Add atan2 to math2

cplusplus/include/vips/VImage8.h

@@ -1468,6 +1468,35 @@ public:
 		return( math2_const( VIPS_OPERATION_MATH2_WOP, 
 			other, options ) );
 	}
+	
+	/**
+	 * Calculate atan2 of each pixel.
+	 */
+	VImage 
+	atan2( VImage other, VOption *options = 0 ) const
+	{
+		return( math2( other, VIPS_OPERATION_MATH2_ATAN2, options ) );
+	}
+
+	/**
+	 * Calculate atan2 of each pixel.
+	 */
+	VImage 
+	atan2( double other, VOption *options = 0 ) const
+	{
+		return( math2_const( VIPS_OPERATION_MATH2_ATAN2, 
+			to_vector( other ), options ) );
+	}
+
+	/**
+	 * Calculate atan2 of each pixel.
+	 */
+	VImage 
+	atan2( std::vector<double> other, VOption *options = 0 ) const
+	{
+		return( math2_const( VIPS_OPERATION_MATH2_ATAN2, 
+			other, options ) );
+	}
 
 	/**
 	 * Use self as a conditional image (not zero meaning TRUE) to pick

doc/function-list.xml

@@ -949,7 +949,7 @@
 <row>
   <entry>math2</entry>
   <entry>Binary math operations</entry>
-  <entry>vips_math2(), vips_pow(), vips_wop()</entry>
+  <entry>vips_math2(), vips_pow(), vips_wop(), vips_atan2()</entry>
 </row>
 <row>
   <entry>math2_const</entry>

doc/gen-function-list.py

@@ -83,7 +83,7 @@ def gen_function_list():
         'extract_area': ['crop'],
         'linear': ['linear1'],
         'math': ['sin', 'cos', 'tan', 'asin', 'acos', 'atan', 'exp', 'exp10', 'log', 'log10'],
-        'math2': ['pow', 'wop'],
+        'math2': ['pow', 'wop', 'atan2'],
         'rank': ['median'],
         'relational': ['equal', 'notequal', 'less', 'lesseq', 'more', 'moreeq'],
         'remainder_const': ['remainder_const1'],

libvips/arithmetic/math2.c

@@ -146,6 +146,25 @@ vips_math2_build( VipsObject *object )
 
 #define WOP( Y, X, E ) POW( Y, E, X )
 
+ 
+#ifdef HAVE_ATAN2 
+#define ATAN2( Y, L, R ) { \
+	double left = (double) (L); \
+	double right = (double) (R); \
+	\
+	(Y) = VIPS_DEG( atan2( left, right ) ); \
+	if( (Y) < 0.0 ) \
+		(Y) += 360; \
+}
+#else
+#define ATAN2( Y, L, R ) { \
+	double left = (double) (L); \
+	double right = (double) (R); \
+	\
+	(Y) = vips_col_ab2h( left, right ); \
+}
+#endif 
+
 static void
 vips_math2_buffer( VipsArithmetic *arithmetic, 
 	VipsPel *out, VipsPel **in, int width )
@@ -159,6 +178,7 @@ vips_math2_buffer( VipsArithmetic *arithmetic,
 	switch( math2->math2 ) {
 	case VIPS_OPERATION_MATH2_POW: 	SWITCH( LOOP, POW ); break;
 	case VIPS_OPERATION_MATH2_WOP: 	SWITCH( LOOP, WOP ); break;
+	case VIPS_OPERATION_MATH2_ATAN2: 	SWITCH( LOOP, ATAN2 ); break;
 
         default:
 		g_assert_not_reached();
@@ -320,6 +340,31 @@ vips_wop( VipsImage *left, VipsImage *right, VipsImage **out, ... )
 	return( result );
 }
 
+/**
+ * vips_atan2:
+ * @left: left-hand input #VipsImage
+ * @right: right-hand input #VipsImage
+ * @out: (out): output #VipsImage
+ * @...: %NULL-terminated list of optional named arguments
+ *
+ * Perform #VIPS_OPERATION_MATH2_ATAN2 on a pair of images. See
+ * vips_math2().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+vips_atan2( VipsImage *left, VipsImage *right, VipsImage **out, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, out );
+	result = vips_math2v( left, right, out, VIPS_OPERATION_MATH2_ATAN2, ap );
+	va_end( ap );
+
+	return( result );
+}
+
 
 typedef struct _VipsMath2Const {
 	VipsUnaryConst parent_instance;
@@ -380,6 +425,10 @@ vips_math2_const_buffer( VipsArithmetic *arithmetic,
 		SWITCH( LOOPC, WOP ); 
 		break;
 
+	case VIPS_OPERATION_MATH2_ATAN2: 	
+		SWITCH( LOOPC, ATAN2 ); 
+		break;
+
         default:
 		g_assert_not_reached();
 		break;
@@ -536,6 +585,33 @@ vips_wop_const( VipsImage *in, VipsImage **out, const double *c, int n, ... )
 	return( result );
 }
 
+/**
+ * vips_atan2_const: (method)
+ * @in: left-hand input #VipsImage
+ * @out: (out): output #VipsImage
+ * @c: (array length=n): array of constants
+ * @n: number of constants in @c
+ * @...: %NULL-terminated list of optional named arguments
+ *
+ * Perform #VIPS_OPERATION_MATH2_ATAN2 on an image and a constant. See
+ * vips_math2_const().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+vips_atan2_const( VipsImage *in, VipsImage **out, const double *c, int n, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, n );
+	result = vips_math2_constv( in, out, 
+		VIPS_OPERATION_MATH2_ATAN2, c, n, ap );
+	va_end( ap );
+
+	return( result );
+}
+
 /**
  * vips_math2_const1: (method)
  * @in: input image
@@ -614,3 +690,29 @@ vips_wop_const1( VipsImage *in, VipsImage **out, double c, ... )
 
 	return( result );
 }
+
+/**
+ * vips_atan2_const1: (method)
+ * @in: left-hand input #VipsImage
+ * @out: (out): output #VipsImage
+ * @c: constant 
+ * @...: %NULL-terminated list of optional named arguments
+ *
+ * Perform #VIPS_OPERATION_MATH2_ATAN2 on an image and a constant. See
+ * vips_math2_const().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+vips_atan2_const1( VipsImage *in, VipsImage **out, double c, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, c );
+	result = vips_math2_constv( in, out, 
+		VIPS_OPERATION_MATH2_ATAN2, &c, 1, ap );
+	va_end( ap );
+
+	return( result );
+}

libvips/include/vips/arithmetic.h

@@ -71,12 +71,14 @@ typedef enum {
  * VipsOperationMath2:
  * @VIPS_OPERATION_MATH2_POW: pow( left, right )
  * @VIPS_OPERATION_MATH2_WOP: pow( right, left ) 
+ * @VIPS_OPERATION_MATH2_ATAN2: pow( left, right ) 
  *
  * See also: vips_math().
  */
 typedef enum {
 	VIPS_OPERATION_MATH2_POW,
 	VIPS_OPERATION_MATH2_WOP,
+	VIPS_OPERATION_MATH2_ATAN2,
 	VIPS_OPERATION_MATH2_LAST
 } VipsOperationMath2;
 
@@ -368,6 +370,8 @@ int vips_pow( VipsImage *left, VipsImage *right, VipsImage **out, ... )
 	__attribute__((sentinel));
 int vips_wop( VipsImage *left, VipsImage *right, VipsImage **out, ... )
 	__attribute__((sentinel));
+int vips_atan2( VipsImage *left, VipsImage *right, VipsImage **out, ... )
+	__attribute__((sentinel));
 int vips_math2_const( VipsImage *in, VipsImage **out, 
 	VipsOperationMath2 math2, const double *c, int n, ... )
 	__attribute__((sentinel));
@@ -377,6 +381,9 @@ int vips_pow_const( VipsImage *in, VipsImage **out,
 int vips_wop_const( VipsImage *in, VipsImage **out, 
 	const double *c, int n, ... )
 	__attribute__((sentinel));
+int vips_atan2_const( VipsImage *in, VipsImage **out, 
+	const double *c, int n, ... )
+	__attribute__((sentinel));
 int vips_math2_const1( VipsImage *in, VipsImage **out, 
 	VipsOperationMath2 math2, double c, ... )
 	__attribute__((sentinel));
@@ -384,6 +391,8 @@ int vips_pow_const1( VipsImage *in, VipsImage **out, double c, ... )
 	__attribute__((sentinel));
 int vips_wop_const1( VipsImage *in, VipsImage **out, double c, ... )
 	__attribute__((sentinel));
+int vips_atan2_const1( VipsImage *in, VipsImage **out, double c, ... )
+	__attribute__((sentinel));
 
 int vips_avg( VipsImage *in, double *out, ... )
 	__attribute__((sentinel));

libvips/iofuncs/enumtypes.c

@@ -40,6 +40,7 @@ vips_operation_math2_get_type( void )
 		static const GEnumValue values[] = {
 			{VIPS_OPERATION_MATH2_POW, "VIPS_OPERATION_MATH2_POW", "pow"},
 			{VIPS_OPERATION_MATH2_WOP, "VIPS_OPERATION_MATH2_WOP", "wop"},
+			{VIPS_OPERATION_MATH2_ATAN2, "VIPS_OPERATION_MATH2_ATAN2", "atan2"},
 			{VIPS_OPERATION_MATH2_LAST, "VIPS_OPERATION_MATH2_LAST", "last"},
 			{0, NULL, NULL}
 		};