Developer CD Series 1991 July: Desperately Seeking Seven

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Assembly Source File | 1990-05-25 | 47.0 KB | 1,376 lines | [04] ASCII Text (0x0000)

******************************************************************************* * * Math -- Version 3.0 * * (C) Copyright Apple Computer, Inc. 1988-1990 * All rights reserved. * * Developer Technical Support Apple II Sample Code * * by Jim Mensch * * Sample to show how to use the Integer math and SANE tools. This program shows * 2 basic operations performed both with the integer math tools and SANE. The * first is the calculation and display of a simple SINE curve. The second is * a more complex Fast Fourier Transform. * ******************************************************************************* eject ********************************************************************** * * * Apple IIGS Source Code Sampler, Volume I * * * * Copyright (c) Apple Computer, Inc. 1988-1990 * * All Rights Reserved * * * * Written by Apple II Developer Tech Support * * * * * * * * ---------------------------------------------------------------- * * * * This program and its derivatives are licensed only for * * use on Apple computers. * * * * Works based on this program must contain and * * conspicuously display this notice. * * * * This software is provided for your evaluation and to * * assist you in developing software for the Apple IIGS * * computer. * * * * DISCLAIMER OF WARRANTY * * * * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT * * WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, * * WITH RESPECT TO ITS MERCHANTABILITY OR ITS FITNESS * * FOR ANY PARTICULAR PURPOSE. THE ENTIRE RISK AS TO * * THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH * * YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU (AND * * NOT APPLE OR AN APPLE AUTHORIZED REPRESENTATIVE) * * ASSUME THE ENTIRE COST OF ALL NECESSARY SERVICING, * * REPAIR OR CORRECTION. * * * * Apple does not warrant that the functions * * contained in the Software will meet your requirements * * or that the operation of the Software will be * * uninterrupted or error free or that defects in the * * Software will be corrected. * * * * SOME STATES DO NOT ALLOW THE EXCLUSION * * OF IMPLIED WARRANTIES, SO THE ABOVE EXCLUSION MAY * * NOT APPLY TO YOU. THIS WARRANTY GIVES YOU SPECIFIC * * LEGAL RIGHTS AND YOU MAY ALSO HAVE OTHER RIGHTS * * WHICH VARY FROM STATE TO STATE. * * * * * ********************************************************************** eject case on copy 2/ainclude/E16.Quickdraw copy 2/ainclude/E16.Memory copy 2/ainclude/E16.Window copy 2/ainclude/E16.Dialog copy 2/ainclude/E16.SANE mcopy macros/math.mac1 DPHandle gequ 0 DPPointer gequ DPHandle+4 DeRef gequ DPPointer+4 ScreenWidth gequ 640 ScreenMode gequ $80 EJECT ******************************************************************************* * Math start * * Description: This main routine calls the other major routines in the * correct order. * * * Inputs: None * * Outputs: None * * External Refs: * Import QuitParms * Import InitTools * Import InitApp * Import EventLoop * Import CloseTools * Import CloseApp * * Entry Points: None * ******************************************************************************* jsr InitTools jsr InitApp _ShowCursor jsr EventLoop jsr CloseApp jsr CloseTools _Quit QuitParms end EJECT ******************************************************************************* * Globals data * * Description: Global data for use in all routines of this demo. This area * also contains the data used by StandardLib.aii * * * Inputs: None * * Outputs: None * * External Refs: * Import displayCache * * Entry Points: * Export QuitParms ; used by Main * ******************************************************************************* * * Standard global data * ******************************************************************************* TitleString str 'Apple IIgs Integer Math/Sane demo' AutString str 'By Jim Mensch Apple DTS -- Version: 3.0' VersString str 'Copyright (c) 1988-1990 Apple Computer' MenuHeight ds 2 ; Stored height of menu bar MyID ds 2 ; Application ID MyDP ds 2 ; My direct page storage QuitFlag ds 2 QuitParms dc i4'0' ; Pathname of next app dc i2'$00' ; flags EventRecord ANOP EventWhat ds 2 EventMessage ds 4 EventWhen ds 4 EventWhere ds 4 EventModifiers ds 2 TaskData ds 4 TaskMask dc i4'$0000FFFF' portCacheInfo ds 4 ds 4 ds 4 ds 4 dc i2'$C000' dc i2'0,0,175,599' dc i2'0,0,175,599' EJECT ******************************************************************************* * * Application specific global data * ******************************************************************************* ; This is a list of pointers to the text that is used to create our menus. It ; is used by InitApp to find all of the menu templates and use them to create ; our menubar. This loop loads MenuPtrLen-4 into an index, gets the ; corresponding menu template pointer in this table, and uses that in a ; NewMenu call. It then decrements the index by 4, and repeats the procees ; until the index is negative. MenuPtr dc i4'AppMenu' dc i4'FileMenu' MenuPtrLen equ *-MenuPtr ; Menu list: menu items should be numbered consecutivly starting from 250. ; As a convention, use 256 as about and 257 as Quit. AppMenu dc c'$$@\XN1',i1'$0D' dc c'--About Math...\N256V',i1'$00' dc c'.' FileMenu dc c'$$ File \N2',i1'$0D' dc c'--SANE Fast Fourier transform\N260',i1'$00' dc c'--Integer Fast Fourier transform\N261',i1'0' dc c'--Integer Sine wave\N258*Ii',i1'$00' dc c'--SANE Sine wave\N259*SsV',i1'$00' dc c'--Quit\N257*Qq',i1'$00' dc c'.' ; Paramater block used to create the main window for display. All the ; graphing routines will use this window to draw into. MyWindow dc i2'WindEnd-*' ; size of paramBlock dc i2'%0010000000100000' ; frame bits : alert, vis dc i4'0' ; no title bar, no title... dc i4'0' ; ref con 0 dc i2'0,0,0,0' ; zoomed rect dc i4'0' ; color table = default dc i2'0,0' ; scroll bar XY origin dc i2'0,0' ; no scroll no max... dc i2'0,0' ; No zooming... dc i2'0,0' ; no scrolling dc i2'0,0' ; no paging.... dc i4'0' ; no info bar, no ref con dc i2'0' ; info bar height ( none...) dc i4'0' ; Frame defproc, NIL=standard dc i4'0' ; no info bar def proc dc i4'displayCache' ; update procedure to display cache dc i2'20,20,195,619' ; bounds rect... dc i4'$FFFFFFFF' ; plane= on top... dc i4'0' ; NIL storage pointer WindEnd equ * ContRect dc i2'0,0,180,599' ; content rectangle WindPointer ds 4 ; Constants used thru the program both represent PI*2 TwoPi dc i1'$1D,$72,$33,$DC,$80,$CF,$0F,$C9,$01,$40' TwoPiFix dc i2'$487E,$0006' ; Titles for the bottom of the window IntSineTitle str 'Integer Math Demo: plotting Y=SIN(X)' SANESineTitle str 'SANE Demo: plotting Y=SIN(X)' IntHarmTitle str 'Integer Math Demo: plotting complex waveform' SANEHarmTitle str 'SANE Demo: plotting complex waveform' end EJECT ******************************************************************************* * InitApp start * * Description: This routine creates our window and zeros out the quitflag * * * Inputs: None * * Outputs: None * * External Refs: * Import newPort * * Entry Points: None * ******************************************************************************* using Globals Stz QuitFlag ; zero out quit flag PushLong #0 PushLong #MyWindow _NewWindow ; create a window to graph in PullLong WindPointer PushLong WindPointer _SetPort ; make the new window the current port pha pha pea portCacheInfo|-16 pea portCacheInfo jsl newPort pla ; The result is also stored in portCacheInfo. pla rts end EJECT ******************************************************************************* * CloseApp start * * Description: This routine will be called at program end to dispose of * the window. * * * Inputs: None * * Outputs: None * * External Refs: * Import killPort * * Entry Points: None * ******************************************************************************* using Globals PushLong WindPointer _CloseWindow pea portCacheInfo|-16 pea portCacheInfo jsl killPort rts end EJECT ******************************************************************************* * EventLoop start * * Description: Main loop. Handles events until the user selects quit * * * Inputs: None * * Outputs: None * * External Refs: * Import Ignore * Import MenuSelect * * Entry Points: * ******************************************************************************* using Globals pha ; Push on space for TaskMaster result PushWord #$FFFF ; GetNextEvent mask PushLong #EventRecord ; Pointer to Event Record _TaskMaster pla ; Get TaskMaster result beq EventLoop ; Remove if you want to use null events asl A ; Turn it into an index tax jsr (TaskTable,x) ; Call appropriate event handler lda QuitFlag ; Quit selected? beq EventLoop ; no - keep looping rts ; yes- leave the program TaskTable dc i2'Ignore' ; 0 Null dc i2'Ignore' ; 1 MouseDown dc i2'Ignore' ; 2 Mouse Up dc i2'Ignore' ; 3 KeyDown dc i2'Ignore' ; 4 Undefined dc i2'Ignore' ; 5 AutoKey dc i2'Ignore' ; 6 Update dc i2'Ignore' ; 7 undefined dc i2'Ignore' ; 8 activate dc i2'Ignore' ; 9 Switch dc i2'Ignore' ; 10 desk acc dc i2'Ignore' ; 11 device driver dc i2'Ignore' ; 12 ap dc i2'Ignore' ; 13 ap dc i2'Ignore' ; 14 ap dc i2'Ignore' ; 15 ap dc i2'Ignore' ; TASK 0 indesk dc i2'MenuSelect' ; TASK 1 in menuBar dc i2'Ignore' ; TASK 2 in system window dc i2'Ignore' ; TASK 3 in content dc i2'Ignore' ; TASK 4 in Drag dc i2'Ignore' ; TASK 5 in grow dc i2'Ignore' ; TASK 6 in goaway dc i2'Ignore' ; TASK 7 in zoom dc i2'Ignore' ; TASK 8 in info bar dc i2'Ignore' ; TASK 9 in special menu dc i2'Ignore' ; TASK 10 in NDA dc i2'Ignore' ; TASK 11 in frame dc i2'Ignore' ; TASK 12 in drop end EJECT ******************************************************************************* * MenuSelect start * * Description: This routine is called when taskmaster returns a code * indicating that the user selected one of our menu options. * This routine will call whatever routine is indicated for * each menu action * * * Inputs: TaskData - menu selected by the user * * Outputs: None * * External Refs: * Import Ignore * Import doAbout * Import doQuit * Import IntSineCurve * Import SANESineCurve * Import IntHarmWave * Import SANEHarmWave * * Entry Points: * ******************************************************************************* using Globals lda TaskData ; get the ID of the menu item selected sec ; adjust it to be between 0 and 5 sbc #256 asl a ; multiply it by 2 tax ; and use it as an index into our jump jsr (MenuTable,x) ; table. MSDone ANOP PushWord #0 ; menu action complete, unhilite the PushWord TaskData+2 ; selected menu to show we are done _HiliteMenu rts ; and quit MenuTable dc i2'doAbout' ; about shell... dc i2'doQuit' ; quit selected dc i2'IntSineCurve' ; draw integer math sine wave dc i2'SANESineCurve' ; draw sane sine wave dc i2'SANEHarmWave' dc i2'IntHarmWave' end EJECT ******************************************************************************* * doQuit start * * Description: Sets the quit flag to inform the event loop that the user * wants to stop the program * * * Inputs: None * * Outputs: None * * External Refs: None * * Entry Points: None * ******************************************************************************* using Globals lda #$FFFF sta QuitFlag rts end ******************************************************************************* * Ignore start * * Description: Called when the program gets an event or menu selection that * it does not want to handle * * * Inputs: None * * Outputs: None * * External Refs: None * * Entry Points: None * ******************************************************************************* rts end EJECT ******************************************************************************* * setCachePort start * Export setViewPort, displayCache using Globals plx ;Clone enough of the stack. tsc sta keepStackPtr ldy #10 aa lda 10*2-1,s pha dey bne aa phx lda portCacheInfo+2 ;Switch to cache port. pha lda portCacheInfo pha _SetPort rts setViewPort entry plx ;Set the stack back to before cloning. lda keepStackPtr tcs phx lda WindPointer+2 pha lda WindPointer pha _SetPort rts keepStackPtr dc i2'0' displayCache entry pha pha _GetPort lda portCacheInfo+2 pha lda portCacheInfo pha _SetPort pea cacheLocInfo|-16 pea cacheLocInfo _GetPortLoc pea cachePortRect|-16 pea cachePortRect _GetPortRect _SetPort pea cacheLocInfo|-16 pea cacheLocInfo pea cacheBoundsRect|-16 pea cacheBoundsRect lda #0 pha pha pha _PPToPort rtl cacheLocInfo ds 8 cacheBoundsRect ds 8 cachePortRect ds 8 END * ******************************************************************************* ******************************************************************************* * IntSineCurve start * * Description: This routine will calculate a simple Sine curve and display * it graphically on the screen. * * * Inputs: None * * Outputs: None * * External Refs: None * * Entry Points: None * ******************************************************************************* using Globals _WaitCursor PushLong #ContRect ; first, start with a clean screen jsr setCachePort ; by erasing the old screen _EraseRect jsr setViewPort _EraseRect PushWord #10 ; label the bottom of the window PushWord #170 ; to show what we are doing jsr setCachePort _MoveTo jsr setViewPort _MoveTo PushLong #IntSineTitle jsr setCachePort _DrawString jsr setViewPort _DrawString stzL LoopCount ; zero the counter to start this thing PushWord #0 ; start this drawing off PushWord #80 jsr setCachePort _MoveTo jsr setViewPort _MoveTo DIMLoop ANOP LongResult ; space for results here for all the LongResult ; following calculations. by pushing LongResult ; the space here, we do not need to LongResult ; adjust the stack between int math calls LongResult ; and we save time and space PushLong LoopCount ; Calc: LoopCount/180 PushLong One80 ; _FixDiv ; leave result on stack for next calc PushLong RFixPi ; Calc (LoopCount/180)*PI _FixMul ; to convert LoopCount to radians _FracSin ; take the sine of the counter _Frac2Fix ; convert it back to fixed # PushLong Eighty ; multiply it by 80 to scale _FixMul ; we have our number! PullLong YCord ; and its the y coordinate PushWord LoopCount+2 ; X coordinate (HiWord of Fixed) lda YCord+2 ; Y coordinate + 80 clc ; to scale the number between adc #80 ; 0 and 160 pha jsr setCachePort _LineTo ; draw the linesegment for this point jsr setViewPort _LineTo inc LoopCount+2 ; bump the loopcounter lda LoopCount+2 ; and see if we have reached 360 cmp #360 ; for a full SINE curve bge DIMDone ; if so, then finish the loop brl DIMLoop ; if not do the next iteration DIMDone _InitCursor rts ; finish the routine LoopCount ds 4 ; Fixed number to store degrees One80 dc i2'0,180' ; a fixed number representing 180 Eighty dc i2'0,80' ; a FIxed number represenging 80 YCord ds 4 ; temp storage for the y coordinate RFixPi dc i4'$0003243F' ; 3.14159 (PI in fixed format) end EJECT ******************************************************************************* * SANESineCurve start * * Description: This routine will use the SANE toolset to calculate * a Sine curve. It will then plot the points on the screen. * * * Inputs: None * * Outputs: None * * External Refs: None * * Entry Points: None * ******************************************************************************* using Globals _WaitCursor PushLong #ContRect ; first, start with a clean screen jsr setCachePort ; by erasing the old screen _EraseRect jsr setViewPort _EraseRect PushWord #10 ; label the bottom of the window PushWord #170 ; to show what we are doing jsr setCachePort _MoveTo jsr setViewPort _MoveTo PushLong #SANESineTitle jsr setCachePort _DrawString jsr setViewPort _DrawString PushWord #0 ; start this drawing off PushWord #80 ; in the middle of the screen jsr setCachePort _MoveTo jsr setViewPort _MoveTo stz LoopCount DSaneLoop ANOP ExtendEq SanePi,TempResult ; move pi/180 into the result PushLong #LoopCount ; convert LoopCount to Radians PushLong #TempResult FMULI ; by multiplying by pi/180 PushLong #TempResult FSINX ; now get the SINE of it PushLong #Eighty ; multiply by 80 PushLong #TempResult FMULI PushLong #TempResult PushLong #YCord ; convert to an Integer FX2I PushWord LoopCount ; X coordinate lda YCord ; Y coordinate + 80 clc ; to get a number between adc #80 ; 0 and 160 pha jsr setCachePort ; draw the line segement _LineTo jsr setViewPort _LineTo inc LoopCount ; bump the counter lda LoopCount cmp #360 ; and see if we have done all 360 degrees bge DSaneDone ; if so then end brl DSaneLoop ; if not, get next value DSaneDone _InitCursor rts LoopCount ds 4 SanePi dc i1'$AE,$C8,$E9,$94,$12,$35,$FA,$8E,$F9,$3F' ; pi/180 ... TempResult ds 10 Eighty dc i4'80' YCord ds 4 end EJECT ******************************************************************************* * FFTransData data * * Description: Data used by both FFT calculation routines * * * Inputs: None * * Outputs: None * * External Refs: None * * Entry Points: None * ******************************************************************************* FixCount dc i2'0' ; fractional portsion of our Count ds 2 ; fixed point counter LoopCount ds 2 FixSamp dc i2'0' ; fractional portion of the sample var Sample ds 2 ; sample to figure for FixMaxSamp dc i2'0' ; fractional portion of Max Sample MaxSample dc i2'256' ; maximum number of samples MaxHarm dc i2'6' ; maximum number of harmonics MaxValue ds 10 ; maximum vaule of the FFT AmpTbl dc i2'0,10,8,6,4,2,1' ; amplitudes of each harmonic PhaseTbl dc i2'0,1,2,4,6,8,10' ; high word of each fixed phase PhaseTblF dc i4'0,6554,13107,26214,39321,52428,$FFFF' TempValue ds 10 ; intermediate result storage TempFactor ds 10 Temp1 ds 10 Temp2 ds 10 FFTWave ds 2560 ; table to hold intermediate values MyDecForm dc i2'1' dc i2'8' ; 8 digits after the decimal place TempI ds 2 TempF ds 4 Const127 dc i2'79' Const80Fix dc i4'$004F000' Const10 dc i2'10' end EJECT ******************************************************************************* * SANEHarmWave start * * Description: Create a complex harmonic wave using SANE * * * Inputs: None * * Outputs: None * * External Refs: * Import SaneFFTIteration * Import doNormIter * * Entry Points: * ******************************************************************************* using Globals using FFTransData _WaitCursor PushLong #ContRect ; first, start with a clean screen jsr setCachePort ; by erasing the old screen _EraseRect jsr setViewPort _EraseRect PushWord #10 ; label the bottom of the window PushWord #170 ; to show what we are doing jsr setCachePort _MoveTo jsr setViewPort _MoveTo PushLong #SANEHarmTitle jsr setCachePort _DrawString jsr setViewPort _DrawString PushWord #0 ; start this drawing off PushWord #80 ; at the left edge jsr setCachePort _MoveTo jsr setViewPort _MoveTo stz Sample ; and zero out all global values STZEXT MaxValue STZEXT Temp1 STZEXT Temp2 STZEXT TempFactor DHWLoop1 jsr SaneFFTIteration ; do one iteration lda Sample ; now save tempValue into our array asl a ; multiply by 2 sta Temp1 ; and save it for a sec asl a asl a ; multiply by 8 clc adc Temp1 ; x*8+x*2=x*10 tax ; use as an index into the sample array lda TempValue ; now stow the current value sta FFTWave,x ; into our wave table. Later this lda TempValue+2 ; table will be normalized sta FFTWave+2,x lda TempValue+4 sta FFTWave+4,x lda TempValue+6 sta FFTWave+6,x lda TempValue+8 sta FFTWave+8,x inc Sample ; bump the sample counter lda #255 cmp Sample ; test to see if we have reached the bge DHWLoop1 ; last sample, if not do the next one ; if the last sample was reached, it is time to go thru the wavetable and ; convert all the number so they are between 0 and 160. stz Count ; initialize the index DHWLoop2 inc Count jsr doNormIter ; normalize one iteration PushWord Count ; X coordinate PushWord TempValue ; value returned by doNormIter jsr setCachePort ; draw the line _LineTo jsr setViewPort _LineTo lda #255 ; see if the counter has reached the max cmp Count ; sample we recorded bge DHWLoop2 ; if not, do another point _InitCursor ; if it has, then we can simply end rts end EJECT ******************************************************************************* * SaneFFTIteration start * * Description: This routine takes the current sample value and computes * all the harmonic components that make up the wave for that * sample. * * * Inputs: Sample - current sample to compute for * * Outputs: TempValue - output sample value * * External Refs: * * Entry Points: * ******************************************************************************* using Globals using FFTransData STZEXT TempValue PushLong #Sample PushLong #TempFactor FI2X ; convert the max sample rate to extended PushLong #MaxSample PushLong #Temp1 FI2X PushLong #Temp1 PushLong #TempFactor FDIVX ; TempFactor:=TempFactor/Temp1 PushLong #TwoPi PushLong #TempFactor FMULX ; TempFactor:=6.28318*(count/maxSample) stz Count ; zero out the counter FFLoop ANOP ExtendEq TwoPi,Temp2 lda Count ; get the count asl a ; multiply by 2 tax lda PhaseTbl,x sta TempI PushLong #TempI PushLong #Temp1 FI2X ; Temp1:=Phase[count] PushLong #Const10 PushLong #Temp1 FDIVI ; divide by 10 to make it fractional PushLong #Temp1 PushLong #Temp2 FMulX ; Temp2:=(Temp1)/10*TwoPi ExtendEq TempFactor,Temp1 PushLong #Count PushLong #Temp1 FMULI ; tempi:=count*TempFactor PushLong #Temp2 PushLong #Temp1 FADDX ; Temp1:=((count*TempFactor)+(6.28318*Phase[count])) PushLong #Temp1 FCOSX ; Temp1:=Cos(Temp1) lda Count ; get the count asl a ; multiply by 2 tax lda AmpTbl,x sta TempI PushLong #TempI PushLong #Temp1 FMULI ; Temp1:=Temp1*Amp[count] PushLong #Temp1 PushLong #TempValue FADDX ; finally tempValue:=tempValue+Temp1 PushLong #TempValue PushLong #Temp1 FX2X ; copy tempvalue into Temp1 PushLong #Temp1 FABSX PushLong #Temp1 PushLong #MaxValue FCMPX ; now update the max value if needed FBLE FFTL010 ; if the new number <= old max ignore next line ExtendEq Temp1,MaxValue FFTL010 ANOP inc Count lda Count cmp MaxHarm ; are we done yet??? bge FFTDone brl FFLoop FFTDone rts end EJECT ******************************************************************************* * doNormIter start * * Description: Normalize one iteration of the wavetable. This routine * takes the current sample value and converts it to * * * Inputs: Count - current sample number * * Outputs: TempValue - the normalized value * * External Refs: None * * Entry Points: None * ******************************************************************************* using Globals using FFTransData lda Count asl a ; multiply by 2 sta Temp1 ; and save it for a sec asl a asl a ; multiply by 8 clc adc Temp1 ; x*8+x*2=x*10 tax lda FFTWave,x ; now load the current value sta TempValue lda FFTWave+2,x sta TempValue+2 lda FFTWave+4,x sta TempValue+4 lda FFTWave+6,x sta TempValue+6 lda FFTWave+8,x sta TempValue+8 ExtendEq MaxValue,Temp2 PushLong #Temp2 PushLong #TempValue ; divide the two FDIVX PushLong #Const127 ; now scale it PushLong #TempValue FMULI PushLong #Const127 PushLong #TempValue FADDI PushLong #TempValue ; now, convert ot to an integer PushLong #TempI FX2I lda TempI sta TempValue rts end EJECT ******************************************************************************* * IntHarmWave start * * Description: This routine will create a complex waveformusing the * integer math tools * * * Inputs: None * * Outputs: None * * External Refs: * Import IntFFTIteration * Import IntHarmI * * Entry Points: * ******************************************************************************* using Globals using FFTransData _WaitCursor PushLong #ContRect ; first, start with a clean screen jsr setCachePort ; by erasing the old screen _EraseRect jsr setViewPort _EraseRect PushWord #10 ; label the bottom of the window PushWord #170 ; to show what we are doing jsr setCachePort _MoveTo jsr setViewPort _MoveTo PushLong #IntHarmTitle jsr setCachePort _DrawString jsr setViewPort _DrawString PushWord #0 ; start this drawing off PushWord #80 jsr setCachePort _MoveTo jsr setViewPort _MoveTo stz Sample ; zero out some starting values STZL MaxValue STZL Temp1 STZL Temp2 STZL TempFactor DIWLoop1 jsr IntFFTIteration ; do one iteration of the wave lda Sample ; now save tempValue into our array asl a ; multiply by 2 asl a tax lda TempValue ; now stow the temp value sta FFTWave,x ; into an array for later use lda TempValue+2 sta FFTWave+2,x inc Sample ; bump the sample counter lda #255 cmp Sample ; see if we are done bge DIWLoop1 ; if not, get another sample ; Now that the array of values has been created. Go thru and scale ; each value so that it fits in our wave and is between 0 and 160 stz Count ; zero the sample counter DIWLoop2 inc Count jsr IntHarmI ; normalize one iteration PushWord Count ; X coordinate PushWord TempValue jsr setCachePort ; draw the line _LineTo jsr setViewPort _LineTo lda #255 cmp Count bge DIWLoop2 _InitCursor rts end EJECT ******************************************************************************* * IntFFTIteration start * * Description: This routine will calculate one single iteration of the * wave. It will add a the Cosine*amp of each desired * harmonic to create a single sample * * * Inputs: None * * Outputs: None * * External Refs: * * Entry Points: * ******************************************************************************* using Globals using FFTransData stzL TempValue LongResult ; push room on the stack LongResult ; push room on the stack PushLong FixSamp ; sample fixed number format PushLong FixMaxSamp ; max sample fixed point number _FixDiv PushLong TwoPiFix _FixMul ; now multiply the two to get theFactor PullLong TempFactor stz Count ; zero out the counter FFLoop ANOP lda Count ; get the count asl a ; multiply by 2 asl a tax lda PhaseTblF,x sta TempF lda PhaseTblF+2,X sta TempF+2 LongResult ; push room on the stack PushLong TwoPiFix PushLong TempF _FixMul ; Temp2:=Phase(Count)*TwoPi PullLong Temp2 LongResult ; push room on the stack PushLong FixCount PushLong TempFactor _FixMul ; Temp1:=count*TempFactor PullLong Temp1 lda Temp1 ; Temp2:=Temp1+Temp2 clc adc Temp2 sta Temp2 lda Temp1+2 adc Temp2+2 sta Temp2+2 LongResult ; push room on the stack LongResult ; push room on the stack LongResult ; push room on the stack PushLong Temp2 _FracCos ; Temp2:=Cos(Temp2) _Frac2Fix ; convert back to fixed! PullLong Temp2 PushLong Temp2 lda Count ; get the count asl a ; multiply by 2 tax lda AmpTbl,x pha pea $0 ; Low word of fixed count _FixMul ; Temp1:=Temp1*Amp[count] PullLong Temp2 lda TempValue ; now add it to tempValue clc adc Temp2 sta TempValue sta Temp2 lda TempValue+2 adc Temp2+2 sta TempValue+2 ; Now test for max value sta Temp2+2 bpl TestHigh ; number is positive, test for high lda #0 ; Negate this number to get absolute value sec sbc Temp2 ; negate this number sta Temp2 lda #0 sbc Temp2+2 sta Temp2+2 TestHigh lda Temp2+2 cmp MaxValue+2 ; is it bigger than max value+2? beq FFTTestLow ; if equal test the low byte bge FFTStoreMax ; if greater move it to high bra FFTL010 FFTTestLow lda Temp2 cmp MaxValue ; is it bigger? blt FFTL010 FFTStoreMax lda Temp2+2 sta MaxValue+2 lda Temp2 sta MaxValue FFTL010 ANOP inc Count lda Count cmp MaxHarm ; are we done yet??? bge FFTDone brl FFLoop FFTDone rts end EJECT ******************************************************************************* * IntHarmI start * * Description: Takes an iteration of the wave divides it by the max value * and multiplies it by 160 to create a valid screen location * * * Inputs: None * * Outputs: None * * External Refs: * * Entry Points: * ******************************************************************************* using Globals using FFTransData lda Count asl a ; multiply by 4 asl a tax lda FFTWave+2,x ; push current value on stack sta Temp1+2 lda FFTWave,x ; sta Temp1 LongResult ; push room on the stack LongResult ; push room on the stack PushLong Temp1 PushLong MaxValue ; divide it by maxvalue _FixDiv PullLong Temp2 PushLong Temp2 PushWord #$4F PushWord #0 ; now scale it _FixMul PullLong Temp1 lda Temp1+2 clc adc #79 sta TempValue rts end copy math.init.asm END