/* @(#) Decrease the size of an image by a power-of-two factor, summing the * @(#) values of pixels, and shifting to give output of the specified band * @(#) format. * @(#) * @(#) int * @(#) im_rightshift_size( * @(#) IMAGE *in, * @(#) IMAGE *out, * @(#) int xshift, * @(#) int yshift, * @(#) int band_fmt * @(#) ); * @(#) * * Copyright: 2006, Tom Vajzovic * * Author: Tom Vajzovic * * Written on: 2006-07-26 * * 2006-12-17 tcv: * - rewrite generator function macros to produce many smaller functions * - remove post-shift-up functionality * 2007-02-02 jc * - added return 0; on success * - FUNCTION_NAME updated */ /* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk */ /** HEADERS **/ #ifdef HAVE_CONFIG_H #include #endif /*HAVE_CONFIG_H */ #include #include #include #include #ifdef WITH_DMALLOC #include #endif /*WITH_DMALLOC */ /** LOCAL FUNCTION DECLARATIONS **/ /* function prototype macro */ #define GEN_FUNC( SHIFT_MACRO, FROM_T, TO_T, SUM_T ) \ static int gen_ ## SHIFT_MACRO ## _ ## FROM_T ## _to_ ## TO_T ## _with_ ## SUM_T( \ REGION *to_make, REGION *make_from, void *unrequired, int *params ); /* macros to call function prototype macro for all possible combinations of types and macros */ #define GEN_FUNCS_TO( SIGN, FROM_T, TO_T ) \ GEN_FUNC( PRE_POST_SHIFT, FROM_T, TO_T, SIGN ## 64 ) \ GEN_FUNC( POST_SHIFT, FROM_T, TO_T, SIGN ## 64 ) \ GEN_FUNC( POST_SHIFT, FROM_T, TO_T, SIGN ## 32 ) \ GEN_FUNC( NO_SHIFT, FROM_T, TO_T, SIGN ## 32 ) #define GEN_FUNCS_FROM( SIGN, FROM_T ) \ GEN_FUNCS_TO( SIGN, FROM_T, SIGN ## 32 ) \ GEN_FUNCS_TO( SIGN, FROM_T, SIGN ## 16 ) \ GEN_FUNCS_TO( SIGN, FROM_T, SIGN ## 8 ) #define GEN_FUNCS_SIGN( SIGN ) \ GEN_FUNCS_FROM( SIGN, SIGN ## 32 ) \ GEN_FUNCS_FROM( SIGN, SIGN ## 16 ) \ GEN_FUNCS_FROM( SIGN, SIGN ## 8 ) GEN_FUNCS_SIGN( gint ) GEN_FUNCS_SIGN( guint ) /** FUNCTION DEFINITIONS **/ int im_rightshift_size( IMAGE *in, IMAGE *out, int xshift, int yshift, int band_fmt ){ #define FUNCTION_NAME "im_rightshift_size" int *params; int needbits; int outbits; if( im_piocheck( in, out ) ) return -1; if( xshift < 0 || yshift < 0 ){ im_error( FUNCTION_NAME, _( "bad arguments" ) ); return -1; } if( ! xshift && ! yshift ){ im_warn( FUNCTION_NAME, _( "shift by zero: falling back to im_copy" ) ); return im_copy( in, out ); } if( ! in-> Xsize >> xshift || ! in-> Ysize >> yshift ){ im_error( FUNCTION_NAME, _( "would result in zero size output image" ) ); return -1; } if( ! im_isint( in ) ){ im_error( FUNCTION_NAME, _( "integer type images only" ) ); return -1; } if( IM_CODING_NONE != in->Coding ){ im_error( FUNCTION_NAME, _( "uncoded images only" ) ); return -1; } if( im_isuint( in ) ){ if( IM_BANDFMT_UCHAR != band_fmt && IM_BANDFMT_USHORT != band_fmt && IM_BANDFMT_UINT != band_fmt ){ im_error( FUNCTION_NAME, _( "unsigned input means that output must be unsigned int, short or char" ) ); return -1; } } else { if( IM_BANDFMT_CHAR != band_fmt && IM_BANDFMT_SHORT != band_fmt && IM_BANDFMT_INT != band_fmt ){ im_error( FUNCTION_NAME, _( "signed input means that output must be signed int, short or char" ) ); return -1; } } outbits= im_bits_of_fmt( band_fmt ); if( -1 == outbits ) return -1; needbits= im_bits_of_fmt( in-> BandFmt ) + xshift + yshift; params= IM_ARRAY( out, 4, int ); if( ! params ) return -1; params[ 0 ]= xshift; /* xshift */ params[ 1 ]= yshift; /* yshift */ if( im_cp_desc( out, in ) ) return -1; out-> Xsize >>= xshift; out-> Ysize >>= yshift; out-> Xres/= ( 1 << xshift ); /* x scale */ out-> Yres/= ( 1 << yshift ); /* y scale */ out-> BandFmt= band_fmt; out-> Bbits= outbits; if( im_demand_hint( out, IM_THINSTRIP, in, NULL ) ) return -1; #define RETURN_MACRO( MACRO, FROM_T, TO_T, SUM_T ) \ return im_generate( out, im_start_one, gen_ ## MACRO ## _ ## FROM_T ## _to_ ## TO_T ## _with_ ## SUM_T, im_stop_one, in, params ); #define RETURN_MACRO_OUTS( MACRO, SUM_SIZE, OUT_SIZE ) switch( in-> BandFmt ){ \ \ case IM_BANDFMT_CHAR: \ RETURN_MACRO( MACRO, gint8, gint ## OUT_SIZE, gint ## SUM_SIZE ) \ \ case IM_BANDFMT_UCHAR: \ RETURN_MACRO( MACRO, guint8, guint ## OUT_SIZE, guint ## SUM_SIZE ) \ \ case IM_BANDFMT_SHORT: \ RETURN_MACRO( MACRO, gint16, gint ## OUT_SIZE, gint ## SUM_SIZE ) \ \ case IM_BANDFMT_USHORT: \ RETURN_MACRO( MACRO, guint16, guint ## OUT_SIZE, guint ## SUM_SIZE ) \ \ case IM_BANDFMT_INT: \ RETURN_MACRO( MACRO, gint32, gint ## OUT_SIZE, gint ## SUM_SIZE ) \ \ case IM_BANDFMT_UINT: \ RETURN_MACRO( MACRO, guint32, guint ## OUT_SIZE, guint ## SUM_SIZE ) \ } #define RETURN_MACRO_SUMSS( MACRO, SUM_SIZE ) switch( out-> Bbits ){ \ case 32: \ RETURN_MACRO_OUTS( MACRO, SUM_SIZE, 32 ) \ case 16: \ RETURN_MACRO_OUTS( MACRO, SUM_SIZE, 16 ) \ case 8: \ RETURN_MACRO_OUTS( MACRO, SUM_SIZE, 8 ) \ } if( needbits > 64 ){ params[ 2 ]= needbits - 64; params[ 3 ]= 64 - outbits; RETURN_MACRO_SUMSS( PRE_POST_SHIFT, 64 ) } if( needbits > 32 ){ params[ 3 ]= needbits - outbits; RETURN_MACRO_SUMSS( POST_SHIFT, 64 ) } if( needbits > outbits ){ params[ 3 ]= needbits - outbits; RETURN_MACRO_SUMSS( POST_SHIFT, 32 ) } RETURN_MACRO_SUMSS( NO_SHIFT, 32 ) return 0; #undef FUNCTION_NAME } /** LOCAL FUNCTION DEFINITIONS **/ /* macros used in the function creating macro */ #define PRE_POST_SHIFT() pixel+= from[ fx ] >> preshift; \ to[ tx ]= pixel >> postshift; #define POST_SHIFT() pixel+= from[ fx ]; \ to[ tx ]= pixel >> postshift; #define NO_SHIFT() pixel+= from[ fx ]; \ to[ tx ]= pixel; /* function creating macro */ #undef GEN_FUNC #define GEN_FUNC( SHIFT_MACRO, FROM_T, TO_T, SUM_T ) \ static int gen_ ## SHIFT_MACRO ## _ ## FROM_T ## _to_ ## TO_T ## _with_ ## SUM_T( \ REGION *to_make, REGION *make_from, void *unrequired, int *params ){ \ \ int xshift= params[0]; \ int yshift= params[1]; \ int preshift= params[2]; \ int postshift= params[3]; \ Rect need= { \ to_make-> valid. left << xshift, \ to_make-> valid. top << yshift, \ to_make-> valid. width << xshift, \ to_make-> valid. height << yshift \ }; \ TO_T *to_start= (TO_T*) IM_REGION_ADDR( to_make, to_make-> valid. left, to_make-> valid. top ); \ TO_T *to, *ty_stop; \ SUM_T pixel; \ FROM_T *from_start, *from_row, *from, *fy_stop; \ \ int band, tx, fx; \ int tx_max= to_make-> valid. width * to_make-> im-> Bands; \ int fx_max= to_make-> im-> Bands << xshift; \ \ size_t t_skip= IM_REGION_LSKIP( to_make ) / sizeof( TO_T ); \ size_t f_skip; \ \ if( im_prepare( make_from, &need ) || ! im_rect_includesrect( &make_from-> valid, &need ) ) \ return -1; \ \ from_start= (FROM_T*) IM_REGION_ADDR( make_from, need. left, need. top ); \ f_skip= IM_REGION_LSKIP( make_from ) / sizeof( FROM_T ); \ \ for( band= 0; band < make_from-> im-> Bands; ++band ){ \ \ to= to_start + band; \ ty_stop= to + t_skip * to_make-> valid. height; \ \ from_row= from_start + band; \ \ for( ; to < ty_stop; to+= t_skip, from_row+= f_skip << yshift ) \ for( tx= 0; tx < tx_max; tx+= to_make-> im-> Bands ){ \ \ from= from_row + ( tx << xshift ); \ fy_stop= from + ( f_skip << yshift ); \ \ pixel= 0; \ \ for( ; from < fy_stop; from+= f_skip ) \ for( fx= 0; fx < fx_max; fx+= to_make-> im-> Bands ) \ SHIFT_MACRO() \ } \ } \ return 0; \ } /* create functions for all possible combinations of types and macros */ GEN_FUNCS_SIGN( gint ) GEN_FUNCS_SIGN( guint )