text: /* im_multiply.c
   *
   * Copyright: 1990, N. Dessipris.
   *
   * Author: Nicos Dessipris
   * Written on: 02/05/1990
   * Modified on: 
   * 29/4/93 JC
   *	- now works for partial images
   * 1/7/93 JC
   *	- adapted for partial v2
   *	- ANSIfied
   * 19/10/93 JC
   *	- coredump-inducing bug in complex*complex fixed
   * 13/12/93
   *	- char*short bug fixed
   * 12/6/95 JC
   *	- new im_add adapted to make new im_multiply
   * 27/9/04
   *	- updated for 1 band $op n band image -> n band image case
   * 8/12/06
   * 	- add liboil support
   * 18/8/08
   * 	- revise upcasting system
   * 	- add gtkdoc comments
   * 31/7/10
   * 	- remove liboil
   * 7/11/11
   * 	- redo as a class
   */
  
  /*
  
      Copyright (C) 1991-2005 The National Gallery
  
      This library is free software; you can redistribute it and/or
      modify it under the terms of the GNU Lesser General Public
      License as published by the Free Software Foundation; either
      version 2.1 of the License, or (at your option) any later version.
  
      This library is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
      Lesser General Public License for more details.
  
      You should have received a copy of the GNU Lesser General Public
      License along with this library; if not, write to the Free Software
      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
      02110-1301  USA
  
   */
  
  /*
  
      These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
  
   */
  
  /*
  #define DEBUG
   */
  
  #ifdef HAVE_CONFIG_H
  #include <config.h>
  #endif /*HAVE_CONFIG_H*/
  #include <vips/intl.h>
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <math.h>
  
  #include <vips/vips.h>
  
  #include "binary.h"
  
  typedef VipsBinary VipsMultiply;
  typedef VipsBinaryClass VipsMultiplyClass;
  
  G_DEFINE_TYPE( VipsMultiply, vips_multiply, VIPS_TYPE_BINARY );
  
  /* Complex multiply.
   */
  #define CLOOP( TYPE ) { \
  	TYPE * restrict left = (TYPE *) in[0]; \
  	TYPE * restrict right = (TYPE *) in[1]; \
  	TYPE * restrict q = (TYPE *) out; \
  	\
  	for( x = 0; x < sz; x++ ) { \
  		double x1 = left[0]; \
  		double y1 = left[1]; \
  		double x2 = right[0]; \
  		double y2 = right[1]; \
  		\
  		left += 2; \
  		right += 2; \
  		\
  		q[0] = x1 * x2 - y1 * y2; \
  		q[1] = x1 * y2 + x2 * y1; \
  		\
  		q += 2; \
  	} \
  }
  
  /* Real multiply.
   */
  #define RLOOP( IN, OUT ) { \
  	IN * restrict left = (IN *) in[0]; \
  	IN * restrict right = (IN *) in[1]; \
  	OUT * restrict q = (OUT *) out; \
  	\
  	for( x = 0; x < sz; x++ ) \
  		q[x] = left[x] * right[x]; \
  }
  
  static void
  vips_multiply_buffer( VipsArithmetic *arithmetic, 
  	VipsPel *out, VipsPel **in, int width )
  {
  	VipsImage *im = arithmetic->ready[0];
  	const int sz = width * vips_image_get_bands( im );
  
  	int x;
  
  	/* Keep types here in sync with vips_bandfmt_multiply[] 
  	 * below.
           */
          switch( vips_image_get_format( im ) ) {
          case VIPS_FORMAT_CHAR: 	RLOOP( signed char, signed short ); break; 
          case VIPS_FORMAT_UCHAR:	RLOOP( unsigned char, signed short ); break; 
          case VIPS_FORMAT_SHORT:	RLOOP( signed short, signed int ); break; 
          case VIPS_FORMAT_USHORT:RLOOP( unsigned short, signed int ); break; 
          case VIPS_FORMAT_INT: 	RLOOP( signed int, signed int ); break; 
          case VIPS_FORMAT_UINT: 	RLOOP( unsigned int, signed int ); break; 
          case VIPS_FORMAT_FLOAT:	RLOOP( float, float ); break; 
          case VIPS_FORMAT_DOUBLE: RLOOP( double, double ); break;
  
          case VIPS_FORMAT_COMPLEX: CLOOP( float ); break;
          case VIPS_FORMAT_DPCOMPLEX: CLOOP( double ); break;
  
          default:
  		g_assert_not_reached();
          }
  }
  
  /* Save a bit of typing.
   */
  #define UC VIPS_FORMAT_UCHAR
  #define C VIPS_FORMAT_CHAR
  #define US VIPS_FORMAT_USHORT
  #define S VIPS_FORMAT_SHORT
  #define UI VIPS_FORMAT_UINT
  #define I VIPS_FORMAT_INT
  #define F VIPS_FORMAT_FLOAT
  #define X VIPS_FORMAT_COMPLEX
  #define D VIPS_FORMAT_DOUBLE
  #define DX VIPS_FORMAT_DPCOMPLEX
  
  /* Type promotion for multiplication. Sign and value preserving. Make sure 
   * these match the case statement in multiply_buffer() above.
   */
  static int vips_multiply_format_table[10] = {
  /* UC  C   US  S   UI  I  F  X  D  DX */
     US, S,  UI, I,  UI, I, F, X, D, DX
  };
  
  static void
  vips_multiply_class_init( VipsMultiplyClass *class )
  {
  	VipsObjectClass *object_class = (VipsObjectClass *) class;
  	VipsArithmeticClass *aclass = VIPS_ARITHMETIC_CLASS( class );
  
  	object_class->nickname = "multiply";
  	object_class->description = _( "multiply two images" );
  
  	aclass->process_line = vips_multiply_buffer;
  
  	vips_arithmetic_set_format_table( aclass, vips_multiply_format_table ); 
  }
  
  static void
  vips_multiply_init( VipsMultiply *multiply )
  {
  }
  
  /**
   * vips_multiply:
   * @left: left-hand image
   * @right: right-hand image
   * @out: output image
   * @...: %NULL-terminated list of optional named arguments
   *
   * This operation calculates @left * @right and writes the result to @out. 
   *
   * If the images differ in size, the smaller image is enlarged to match the
   * larger by adding zero pixels along the bottom and right.
   *
   * If the number of bands differs, one of the images 
   * must have one band. In this case, an n-band image is formed from the 
   * one-band image by joining n copies of the one-band image together, and then
   * the two n-band images are operated upon.
   *
   * The two input images are cast up to the smallest common format (see table 
   * Smallest common format in 
   * <link linkend="libvips-arithmetic">arithmetic</link>), then the 
   * following table is used to determine the output type:
   *
   * <table>
   *   <title>VipsMultiply type promotion</title>
   *   <tgroup cols='2' align='left' colsep='1' rowsep='1'>
   *     <thead>
   *       <row>
   *         <entry>input type</entry>
   *         <entry>output type</entry>
   *       </row>
   *     </thead>
   *     <tbody>
   *       <row>
   *         <entry>uchar</entry>
   *         <entry>ushort</entry>
   *       </row>
   *       <row>
   *         <entry>char</entry>
   *         <entry>short</entry>
   *       </row>
   *       <row>
   *         <entry>ushort</entry>
   *         <entry>uint</entry>
   *       </row>
   *       <row>
   *         <entry>short</entry>
   *         <entry>int</entry>
   *       </row>
   *       <row>
   *         <entry>uint</entry>
   *         <entry>uint</entry>
   *       </row>
   *       <row>
   *         <entry>int</entry>
   *         <entry>int</entry>
   *       </row>
   *       <row>
   *         <entry>float</entry>
   *         <entry>float</entry>
   *       </row>
   *       <row>
   *         <entry>double</entry>
   *         <entry>double</entry>
   *       </row>
   *       <row>
   *         <entry>complex</entry>
   *         <entry>complex</entry>
   *       </row>
   *       <row>
   *         <entry>double complex</entry>
   *         <entry>double complex</entry>
   *       </row>
   *     </tbody>
   *   </tgroup>
   * </table>
   *
   * In other words, the output type is just large enough to hold the whole
   * range of possible values.
   *
   * See also: vips_add(), vips_linear().
   *
   * Returns: 0 on success, -1 on error
   */
  int
  vips_multiply( VipsImage *left, VipsImage *right, VipsImage **out, ... )
  {
  	va_list ap;
  	int result;
  
  	va_start( ap, out );
  	result = vips_call_split( "multiply", ap, left, right, out );
  	va_end( ap );
  
  	return( result );
  }
  