;********************************************************** ;** ;** MSLOPEHEIGHT: ;** m_bigx = object's x ;** m_bigz = object's z ;** m_spra = x normal ;** m_sprb = y normal ;** m_sprc = z normal ;** m_bigy = distance of plane ;** ;** Exit: m_bigy = y position intersecting the plane ;** ;** m_bigy = -(m_bigx*m_spra + m_bigz*m_sprc - m_bigy) ;** ---------------------------------------- ;** m_sprb ;** ;********************************************************** rsp equr 10 mslopeheight sub r0 romb ramb miwt r10,m_stack&WM lms r0,[m_bigx] lms r6,[m_spra] fmult to r1 ; x*nx add r0 lms r0,[m_bigz] lms r6,[m_sprc] fmult add r0 to r1 add r1 ; + z*nz lms r0,[m_bigy] with r1 sub r0 ; - d move r5,r1 ibt r4,#0 lms r6,[m_sprb] mcall mdivs3216_s ; r4.r5/r6 = r4 nop with r4 asr sms [m_bigy],r4 stop nop ;************************************************ ; Square root of 32 bit number ; ; in: rsqr = low 16 bits of square ; rsqrhi = high 16 bits of square ; out: rsqrt = square root ; dead: rt,rt2,r11,r12,r13 rsqrhi equr 4 rsqr equr 5 rsqrt equr 6 rt2 equr 7 rt equr 8 ;************************************************ msqrt32_s ibt rsqrt,#0 ibt rt,#0 ibt r12,#16 miwt r13,.2 with rsqr .2 add rsqr with rsqrhi rol with rt rol with rsqr add rsqr with rsqrhi rol with rt rol with rsqrt add rsqrt from rsqrt to rt2 add rsqrt from rt2 sub rt bcs .1 ; nop with rt sbc rt2 inc rsqrt .1 loop with rsqr jmp r11 nop ;************************************************ ;************************************************ ; Signed 32 bit by 16 bit divide ; with signed 16 bit quotient and 15 bit unsigned remainder ; ; In: r5 = dividend.h ; r4 = dividend.l ; r6 = divisor ; Out: r0 = remainder ; r4 = quotient ; r6 = divisor ; r7 = sign of quotient ; Uses: r7,r12,r13 ; Cycles: 140-176 ; Bytes: 53 rdividendlo equr 4 rdividendhi equr 5 rdivisor equr 6 rdivsign equr 7 mdivs3216_s mcache from rdividendhi to rdivsign xor rdivisor ; = 3 sub r0 moves rdivisor,rdivisor bpl .16m ; nop to rdivisor sub rdivisor .16m ; = 6/7 moves rdividendhi,rdividendhi bpl .32p ; nop to rdividendlo sub rdividendlo to rdividendhi sbc rdividendhi .32p ; = 5/9 ; unsigned divide with rdividendlo ; 1 add rdividendlo ; 1 from rdividendhi ; 1 rol ; 1 ibt r12,#16 ; 2 move r13,pc ; 2 = 8 mdivs3216loop_s sub rdivisor ; 1 bcc mdivs3216cc_s ; 2 nop ; 1 with rdividendlo ; 1 rol ; 1 loop ; 1 rol ; 1 = 8 bra mdivs3216end_s ; 1 nop ; 1 mdivs3216cc_s add rdivisor ; 1 with rdividendlo ; 1 add rdividendlo ; 1 loop ; 1 rol ; 1 = 9 ; sign result mdivs3216end_s moves rdivsign,rdivsign bpl mdivs3216rts_s ; nop with rdividendlo not inc rdividendlo mdivs3216rts_s ; 5/7 jmp r11 nop ;********************************************************** ;** ;** MSCALEXZ (air or slope) ;** m_bigx = vec x ;** m_bigz = vec z ;** ;********************************************************** mscalexz_a iwt r7,#$7800 ; almost zero friction bra mscalexz nop mscalexz_s iwt r7,#$6000 ; $6000 mscalexz sub r0 romb ramb lms r0,[m_bigx] move r6,r7 add r0 ; friction fmult sms [m_bigx],r0 lms r0,[m_bigz] move r6,r7 add r0 ; friction fmult sms [m_bigz],r0 stop nop ;********************************************************** ;** ;** MSLOPEBOUNCE ;** m_bigx = vec x ;** m_bigy = vec y ;** m_bigz = vec z ;** m_spra = x normal ;** m_sprb = y normal ;** m_sprc = z normal ;** m_sprd = bouncyness (fraction) 0-ffffh ;** m_spr0 = distance beneath slope (momentum of slope) ;** ;** Exit: m_bigx,m_bigy,m_bigz = new vec x,y,z. ;** ;** val = m_bigx*m_spra + m_bigy*m_spry + m_bigz*m_sprc ;** ;** m_bigx += m_spra*val+m_spra*m_spr0 ;** m_bigy += m_sprb*val+m_sprb*m_spr0 ;** m_bigz += m_sprc*val+m_sprc*m_spr0 ;** ;** m_bigx *= m_sprd ;** m_bigy *= m_sprd ;** m_bigz *= m_sprd ;** ;********************************************************** mslopebounce sub r0 romb ramb miwt r10,m_stack&WM ; first, r1 = x*nx+y*ny+z*nz lms r0,[m_bigx] lms r6,[m_spra] add r0 to r1 fmult ; x*nx lms r0,[m_bigy] lms r6,[m_sprb] add r0 fmult to r1 add r1 ; + y*ny lms r0,[m_bigz] lms r6,[m_sprc] add r0 fmult to r1 add r1 ; + z*nz ; then multiply the normals by r1 lms r2,[m_bigx] lms r3,[m_bigy] lms r4,[m_bigz] lms r5,[m_sprd] ; bounciness lms r7,[m_spr0] ; slope velocity iwt r7,#0 iwt r5,#$4000 ; no bounce with r1 add r1 lms r8,[m_spra] move r6,r7 from r8 fmult to r9 add r0 move r6,r1 from r8 fmult move r6,r5 add r0 fmult ; bigx += r1*nx*scale add r0 add r2 add r9 sms [m_bigx],r0 lms r8,[m_sprb] iwt r0,#-1 to r6 xor r7 from r8 fmult to r9 add r0 iwt r0,#-1 to r6 xor r1 from r8 fmult move r6,r5 add r0 fmult ; bigy += r1*ny*scale add r0 add r3 add r9 sms [m_bigy],r0 lms r8,[m_sprc] move r6,r7 from r8 fmult to r9 add r0 lms r0,[m_sprc] move r6,r1 from r8 fmult move r6,r5 add r0 fmult ; bigz += r1*nz*scale add r0 add r4 add r9 sms [m_bigz],r0 stop nop ;************************************************************ ;** ;** mveclen ;** ;** calculates |R| (m_z1) ;** where R = bigx+bigy+bigz ;** ;** _____________________________ ;** / ;** \/ bigx*bigx+bigy*bigy+bigz*bigz ;** ;************************************************************ rsqr equr 5 rsqrhi equr 4 rsqrt equr 6 mveclen sub r0 romb ramb iwt r10,#m_stack&WM lms r0,[m_bigx] move r6,r0 lmult move r1,r0 move r2,r4 lms r0,[m_bigy] move r6,r0 lmult with r2 add r4 to r1 adc r1 lms r0,[m_bigz] move r6,r0 lmult with r2 add r4 to r1 adc r1 ; now for the sqroot (r1,r2) move rsqrhi,r1 move rsqr,r2 mcall msqrt32_s nop sms [m_z1],rsqrt stop nop ;************************************************ ; Approx. unsigned 32 bit by 16 bit divide ; with 16 bit quotient ; ; In: r0 = dividend.h ; r4 = dividend.l ; r6 = divisor ; Out: r0 = remainder ; r4 = quotient ; r6 = divisor ; Uses: r12,r13 ; Cycles: 150-171 ; Bytes: 39 mdivu3216_s ; NB this is not accurate! mtest r0 bmi mdivu3216m_s ; if divisor > $7fff nop mtest rdivisor bpl mdivu3115_s ; or dividend > $7fffffff nop mdivu3216m_s ; then halve divisor and dividend with rdivisor lsr lsr with rdividendlo ror ;************************************************ ; Unsigned 31 bit by 15 bit divide ; with 16 bit quotient and 15 bit remainder ; ; In: r0 = dividend.h ; r4 = dividend.l ; r6 = divisor ; Out: r0 = remainder ; r4 = quotient ; r6 = divisor ; Uses: r12,r13 ; Cycles: 137-153 ; Bytes: 24 mdivu3115_s ibt r12,#16 ; 2 with rdividendlo ; 1 asl32 r0,rdividendlo add rdividendlo ; 1 rol ; 1 move r13,pc ; 2 = 7 mdivu3115loop_s sub rdivisor ; 1 bcc mdivu3115cc_s ; 2 nop ; 1 with rdividendlo ; 1 rol ; 1 loop ; 1 rol ; 1 = 8 jmp r11 ; 1 lsr ; 1 mdivu3115cc_s add rdivisor ; 1 with rdividendlo ; 1 add rdividendlo ; 1 loop ; 1 rol ; 1 = 9 jmp r11 lsr ;*********************************************88 ; normalise a 16 bit x,y,z vector in r1,r2,r3 rx equr 1 ry equr 2 rz equr 3 rxhi equr 7 ryhi equr 8 rshiftcnt equr 9 rsqrhi equr 4 rsqr equr 5 rsqrt equr 6 rt2 equr 7 rt equr 8 mnormalise16_s mpush r11 mmul rx,rx mmuladd ry,ry mmuladd rz,rz ; r0,r5 = x*x + y*y + z*z mtest r0 bne .1 ; check for r0,r5 = 0 nop mtest r5 bne .1 nop ibt rx,#0 ibt ry,#0 ibt rz,#0 mpop pc nop .1 ; move rsqr,r5 move rsqrhi,r0 mcall msqrt32_s ; rsqrt = sqrt(rsqrhi,rsqr) nop move r0,rsqrt ibt rshiftcnt,#0 .vnormlp lsr beq .novalshft nop bra .vnormlp inc rshiftcnt .novalshft sub r0 miwt r4,32767 ; r0,r4 = 32767 moves r12,rshiftcnt beq .noshift nop move r13,pc .shift with r4 add r4 loop rol .noshift move r6,rsqrt mcall mdivu3216_s ; r4 = r0,r4 / r6 nop move r6,r4 from rx to rxhi lmult move rx,r4 from ry to ryhi lmult move ry,r4 from rz lmult move rz,r4 moves r12,rshiftcnt beq .noshift2 nop move r13,pc .shift2 with rxhi asr with rx ror with ryhi asr with ry ror asr with rz ror loop nop .noshift2 mpop pc nop ;**************************************************************************** ;** ;** mdividevecs ;** ;** calculates the unit vector and multiplies it by m_x1 ;** ie. it resizes a vector (the direction is kept) ;** mdividevecs(mveclen()) == original vector (give or take a few errors) ;** ;**************************************************************************** mdividevecs sub r0 romb ramb iwt r10,#m_stack&WM lms r1,[m_bigx] lms r2,[m_bigy] lms r3,[m_bigz] mcall mnormalise16_s nop lms r6,[m_x1] with r6 add r6 from r1 fmult sms [m_bigx],r0 from r2 fmult sms [m_bigy],r0 from r3 fmult sms [m_bigz],r0 stop nop ;********************************************************************** ;** ;** mwhichside ;** ;** bigx*x1+bigy*y1+bigz*z1 = m_spra ;** ;********************************************************************** mwhichside sub r0 romb ramb ; first, r1 = x*nx+y*ny+z*nz lms r0,[m_bigx] lms r6,[m_x1] add r0 to r1 fmult ; x*nx lms r0,[m_bigy] lms r6,[m_y1] add r0 fmult to r1 add r1 ; + y*ny lms r0,[m_bigz] lms r6,[m_z1] add r0 fmult add r1 ; + z*nz sms [m_spra],r0 ; store the result stop nop ;********************************************************************** ;** ;** mrevec ;** ;** spra*x1+bigx -> bigx ;** spra*y1+bigy -> bigy ;** spra*z1+bigz -> bigz ;** ;********************************************************************** mrevec sub r0 romb ramb lms r0,[m_spra] to r6 not inc r6 lms r0,[m_x1] add r0 fmult ; x1*spra lms r1,[m_bigx] add r1 ; + bigx sbk lms r0,[m_y1] add r0 fmult ; y1*spra lms r1,[m_bigy] add r1 ; + bigy sbk lms r0,[m_z1] add r0 fmult ; z1*spra lms r1,[m_bigz] add r1 ; + bigz sbk stop nop ;********************************************************** ; MWithinPoly ; ; Go through a list of polygon points and check if the position ; M_BIGX and M_BIGZ is within the polygon's bounds. ; ; M_BIGX = x relative to slope's centre ; M_BIGY = z relative to slope's centre ; ; M_PNTPTR = list of word points (first byte is count) ; returns M_PNTPTR = -1 if point is outside polygon mwp_scale MACRO [reg] lms {reg},[m_scale] moves {reg},{reg} beq .ns\@ .l\@ dec {reg} bne .l\@ add r0 ; scale it up .ns\@ move {reg},r0 ENDM MWithinPoly ibt r0,#$70 ramb ibt r0,#slopedata>>16 romb lms r14,[m_pntptr] lms r1,[m_bigx] lms r2,[m_bigz] to r12 getb inc r14 dec r12 mcache ; get first x coord getbs inc r14 mwp_scale r7 ; get first z coord getbs inc r14 mwp_scale r8 move r13,r15 .loop ; get next x coord getbs inc r14 mwp_scale r9 ; get next z coord getbs inc r14 mwp_scale r10 ; calculate coords into relative values (r3,r5 are free) from r9 to r3 sub r7 ; r3 = dx1 from r10 to r5 sub r8 ; r5 = dz1 from r1 to r7 sub r7 ; r7 = dx2 from r2 to r8 sub r8 ; r8 = dz2 ; now to cross multiply dz1*dx2 - dz2*dx1 move r6,r8 with r3 lmult ; r3(h):r4(l) = dz2*dx1 move r8,r4 ; r3:r8 = result move r6,r5 with r7 lmult ; r7(h):r4(l) = dz2*dx1 move r5,r4 ; r7:r5 = result with r5 sub r8 with r7 sbc r3 ; subtract the two results bmi .reject move r7,r9 ; old x = new x move r8,r10 ; old z = new z loop nop ibt r0,#0 bra .zeroit nop .reject ibt r0,#-1 .zeroit sms [m_pntptr],r0 stop nop ;********************************************************** ; MRotatePoint ; ; Rotates m_x1, m_z1 by m_roty ; MRotatePoint ibt r0,#sintab>>16 romb ibt r0,#$70 ramb iwt r10,#m_stack&WM lms r0,[m_x1] add r0 to r1 add r0 lms r0,[m_z1] add r0 to r3 add r0 lms r0,[m_roty] to r2 lob mcall mrotpnty_s ; go ahead and rotate nop sms [m_x1],r3 sms [m_z1],r1 stop nop ;********************************************************** ; MClosestLine ; ; Goes through a list of polygon points and checks which side ; M_BIGX and M_BIGZ is closest to and then generates a 'clip' ; along the side where the normal would cross. ; ; M_BIGX = x relative to slope's centre ; M_BIGY = z relative to slope's centre ; ; M_PNTPTR = list of word points (first byte is count) ; returns M_PNTPTR = -1 if point is outside polygon ; ; Method: ; This calculates a normal to the line and then makes one of the ; points of the line relative to m_bigx,m_bigz. (ie. m_bigx,m_bigz = origin) ; Then the distance to the line is calculated by the following: ; d = x*nx + z*nz (nx,nz = normal, x,z = relative point anywhere along line) ; ; To calculate the 'clipped' point, d+1 is multiplied by the normal and added ; to m_bigx and m_bigz. rbx equr r1 rbz equr r2 rx1 equr r7 rz1 equr r8 rx2 equr r3 rz2 equr r5 rnx equr r7 rnz equr r8 rclosest equr r13 MClosestLine ibt r0,#$70 ramb ibt r0,#slopedata>>16 romb iwt r10,#m_stack&WM lms r14,[m_pntptr] lms rbx,[m_bigx] lms rbz,[m_bigz] to r12 getb inc r14 dec r12 ;------------------ ; get first x coord ;------------------ getbs inc r14 mwp_scale rx1 ;------------------ ; get first z coord ;------------------ getbs inc r14 mwp_scale rz1 ibt rclosest,#-1 ; set default distance to 65535 mcache ;------------------ ; begin the loop ;------------------ .loop mpush r12 ;------------------ ; get next x coord ;------------------ getbs inc r14 mwp_scale rx2 ;------------------ ; get next z coord ;------------------ getbs inc r14 mwp_scale rz2 ;--------------------------------------------------------------------- ; Calculate the normal (first rotating the vector through 90 degrees) ;--------------------------------------------------------------------- mpush rclosest mpush rx2 mpush rz2 mpush rbx mpush rbz from rx2 to r3 ; set vx (x2-x1) sub rx1 mneg r3 ; z = -vx from rz2 ; set vz (z2-z1) to r1 sub rz1 ; x = vz ibt r2,#0 ; zero y mcall mnormalise16_s nop move rnx,r1 move rnz,r3 ; nx,nz mpop rbz mpop rbx mpop rz2 mpop rx2 ;--------------------------------------------------------- ; Now to calculate D = (nx*(rx2-rbx)+nz*(rz2-rbz)) ;--------------------------------------------------------- move r6,rnx from rx2 sub rbx add r0 ; *2 to rclosest ; store result of (nx*(rx2-rbx) fmult move r6,rnz from rz2 sub rbz add r0 ; *2 fmult add rclosest ; add previously stored result bpl .ok nop mneg r0 ; if negative make it positive .ok mpop rclosest cmp rclosest bcs .notclose nop move rclosest,r0 sms [m_spra],rnx sms [m_sprc],rnz ; store the closest normal .notclose ;------------------ ; end of loop ;------------------ move rx1,rx2 ; old x = new x move rz1,rz2 ; old z = new z mpop r12 ;------------------ dec r12 mlbne .loop ;------------------ sms [m_pntptr],rclosest ;------------------ ; now to calculate the new 'clipped' coordinates lms rnx,[m_spra] lms rnz,[m_sprc] with rclosest add #6 ; this value is mainly to correct math errors with rclosest ; and to make sure the object definitely isn't within the polygon add rclosest ; multiply by 2 and add 4 move r6,rclosest from rnx fmult sms [m_bigx],r0 move r6,rclosest from rnz fmult sms [m_bigz],r0 ;------------------ stop nop ;**************************************************** ifne 1 ; Y rotate 16 bit x,z pos by 8 bit angle ; ; In: rx = x pos ; rz = z pos ; ryrot = y rot angle ; ; Out: rx = y rotated x pos ; rz = y rotated x pos ; ; Dead: r0-r9 rx equr 1 ryrot equr 2 rt equr 2 rz equr 3 rcosy equr 5 rprodlo equr 7 rprodhi equr 8 rsiny equr 9 mrotpnty_s mpush r11 miwt r0,costab to r14 add ryrot getb to rcosy swap miwt r0,sintab to r14 add ryrot getb to rsiny swap move r6,rx from rsiny to rprodhi lmult move rprodlo,r4 move r6,rz from rcosy lmult with rprodlo add r4 adc rprodhi to rt asr move r6,rz from rsiny to rprodhi lmult move rprodlo,r4 move r6,rx from rcosy lmult with rprodlo sub r4 sbc rprodhi to rz asr move rx,rt mpop pc nop ; jmp r11 ; nop endc