gistfile1.txt

my $lib = q:to/END/;
#include <stdio.h>

typedef struct {
  int x;
  int y;
  int w;
  int h;
} GstVideoRectangle;

void gst_video_sink_center_rect(GstVideoRectangle src,
	   GstVideoRectangle dst,
	   GstVideoRectangle * result,
	   int scaling) {
  printf("src: x: %d y: %d w: %d h: %d\n", src.x, src.y, src.w, src.h);
  printf("dst: x: %d y: %d w: %d h: %d\n", dst.x, dst.y, dst.w, dst.h);
  printf("result: %lld\n", (long long)result);
  printf("scaling: %d\n", scaling);
}
END

my $fh = open :w, './a.c';
$fh.say: $lib;
$fh.close;

run 'gcc', '-shared', '-o', 'liba.so', '-fPIC', './a.c';

use NativeCall;

class GstVideoRectangle is repr("CStruct") {
      has int32 $.x;
      has int32 $.y;
      has int32 $.w;
      has int32 $.h;
}

sub gst_video_sink_center_rect(
          int64, int64,
          int64, int64,
	  Pointer,
	  int32     ) is native('./liba.so') { * }

sub malloc(int32 --> Pointer) is native { * }

sub gst_video_sink_center_rect_wrapper($src,
		  $dst,
		  $result,
		  $scaling) {
    gst_video_sink_center_rect($src.x + $src.y +< 32, $src.w + $src.h +< 32,
          	               $dst.x + $dst.y +< 32, $dst.w + $dst.h +< 32,
	  		       $result,
	  		       $scaling);
}

my $src = GstVideoRectangle.new(:50x, :51y, :53w, :54h);
dd $src;
my $dst = GstVideoRectangle.new(:70x, :71y, :73w, :74h);
dd $dst;
my $result = malloc(16);
dd $result;
my $scaling = 1;
dd $scaling;

gst_video_sink_center_rect_wrapper($src,
		  $dst,
		  $result,
		  $scaling)