******************************************************************** * * Landscape_Calc * * Calculation routines for 'landscape' (PPC) * * assemble with: * powerasm Landscape_Calc.s to Landscape_Calc.o * * link with smalldata and smallcode enabled * * © 1997 HAAGE&PARTNER Computer GmbH * ******************************************************************** ;// XDEF / XREF xref PrepareFlight xref _PowerPCBase xref ChunkyBuffer xref MapSize xref MapSizeExp xref MapMem xref MapMemEnd xref MapScale xref browntab xref Code xref H xref Iterations xref Variation xref Water xref Shadow xref LightDir xref LightAngle xref RanCount xref Highest xref Lowest xref tantab xref MapDim xref MapHeight xref AreaWidth xref AreaHeight xref BitmapWidth xdef CreateLandscape_PPC ;;/ ;// macros **** citf: Convert Integer to Floating Signed (Double Precision) * * parameters: * 1: destination FP-Register * 2: intermediate FP-Register (MUST hold the value $4330000080000000) * 3: intermediate GP-Register (MUST point to the value $4330000000000000) * 4: source GP-Register * * r0 is trashed citf macro xoris trash,\4,$8000 stw trash,4(\3) lfd \1,0(\3) fsub \1,\1,\2 endm ;;/ CPU POWERPC smalldata smallcode section "Lanscape_Calc_Code",code * landscape generator stuff ;// CreateLandscape_PPC (creates the landscape) ****************************************************************************** * * CreateLandscape_PPC * * creates the landscape * ****************************************************************************** CreateLandscape_PPC prolog 1024 pushgpr r14-r16/r28-r31 pushfpr f14-f16 liw r14,630360016 ;r14 = GLOBAL (for URN30) liw r15,$7fffffff ;r15 = GLOBAL (for URN30) la r16,CITF_TEMP ;r16 = GLOBAL (for macro CITF) lf f14,CITF_0 ;f14 = GLOBAL (for macro CITF) citf f15,f14,r16,r14 ;f15 = GLOBAL (for URN30) citf f16,f14,r16,r15 ;f16 = GLOBAL (for URN30) bl SetRNDModeRZ ;enable rounding mode RZ mr r31,r3 ;save old FPSCR lw r30,MapMem ;-> map space mr r3,r30 la r4,browntab ;-> math table lb r5,MapSizeExp ;map size exponential lb r6,Iterations ;iterations for subdivision lb r7,H ;fractal parameter lb r29,RanCount mr r8,r29 bl BuildLandscape ;build landscape mr r3,r30 ;-> map space lw r28,MapSize ;map size mr r4,r28 lb r5,Water ;water area bl ScaleLandscape ;scale landscape mr r3,r30 ;-> map space mr r4,r28 ;map size lb r5,Variation ;color variation mr r6,r29 bl CreateColors ;define colors lb r3,Shadow ;shadow enabled? tstw r3 beq .noshadow ;no -> jump mr r3,r30 ;-> map space la r4,tantab ;tangens table mr r5,r28 ;map size lb r6,LightDir ;light direction lb r7,LightAngle ;light angle bl CreateShadow ;create shadow .noshadow mr r3,r31 ;get FPSCR bl RestoreRNDMode ;restore FPSCR popfpr popgpr epilog ;;/ ;// BuildLandscape (creates the landscape using a fractal algorithm) ****************************************************************************** * * BuildLandscape (r3,r4,r5,r6,r7,r8,r9) * * creates the landscape using a fractal algorithm * height = average_height + random * 0.5^(Iterations*H) * * In: r3 -> map memory * r4 -> math table for fractal computation * r5 = map border size (exp.) * r6 = number of iterations for subdivision * r7 = H (fractal parameter) * r8 = number of uniform random numbers for one normal random number * ****************************************************************************** BuildLandscape pushlr pushgpr r17-r31 mr r31,r3 slwi r0,r6,5 ;calc offset into math table add r30,r4,r0 ;r30 -> current entry add r7,r7,r7 ;calc offset for H parameter add r30,r30,r7 ;r30 -> 0.5^(It.*H)<<14 mr r29,r8 ;save random count subf r28,r6,r5 ;r28 = number of iterations li r0,1 slw r27,r0,r5 ;r27 = map border size slw r26,r0,r6 ;r26 = vertical loop counter slw r25,r0,r6 ;r25 = horizontal loop counter srw r0,r27,r6 ;calc map step value add r24,r0,r0 ;r24 = horizontal step value mullw r23,r24,r27 ;r23 = vertical step value add r3,r27,r27 ;calc map mask values subi r22,r3,1 ;r22 = horizontal map mask mullw r21,r3,r27 subi r21,r21,1 ;r21 = vertical map mask .loop mr r20,r26 ;r20 = vertical loop counter li r18,0 ;reset vertical position .loop2 mr r19,r25 ;r19 = horizontal loop counter li r17,0 ;reset horizontal position .loop3 mr r3,r31 mr r4,r30 mr r5,r22 mr r6,r18 mr r7,r23 mr r8,r17 mr r9,r24 mr r10,r21 mr r11,r29 bl SetCenter ;calc height of center field add r17,r17,r24 ;increase horizontal position subic. r19,r19,1 bne .loop3 add r18,r18,r23 ;increase vertical position subic. r20,r20,1 bne .loop2 addi r30,r30,32 ;next math table entry mr r20,r26 ;r20 = vertical loop counter li r18,0 ;reset vertical position .loop4 mr r19,r25 ;r19 = horizontal loop counter li r17,0 ;reset horizontal position .loop5 mr r3,r31 mr r4,r30 mr r5,r22 mr r6,r18 mr r7,r23 mr r8,r17 mr r9,r24 mr r10,r21 mr r11,r29 bl SetUpper ;calc height of upper field mr r3,r31 mr r4,r30 mr r5,r22 mr r6,r18 mr r7,r23 mr r8,r17 mr r9,r24 mr r10,r21 mr r11,r29 bl SetLeft ;calc height of lower field add r17,r17,r24 ;increase horizontal position subic. r19,r19,1 bne .loop5 add r18,r18,r23 ;increase vertical position subic. r20,r20,1 bne .loop4 addi r30,r30,32 ;next math table entry add r25,r25,r25 ;double horizontal counter add r26,r26,r26 ;double vertical counter srwi r24,r24,1 ;halve horizontal step value srwi r23,r23,1 ;halve vertical step value subic. r28,r28,1 bne .loop ;next iteration popgpr poplr blr ;;/ ;// SetCenter (sets the height of the center of a specific square) ****************************************************************************** * * SetCenter (r3,r4,r5,r6,r7,r8,r9,r10,r11) * * sets the height of the center of a specific square * * In: r3 -> map memory * r4 -> fractal exponent * r5 = horizontal map mask * r6 = vertical offset of the top border of the square * r7 = differential vertical offset * r8 = horizontal offset of the left border of the square * r9 = differential horizontal offset * r10 = vertical map mask * r11 = number of uniform random numbers for one normal random number * ****************************************************************************** SetCenter pushlr pushgpr r27-r31 mtctr r11 mr r30,r4 add r11,r6,r8 lhax r31,r3,r11 ;read left top height add r4,r8,r9 and r0,r4,r5 add r0,r0,r6 lhax r0,r3,r0 ;read right top height add r31,r31,r0 ;add to r31 add r12,r6,r7 and r0,r12,r10 add r0,r0,r8 lhax r0,r3,r0 ;read left bottom height add r31,r31,r0 ;add to r31 and r0,r4,r5 and r4,r12,r10 add r0,r0,r4 lhax r0,r3,r0 ;read right bottom height add r31,r31,r0 ;add to r31 srawi r31,r31,2 ;calc average height srwi r9,r9,1 ;halve square width srwi r7,r7,1 ;halve square height add r0,r11,r9 add r0,r0,r7 ;calc offset into center add r29,r3,r0 ;r29 -> center field li r28,0 ;init sum value liw r27,$3fffffff .loop bl URN30 ;get random value subf r3,r27,r3 ;scale random value srawi r3,r3,4 add r28,r28,r3 ;add to sum value bdnz .loop srawi r28,r28,16 lhz r3,0(r30) ;read fractal exponent mullw r3,r3,r28 ;multiply with random value srawi r3,r3,12 ;scale result add r31,r31,r3 ;add to average height lh r3,Highest ;check if highest point cmpw r31,r3 ble .cont sh r31,Highest ;yes -> replace .cont lhs r3,Lowest ;check if lowest point cmpw r31,r3 bge .cont2 sh r31,Lowest ;yes -> replace .cont2 sth r31,0(r29) ;store height into center field popgpr poplr blr ;;/ ;// SetUpper (sets the height of the upper point of a specific square) ****************************************************************************** * * SetUpper (r3,r4,r5,r6,r7,r8,r9,r10,r11) * * sets the height of the upper point of a specific square * * In: r3 -> map memory * r4 -> fractal exponent * r5 = horizontal map mask * r6 = vertical offset of the top border of the square * r7 = differential vertical offset * r8 = horizontal offset of the left border of the square * r9 = differential horizontal offset * r10 = vertical map mask * r11 = number of uniform random numbers for one normal random number * ****************************************************************************** SetUpper pushlr pushgpr r27-r31 mtctr r11 mr r30,r4 add r0,r6,r8 lhax r31,r3,r0 ;read left top height add r0,r8,r9 and r0,r0,r5 add r0,r0,r6 lhax r0,r3,r0 ;read right top height add r31,r31,r0 ;add to r31 srwi r7,r7,1 ;halve square width srwi r9,r9,1 ;halve square height add r11,r8,r9 add r4,r7,r6 and r4,r4,r10 add r0,r4,r11 lhax r0,r3,r0 ;read center bottom height add r31,r31,r0 ;add to r31 subf r4,r7,r6 and r4,r4,r10 add r0,r4,r11 lhax r0,r3,r0 ;read center top height add r31,r31,r0 ;add to r31 srawi r31,r31,2 ;calc average height add r0,r11,r6 ;calc offset into upper field add r29,r3,r0 ;r29 -> upper field li r28,0 ;init sum value liw r27,$3fffffff .loop bl URN30 ;get random value subf r3,r27,r3 ;scale random value srawi r3,r3,4 add r28,r28,r3 ;add to sum value bdnz .loop srawi r28,r28,16 lhz r3,0(r30) ;read fractal exponent mullw r3,r3,r28 ;multiply with random value srawi r3,r3,12 ;scale result add r31,r31,r3 ;add to average height lh r3,Highest ;check if highest point cmpw r31,r3 ble .cont sh r31,Highest ;yes -> replace .cont lhs r3,Lowest ;check if lowest point cmpw r31,r3 bge .cont2 sh r31,Lowest ;yes -> replace .cont2 sth r31,0(r29) ;store height into center field popgpr poplr blr ;;/ ;// SetLeft (sets the height of the left point of a specific square) ****************************************************************************** * * SetLeft (r3,r4,r5,r6,r7,r8,r9,r10,r11) * * sets the height of the left point of a specific square * * In: r3 -> map memory * r4 -> fractal exponent * r5 = horizontal map mask * r6 = vertical offset of the top border of the square * r7 = differential vertical offset * r8 = horizontal offset of the left border of the square * r9 = differential horizontal offset * r10 = vertical map mask * r11 = number of uniform random numbers for one normal random number * ****************************************************************************** SetLeft pushlr pushgpr r27-r31 mtctr r11 mr r30,r4 add r11,r6,r8 lhax r31,r3,r11 ;read left top height add r4,r6,r7 and r0,r4,r10 add r0,r0,r8 lhax r0,r3,r0 ;read left bottom height add r31,r31,r0 ;add to r31 srwi r7,r7,1 ;halve square width srwi r9,r9,1 ;halve square height add r11,r7,r6 add r4,r9,r8 and r4,r4,r5 add r0,r4,r11 lhax r0,r3,r0 ;read center right height add r31,r31,r0 ;add to r31 subf r4,r9,r8 and r4,r4,r5 add r0,r4,r11 lhax r0,r3,r0 ;read center left height add r31,r31,r0 ;add to r31 srawi r31,r31,2 ;calc average height add r0,r11,r8 ;calc offset into upper field add r29,r3,r0 ;r29 -> upper field li r28,0 ;init sum value liw r27,$3fffffff .loop bl URN30 ;get random value subf r3,r27,r3 ;scale random value srawi r3,r3,4 add r28,r28,r3 ;add to sum value bdnz .loop srawi r28,r28,16 lhz r3,0(r30) ;read fractal exponent mullw r3,r3,r28 ;multiply with random value srawi r3,r3,12 ;scale result add r31,r31,r3 ;add to average height lh r3,Highest ;check if highest point cmpw r31,r3 ble .cont sh r31,Highest ;yes -> replace .cont lhs r3,Lowest ;check if lowest point cmpw r31,r3 bge .cont2 sh r31,Lowest ;yes -> replace .cont2 sth r31,0(r29) ;store height into center field popgpr poplr blr ;;/ ;// ScaleLandscape (scales the landscape) ****************************************************************************** * * ScaleLandscape (r3,r4,r5) * * scales the landscape * * In: r3 -> map memory * r4 = map border size * r5 = water area * ****************************************************************************** ScaleLandscape pushlr subi r3,r3,2 ;prepare for postincrement li r9,100 li r11,255 lhs r6,Highest ;read highest point lhs r7,Lowest ;read lowest point subf r8,r7,r6 ;calc difference mullw r0,r8,r5 divwu r0,r0,r9 add r7,r7,r0 ;r7 = water NULL height subf r6,r7,r6 ;r6 = height above water mr r9,r4 .loop mr r10,r4 .loop2 lha r5,2(r3) ;read height subf r0,r7,r5 ;shift up/down height mullw r0,r0,r11 ;scale height divw r0,r0,r6 sthu r0,2(r3) ;write new height subic. r10,r10,1 bne .loop2 subic. r9,r9,1 bne .loop poplr blr ;;/ ;// CreateColors (defines the color values for each zone) ****************************************************************************** * * CreateColors (r3,r4,r5,r6) * * defines the color values for each zone * * In: r3 -> map memory * r4 = map border size * r5 = variation parameter (0 = standard) * r6 = number of uniform random numbers for one normal random number * ****************************************************************************** CreateColors pushlr pushgpr r23-r31 mr r24,r3 mr r31,r5 mr r30,r6 mullw r29,r4,r4 add r29,r29,r29 ;r29 = map full size (in bytes) add r23,r4,r4 ;r23 = line size in bytes subf r29,r29,r23 ;r29=offs. from last to 1st line neg r28,r23 ;r28 = offs. from right to left subi r27,r4,1 ;create loop counters (one less subi r26,r4,1 ;than usual) mr r25,r27 ;save inner loop counter mtctr r25 .loop mr r27,r25 .loop2 lha r4,0(r24) ;calc average height of lha r0,2(r24) ;corresponding polygon add r4,r4,r0 lhax r0,r24,r23 add r4,r4,r0 addi r0,r23,2 lhax r0,r24,r0 add r4,r4,r0 srawi r4,r4,2 ;r4 = average height mr r3,r24 mr r5,r31 mr r6,r30 bl DefineColor ;assign color addi r24,r24,2 ;next height subic. r27,r27,1 bne .loop2 lha r4,0(r24) ;special case: polygon between lha r0,2(r24) ;rightmost and leftmost point add r4,r4,r0 lhax r0,r24,r23 add r4,r4,r0 addi r0,r28,2 lhax r0,r24,r0 add r4,r4,r0 srawi r4,r4,2 ;r4 = average height mr r3,r24 mr r5,r31 mr r6,r30 bl DefineColor ;assign color addi r24,r24,2 ;next height subic. r26,r26,1 bne .loop .loop3 lha r4,0(r24) ;special case: polygons between lha r0,2(r24) ;bottom line and top line add r4,r4,r0 lhax r0,r24,r29 add r4,r4,r0 addi r0,r29,2 lhax r0,r24,r0 add r4,r4,r0 srawi r4,r4,2 ;r4 = average height mr r3,r24 mr r5,r31 mr r6,r30 bl DefineColor ;assign color addi r24,r24,2 ;next height bdnz .loop3 lha r4,0(r24) ;special case: polygon between lhax r0,r24,r28 ;right-bottom point and left-top add r4,r4,r0 ;point addi r0,r28,2 lhax r0,r24,r0 add r4,r4,r0 lhax r0,r24,r29 add r4,r4,r0 add r0,r28,r29 lhax r0,r24,r0 add r4,r4,r0 srawi r4,r4,2 ;r4 = average height mr r3,r24 mr r5,r31 mr r6,r30 bl DefineColor ;assign color popgpr poplr blr ;;/ ;// DefineColor (calulates one color value) ****************************************************************************** * * DefineColor (r3,r4,r5,r6) * * defines the color values for each zone * * In: r3 -> 16 bit height element * r4 = average height of corresponding polygon * r5 = variation parameter * r6 = number of uniform random numbers for one normal random number * ****************************************************************************** DefineColor pushlr pushctr pushgpr r26-r31 lha r31,0(r3) ;read height mr r26,r3 mr r27,r31 mr. r28,r5 ;any variation wanted? beq .novariation ;no -> jump mtctr r6 ;number of random numbers li r30,0 ;init sum value liw r29,$3fffffff .loop bl URN30 ;calc random value subf r3,r29,r3 ;scale random value srawi r3,r3,4 add r30,r30,r3 ;add to sum bdnz .loop srawi r30,r30,16 mullw r30,r30,r28 ;multiply with variation srawi r30,r30,14 ;scale result tstw r31 ;polygon in water? ble .water1 ;yes -> jump add. r27,r27,r30 ;add variation to height bgt .cont ;still over water? -> jump li r27,1 ;lowest point above water b .novariation .cont cmpwi r27,255 ;overflow? ble .novariation ;no -> jump li r27,255 ;limit to highest point b .novariation .water1 add. r27,r27,r30 ;add variation to height ble .novariation ;still under water? -> jump li r27,0 ;least deep water .novariation tstw r31 ;polygon in water? ble .water ;yes -> jump subfic r27,r27,255 stb r31,0(r26) ;store height in first byte srawi. r27,r27,2 ;calc color value bne .cont2 ;not zero? li r27,1 ;if zero than one (no water) .cont2 stb r27,1(r26) ;store color into second byte b .end .water neg r27,r27 srawi r27,r27,2 addi r27,r27,64 ;calc color value li r0,0 stb r0,0(r26) ;height = 0 cmpwi r27,127 ;if water too deep ble .cont3 li r27,127 ;limit to darkest blue .cont3 stb r27,1(r26) ;store color .end popgpr popctr poplr blr ;;/ ;// CreateShadow (calculates the shadow) ****************************************************************************** * * CreateShadow (r3,r4,r5,r6,r7) * * divides the landscape in smaller parts * * In: r3 -> map memory * r4 -> tangens table for tangens calculation * r5 = map border size * r6 = light direction (0-3) * r7 = light angle (0-89) * ****************************************************************************** CreateShadow pushlr pushgpr r27-r31 mr r30,r5 slwi r7,r7,8 ;calc tan (lightangle) li r0,90 divwu r0,r7,r0 add r0,r0,r0 lhzx r29,r4,r0 ;r29 = tan (angle) << 7 mullw r5,r5,r5 add r5,r5,r5 ;r5 = map size in bytes tstw r6 ;case direction beq .left cmpwi r6,1 beq .top cmpwi r6,2 beq .right .bottom add r3,r3,r5 ;rays from bottom subi r3,r3,2 ;r3 -> last element in map add r28,r30,r30 neg r28,r28 ;vertical step value li r27,-2 ;horizontal line step value b .cont .right add r3,r3,r5 ;rays from right subi r3,r3,2 ;r3 -> last element in map add r27,r30,r30 neg r27,r27 ;horizontal step value li r28,-2 ;vertical line step value b .cont .top add r28,r30,r30 li r27,2 b .cont .left add r27,r30,r30 li r28,2 .cont mtctr r30 mr r31,r3 .loop mr r4,r30 mr r3,r31 mr r5,r29 mr r6,r28 bl ShadowLine add r31,r31,r27 bdnz .loop popgpr poplr blr ;;/ ;// ShadowLine (shadows one map line) ****************************************************************************** * * ShadowLine (r3,r4,r5,r6) * * shadows one map line * * In: r3 -> map memory (or last element) * r4 = map border size * r5 = vertical difference * r6 = map step value * ****************************************************************************** ShadowLine pushlr mr r7,r3 li r8,0 ;init point counter .loop lbz r9,0(r3) ;read height slwi r9,r9,7 ;shift left subf r9,r5,r9 ;subtract tangens .entry add r3,r3,r6 ;goto next point addi r8,r8,1 cmpw r8,r4 ;warp around? bne .cont ;no -> jump mr r3,r7 ;begin again .cont lbz r10,0(r3) ;read height of next pixel slwi r10,r10,7 cmpw r10,r9 ;below shadow line? blt .shade ;yes -> shade point cmpw r8,r4 ;if no shadow and line done bgt .end ;-> exit b .loop ;try next point .shade lbz r11,1(r3) ;read color value cmpwi r11,127 ;already shaded? bgt .next ;yes -> jump addi r11,r11,128 ;shade point stb r11,1(r3) ;store new color value .next subf r9,r5,r9 ;subtract tangens b .entry .end poplr blr ;;/ ;// SetRNDModeRZ (set rounding mode for the FPU to 'round to zero') ****************************************************************************** * * r3 = SetRNDModeRZ * * set rounding mode for the FPU to 'round to zero' * * Out: r3 = old FPCR value * ****************************************************************************** SetRNDModeRZ mffs f0 stfd f0,-8(local) lwz r3,-4(local) ori r0,r3,$1 stw r0,-4(local) lfd f0,-8(local) mtfsf $ff,f0 blr ;;/ ;// RestoreRNDMode (restores rounding mode for the FPU) ****************************************************************************** * * RestoreRNDMode (r3) * * restores rounding mode for the FPU * * In: r3 = FPCR value to be restored * ****************************************************************************** RestoreRNDMode stw r3,-4(local) lfd f0,-8(local) mtfsf $ff,f0 blr ;;/ ;// URN30 (calculates one uniform random number) ****************************************************************************** * * r3 = URN30 (GLOBAL r14, GLOBAL r15, GLOBAL r16 * GLOBAL f14, GLOBAL f15, GLOBAL f16) * * calculates one uniform random number (rounding mode for the FPU * MUST be set to 'round to zero') * 'Code' must hold a start random value if it's first used * URN30 algorithm is taken: Xn+1 = 630360016 * Xn mod $7fffffff * * In: GLOBAL r14 = 630360016 * GLOBAL r15 = $7fffffff * GLOBAL r16 -> temporary space for macro CITF * GLOBAL f14 = $4330000080000000 * GLOBAL f15 = 630360016 * GLOBAL f16 = double($7fffffff) * * Out: d0 = new random number (0-$7ffffffe) * ****************************************************************************** URN30 lw r3,Code ;get previous result/start res. citf f0,f14,r16,r3 fmul f1,f0,f15 mullw r4,r3,r14 fdiv f2,f1,f16 fctiw f3,f2 stfd f3,-8(local) lwz r5,-4(local) mullw r0,r15,r5 subf r3,r0,r4 ;r3 = new random number sw r3,Code ;store actual result blr ;;/ section "Lanscape_Calc_Data",data CITF_0 dc.l $43300000,$80000000 CITF_TEMP dc.l $43300000,0