/* Affine transforms. */ /* Copyright (C) 1991-2003 The National Gallery This program 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 */ #ifndef VIPS_TRANSFORM_H #define VIPS_TRANSFORM_H #ifdef __cplusplus extern "C" { #endif /*__cplusplus*/ /* Params for an affine transformation. */ typedef struct { /* Area of input we can use. This can be smaller than the real input * image: we expand the input to add extra pixels for interpolation. */ VipsRect iarea; /* The area of the output we've been asked to generate. left/top can * be negative. */ VipsRect oarea; /* The transform. */ double a, b, c, d; double idx, idy; double odx, ody; double ia, ib, ic, id; /* Inverse of matrix abcd */ } VipsTransformation; void vips__transform_init( VipsTransformation *trn ); int vips__transform_calc_inverse( VipsTransformation *trn ); int vips__transform_isidentity( const VipsTransformation *trn ); int vips__transform_add( const VipsTransformation *in1, const VipsTransformation *in2, VipsTransformation *out ); void vips__transform_print( const VipsTransformation *trn ); void vips__transform_forward_point( const VipsTransformation *trn, const double x, const double y, double *ox, double *oy ); void vips__transform_invert_point( const VipsTransformation *trn, const double x, const double y, double *ox, double *oy ); void vips__transform_forward_rect( const VipsTransformation *trn, const VipsRect *in, VipsRect *out ); void vips__transform_invert_rect( const VipsTransformation *trn, const VipsRect *in, VipsRect *out ); void vips__transform_set_area( VipsTransformation * ); int vips__affine( VipsImage *in, VipsImage *out, VipsTransformation *trn ); #ifdef __cplusplus } #endif /*__cplusplus*/ #endif /*VIPS_TRANSFORM_H*/