boot3/QuickDraw/Angles.a
Elliot Nunn 5b0f0cc134 Bring in CubeE sources
Resource forks are included only for .rsrc files. These are DeRezzed into their data fork. 'ckid' resources, from the Projector VCS, are not included.

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2017-12-26 10:02:57 +08:00

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;EASE$$$ READ ONLY COPY of file ÒANGLES.aÓ
;¥1.5 BAL 05/29/1989 Blasting in 32-Bit QuickDraw version 1.0 Final
;¥1.4 BAL 04/12/1989 Blasting in 32-Bit QuickDraw 1.0B1
;¥1.3 BAL 04/12/1989 -d
; File Angles.a
;
; Copyright Apple Computer, Inc. 1981-1986
; All Rights Reserved
;
;
BLANKS ON
STRING ASIS
AngleFromSlope FUNC EXPORT
EXPORT SlopeFromAngle
;-----------------------------------------------------
;
; FUNCTION AngleFromSlope(slope: Fixed): INTEGER;
;
; Scans slope table for angle and returns angle 0..180
;
MOVE.L 4(SP),D0 ;GET SLOPE
SMI D2 ;REMEMBER IF IT WAS NEGATIVE
BPL.S NOTNEG ;CONTINUE IF POSITIVE
NEG.L D0 ;ELSE MAKE SLOPE POS
NOTNEG SUB.L #500,D0 ;BIAS THE COMPARE
MOVE.L D0,4(SP)
LEA CONTINUE,A0 ;POINT TO TABLE OF SLOPES
MOVEQ #-1,D1 ;INIT ANGLE COUNT
SCAN ADD.W #1,D1
MOVE.W D1,D0
CLR.L -(SP)
BRA.S A2SLOPE
CONTINUE
MOVE.L 8(SP),D0 ;GET SLOPE
CMP.L (SP)+,D0 ;SCAN THRU SLOPE TABLE
BGT.S SCAN
MOVE #180,D0
SUB D1,D0 ;CALC 180-ANGLE = 90..180
TST.B D2 ;WAS DH POS ?
BPL.S DONE ;NO, RETURN 90..180
MOVE D1,D0 ;YES, RETURN 0..90
DONE MOVE.L (SP)+,(SP) ;STRIP PARAM
MOVE.W D0,4(SP) ;RETURN FUNCTION RESULT
RTS
;----------------------------------------------------------------
;
; FUNCTION SlopeFromAngle(angle: INTEGER): Fixed;
;
; calculate the fixed point slope of a line, DH/DV = -65536 * Tan(angle).
; Input angle is treated MOD 180.
;
SlopeFromAngle
MOVE.L (SP)+,A0 ;POP RETURN ADDR
MOVE (SP)+,D0 ;GET INTEGER ANGLE
EXT.L D0 ;SIGN EXTEND FOR DIVIDE
DIVS #180,D0 ;TREAT ANGLE MOD 180
SWAP D0 ;GET THE REMAINDER
TST D0 ;WAS IT NEGATIVE ?
BPL.S OK1 ;NO, CONTINUE
ADD #180,D0 ;YES, PUT IN RANGE 0..179
OK1 MOVE #$8000,(SP)
A2SLOPE CMP #90,D0
BLE.S OK2
CLR.W (SP)
SUB #180,D0
NEG D0
OK2 CMP #45,D0
BLT.S SHARE
ADD #1,(SP)
CMP #64,D0
BLT.S SHARE
MOVE.B SLOPE-91(D0),1(SP)
BPL.S SHARE
OR.B #$7F,(SP)
SHARE ADD D0,D0
MOVE.W SLOPE(D0),2(SP)
CHECK BCLR #7,(SP)
BEQ.S OK3
NEG.L (SP)
OK3 JMP (A0)
; .BYTE $01 ;45
; .BYTE $01
; .BYTE $01
; .BYTE $01
; .BYTE $01
; .BYTE $01 ;50
; .BYTE $01
; .BYTE $01
; .BYTE $01
; .BYTE $01
; .BYTE $01 ;55
; .BYTE $01
; .BYTE $01
; .BYTE $01
; .BYTE $01
; .BYTE $01 ;60
; .BYTE $01
; .BYTE $01
DC.B $01
DC.B $02
DC.B $02 ;65
DC.B $02
DC.B $02
DC.B $02
DC.B $02
DC.B $02 ;70
DC.B $02
DC.B $03
DC.B $03
DC.B $03
DC.B $03 ;75
DC.B $04
DC.B $04
DC.B $04
DC.B $05
DC.B $05 ;80
DC.B $06
DC.B $07
DC.B $08
DC.B $09
DC.B $0B ;85
DC.B $0E
DC.B $13
DC.B $1C
DC.B $39
DC.B $FF ;90
SLOPE
DC.W $0000 ;0
DC.W $0478
DC.W $08F1
DC.W $0D6B
DC.W $11E7
DC.W $1666 ;5
DC.W $1AE8
DC.W $1F6F
DC.W $23FA
DC.W $288C
DC.W $2D24 ;10
DC.W $31C3
DC.W $366A
DC.W $3B1A
DC.W $3FD4
DC.W $4498 ;15
DC.W $4968
DC.W $4E44
DC.W $532E
DC.W $5826
DC.W $5D2D ;20
DC.W $6245
DC.W $676E
DC.W $6CAA
DC.W $71FB
DC.W $7760 ;25
DC.W $7CDC
DC.W $8270
DC.W $881E
DC.W $8DE7
DC.W $93CD ;30
DC.W $99D2
DC.W $9FF7
DC.W $A640
DC.W $ACAD
DC.W $B341 ;35
DC.W $B9FF
DC.W $C0E9
DC.W $C802
DC.W $CF4E
DC.W $D6CF ;40
DC.W $DE8A
DC.W $E681
DC.W $EEB9
DC.W $F737
DC.W $0000 ;45
DC.W $0919
DC.W $1287
DC.W $1C51
DC.W $267F
DC.W $3117 ;50
DC.W $3C22
DC.W $47AA
DC.W $53B9
DC.W $605B
DC.W $6D9B ;55
DC.W $7B89
DC.W $8A35
DC.W $99AF
DC.W $AA0E
DC.W $BB68 ;60
DC.W $CDD6
DC.W $E177
DC.W $F66E
DC.W $0CE1
DC.W $24FE ;65
DC.W $3EFC
DC.W $5B19
DC.W $799F
DC.W $9AE7
DC.W $BF5B ;70
DC.W $E77A
DC.W $13E3
DC.W $4556
DC.W $7CC7
DC.W $BB68 ;75
DC.W $02C2
DC.W $54DB
DC.W $B462
DC.W $2501
DC.W $ABD9 ;80
DC.W $5051
DC.W $1D88
DC.W $24F3
DC.W $83AD
DC.W $6E17 ;85
DC.W $4CF5
DC.W $14BD
DC.W $A2D7
DC.W $4A30
DC.W $FFFF ;90
PtToAngle PROC EXPORT
IMPORT AngleFromSlope
;--------------------------------------------------------------
;
; PROCEDURE PtToAngle(r: Rect; pt: Point; VAR angle: INTEGER);
;
; Given a rectangle and a point, return the angle subtended by pt.
;
; A6 OFFSETS OF PARAMETERS AFTER LINK:
;
PARAMSIZE EQU 12 ;TOTAL BYTES OF PARAMS
RECT EQU PARAMSIZE+8-4 ;ADDR OF RECT
PT EQU RECT-4 ;POINT
ANGLE EQU PT-4 ;ADDR OF INTEGER;
LINK A6,#0 ;NO LOCALS
MOVEM.L D6-D7/A4,-(SP) ;SAVE REGS
MOVE.L RECT(A6),A4 ;POINT TO RECT
MOVE BOTTOM(A4),D0
ADD TOP(A4),D0
ASR #1,D0 ;CENTER.V := (TOP+BOTTOM)/2
MOVE PT+V(A6),D1
SUB D0,D1 ;DV := PT.V - CENTER.V
MOVE RIGHT(A4),D0
ADD LEFT(A4),D0
ASR #1,D0 ;CENTER.H := (LEFT+RIGHT)/2
MOVE PT+H(A6),D7
SUB D0,D7 ;DH := PT.H - CENTER.H
BNE.S DHOK ;CONTINUE IF DH <> 0
TST D1 ;WAS DV > 0 ?
BLE.S ZERO ;NO, RETURN ANGLE = 0
MOVE #180,D0 ;YES, RETURN ANGLE = 180
BRA.S DONE
DHOK CLR.L -(SP) ;ROOM FOR FCN RESULT
MOVE D7,-(SP) ;PUSH DH
MOVE D1,-(SP) ;PUSH DV
_FixRatio ;CALC SLOPE := DH/DV
MOVE.L (SP)+,D6 ;GET SLOPE RESULT
CLR.L -(SP) ;ROOM FOR FCN RESULT
MOVE BOTTOM(A4),D0
SUB TOP(A4),D0
MOVE D0,-(SP) ;PUSH HEIGHT
MOVE RIGHT(A4),D0
SUB LEFT(A4),D0
MOVE D0,-(SP) ;PUSH WIDTH
_FixRatio ;CALC ASPECT := HT/WD
MOVE.L (SP)+,D0 ;GET ASPECT RESULT
CLR.L -(SP) ;ROOM FOR FCN RESULT
MOVE.L D6,-(SP) ;PUSH SLOPE
MOVE.L D0,-(SP) ;PUSH ASPECT
_FixMul ;CALC SLOPE*ASPECT
MOVE.L (SP)+,D0 ;GET RESULT SLOPE2
CLR.W -(SP) ;ROOM FOR FCN RESULT
MOVE.L D0,-(SP) ;PUSH SLOPE2
_AngleFromSlope ;SCAN FOR ARCTAN
MOVE (SP)+,D0 ;GET RESULT ANGLE
TST D7 ;WAS DH POSITIVE ?
BPL.S DONE ;YES, CONTINUE
ADD #180,D0 ;NO, ADD 180 TO ANG
CMP #360,D0 ;IS RESULT = 360 ?
BNE.S DONE ;NO, CONTINUE
ZERO CLR D0 ;YES, ANGLE := 0
DONE MOVE.L ANGLE(A6),A0 ;GET VAR ADDR
MOVE D0,(A0) ;STORE INTO ANGLE
MOVEM.L (SP)+,D6-D7/A4 ;RESTORE REGS
UNLINK PARAMSIZE,'PTTOANGL'
ENDPROC