y difference add.w d2,d6 add on the first y coordinate asr.w #1,d6 divide this by 2 beq.s .xint_end if this is 0 we have the intersect bgt.s .xint_loop greater than 0 so off we go ; less than zero move d6,d2 the y value into d2 move d5,d1 x into d1 bra.s .xint_in iterate backwards .xint_loop: move d5,d3 x into d3 move d6,d4 y into d4 bra.s .xint_in iterate backwards. .xint_end: move.w d5,(a1)+ store the x value move.w d0,(a1)+ store the intersect value addq.w #1,(a2) increment the counter. movem (sp)+,d5/d6 pull the contents off the stack. .xint_out ymax_save: move.w d5,(a1)+ store the x coordinate move.w d6,(a1)+ store the y coordinate addq.w #1,(a2) increment the counter ymax_update: move d5,d1 move x into the other x move d6,d2 move the y into the other one dbf d7,ymax_next loop back. tst.w (a2) check if there are no points. beq.s clip_end no points so jump off. subq #4,a1 check if the first and last cmpm.l (a4)+,(a1)+ points are the same beq.s clip_end if they aren't copy the move.l -(a4),(a1) first to the last point and addq.w #1,(a2) increment the counter. clip_end: lea MP_PointBuffer2(a6),a1 the final resting place of the polygon move.w (a2),d0 get the number of points cmp.w #1,d0 only one point ? bne.s clip_poly no so jump off move.w #0,d0 if yes we don't bother drawing it. clip_poly PULL a0/d1 tst.w d0 check if we have any points beq Fill_Poly_Done no then don't bother drawing move.w SS_Height+2(a0),y_min this section is used to calculate move.w #0,y_max the boundaries of the polygon move.w SS_Width+2(a0),x_min move.w #0,x_max move.b d1,-(sp) store the colour value. move.w d0,d7 number of points. subq.w #2,d7 subtract 2 move.l a1,a2 store the base address of the points move.w (a1)+,d2 first x point move.w (a1)+,d3 first y point Fill_Poly_Loop move.w d2,d0 move the points into the other pos move.w d3,d1 move.w (a1)+,d2 get the next x point move.w (a1)+,d3 get the next y point cmp.w x_min,d0 this section is used to calculate bgt.s x_great_x_min the boundaries of the polygon move.w d0,x_min it works by checking the maximum x_great_x_min: cmp.w x_max,d0 and minimum x and y values and blt.s x_check_done updating the variables accordingly. move.w d0,x_max x_check_done cmp.w y_min,d1 bgt.s y_great_y_min move.w d1,y_min y_great_y_min cmp.w y_max,d1 blt.s y_check_done move.w d1,y_max y_check_done movem.l d2-d7/a0-a1,-(sp) store lots of variables on the stack. Fill_Line ; Draws a line for filling a polygon ; internal routine DONT CALL!!!! ; d0,d1=x1,y1 ; d2,d3=x2,y2 ; a0=screen structure ; *** This line drawing routine bashes the hardware quite violently. ; *** It is not my work but is taken from the How To Code 7 manual. ; *** Thank you to those responsible for it! CALLGRAF OwnBlitter lea $dff000,a6 move.l SS_Width(a0),d6 lsr.w #3,d6 move.l SS_MaskPlane(a0),a0 move.l MP_MaskPlane(a0),a0 cmp.w d1,d3 beq noline ble.s lin1 exg d1,d3 exg d0,d2 lin1: sub.w d2,d0 move.w d2,d5 asr.w #3,d2 ext.l d2 sub.w d3,d1 muls d6,d3 add.l d2,d3 add.l d3,a0 and.w #$f,d5 move.w d5,d2 eor.b #$f,d5 ror.w #4,d2 or.w #$0b4a,d2 swap d2 tst.w d0 bmi.s lin2 cmp.w d0,d1 ble.s lin3 move.w #$41,d2 exg d1,d0 bra.s lin6 lin3: move.w #$51,d2 bra.s lin6 lin2: neg.w d0 cmp.w d0,d1 ble.s lin4 move.w #$49,d2 exg d1,d0 bra.s lin6 lin4: move.w #$55,d2 lin6: asl.w #1,d1 move.w d1,d4 move.w d1,d3 sub.w d0,d3 ble.s lin5 and.w #$ffbf,d2 lin5: move.w d3,d1 sub.w d0,d3 or.w #2,d2 lsl.w #6,d0 add.w #$42,d0 bltwt: btst #6,2(a6) bne.s bltwt bchg d5,(a0) move.l d2,bltcon0(a6) move.l #-1,bltafwm(a6) move.l a0,bltcpt(a6) move.w d1,bltapt+2(a6) move.l a0,bltdpt(a6) move.w d6,bltcmod(a6) ;width move.w d4,bltbmod(a6) move.w d3,bltamod(a6) move.w d6,bltdmod(a6) ;width move.l #-$8000,bltbdat(a6) move.w d0,bltsize(a6) noline: CALLGRAF DisownBlitter movem.l (sp)+,d2-d7/a0-a1 values off the stack dbra d7,Fill_Poly_Loop branch back till all lines are done move.l a0,a4 move.w x_max,d0 calculate the offset into the bitmap lsr.w #4,d0 of the polygon in terms of the move.w d0,d2 calue that the blitter wants add.w d2,d2 move.w y_max,d1 mulu #40,d1 add.w d2,d1 move.w d1,bltstrt move.l SS_Width(a0),d6 lsr.l #3,d6 byte width of the screen move.l SS_MaskPlane(a0),a0 move.l MP_MaskPlane(a0),a0 add.w d1,a0 this is the address of the first word ;of the polygon move.w x_min,d1 calculate the width of the polygon lsr.w #4,d1 in terms of a value that the sub.w d1,d0 blitter likes addq.w #1,d0 move.w d0,bltwidth move.w d6,d2 calculate the blit modulo add.w d0,d0 sub.w d0,d2 move.w d2,blitmod move.w y_max,d0 calculate the size of the polygon sub.w y_min,d0 for the blitter addq.w #1,d0 lsl.w #6,d0 add.w bltwidth,d0 move.w d0,blitsize CALLGRAF OwnBlitter This section fills in the polygon ;using the blitter fill mode CALLGRAF WaitBlit move.l #$dff000,a5 move.l a0,bltapt(a5) move.l a0,bltdpt(a5) move.w d2,bltamod(a5) move.w d2,bltdmod(a5) move.w #%0000100111110000,bltcon0(a5) move.w #%0000000000001010,bltcon1(a5) move.l #$ffffffff,bltafwm(a5) move.w blitsize,bltsize(a5) pln_copy: ; This section copies the polygon from the maskplane ; to the desination plane memory using the blitter. move.l SS_Screen(a4),a0 adda.w bltstrt,a0 move.l SS_Planes(a4),d7 subq.l #1,d7 move.w blitmod,d0 ; Get the colour off the stack into d6 move.b (sp)+,d6 extb.l d6 ; Set the initial values for the blitter CALLGRAF WaitBlit move.w #$0002,bltcon1(a5) move.w d0,bltamod(a5) move.w d0,bltbmod(a5) move.w d0,bltdmod(a5) move.l SS_MaskPlane(a4),a1 move.l MP_MaskPlane(a1),a1 add.w bltstrt,a1 move.w blitsize,d2 nxtplane: ; The loop for the plane copy CALLGRAF WaitBlit move.l a1,bltapt(a5) move.l a0,bltbpt(a5) move.l a0,bltdpt(a5) ; shift the colour bit right ; if the carry bit is clear we want to clear the destination memory ; else we want to fill it lsr.w #1,d6 bcc.s bltclr move.w #%0000110111111100,bltcon0(a5) 11011111100 bra.s bltcopy bltclr: move.w #%0000110100001100,bltcon0(a5) bltcopy: ; do the copy to destination memory move.w d2,bltsize(a5) ; increment the plane pointer move.l SS_Width(a4),d0 lsr.l #3,d0 muls.l SS_Height(a4),d0 add.l d0,a0 ; loop back to the number of planes dbf d7,nxtplane CALLGRAF DisownBlitter ; clear the section of the maskplane occupied by the polygon ; using the blitter CALLGRAF OwnBlitter CALLGRAF WaitBlit move.l a1,bltdpt(a5) move.w blitmod,bltdmod(a5) move.w #$0002,bltcon1(a5) move.w #$100,bltcon0(a5) move.w blitsize,bltsize(a5) CALLGRAF DisownBlitter Fill_Poly_Done rts Draw_Polygon ; a0=screen to draw onto ; a1=list of vertices ; d0=npoints ; d1=colour move.b d1,-(sp) colour onto the stack move.w d0,d7 number of points onto counter subq.w #2,d7 decrement d7 move.l a1,a2 store vertex list move.w (a1)+,d2 get first point move.w (a1)+,d3 Poly_Loop move.w d2,d0 prev point onto first coords move.w d3,d1 move.w (a1)+,d2 get next point move.w (a1)+,d3 move.b (sp)+,d4 colour off stack movem.l d2-d7/a0-a1,-(sp) bsr.s Draw_Line draw the line. movem.l (sp)+,d2-d7/a0-a1 move.b d4,-(sp) colour onto stack dbra d7,Poly_Loop loop back to all lines move.b (sp)+,d4 restore stack Poly_Done rts Draw_Line ; Draws a line ; d0,d1=x1,y1 ; d2,d3=x2,y2 ; d4=colour ; a0=screen structure ; *** Unlike the fill_polygon procedure this routine uses the bresenham ; *** line drawing algorithm. move.b d4,-(sp) moveq.w #1,d6 d6=IC cmp.w d1,d3 (y2-y1)=dy bgt.s ascend branch if slope>0 ; the line must be descending so swap the vertices exg d0,d2 exchange x1 and x2 exg d1,d3 exchange y1 and y2 ascend sub.w d1,d3 dy is now +ve sub.w d0,d2 (x2-x1)=dx bgt.s pos_slope branch if the slope is +ve ; the slope must be -ve so make ic -ve neg.w d6 neg.w d2 now dx is +ve pos_slope cmp.w d2,d3 test dy-dx bgt.s HiSlope slope is >1 ; the slope is <1 so increment x each time and check y ; d0=xs, d1=ys, d2=dx, d3=dy move.w d3,d5 dy into d5 add.w d5,d5 error1 move.w d5,d7 2*dy into d7 move.w d2,d4 dx into d4 add.w d4,d4 2*dx sub.w d4,d7 2*dy-2*dx move.w d7,d4 error2 move.w d2,d7 dx as the counter subq.w #1,d7 dx-1 add.w d3,d3 2*dy sub.w d2,d3 (2*dy)-dx:-initial value of D move.b (sp)+,d2 line_loop1 tst.w d3 test error bpl.s inc_y_and_x add.w d6,d0 add ic onto xs add.w d5,d3 increment error bra.s point_1 inc_y_and_x add.w d6,d0 add ic onto xs addq.w #1,d1 increment ys add.w d4,d3 increment error point_1 PUSHALL cmp.w #0,d0 check x minimum bmi.s no_line_point_1 cmp.w SS_Width+2(a0),d0 bpl.s no_line_point_1 cmp.w #0,d1 bmi.s no_line_point_1 cmp.w SS_Height+2(a0),d1 bpl.s no_line_point_1 move.l a0,a1 bsr.s Write_Pixel no_line_point_1 PULLALL dbra d7,line_loop1 rts HiSlope ; the line slope>1 so increment y and check for x ; d0=xs, d1=ys, d2=dx, d3=dy move.w d2,d5 dx into d5 add.w d5,d5 error1 move.w d5,d7 2*dx into d7 move.w d3,d4 dy into d4 add.w d4,d4 2*dy sub.w d4,d7 2*dx-2*dy move.w d7,d4 error2 move.w d3,d7 dy as the counter subq.w #1,d7 dy-1 add.w d2,d2 2*dx sub.w d3,d2 (2*dx)-dy:-initial value of D move.b (sp)+,d3 line_loop2 tst.w d2 test error bpl.s inc_y addq.w #1,d1 add ic onto xs add.w d5,d2 increment error bra.s point_2 inc_y add.w d6,d0 add ic onto xs addq.w #1,d1 increment ys add.w d4,d2 increment error point_2 PUSHALL cmp.w #0,d0 check x minimum bmi.s no_line_point_2 cmp.w SS_Width+2(a0),d0 bpl.s no_line_point_2 cmp.w #0,d1 bmi.s no_line_point_2 cmp.w SS_Height+2(a0),d1 bpl.s no_line_point_2 move.b d3,d2 move.l a0,a1 bsr.s Write_Pixel no_line_point_2 PULLALL dbra d7,line_loop2 rts Write_Pixel: ; Duuuuuuuhhhhhhhhhhn ; ; input:- d0=x,d1=y ; d2=colour ; a0=destination screen struct ; probably not as tidy as other write pixels but it has ; to be like this for clipping PUSHALL move.l a0,a5 move.l SS_Screen(a5),a0 move.l SS_Width(a5),d3 lsr.l #3,d3 byte width of a screen muls.l d3,d1 move.w d0,d3 lsr.w #3,d0 byte offset into the bitplane add.w d1,d0 andi.w #%0000000000000111,d3 subq.w #7,d3 neg.w d3 bit offset of pixel move.l SS_Planes(a5),d6 subq.l #1,d6 add.w d0,a0 the destination byte in the bitmap pcol lsr.w d2 rotate the colour right bcc.s clrpoint carry clear = clear point bset d3,(a0) bra.s ploop clrpoint bclr d3,(a0) ploop move.l SS_Width(a5),d0 lsr.l #3,d0 muls.l SS_Height(a5),d0 add.l d0,a0 increment onto next plane dbra d6,pcol loop back PULLALL rts Screen_Clear ; clears a screen using the Blit Clear routine ; Should be self explanatory ; a0=screen structure move.l a0,a5 move.l SS_Screen(a5),a1 move.l SS_Width(a5),d0 lsr.l #3,d0 muls.l SS_Height(a5),d0 muls.l SS_Planes(a5),d0 move.l #1,d1 CALLGRAF BltClear rts ;--------------------------------------------------------------------- ;-------- Fade Routines------------------------------------------------ ; Fade_To_White(a0,a1) source screen,source colourmap ; Fade_To_Black(a0,a1) source screen,source colourmap ; Fade(a0,a1,a2) screen,source,destination Fade_To_White ; Fades the screen to White and sets the colormap ; a0=screen ; a1=colortable move.l a0,a5 store the screen move.l a1,a2 store the colortable White_Main_Loop move.l a2,a0 get the colortable sf fade_flag set the fade flag to false move.w (a0),d7 get the number of colurs ext.l d7 extend to longword subq.l #1,d7 -1 for dbra addq.l #4,a0 point to first colour value White_Fader_Loop move.l (a0),d0 colour red component cmp.l #$ffffffff,d0 full on ? beq.s White_red_done yes, so don't increment value add.l #$01010101,d0 else increment red component move.l d0,(a0) store the new value st fade_flag signal that we have made changes White_red_done addq.l #4,a0 offset to blue value move.l (a0),d0 get the blue component cmp.l #$ffffffff,d0 full on ? beq.s White_blue_done yes so don't change add.l #$01010101,d0 else increment value move.l d0,(a0) store the new value st fade_flag signal change White_blue_done addq.l #4,a0 same here as above but for green move.l (a0),d0 components cmp.l #$ffffffff,d0 beq.s White_green_done add.l #$01010101,d0 move.l d0,(a0) st fade_flag White_green_done addq.l #4,a0 point to next full colour ; loop for all colours dbra d7,White_Fader_Loop ; If this flag isn't set we are all done so exit out tst.b fade_flag beq.s White_fade_done ; else load the new values into the viewport move.l SS_ViewPort(a5),a0 move.l a2,a1 CALLGRAF LoadRGB32 CALLGRAF WaitTOF bra White_Main_Loop White_fade_done rts Fade_To_Black ; Fades the screen to black and clears the colormap ; operates in a similar way to the above procedure ; but instead of incrementing the colour values we decrement them. ; a0=screen ; a1=source colourmap move.l a1,a2 move.l a0,a5 Black_Main_Loop move.l a2,a0 sf fade_flag move.w (a0),d7 ext.l d7 subq.l #1,d7 addq.l #4,a0 Black_Fader_Loop move.l (a0),d0 beq.s black_red_done sub.l #$01010101,d0 move.l d0,(a0) st fade_flag black_red_done addq.l #4,a0 move.l (a0),d0 beq.s black_blue_done sub.l #$01010101,d0 move.l d0,(a0) st fade_flag black_blue_done addq.l #4,a0 move.l (a0),d0 beq.s black_green_done sub.l #$01010101,d0 move.l d0,(a0) st fade_flag black_green_done addq.l #4,a0 dbra d7,Black_Fader_Loop tst.b fade_flag beq.s black_fade_done move.l SS_ViewPort(a5),a0 move.l a2,a1 CALLGRAF LoadRGB32 CALLGRAF WaitTOF bra Black_Main_Loop black_fade_done rts Fade ; fades between 2 colourmaps ; a0=screen ; a1=source cmap ; a2=destination cmap move.l a0,a5 move.l a2,a3 move.l a1,a2 move.l SS_Planes(a5),d1 allocate a temporary colourmap move.l #0,d0 for the fading bset d1,d0 muls #12,d0 add.l #8,d0 move.l d0,d3 move.l #MEMF_ANY,d1 CALLEXEC AllocMem move.l d0,a4 storage for temporary cmap move.l a2,a0 copy the initial colourmap to the move.l a4,a1 temporary one move.l d3,d0 CALLEXEC CopyMem Fader_Main_Loop move.l a5,-(sp) store the screen structure move.l a4,a5 temporary cmap into a5 move.l a2,a0 both cmaps to temporary areas move.l a3,a1 sf fade_flag clear the fade flag move.w (a0),d7 number of colours ext.l d7 extend to longword subq.l #1,d7 addq.l #4,a5 update the cmaps to first colour addq.l #4,a1 Fader_Loop move.l (a5),d0 source colour move.l (a1),d1 destination colour cmp.l d0,d1 compare the 2 beq.s red_done if they are equal we are done bcs.s decrement_red less so decrement the value increment_red ; if we get to here we want to increment the value add.l #$01010101,d0 bra.s put_red decrement_red sub.l #$01010101,d0 decrement the value put_red move.l d0,(a5) store the flag st fade_flag set the status flag red_done addq.l #4,a5 next component addq.l #4,a1 move.l (a5),d0 does the same as above but for the move.l (a1),d1 blue components cmp.l d0,d1 beq.s blue_done bcs.s decrement_blue increment_blue add.l #$01010101,d0 bra.s put_blue decrement_blue sub.l #$01010101,d0 put_blue move.l d0,(a5) st fade_flag blue_done addq.l #4,a5 addq.l #4,a1 move.l (a5),d0 does the same but for green components move.l (a1),d1 cmp.l d0,d1 beq.s green_done bcs.s decrement_green increment_green add.l #$01010101,d0 bra.s put_green decrement_green sub.l #$01010101,d0 put_green move.l d0,(a5) st fade_flag green_done addq.l #4,a5 addq.l #4,a1 dbra d7,Fader_Loop move.l (sp)+,a5 tst.b fade_flag beq.s fade_done move.l SS_ViewPort(a5),a0 move.l a4,a1 CALLGRAF LoadRGB32 CALLGRAF WaitTOF bra Fader_Main_Loop fade_done move.l SS_Planes(a5),d1 move.l #0,d0 bset d1,d0 muls #12,d0 add.l #8,d0 move.l d0,d3 move.l a4,a1 CALLEXEC FreeMem free the temporary map rts ;--------------------------------------------------------------------- ;-------- IFF Handling routines reading and writing of bitmaps --------- ; Save_IFF(a0,a1)=filename APTR, screen ADDR ; Load_IFF(a0,a1)=filename APTR, screen ADDR ; These procedures use the IFF_Library v23.2 by CHRISTIAN A. WEBE ; For more information please see the distribution along ; with this file Load_IFF ; loads an iff into one a screen ; a0=filename ; a1=destination screen structure ; movem.l a0-a1,-(sp) OPENLIB _IFFLib,0,_IFFBase open the library movem.l (sp)+,a0-a1 move.l a1,-(sp) store the screen structure moveq.l #IFFL_MODE_READ,d0 CALLIFF IFFL_OpenIFF open the IFF file move.l d0,a4 iff_handle move.l (sp)+,a5 screen structure into a5 move.l SS_BitMap(a5),a0 destination bitmap into a0 move.l a4,a1 CALLIFF IFFL_DecodePic decode the iff picture data move.l a4,a0 move.l SS_ColorTable(a5),a1 bsr Full_Palette get the full 24 bit palette data move.l SS_ViewPort(a5),a0 move.l SS_ColorTable(a5),a1 CALLGRAF LoadRGB32 load the colour data move.l a4,a1 CALLIFF IFFL_CloseIFF close the file CLOSELIB _IFFBase close the library rts Save_IFF: ; save a screen as an iff ; a0=filename ; a1=screen to save movem.l a0-a1,-(sp) OPENLIB _IFFLib,0,_IFFBase open the library movem.l (sp)+,a0-a1 move.l a1,a5 move.l #IFFL_MODE_WRITE,d0 CALLIFF IFFL_OpenIFF open a new iff file move.l d0,a4 ;------- Write the BMHD chunk to the IFF file move.l a4,a0 move.l #ID_ILBM,d0 move.l #ID_BMHD,d1 CALLIFF IFFL_PushChunk make a new chunk move.l #20,d0 move.l #MEMF_ANY,d1 CALLEXEC AllocMem allocate temporary memory move.l d0,a3 move.l a3,a0 move.w SS_Width+2(a5),(a0)+ width in pixels move.w SS_Height+2(a5),(a0)+ height in pixels move.w #0,(a0)+ x offset move.w #0,(a0)+ y offset move.b SS_Planes+3(a5),(a0)+ number of bitplanes move.b #0,(a0)+ masking bit move.b #1,(a0)+ compression y/n move.b #0,(a0)+ pad bit move.w #0,(a0)+ transparent move.b #$2c,(a0)+ x aspect assume lowres move.b #$2c,(a0)+ y aspect assume lowres move.w SS_Width+2(a5),(a0)+ page width move.w SS_Height+2(a5),(a0)+ page height move.l a4,a0 move.l a3,a1 move.l #20,d0 CALLIFF IFFL_WriteChunkBytes write the chunk to the file move.l a3,a1 move.l #20,d0 CALLEXEC FreeMem free the temp memory move.l a4,a0 CALLIFF IFFL_PopChunk finished with this chunk ;-------- Done writing the BMHD chunk ;-------- Write the CMAP chunk move.l a4,a0 move.l #ID_ILBM,d0 move.l #ID_CMAP,d1 CALLIFF IFFL_PushChunk set up a new chunk move.l #0,d0 clear d0 move.l SS_Planes(a5),d1 nplanes into d1 bset d1,d0 ncol muls #3,d0 *3 move.l d0,d3 move.l #MEMF_ANY,d1 CALLEXEC AllocMem allocate some temp memory move.l d0,a3 ; Here we want to copy the colourtable data into our temporary ; storage and pop it out onto our IFF file move.l a3,a0 move.l SS_ColorTable(a5),a1 move.l d3,d7 subq.l #1,d7 add.l #4,a1 CMAP_loop move.l (a1)+,d0 move.b d0,(a0)+ dbra d7,CMAP_loop move.l a4,a0 move.l a3,a1 move.l d3,d0 CALLIFF IFFL_WriteChunkBytes write the new chunk data move.l a3,a1 move.l d3,d0 CALLEXEC FreeMem free the temporary memory move.l a4,a0 CALLIFF IFFL_PopChunk done with this chunk ;-------- Done writing the CMAP chunk to the file ;-------- Write the BODY data of the file move.l a4,a0 move.l #ID_ILBM,d0 move.l #ID_BODY,d1 CALLIFF IFFL_PushChunk make a new chunk move.l SS_Width(a5),d0 WIDTH lsr.l #3,d0 /8 muls.l SS_Height(a5),d0 *HEIGHT muls.l SS_Planes(a5),d0 *NPLANES move.l #MEMF_ANY,d1 CALLEXEC AllocMem allocate some temp memory move.l d0,a3 move.l #0,d5 compressed size move.l a3,a1 temporary memory move.l #0,d6 y counter Comp_Height_Loop move.l SS_Screen(a5),a0 move.l d6,d0 move.l SS_Width(a5),d1 lsr.l #3,d1 muls d1,d0 add.l d0,a0 ; set up for the compression loop ; compressed image data has to be interleaved move.l SS_Planes(a5),d7 subq.l #1,d7 Comp_Plane_Loop move.l a0,-(sp) move.l SS_Width(a5),d0 lsr.l #3,d0 move.l #IFFL_COMPR_BYTERUN1,d1 compress the current scan line CALLIFF IFFL_CompressBlock move.l (sp)+,a0 add.l d0,d5 move.l SS_Width(a5),d0 lsr.l #3,d0 muls.l SS_Height(a5),d0 add.l d0,a0 dbra d7,Comp_Plane_Loop onto the next plane move.l SS_Height(a5),d0 subq.l #1,d0 cmp.l d0,d6 bge.s comp_done addq.l #1,d6 bra.s Comp_Height_Loop onto the next scan line comp_done move.l a4,a0 move.l a3,a1 move.l d5,d0 CALLIFF IFFL_WriteChunkBytes write the data move.l a3,a1 move.l SS_Width(a5),d0 WIDTH lsr.l #3,d0 /8 muls.l SS_Height(a5),d0 *HEIGHT muls.l SS_Planes(a5),d0 *NPLANES CALLEXEC FreeMem free our temporary memory move.l a4,a0 CALLIFF IFFL_PopChunk pop this chunk off ;-------- Done writing the BODY data move.l a4,a1 CALLIFF IFFL_CloseIFF finished with the file CLOSELIB _IFFBase close the library rts Full_Palette ; Gets the 24 bit colour information from an iff file ; needs IFF Library ; Internal IFF Routine used by load iff ; in:- a0=handle ; a1=destination colourmap PUSH a0-a1 move.l a0,a1 move.l #ID_CMAP,d0 CALLIFF IFFL_FindChunk find the CMAP Chunk move.l d0,a2 store this memory PULL a0-a1 addq.w #4,a2 move.l (a2)+,d7 number of colours to move.l d7,d0 amount of data to strip out divs #3,d0 move.w d0,(a1)+ number of colours into colormap addq.w #2,a1 onto first location subq.l #1,d7 _col_loop moveq.l #0,d0 move.b (a2),d0 first value lsl.l #8,d0 shift up move.b (a2),d0 get value again lsl.l #8,d0 shift up move.b (a2),d0 get value again lsl.l #8,d0 shift up move.b (a2)+,d0 get value again move.l d0,(a1)+ write colour data dbra d7,_col_loop rts ;-------- End of IFF Routines ----------------------------------------------- ;-------- File handling Routines ---------------------------------------- ; Load_Data(a0,d0,a1) filename, buffer length, destination ; Save_Data(a0,d0,d1) filename, buffer length, source Load_Data ; Loads data from a file ; input a0=filename ; d0=byte size of data to read ; a1=destination buffer move.l d0,-(sp) PUSHALL OPENLIB _DosLib,0,_DOSBase PULLALL move.l a0,d1 filename into d1 move.l #MODE_OLDFILE,d2 type of file PUSH d0-d3/a0-a1 store registers CALLDOS Open open the file tst.l d0 beq.s Open_Failed move.l d0,d5 store the filehandle PULL d0-d3/a0-a1 restore registers move.l d5,d1 filehandle into d1 move.l a1,d2 desination for the data move.l (sp)+,d3 size of the data CALLDOS Read read the data move.l d5,d1 filehandle into d1 CALLDOS Close close the file Open_Failed CLOSELIB _DOSBase rts Save_Data ; saves data from a file ; input a0=filename ; d0=byte size of data to write ; a1=source buffer move.l d0,-(sp) PUSHALL OPENLIB _DosLib,0,_DOSBase PULLALL move.l a0,d1 filename into d1 move.l #MODE_NEWFILE,d2 type of file PUSH d0-d3/a0-a1 store registers CALLDOS Open open the file tst.l d0 beq.s Save_Open_Failed move.l d0,d5 store the filehandle PULL d0-d3/a0-a1 restore registers move.l d5,d1 filehandle into d1 move.l a1,d2 source for the data move.l (sp)+,d3 size of the data CALLDOS Write read the data move.l d5,d1 filehandle into d1 CALLDOS Close close the file Save_Open_Failed CLOSELIB _DOSBase rts ;------------------------------------------------------------------------ ;-------- Text handling routines ------------------------------------------- ; Write_Text(a0,a1,d0,d1,d2,d3) screen, text, x, y, colour, length ; Num_To_String(d0) word Write_Text ; writes the text to the screen using the current font ; a0=screen ; a1=text ; d0=x ; d1=y ; d2=colour ; d3=string length exg.l a1,a0 get the screen and text into the right reg move.l SS_RastPort(a1),a1 rastport into a1 movem.l a0-a1/d0-d3,-(sp) CALLGRAF Move move to the text position movem.l (sp)+,a0-a1/d0-d3 movem.l a0-a1/d0-d3,-(sp) move.l d2,d0 CALLGRAF SetAPen set the colour movem.l (sp)+,a0-a1/d0-d3 move.l d3,d0 text length into d0 CALLGRAF Text write the text rts Num_To_String: ; converts a word value into a hex string ; string returned in a1 ; d0=word move.w d0,d1 move.w d1,d2 move.w d2,d3 and.w #%0000000000001111,d0 get the lower byte value and.w #%0000000011110000,d1 get the successive bytes and.w #%0000111100000000,d2 and.w #%1111000000000000,d3 lsr.w #4,d1 get these values to the lowest lsr.w #8,d2 position by shifting lsr.w #6,d3 lsr.w #6,d3 cmp.b #9,d0 if we have a number bgt.s do_char_d0 add.b #$30,d0 add the '0' onto it bra.s done_d0 all done do_char_d0 sub.b #10,d0 else subtract 10 add.b #$41,d0 add the 'A' onto it done_d0 cmp.b #9,d1 do the same for the four other bgt.s do_char_d1 registers add.b #$30,d1 bra.s done_d1 do_char_d1 sub.b #10,d1 add.b #$41,d1 done_d1 cmp.b #9,d2 bgt.s do_char_d2 add.b #$30,d2 bra.s done_d2 do_char_d2 sub.b #10,d2 add.b #$41,d2 done_d2 cmp.b #9,d3 bgt.s do_char_d3 add.b #$30,d3 bra.s done_d3 do_char_d3 sub.b #10,d3 add.b #$41,d3 done_d3 lea num_string,a0 move.b d3,(a0)+ write the data to the number string move.b d2,(a0)+ move.b d1,(a0)+ move.b d0,(a0)+ move.b #0,(a0)+ lea num_string,a1 rts ;------------------------------------------------------------------------ ;-------- Copper handling routines ------------------------------------- ; Add_Copper(a0,a1) screen,copper list Add_Copper ; Adds a copper list stream to the specified screen ; a0=screen ; a1=copper instructions move.l a0,a5 move.l a1,a2 move.l #12,d0 enough space for a user copper struc move.l #MEMF_PUBLIC!MEMF_CLEAR,d1 CALLEXEC AllocMem allocate memory for a user copper structure move.l d0,SS_UserCopperList(a5) move.l SS_UserCopperList(a5),a0 move.l #5000,d0 allocate enough space for 5000 entries CALLGRAF UCopperListInit .Copper_Loop move.l (a2),d0 cmp.l #$fffffffe,d0 check if we have a copper end instruction beq.s .Copper_Done move.w 2(a2),d0 cmp.w #$fffe,d0 else check if it is a copper move bne.s .Copper_Move .Copper_Wait move.w (a2),d0 we want to feed a copper wait move.w #0,d1 into the copper stream move.b d0,d1 so decode and write it lsr.w #8,d0 move.l SS_UserCopperList(a5),a1 CALLGRAF CWait move.l SS_UserCopperList(a5),a1 CALLGRAF CBump add.w #4,a2 bra.s .Copper_Loop .Copper_Move move.w (a2)+,d0 decode the move instruction move.w (a2)+,d1 and feed it into the copper move.l SS_UserCopperList(a5),a1 stream CALLGRAF CMove move.l SS_UserCopperList(a5),a1 CALLGRAF CBump bra.s .Copper_Loop .Copper_Done move.l SS_UserCopperList(a5),a1 all done so write the copper move.w #10000,d0 end instruction to the stream move.w #255,d1 CALLGRAF CWait move.l SS_UserCopperList(a5),a1 CALLGRAF CBump CALLEXEC Forbid latch the copper list onto move.l SS_ViewPort(a5),a0 the viewport move.l SS_UserCopperList(a5),vp_UCopIns(a0) move.l SS_View(a5),a0 move.l SS_ViewPort(a5),a1 CALLGRAF MakeVPort remake the viewport move.l SS_View(a5),a1 CALLGRAF MrgCop merge the copperlist SHOW a5 show the screen CALLEXEC Permit rts ;------------------------------------------------------------------------ ;-------- Input Handling Routines --------------------------------------- ; GetKey() GetKey moveq.l #0,d0 clear the register move.b $BFEC01,d0 get value from CIA chip not.b d0 manipulate it to form raw ror.b #1,d0 key code rts ;------------------------------------------------------------------------ Section System_Data,DATA_F ; Data required by the above routines _DosLib DOSNAME even _graphics_lib GRAFNAME even _IFFLib IFFNAME even *TagItem structure vctags: dc.l VTAG_ATTACH_CM_SET,0 dc.l VTAG_VIEWPORTEXTRA_SET,0 dc.l VTAG_NORMAL_DISP_SET,0 dc.l VTAG_END_CM,0 Section System_BSS,BSS_F ; storage required by the above routines _IntuitionBase: ds.l 1 _GfxBase ds.l 1 _IFFBase ds.l 1 _DOSBase ds.l 1 _oldview ds.l 1 clip_out ds.l 1 line_flag ds.l 1 fade_flag ds.l 1 x_min ds.w 1 x_max ds.w 1 y_min ds.w 1 y_max ds.w 1 blitmod ds.w 1 bltwidth ds.w 1 blitsize ds.w 1 bltstrt ds.w 1 num_string ds.b 5