[Pixman] [PATCH v10 04/15] pixman-image: Added enable-gnuplot config to view filters in gnuplot

[Oded Gabbay]

On Tue, Feb 2, 2016 at 8:28 AM,  <spitzak at gmail.com> wrote:
> From: Bill Spitzak <spitzak at gmail.com>
>
> If enable-gnuplot is configured, then you can pipe the output of a pixman-using program
> to gnuplot and get a continuously-updated plot of the horizontal filter. This
> works well with demos/scale to test the filter generation.
>
> The plot is all the different subposition filters shuffled together. This is
> misleading in a few cases:
>
>   IMPULSE.BOX - goes up and down as the subfilters have different numbers of non-zero samples
>   IMPULSE.TRIANGLE - somewhat crooked for the same reason
>   1-wide filters - looks triangular, but a 1-wide box would be more accurate
>
> v7: First time this ability was included
>
> v8: Use config option
>     Moved code to the filter generator
>     Modified scale demo to not call filter generator a second time.
>
> v10: Only print if successful generation of plots
>      Use #ifdef, not #if
>
> Signed-off-by: Bill Spitzak <spitzak at gmail.com>
> ---
>  configure.ac           | 13 +++++++++++++
>  pixman/pixman-filter.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 58 insertions(+)
>
> diff --git a/configure.ac b/configure.ac
> index 6b2134e..8066cb2 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -834,6 +834,19 @@ fi
>  AC_SUBST(PIXMAN_TIMERS)
>
>  dnl ===================================
> +dnl gnuplot
> +
> +AC_ARG_ENABLE(gnuplot,
> +   [AC_HELP_STRING([--enable-gnuplot],
> +                   [enable output of filters that can be piped to gnuplot [default=no]])],
> +   [enable_gnuplot=$enableval], [enable_gnuplot=no])
> +
> +if test $enable_gnuplot = yes ; then

You have an extra whitespace at the end of the above line.

> +   AC_DEFINE(PIXMAN_GNUPLOT, 1, [enable output that can be piped to gnuplot])
> +fi
> +AC_SUBST(PIXMAN_GNUPLOT)
> +
> +dnl ===================================
>  dnl GTK+
>
>  AC_ARG_ENABLE(gtk,
> diff --git a/pixman/pixman-filter.c b/pixman/pixman-filter.c
> index b2bf53f..11c8548 100644
> --- a/pixman/pixman-filter.c
> +++ b/pixman/pixman-filter.c
> @@ -297,6 +297,47 @@ create_1d_filter (int             *width,
>      return params;
>  }
>
> +#ifdef PIXMAN_GNUPLOT
> +/* If enable-gnuplot is configured, then you can pipe the output of a
> + * pixman-using program to gnuplot and get a continuously-updated plot
> + * of the horizontal filter. This works well with demos/scale to test
> + * the filter generation.
> + *
> + * The plot is all the different subposition filters shuffled
> + * together. This is misleading in a few cases:
> + *
> + *  IMPULSE.BOX - goes up and down as the subfilters have different
> + *                numbers of non-zero samples
> + *  IMPULSE.TRIANGLE - somewhat crooked for the same reason
> + *  1-wide filters - looks triangular, but a 1-wide box would be more
> + *                   accurate
> + */
> +static void
> +gnuplot_filter(int width, int samples, const pixman_fixed_t* p)
> +{
> +    int x,y;
> +    printf("plot '-' with linespoints\n");
> +    printf("%g 0\n", - width * .5);
> +    for (x = 0; x < width; ++x) {
> +       for (y = 0; y < samples; ++y) {
> +           int yy;
> +           if (width & 1)
> +               yy = y;
> +           else if (y >= samples / 2)
> +               yy = y - samples / 2;
> +           else
> +               yy = samples / 2 + y;
> +           printf("%g %g\n",
> +                  x - width * 0.5 + (y + 0.5) * (1.0 / samples),
> +                  pixman_fixed_to_double(p[(yy + 1) * width - x - 1]));
> +       }
> +    }
> +    printf("%g 0\n", width * .5);
> +    printf("e\n");
> +    fflush(stdout);
> +}
> +#endif
> +
>  /* Create the parameter list for a SEPARABLE_CONVOLUTION filter
>   * with the given kernels and scale parameters
>   */
> @@ -342,6 +383,10 @@ pixman_filter_create_separable_convolution (int             *n_values,
>      memcpy (params + 4 + width * subsample_x, vert,
>             height * subsample_y * sizeof (pixman_fixed_t));
>
> +#ifdef PIXMAN_GNUPLOT
> +    gnuplot_filter(width, subsample_x, params+4);
> +#endif
> +
>  out:
>      free (horz);
>      free (vert);
> --
> 1.9.1
>
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> Pixman at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/pixman

With the above fixed, this patch is:
Reviewed-by: Oded Gabbay <oded.gabbay at gmail.com>