From 85204f4a28009408c97bd49df8a205be4e80638e Mon Sep 17 00:00:00 2001
From: Flatmush <Flatmush@gmail.com>
Date: Wed, 25 Jul 2012 14:49:11 +0000
Subject: Updated coding style document. Cleaned up some code.

---
 libfixmath/code_style.txt | 37 ++++++++++++++++++++++++++++++++++++-
 libfixmath/fix16_trig.c   | 28 +++++++++++++++-------------
 2 files changed, 51 insertions(+), 14 deletions(-)

diff --git a/libfixmath/code_style.txt b/libfixmath/code_style.txt
index 604566a..cb12373 100644
--- a/libfixmath/code_style.txt
+++ b/libfixmath/code_style.txt
@@ -190,7 +190,7 @@ Suffixes must be used for the various types:
 Enums must always be typedef'd.
 Enum values must be prefixed by the enum name.
 Structs which rely on ordering must use __attribute__((__packed__)).
-
+Unions must use __attribute__((__packed__)).
 Bitfields:
 	- must always use __attribute__((__packed__)).
 	- must always follow the GCC rules regarding bitfields.
@@ -212,6 +212,7 @@ Examples:
 	typedef struct vector_s vector_t;
 2:
 	union types_u
+	__attribute__((__packed__))
 	{
 		int      i;
 		unsigned u;
@@ -227,3 +228,37 @@ Examples:
 		unsigned reserved : 2;
 		unsigned alpha    : 4;
 	} img_desc_t;
+
+
+
+11.0 - MACROS
+
+Macros should only be used for condtional compilation and header protection
+where this is possible.
+For function like macros static inline functions should be defined.
+For variable like macros static const variables should be defined.
+For enums the enum type should always be used.
+
+Examples:
+0:
+	static const unsigned max(unsigned x, unsigned y)
+		{ return (x > y ? x : y); }
+1:
+	static const float pi = 3.14152f;
+2:
+	typedef enum
+	{
+		fuzzy_no = 0,
+		fuzzy_yes,
+		fuzzy_maybe,
+	} fuzzy_e;
+
+Counter-examples:
+0:
+	#define MAX(x, y) ((x) > (y) ? (x) : (y))
+1:
+	#define PI 3.14152
+2:
+	#define FUZZY_NO    0
+	#define FUZZY_YES   1
+	#define FUZZY_MAYBE 2
diff --git a/libfixmath/fix16_trig.c b/libfixmath/fix16_trig.c
index 864dc22..07c98bd 100644
--- a/libfixmath/fix16_trig.c
+++ b/libfixmath/fix16_trig.c
@@ -116,22 +116,22 @@ fix16_t fix16_tan(fix16_t inAngle)
 	return fix16_sdiv(fix16_sin(inAngle), fix16_cos(inAngle));
 }
 
-fix16_t fix16_asin(fix16_t inValue)
+fix16_t fix16_asin(fix16_t x)
 {
-	if((inValue > fix16_one)
-		|| (inValue < -fix16_one))
+	if((x > fix16_one)
+		|| (x < -fix16_one))
 		return 0;
 
-	fix16_t tempOut;
-	tempOut = (fix16_one - fix16_mul(inValue, inValue));
-	tempOut = fix16_div(inValue, fix16_sqrt(tempOut));
-	tempOut = fix16_atan(tempOut);
-	return tempOut;
+	fix16_t out;
+	out = (fix16_one - fix16_mul(x, x));
+	out = fix16_div(x, fix16_sqrt(out));
+	out = fix16_atan(out);
+	return out;
 }
 
-fix16_t fix16_acos(fix16_t inValue)
+fix16_t fix16_acos(fix16_t x)
 {
-	return ((fix16_pi >> 1) - fix16_asin(inValue));
+	return ((fix16_pi >> 1) - fix16_asin(x));
 }
 
 fix16_t fix16_atan2(fix16_t inY , fix16_t inX)
@@ -158,7 +158,9 @@ fix16_t fix16_atan2(fix16_t inY , fix16_t inX)
 	} else {
 		r = fix16_div( (inX + abs_inY), (abs_inY - inX));
 		r_3 = fix16_mul(fix16_mul(r, r),r);
-		angle = fix16_mul(0x00003240 , r_3) - fix16_mul(0x0000FB50,r) + THREE_PI_DIV_4;
+		angle = fix16_mul(0x00003240 , r_3)
+			- fix16_mul(0x0000FB50,r)
+			+ THREE_PI_DIV_4;
 	}
 	if (inY < 0)
 	{
@@ -174,7 +176,7 @@ fix16_t fix16_atan2(fix16_t inY , fix16_t inX)
 	return angle;
 }
 
-fix16_t fix16_atan(fix16_t inValue)
+fix16_t fix16_atan(fix16_t x)
 {
-	return fix16_atan2(inValue, fix16_one);
+	return fix16_atan2(x, fix16_one);
 }
-- 
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