/* 'lossless' 45 degree rotate ... odd-sized square images only * * Author: N. Dessipris (Copyright, N. Dessipris 1991) * Written on: 08/05/1991 * Modified on: 28/05/1991 * 12/10/95 JC * - small revisions, needs rewriting really * 7/8/96 JC * - absolutely foul desp code revised * - many bugs and mem leaks fixed * 1/3/99 JC * - oops, fns were not preserving scale and offset * 1/12/10 * - allow any size mask for the 90 degree rot45ates by using im_rot4590(). * 12/10/13 * - rewritten as a class */ /* This file is part of VIPS. VIPS 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 of the License, or (at your option) any later version. This program 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 program; 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 VIPS_DEBUG */ #ifdef HAVE_CONFIG_H #include #endif /*HAVE_CONFIG_H*/ #include #include #include #include #include #include #include #include "pconversion.h" typedef struct _VipsRot45 { VipsConversion parent_instance; /* The input image. */ VipsImage *in; /* Rotate by ... */ VipsAngle45 angle; } VipsRot45; typedef VipsConversionClass VipsRot45Class; G_DEFINE_TYPE( VipsRot45, vips_rot45, VIPS_TYPE_CONVERSION ); #define COPY( Q, P ) { \ VipsPel *q = (Q); \ VipsPel *p = (P); \ int b;\ \ for( b = 0; b < ps; b++ )\ q[b] = p[b];\ } #define ASSIGN( Xout, Yout, Xin, Yin ) \ COPY( VIPS_IMAGE_ADDR( out, Xout, Yout ), \ VIPS_IMAGE_ADDR( in, Xin, Yin ) ) #define POINT_TO_TEMP( q, Xin, Yin ) \ COPY( q, VIPS_IMAGE_ADDR( in, Xin, Yin ) ) #define TEMP_TO_POINT( Xout, Yout, p ) \ COPY( VIPS_IMAGE_ADDR( out, Xout, Yout ), p ) /* This can work inplace, ie. in == out is allowed. */ static void vips_rot45_rot45( VipsImage *out, VipsImage *in ) { size_t ps = VIPS_IMAGE_SIZEOF_PEL( in ); VipsPel *temp = VIPS_ARRAY( in, ps, VipsPel ); int size = in->Xsize; int size_2 = size / 2; int x, y; g_assert( in->Xsize == in->Ysize ); g_assert( out->Xsize == out->Ysize ); g_assert( in->Xsize == out->Xsize ); g_assert( in->Xsize % 2 == 1 ); /* Split the square into 8 triangles. Loop over the top-left one, * reflect to index the others. * * 1 1 2 2 3 * 8 1 2 3 3 * 8 8 x 4 4 * 7 7 6 5 4 * 7 6 6 5 5 * * do the centre separately. */ for( y = 0; y < size_2; y++ ) for( x = y; x < size_2; x++ ) { /* Save 1, it goes into 2 at the end. */ POINT_TO_TEMP( temp, x, y ); /* Fill 1 from 8. */ ASSIGN( x, y, y, size_2 - (x - y) ); /* 8 from 7. */ ASSIGN( y, size_2 - (x - y), y, (size - 1) - x ); /* 7 from 6. */ ASSIGN( y, (size - 1) - x, size_2 - (x - y), (size - 1) - y ); /* 6 from 5. */ ASSIGN( size_2 - (x - y), (size - 1) - y, (size - 1) - x, (size - 1) - y ); /* 5 from 4. */ ASSIGN( (size - 1) - x, (size - 1) - y, (size - 1) - y, (x - y) + size_2 ); /* 4 from 3. */ ASSIGN( (size - 1) - y, (x - y) + size_2, (size - 1) - y, x ); /* 3 from 2. */ ASSIGN( (size - 1) - y, x, (x - y) + size_2, y ); /* 2 from saved 1. */ TEMP_TO_POINT( (x - y) + size_2, y, temp ); } /* Centre. */ ASSIGN( size_2, size_2, size_2, size_2 ); } static int vips_rot45_build( VipsObject *object ) { VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object ); VipsConversion *conversion = VIPS_CONVERSION( object ); VipsRot45 *rot45 = (VipsRot45 *) object; VipsImage **t = (VipsImage **) vips_object_local_array( object, 2 ); VipsImage *in; if( VIPS_OBJECT_CLASS( vips_rot45_parent_class )->build( object ) ) return( -1 ); if( vips_check_oddsquare( class->nickname, rot45->in ) ) return( -1 ); if( rot45->angle == VIPS_ANGLE45_D0 ) return( vips_image_write( rot45->in, conversion->out ) ); if( !(t[1] = vips_image_copy_memory( rot45->in )) ) return( -1 ); in = t[1]; t[0] = vips_image_new_memory(); if( vips_image_pipelinev( t[0], VIPS_DEMAND_STYLE_ANY, rot45->in, NULL ) ) return( -1 ); if( vips_image_write_prepare( t[0] ) ) return( -1 ); switch( rot45->angle ) { case VIPS_ANGLE45_D315: vips_rot45_rot45( t[0], in ); in = t[0]; case VIPS_ANGLE45_D270: vips_rot45_rot45( t[0], in ); in = t[0]; case VIPS_ANGLE45_D225: vips_rot45_rot45( t[0], in ); in = t[0]; case VIPS_ANGLE45_D180: vips_rot45_rot45( t[0], in ); in = t[0]; case VIPS_ANGLE45_D135: vips_rot45_rot45( t[0], in ); in = t[0]; case VIPS_ANGLE45_D90: vips_rot45_rot45( t[0], in ); in = t[0]; case VIPS_ANGLE45_D45: vips_rot45_rot45( t[0], in ); in = t[0]; break; default: g_assert_not_reached(); } if( vips_image_write( in, conversion->out ) ) return( -1 ); return( 0 ); } static void vips_rot45_class_init( VipsRot45Class *class ) { GObjectClass *gobject_class = G_OBJECT_CLASS( class ); VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class ); VIPS_DEBUG_MSG( "vips_rot45_class_init\n" ); gobject_class->set_property = vips_object_set_property; gobject_class->get_property = vips_object_get_property; vobject_class->nickname = "rot45"; vobject_class->description = _( "rotate an image" ); vobject_class->build = vips_rot45_build; VIPS_ARG_IMAGE( class, "in", 1, _( "Input" ), _( "Input image" ), VIPS_ARGUMENT_REQUIRED_INPUT, G_STRUCT_OFFSET( VipsRot45, in ) ); VIPS_ARG_ENUM( class, "angle", 6, _( "Angle" ), _( "Angle to rotate image" ), VIPS_ARGUMENT_OPTIONAL_INPUT, G_STRUCT_OFFSET( VipsRot45, angle ), VIPS_TYPE_ANGLE45, VIPS_ANGLE45_D45 ); } static void vips_rot45_init( VipsRot45 *rot45 ) { rot45->angle = VIPS_ANGLE45_D45; } /** * vips_rot45: (method) * @in: input image * @out: (out): output image * @...: %NULL-terminated list of optional named arguments * * Optional arguments: * * * @angle: #VipsAngle45 rotation angle * * Rotate @in by a multiple of 45 degrees. Odd-length sides and square images * only. * * This operation is useful for rotating convolution masks. Use * vips_similarity() to rotate images by arbitrary angles. * * See also: vips_rot(), vips_similarity(). * * Returns: 0 on success, -1 on error */ int vips_rot45( VipsImage *in, VipsImage **out, ... ) { va_list ap; int result; va_start( ap, out ); result = vips_call_split( "rot45", ap, in, out ); va_end( ap ); return( result ); }