X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?p=rmac;a=blobdiff_plain;f=fltpoint.c;h=7e516fbd360686985aa160bb45f7f38658c6a67a;hp=8739e88c1500d73397e6974df8c506377ee2e91a;hb=HEAD;hpb=bdbf34766f4d074a5933eb1326fe4ce03d249e10

diff --git a/fltpoint.c b/fltpoint.c
index 8739e88..ffde55e 100644
--- a/fltpoint.c
+++ b/fltpoint.c
@@ -15,6 +15,7 @@
 #include <float.h>
 #include <math.h>
 #include <stdio.h>
+#include "error.h"
 
 //
 // Check for IEEE-754 conformance (C99 compilers should be OK here)
@@ -171,6 +172,28 @@ void DoubleToExtended(double d, uint8_t out[])
 }
 
 
+//
+// Convert a double to a DSP56001 style fixed point float.
+// Seems to be 23 bits of float value with 1 bit (MSB) for the sign.
+//
+uint32_t DoubleToDSPFloat(double d)
+{
+	if (d >= 1)
+	{
+		warn("DSP value clamped to +1.");
+		return 0x7FFFFF;
+	}
+	else if (d <= -1)
+	{
+		warn("DSP value clamped to -1.");
+		return 0x800000;
+	}
+
+	// The casts are here because some compilers do weird shit.  See bug #149.
+	return (uint32_t)((int32_t)trunc(round(ldexp(d, 23))));
+}
+
+
 //
 // Convert a host native floating point number to a fixed point number.
 //
@@ -187,7 +210,7 @@ uint64_t DoubleToFixedPoint(double d, int intBits, int fracBits)
 
 	// Invert the result, if necessary
 	if (signBit == 1)
-		result = (result = 0xFFFFFFFFFFFFFFFFLL) + 1;
+		result = (result ^ 0xFFFFFFFFFFFFFFFFLL) + 1;
 
 	return result;
 }