//
//  Negative.cpp
//  testVipsExtend
//
//  Created by Angel on 23/05/2018.
//

#include "Negative.h"

G_DEFINE_TYPE( Negative, negative, VIPS_TYPE_OPERATION );


static int negative_generate( VipsRegion *oregion, void *vseq, void *a, void *b, gboolean *stop )
{
    /* The area of the output region we have been asked to make.
     */
    VipsRect *r = &oregion->valid;
    
    /* The sequence value ... the thing returned by vips_start_one().
     */
    VipsRegion *ir = (VipsRegion *) vseq;
    
    VipsImage *in = (VipsImage *) a;
    Negative *negative = (Negative *) b;
    int line_size = r->width * negative->in->Bands;
    
    int x, y;
    
    /* Request matching part of input region.
     */
    if( vips_region_prepare( ir, r ) )
        return( -1 );
    
    for( y = 0; y < r->height; y++ ) {
        unsigned char *p = (unsigned char *)
        VIPS_REGION_ADDR( ir, r->left, r->top + y );
        unsigned char *q = (unsigned char *)
        VIPS_REGION_ADDR( oregion, r->left, r->top + y );
        
        for( x = 0; x < line_size; x++ )
            q[x] = negative->image_max - p[x];
    }
    
    return( 0 );
}

static int
negative_build( VipsObject *object )
{
    VipsObjectClass *myclass = VIPS_OBJECT_GET_CLASS( object );
    Negative *negative = (Negative *) object;
    
    if( VIPS_OBJECT_CLASS( negative_parent_class )->build( object ) )
        return( -1 );
    
    if( vips_check_uncoded( myclass->nickname, negative->in ) ||
       vips_check_format( myclass->nickname, negative->in, VIPS_FORMAT_UCHAR ) )
        return( -1 );
    
    g_object_set( object, "out", vips_image_new(), NULL );
    
    if( vips_image_pipelinev( negative->out,
                             VIPS_DEMAND_STYLE_THINSTRIP, negative->in, NULL ) )
        return( -1 );
    
    if( vips_image_generate( negative->out,
                            vips_start_one,
                            negative_generate,
                            vips_stop_one,
                            negative->in, negative ) )
        return( -1 );
    
    return( 0 );
}

static void
negative_init( Negative *negative )
{
    negative->image_max = 255;
}

static void
negative_class_init( NegativeClass *myclass )
{
    GObjectClass *gobject_class = G_OBJECT_CLASS( myclass );
    VipsObjectClass *object_class = VIPS_OBJECT_CLASS( myclass );
    
    gobject_class->set_property = vips_object_set_property;
    gobject_class->get_property = vips_object_get_property;
    
    object_class->nickname = "negative";
    object_class->description = "photographic negative";
    object_class->build = negative_build;
    
    VIPS_ARG_IMAGE( myclass, "in", 1,
                   "Input",
                   "Input image",
                   VIPS_ARGUMENT_REQUIRED_INPUT,
                   G_STRUCT_OFFSET( Negative, in ) );
    
    VIPS_ARG_IMAGE( myclass, "out", 2,
                   "Output",
                   "Output image",
                   VIPS_ARGUMENT_REQUIRED_OUTPUT,
                   G_STRUCT_OFFSET( Negative, out ) );
    
    VIPS_ARG_INT( myclass, "image_max", 4,
                 "Image maximum",
                 "Maximum value in image: pivot about this",
                 VIPS_ARGUMENT_OPTIONAL_INPUT,
                 G_STRUCT_OFFSET( Negative, image_max ),
                 0, 255, 255 );
}

int
my_negative( VipsImage *in, VipsImage **out, ... )
{
    va_list ap;
    int result;
    
    va_start( ap, out );
    result = vips_call_split( "negative", ap, in, out );
    va_end( ap );
    
    return( result );
}