Merged the sine/cosine routines into one file, because they're often used

together, we save some code in this case, and the sine table isn't of real use
for programs, because it contains some specialities.


git-svn-id: svn://svn.cc65.org/cc65/trunk@4400 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/common/Makefile

@@ -99,9 +99,7 @@ S_OBJS = 	_cwd.o          \
 		atexit.o  	\
 		atoi.o	  	\
 		calloc.o  	\
-                cc65_cos.o      \
-                cc65_sin.o      \
-                cc65_sintab.o   \
+                cc65_sincos.o   \
                 chdir.o         \
 		copydata.o	\
                 creat.o         \

libsrc/common/cc65_cos.s

@@ -1,48 +0,0 @@
-;
-; Fixed point cosine function.
-;
-; Returns the cosine for the given argument as angular degree.
-; Valid argument range is 0..360
-;
-;
-; Ullrich von Bassewitz, 2009-10-29
-;
-
-        .export         _cc65_cos
-
-        .import         _cc65_sin
-
-
-
-; ---------------------------------------------------------------------------
-;
-
-.code
-
-.proc   _cc65_cos         
-
-; cos(x) = sin(x+90)
-
-        clc
-        adc     #90
-        bcc     L1
-        inx
-
-; If x is now larger than 360, we need to subtract 360.
-
-L1:     cpx     #>360
-        bne     L2
-        cmp     #<360
-L2:     bcc     L4
-
-        sbc     #<360
-        bcs     L3
-        dex
-L3:     dex
-
-L4:     jmp     _cc65_sin
-
-
-.endproc
-
-

libsrc/common/cc65_sincos.s

@@ -1,24 +1,74 @@
 ;
-; Fixed point sine function.
+; Fixed point cosine/sine functions.
 ;
-; Returns the cosine for the given argument as angular degree.
-; Valid argument range is 0..360
+; Returns the cosine/sine for the given argument as angular degree.
+; Valid argument range is 0..360 for both functions. They will return
+; garbage if the argument is not in a valid range. Result is in 8.8 fixed
+; point format, so $100 is 1.0 and $FF00 is -1.0.
 ;
 ;
 ; Ullrich von Bassewitz, 2009-10-29
 ;
 
-        .export         _cc65_sin
-
-        .import         _cc65_sintab
+        .export         _cc65_cos, _cc65_sin
 
 
 ; ---------------------------------------------------------------------------
-;
+; Sinus table covering values from 0..86° as 0.8 fixed point values. Values
+; for 87..90° are actually 1.0 (= $100), will therefore not fit in the table
+; and are covered specially in the code below.
+
+.rodata
+
+_cc65_sintab:
+        .byte   $00, $04, $09, $0D, $12, $16, $1B, $1F, $24, $28
+        .byte   $2C, $31, $35, $3A, $3E, $42, $47, $4B, $4F, $53
+        .byte   $58, $5C, $60, $64, $68, $6C, $70, $74, $78, $7C
+        .byte   $80, $84, $88, $8B, $8F, $93, $96, $9A, $9E, $A1
+        .byte   $A5, $A8, $AB, $AF, $B2, $B5, $B8, $BB, $BE, $C1
+        .byte   $C4, $C7, $CA, $CC, $CF, $D2, $D4, $D7, $D9, $DB
+        .byte   $DE, $E0, $E2, $E4, $E6, $E8, $EA, $EC, $ED, $EF
+        .byte   $F1, $F2, $F3, $F5, $F6, $F7, $F8, $F9, $FA, $FB
+        .byte   $FC, $FD, $FE, $FE, $FF, $FF, $FF
+
+
+
+; ---------------------------------------------------------------------------
+; Cosine function. Is actually implemented as cos(x) = sin(x+90)
 
 .code
 
-.proc   _cc65_sin
+_cc65_cos:
+
+; cos(x) = sin(x+90)
+
+        clc
+        adc     #90
+        bcc     @L1
+        inx
+
+; If x is now larger than 360, we need to subtract 360.
+
+@L1:    cpx     #>360
+        bne     @L2
+        cmp     #<360
+@L2:    bcc     _cc65_sin
+
+        sbc     #<360
+        bcs     @L3
+        dex
+@L3:    dex
+
+; ---------------------------------------------------------------------------
+; Sine function. Uses
+;
+;       table lookup            for 0..89°
+;       sin(x) = sin(180-x)     for 90°..179°
+;       sin(x) = -sin(x-180)    for 180..360°
+;
+; Plus special handling for the values missing in the table.
+
+_cc65_sin:
 
 ; If the high byte is non zero, argument is > 255
 
@@ -108,6 +158,4 @@ L6:     tay
         inx
 L7:     rts
 
-.endproc
-
 

libsrc/common/cc65_sintab.s

@@ -1,24 +0,0 @@
-;
-; Sinus table
-;
-; Ullrich von Bassewitz, 2009-10-29
-;
-
-        .export         _cc65_sintab
-
-
-; ---------------------------------------------------------------------------
-;
-
-.rodata
-
-_cc65_sintab:
-        .byte   $00, $04, $09, $0D, $12, $16, $1B, $1F, $24, $28
-        .byte   $2C, $31, $35, $3A, $3E, $42, $47, $4B, $4F, $53
-        .byte   $58, $5C, $60, $64, $68, $6C, $70, $74, $78, $7C
-        .byte   $80, $84, $88, $8B, $8F, $93, $96, $9A, $9E, $A1
-        .byte   $A5, $A8, $AB, $AF, $B2, $B5, $B8, $BB, $BE, $C1
-        .byte   $C4, $C7, $CA, $CC, $CF, $D2, $D4, $D7, $D9, $DB
-        .byte   $DE, $E0, $E2, $E4, $E6, $E8, $EA, $EC, $ED, $EF
-        .byte   $F1, $F2, $F3, $F5, $F6, $F7, $F8, $F9, $FA, $FB
-        .byte   $FC, $FD, $FE, $FE, $FF, $FF, $FF