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[gbajam22] / src / gamescr.c

diff --git a/src/gamescr.c b/src/gamescr.c
index a6ae3fa..cf3b916 100644 (file)
--- a/src/gamescr.c
+++ b/src/gamescr.c
@@ -204,13 +204,19 @@ static void draw(void)
 ARM_IWRAM
 static void gamescr_vblank(void)
 {
-       static int bank, bankdir, theta, scale;
+       static int bank, bankdir, theta, s;
        int32_t sa, ca;
 
        theta = -(bank << 3);
-       scale = MAXBANK + (abs(bank) >> 3);
-       sa = SIN(theta) / scale;
-       ca = COS(theta) / scale;
+#if 0
+       s = 0x100000 / (MAXBANK + (abs(bank) >> 3));
+       sa = ((SIN(theta) >> 8) * s) >> 12;
+       ca = ((COS(theta) >> 8) * s) >> 12;
+#else
+       s = (MAXBANK + (abs(bank) >> 3));
+       sa = SIN(theta) / s;
+       ca = COS(theta) / s;
+#endif
 
        REG_BG2X = -ca * 120 - sa * 80 + (120 << 8);
        REG_BG2Y = sa * 120 - ca * 80 + (80 << 8);