# # Copyright (C) 1996-1997 Id Software, Inc. # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License # as published by the Free Software Foundation; either version 2 # of the License, or (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. # # See the GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. # ## ## Quake for AMIGA ## ## d_skyPPC.s ## ## Define WOS for PowerOpen ABI, otherwise SVR4-ABI is used. ## .set NOLR,1 .include "macrosPPC.i" # # external references # xrefv d_viewbuffer xrefv screenwidth xrefa r_refdef xrefv r_skysource xrefa vid xrefa vright xrefa vpn xrefa vup xrefv skytime xrefv skyspeed xrefv INT2DBL_0 xrefv c0 xrefv c0_5 xrefv c65536 xrefa _ReciprocTable # # defines # .set PSPAN_NEXT ,12 .set REFDEF_VRECT_X ,0 .set REFDEF_VRECT_Y ,4 .set REFDEF_VRECT_WIDTH ,8 .set REFDEF_VRECT_HEIGHT,12 .set VID_WIDTH ,20 .set VID_HEIGHT ,24 .set SKYSHIFT ,7 .set SKYSIZE ,(1<> 1 lwz r12,VID_HEIGHT(r12) srawi r12,r12,1 #r12 = vid.height >> 1 int2dbl f9,r12,r4,local,f1 #f9 = (float)vid.height >> 1 ls f14,skytime ls f4,skyspeed fmuls f14,f14,f4 ls f4,c65536 fmuls f14,f14,f4 fctiwz f14,f14 stfd f14,local+8(r1) lwz r27,local+12(r1) #r27 = skytime * skyspeed*$10000 .loop: lwzu r9,4(r3) #r9 = u lwzu r10,4(r3) #r10 = v int2dbl f4,r10,r4,local,f1 #f4 = (float)pspan->v mullw r0,r10,r6 add r0,r0,r9 add r11,r5,r0 #r11 = pdest = d_viewbuffer + ... subi r11,r11,1 #prepare for postincrement fsubs f10,f9,f4 #f10 = ((vid.height>>1)-v) fmuls f10,f10,f3 #wv = 8192 * fp0 / temp lfs f11,0(r30) fmadds f23,f11,f10,f6 #f23 = 4096*vpn[0] + wv*vup[0] lfs f11,4(r30) fmadds f24,f11,f10,f7 #f24 = 4096*vpn[1] + wv*vup[1] lfs f11,8(r30) fmadds f25,f11,f10,f8 #f25 = 4096*vpn[2] + wv*vup[2] lfs f4,0(r29) fmuls f4,f4,f3 #f4 = 8192 * vright[0] / temp lfs f12,4(r29) fmuls f12,f12,f3 #f12 = 8192 * vright[1] / temp lfs f13,8(r29) fmuls f13,f13,f3 #f13 = 8192 * vright[2] / temp fmuls f25,f25,f0 fmuls f13,f13,f0 lwzu r28,4(r3) #r28 = count = pspan->count li r0,1 dcbtst r11,r0 ###### D_Sky_uv_To_st (inlined) subf r0,r31,r9 int2dbl f16,r0,r4,local,f1 #f16 = (float(u-vid.width>>1)) fmadds f21,f16,f4,f23 #f17 = end[0] fmuls f17,f21,f21 fmadds f22,f16,f12,f24 #f18 = end[1] fmadds f17,f22,f22,f17 #f17 = end[0]^2 + end[1]^2 fmadds f18,f16,f13,f25 #f18 = end[2] fmadds f17,f18,f18,f17 #f17 = end[0]^2 + end[1]^2 + end[2]^2 fcmpo cr0,f17,f19 beq .zero frsqrte f16,f17 fres f16,f16 fdivs f18,f17,f16 fadd f16,f18,f16 fmul f17,f16,f20 #f17 = sqrt(...) .zero: fdivs f18,f15,f17 fmuls f21,f21,f18 #f21 = 6*(SKYSIZE/2-1)*end[0] fmuls f22,f22,f18 #f22 = 6*(SKYSIZE/2-1)*end[1] fctiwz f21,f21 stfd f21,local+8(r1) lwz r26,local+12(r1) add r26,r26,r27 #r26 = s fctiwz f22,f22 stfd f22,local+8(r1) lwz r25,local+12(r1) add r25,r25,r27 #r25 = t ###### end of D_Sky_uv_To_st ###### Second loop. In every iteration one part of the whole span is drawn # do # { # if (count >= SKY_SPAN_MAX) # spancount = SKY_SPAN_MAX; # else # spancount = count; # # count -= spancount; # # if (count) # { .loop2: cmpwi r28,SKY_SPAN_MAX bgt .cont mtctr r28 subi r20,r28,1 #r20 = spancountminus1 li r28,0 #r28 = count -= spancount b .finalpart .cont: li r20,SKY_SPAN_MAX #r20 = spancount = SKY_SPAN_MAX subf r28,r20,r28 #r28 = count -= spancount mtctr r20 ###### Evaluation of the values for the inner loop. This version is used for ###### span size = SKY_SPAN_MAX # // calculate s and t at far end of span, # // calculate s and t steps across span by shifting # u += spancount; # # D_Sky_uv_To_st (u, v, &snext, &tnext); # # sstep = (snext - s) >> SKY_SPAN_SHIFT; # tstep = (tnext - t) >> SKY_SPAN_SHIFT; # } add r9,r9,r20 #u += spancount ###### D_Sky_uv_To_st (inlined) subf r0,r31,r9 int2dbl f16,r0,r4,local,f1 #f16 = (float(u-vid.width>>1)) fmadds f21,f16,f4,f23 #f17 = end[0] fmuls f17,f21,f21 fmadds f22,f16,f12,f24 #f18 = end[1] fmadds f17,f22,f22,f17 #f17 = end[0]^2 + end[1]^2 fmadds f18,f16,f13,f25 #f18 = end[2] fmadds f17,f18,f18,f17 #f17 = end[0]^2 + end[1]^2 + end[2]^2 fcmpo cr0,f17,f19 beq .zero2 frsqrte f16,f17 fres f16,f16 fdivs f18,f17,f16 fadd f16,f18,f16 fmul f17,f16,f20 #f17 = sqrt(...) .zero2: fdivs f18,f15,f17 fmuls f21,f21,f18 #f21 = 6#(SKYSIZE/2-1)*end[0] fctiwz f21,f21 stfd f21,local+8(r1) fmuls f22,f22,f18 #f22 = 6*(SKYSIZE/2-1)*end[1] lwz r24,local+12(r1) fctiwz f22,f22 stfd f22,local+8(r1) add r24,r24,r27 #r24 = snext lwz r23,local+12(r1) add r23,r23,r27 #r23 = tnext ###### end of D_Sky_uv_To_st subf r22,r26,r24 #r22 = snext - s subf r21,r25,r23 #r21 = tnext - t srawi r22,r22,SKY_SPAN_SHIFT #r22 = sstep srawi r21,r21,SKY_SPAN_SHIFT #r21 = tstep b .mainloop .finalpart: add r9,r9,r20 #u += spancountminus1 ###### D_Sky_uv_To_st (inlined) subf r0,r31,r9 int2dbl f16,r0,r4,local,f1 #f16 = (float(u-vid.width>>1)) fmadds f21,f16,f4,f23 #f17 = end[0] fmuls f17,f21,f21 fmadds f22,f16,f12,f24 #f18 = end[1] fmadds f17,f22,f22,f17 #f17 = end[0]^2 + end[1]^2 fmadds f18,f16,f13,f25 #f18 = end[2] fmadds f17,f18,f18,f17 #f17 = end[0]^2 + end[1]^2 + end[2]^2 fcmpo cr0,f17,f19 beq .zero3 frsqrte f16,f17 fres f16,f16 fdivs f18,f17,f16 fadd f16,f18,f16 fmul f17,f16,f20 #f17 = sqrt(...) .zero3: cmplwi r20,5 fdivs f18,f15,f17 fmuls f21,f21,f18 #f21 = 6*(SKYSIZE/2-1)*end[0] fctiwz f21,f21 stfd f21,local+8(r1) fmuls f22,f22,f18 #f22 = 6*(SKYSIZE/2-1)*end[1] lwz r24,local+12(r1) fctiwz f22,f22 stfd f22,local+8(r1) add r24,r24,r27 #r24 = snext lwz r23,local+12(r1) add r23,r23,r27 #r23 = tnext ###### end of D_Sky_uv_To_st subf r22,r26,r24 #r22 = snext - s subf r21,r25,r23 #r21 = tnext - t blt .special .qdiv: slwi r0,r20,2 lwzx r0,r8,r0 mulhw r22,r22,r0 mulhw r21,r21,r0 b .mainloop .special: cmplwi r20,1 ble .mainloop cmplwi r20,3 beq .qdiv blt .spec_2 srawi r22,r22,2 srawi r21,r21,2 b .mainloop .spec_2: srawi r22,r22,1 srawi r21,r21,1 ###### Main drawing loop. # do # { # *pdest++ = r_skysource[((t & R_SKY_TMASK) >> 8) + # ((s & R_SKY_SMASK) >> 16)]; # s += sstep; # t += tstep; # } while (--spancount > 0); .mainloop: rlwinm r0,r25,24,17,23 #implied: R_SKY_TMASK add r25,r25,r21 #t += tstep rlwimi r0,r26,16,25,31 #implied: R_SKY_SMASK add r26,r26,r22 #s += sstep lbzx r0,r7,r0 #r_skysource[...] stbu r0,1(r11) bdnz .mainloop ###### loop terminations mr r26,r24 #s = snext mr r25,r23 #t = tnext mr. r28,r28 bgt .loop2 lwz r3,4(r3) mr. r3,r3 subi r3,r3,4 bne .loop lfd f14,fb+0*8(r1) lfd f15,fb+1*8(r1) lfd f16,fb+2*8(r1) lfd f17,fb+3*8(r1) lfd f18,fb+4*8(r1) lfd f19,fb+5*8(r1) lfd f20,fb+6*8(r1) lfd f21,fb+7*8(r1) lfd f22,fb+8*8(r1) lfd f23,fb+9*8(r1) lfd f24,fb+10*8(r1) lfd f25,fb+11*8(r1) lmw r20,gb(r1) exit funcend D_DrawSkyScans8 .ifdef WOS .tocd .else .data .endif lab c8192 .float 8192.0 lab c4096 .float 4096.0 lab c3 .float 3.0 lab ca .float 24772608.0 # => 65536*6*(SKYSIZE/2-1)