1IM_AND(3)                  Library Functions Manual                  IM_AND(3)
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NAME

6       im_paintrect,  im_plotmask,  im_readpoint,  im_plotpoint,  im_fastline,
7       im_fastlineuser - suck pels up, and paint them down somewhere else
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SYNOPSIS

10       #include <vips/vips.h>
11       #include <vips/rect.h>
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13       int im_readpoint( im, x, y, ink )
14       IMAGE *im;
15       int x, y;
16       PEL *ink;
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18       int im_plotpoint( im, x, y, ink )
19       IMAGE *im;
20       int x, y;
21       PEL *ink;
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23       int im_plotmask( im, ix, iy, ink, mask, r )
24       IMAGE *im;
25       int ix, iy;
26       PEL *ink;
27       PEL *mask;
28       Rect *r;
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30       int im_paintrect( im, r, ink )
31       IMAGE *im;
32       Rect *r;
33       PEL *ink;
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35       int im_fastline( im, x1, y1, x2, y2, ink )
36       IMAGE *im;
37       int x1, y1, x2, y2;
38       PEL *ink;
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40       int im_fastlineuser( im, x1, y1, x2, y2,
41           plot_fn, client1, client2, client3 )
42       IMAGE *im;
43       int x1, y1, x2, y2;
44       int (*plot_fn)();
45       void *client1, *client2, *client3;
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47       int plot_fn( im, x, y, client1, client2, client3 )
48       IMAGE *im;
49       int x, y;
50       void *client1, *client2, *client3;
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DESCRIPTION

53       im_readpoint(3) sucks a pel from position  (x,y)  into  a  buffer;  all
54       other  functions  paint  that  buffer back again in various ways. These
55       functions will work for an image  of  any  type,  since  they  rely  on
56       im_readpoint(3)  for  their  data. If you read a pel from one image and
57       paint with it to another, it is your responsibility to check  that  the
58       two images have identical pels.
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60       All these functions are `in place,' that is, they write directly to the
61       output image! Be very careful, you can destroy data.
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63       im_plotmask(3) takes an array of 0/255s and a Rect describing the  size
64       and  offset of the array. It adds (ix,iy) to the array offset, and then
65       paint pels into all array positions which are non-zero. Rect  need  not
66       lie inside the image - the function clips carefully at the edges.
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68       im_paintrect(3) fills the rectangle described with ink. The Rect can be
69       any size and at any position - the function clipps against the edges of
70       the image.
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72       im_fastline(3)  is  a replacement for im_line(3) which plots the speci‐
73       fied ink in the image. The start  and  end  points  must  lie  entirely
74       inside the image.
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76       im_fastlineuser(3)  does  not plot points, instead it calls a user plot
77       function for every position along the line. There is no clipping -  the
78       endpoints  may  be  anywhere  at  all.  Three client values are carried
79       around and passed into the user function.
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RETURN VALUE

82       All functions return 0 on success and -1 on error.
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SEE ALSO

85       im_insertplace(3), im_smudge(3).
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88       National Gallery, 1992
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AUTHOR

91       J. Cupitt
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95                                30 October 1992                      IM_AND(3)
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