Fixed errors in asin/atan, where incorrect integer maths was used.

Added a macro (FIXMATH_NO_CACHE) to disable caching.
Added fix16_lerp8 and fix16_lerp32 (should be part of fract module really).

4 files changed, 45 insertions, 11 deletions

diff --git a/libfixmath/fix16.c b/libfixmath/fix16.c
index 3fef27d..32fc3d1 100644
--- a/libfixmath/fix16.c
+++ b/libfixmath/fix16.c
@@ -91,6 +91,14 @@ fix16_t fix16_sdiv(fix16_t inArg0, fix16_t inArg1) {
 

 

 

+fix16_t fix16_lerp8(fix16_t inArg0, fix16_t inArg1, uint8_t inFract) {

+	int64_t tempOut;

+	tempOut   = ((int64_t)inArg0 * (256 - inFract));

+	tempOut  += ((int64_t)inArg1 * inFract);

+	tempOut >>= 8;

+	return (fix16_t)tempOut;

+}

+

 fix16_t fix16_lerp16(fix16_t inArg0, fix16_t inArg1, uint16_t inFract) {

 	int64_t tempOut;

 	tempOut   = ((int64_t)inArg0 * (fix16_one - inFract));

@@ -98,3 +106,11 @@ fix16_t fix16_lerp16(fix16_t inArg0, fix16_t inArg1, uint16_t inFract) {
 	tempOut >>= 16;

 	return (fix16_t)tempOut;

 }

+

+fix16_t fix16_lerp32(fix16_t inArg0, fix16_t inArg1, uint32_t inFract) {

+	int64_t tempOut;

+	tempOut   = ((int64_t)inArg0 * (0 - inFract));

+	tempOut  += ((int64_t)inArg1 * inFract);

+	tempOut >>= 32;

+	return (fix16_t)tempOut;

+}

diff --git a/libfixmath/fix16.h b/libfixmath/fix16.h
index aacfd8e..7913b9c 100644
--- a/libfixmath/fix16.h
+++ b/libfixmath/fix16.h
@@ -73,7 +73,9 @@ extern fix16_t fix16_sdiv(fix16_t inArg0, fix16_t inArg1);
 

 /*! Returns the linear interpolation: (inArg0 * (1 - inFract)) + (inArg1 * inFract)

 */

+extern fix16_t fix16_lerp8(fix16_t inArg0, fix16_t inArg1, uint8_t inFract);

 extern fix16_t fix16_lerp16(fix16_t inArg0, fix16_t inArg1, uint16_t inFract);

+extern fix16_t fix16_lerp32(fix16_t inArg0, fix16_t inArg1, uint32_t inFract);

 

 

 

diff --git a/libfixmath/fix16_sqrt.c b/libfixmath/fix16_sqrt.c
index f913a62..3d8e164 100644
--- a/libfixmath/fix16_sqrt.c
+++ b/libfixmath/fix16_sqrt.c
@@ -2,15 +2,19 @@
 

 

 

+#ifndef FIXMATH_NO_CACHE

 fix16_t _fix16_sqrt_cache_index[4096] = { 0 };

 fix16_t _fix16_sqrt_cache_value[4096] = { 0 };

+#endif

 

 

 

 fix16_t fix16_sqrt(fix16_t inValue) {

+	#ifndef FIXMATH_NO_CACHE

 	fix16_t tempIndex = (((inValue >> 16) ^ (inValue >> 4)) & 0x00000FFF);

 	if(_fix16_sqrt_cache_index[tempIndex] == inValue)

 		return _fix16_sqrt_cache_value[tempIndex];

+	#endif

 

 	int64_t tempOp = inValue; tempOp <<= 16;

 	int64_t tempOut = 0;

@@ -28,8 +32,10 @@ fix16_t fix16_sqrt(fix16_t inValue) {
 		tempOne >>= 2;

 	}

 

+	#ifndef FIXMATH_NO_CACHE

 	_fix16_sqrt_cache_index[tempIndex] = inValue;

 	_fix16_sqrt_cache_value[tempIndex] = tempOut;

+	#endif

 

 	return tempOut;

 }

diff --git a/libfixmath/fix16_trig.c b/libfixmath/fix16_trig.c
index 9d5046b..c162b61 100644
--- a/libfixmath/fix16_trig.c
+++ b/libfixmath/fix16_trig.c
@@ -2,10 +2,12 @@
 

 

 

-fix16_t _fix16_sin_cache_index[4096] = { 0 };

-fix16_t _fix16_sin_cache_value[4096] = { 0 };

-fix16_t _fix16_atan_cache_index[4096] = { 0 };

-fix16_t _fix16_atan_cache_value[4096] = { 0 };

+#ifndef FIXMATH_NO_CACHE

+static fix16_t _fix16_sin_cache_index[4096]  = { 0 };

+static fix16_t _fix16_sin_cache_value[4096]  = { 0 };

+static fix16_t _fix16_atan_cache_index[4096] = { 0 };

+static fix16_t _fix16_atan_cache_value[4096] = { 0 };

+#endif

 

 

 

@@ -16,9 +18,11 @@ fix16_t fix16_sin(fix16_t inAngle) {
 	else if(tempAngle < -fix16_pi)

 		tempAngle += (fix16_pi << 1);

 

+	#ifndef FIXMATH_NO_CACHE

 	fix16_t tempIndex = ((inAngle >> 5) & 0x00000FFF);

 	if(_fix16_sin_cache_index[tempIndex] == inAngle)

 		return _fix16_sin_cache_value[tempIndex];

+	#endif

 

 	fix16_t tempAngleSq = fix16_mul(tempAngle, tempAngle);

 

@@ -34,8 +38,10 @@ fix16_t fix16_sin(fix16_t inAngle) {
 	tempAngle = fix16_mul(tempAngle, tempAngleSq);

 	tempOut -= (tempAngle / 39916800);

 

+	#ifndef FIXMATH_NO_CACHE

 	_fix16_sin_cache_index[tempIndex] = inAngle;

 	_fix16_sin_cache_value[tempIndex] = tempOut;

+	#endif

 

 	return tempOut;

 }

@@ -49,11 +55,11 @@ fix16_t fix16_tan(fix16_t inAngle) {
 }

 

 fix16_t fix16_asin(fix16_t inValue) {

-	if((inValue > 1) || (inValue < -1))

+	if((inValue > fix16_one) || (inValue < -fix16_one))

 		return 0;

 	fix16_t tempOut;

-	tempOut = (1 - fix16_mul(inValue, inValue));

-	tempOut = (inValue / fix16_sqrt(tempOut));

+	tempOut = (fix16_one - fix16_mul(inValue, inValue));

+	tempOut = fix16_div(inValue, fix16_sqrt(tempOut));

 	tempOut = fix16_atan(tempOut);

 	return tempOut;

 }

@@ -62,12 +68,12 @@ fix16_t fix16_acos(fix16_t inValue) {
 	return ((fix16_pi >> 1) - fix16_asin(inValue));

 }

 

-fix16_t _fix16_atan(fix16_t inValue) {

+static fix16_t _fix16_atan(fix16_t inValue) {

 	fix16_t tempOut;

 	if(inValue > 29736) {

-		tempOut = (1 + fix16_mul(inValue, inValue));

-		tempOut = (1 + fix16_sqrt(tempOut));

-		tempOut = (inValue / tempOut);

+		tempOut = (fix16_one + fix16_mul(inValue, inValue));

+		tempOut = (fix16_one + fix16_sqrt(tempOut));

+		tempOut = fix16_div(inValue, tempOut);

 		tempOut = _fix16_atan(tempOut);

 		return (tempOut << 1);

 	}

@@ -90,12 +96,16 @@ fix16_t _fix16_atan(fix16_t inValue) {
 }

 

 fix16_t fix16_atan(fix16_t inValue) {

+	#ifndef FIXMATH_NO_CACHE

 	fix16_t tempIndex = (((inValue >> 16) ^ (inValue >> 4)) & 0x00000FFF);

 	if(_fix16_atan_cache_index[tempIndex] == inValue)

 		return _fix16_atan_cache_value[tempIndex];

+	#endif

 	fix16_t tempOut = _fix16_atan(inValue);

+	#ifndef FIXMATH_NO_CACHE

 	_fix16_atan_cache_index[tempIndex] = inValue;

 	_fix16_atan_cache_value[tempIndex] = tempOut;

+	#endif

 	return tempOut;

 }