Use fixed-point DIV function for a generalized sine_wave table macro

pret · Feb 3, 2018 · b0d84c6 · b0d84c6
1 parent d11cac9
commit b0d84c6
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Showing 2 changed files with 5 additions and 4 deletions.
diff --git a/macros/code.asm b/macros/code.asm
@@ -41,8 +41,8 @@ maskbits: MACRO
 ; example usage in rejection sampling:
 ; .loop
 ; 	call Random
-; 	maskbits 30
-; 	cp 30
+; 	maskbits 26
+; 	cp 26
 ; 	jr nc, .loop
 x = 1
 rept 8

diff --git a/macros/data.asm b/macros/data.asm
@@ -112,10 +112,11 @@ ENDM
 
 
 sine_wave: MACRO
-x = 0.0
+; \1 samples of sin(x) from x=0 to x<32768 (pi radians)
+x = 0
 rept \1
 	dw (sin(x) + (sin(x) & $ff)) >> 8 ; round up
-x = x + 1024.0 ; a circle has 65536.0 "degrees"
+x = x + DIV(32768, \1) ; a circle has 65536 "degrees"
 endr
 ENDM