Re: [Pixman] [PATCH 03/13] pixman-image: Added GNUPLOT_OUTPUT compile-time option to view filters in gnuplot

[Oded Gabbay]

On Mon, Jan 4, 2016 at 7:34 PM, Bill Spitzak  wrote:
>
>
> On Mon, Jan 4, 2016 at 3:25 AM, Oded Gabbay  wrote:
>>
>> On Mon, Jan 4, 2016 at 5:12 AM,   wrote:
>> > From: Bill Spitzak 
>> >
>> > If GNUPLOT_OUTPUT is set, 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
>> > ---
>> >  pixman/pixman-image.c | 40 
>> >  1 file changed, 40 insertions(+)
>> >
>> > diff --git a/pixman/pixman-image.c b/pixman/pixman-image.c
>> > index 1ff1a49..69743c4 100644
>> > --- a/pixman/pixman-image.c
>> > +++ b/pixman/pixman-image.c
>> > @@ -531,6 +531,46 @@ compute_image_info (pixman_image_t *image)
>> >
>> >  image->common.flags = flags;
>> >  image->common.extended_format_code = code;
>> > +/* If GNUPLOT_OUTPUT is set, 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
>> > + */
>> > +/* #define GNUPLOT_OUTPUT 1 */
>> > +#if GNUPLOT_OUTPUT
>> > +if ((flags & FAST_PATH_SEPARABLE_CONVOLUTION_FILTER) &&
>> > image->common.filter_params) {
>> > +   const pixman_fixed_t* p = image->common.filter_params;
>> > +   int width = pixman_fixed_to_int(p[0]);
>> > +   int samples = 1 << pixman_fixed_to_int(p[2]);
>> > +   int x,y;
>> > +   p += 4;
>> > +   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 * .5 + (y + .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
>> >  }
>> >
>> >  void
>> > --
>> > 1.9.1
>> >
>> > ___
>> > Pixman mailing list
>> > Pixman@lists.freedesktop.org
>> > http://lists.freedesktop.org/mailman/listinfo/pixman
>>
>> I get the big picture of this feature, and it seems useful, but we
>> need write this according to standards.
>> I would like to see the following changes:
>>
>> 1. We can do something more nice than a hard-coded #define. Let's add
>> a flag to configure.ac called "enable-gnuplot-output". For something
>> similar, see "enable-timers" in configure.ac. The default will be
>> "no".
>
>
> That makes sense. I actually gave up trying to figure out how to set the
> CFLAGS and was forced to edit the source code to turn this on/off, which
> meant I often mistakenly checked the code in with it turned on. I guess
> configure is the way to go.
>
>>
>> 2. Take your code and put it in a new function in pixman-utils.c, and
>> make sure the code inside the function is encompassed with
>> #ifdef/#endif around it. In case enable-gluplot-output wasn't called,
>> the function will be an empty function.
>>
>> 3. Call that function from compute_image_info. I guess you will want
>> to call it only if:
>> ((flags & FAST_PATH_SEPARABLE_CONVOLUTION_FILTER) &&
>> image->common.filter_params)
>> is true.
>> However, we don't need to put #ifdef around the call itself.
>
>
> I would prefer that there not be a call to the empty function there, and
> that instead the config option removes the call to it here. In addition the
> arguments may be non-trivial as I would like this to be able to print
> filters from a future mulit-resolution data structure, to extract this from
> the current structure I need to pass the width, subsamples, and pointer to
> array.

Re: [Pixman] [PATCH 03/13] pixman-image: Added GNUPLOT_OUTPUT compile-time option to view filters in gnuplot

[Oded Gabbay]

On Mon, Jan 4, 2016 at 5:12 AM,   wrote:
> From: Bill Spitzak 
>
> If GNUPLOT_OUTPUT is set, 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
> ---
>  pixman/pixman-image.c | 40 
>  1 file changed, 40 insertions(+)
>
> diff --git a/pixman/pixman-image.c b/pixman/pixman-image.c
> index 1ff1a49..69743c4 100644
> --- a/pixman/pixman-image.c
> +++ b/pixman/pixman-image.c
> @@ -531,6 +531,46 @@ compute_image_info (pixman_image_t *image)
>
>  image->common.flags = flags;
>  image->common.extended_format_code = code;
> +/* If GNUPLOT_OUTPUT is set, 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
> + */
> +/* #define GNUPLOT_OUTPUT 1 */
> +#if GNUPLOT_OUTPUT
> +if ((flags & FAST_PATH_SEPARABLE_CONVOLUTION_FILTER) && 
> image->common.filter_params) {
> +   const pixman_fixed_t* p = image->common.filter_params;
> +   int width = pixman_fixed_to_int(p[0]);
> +   int samples = 1 << pixman_fixed_to_int(p[2]);
> +   int x,y;
> +   p += 4;
> +   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 * .5 + (y + .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
>  }
>
>  void
> --
> 1.9.1
>
> ___
> Pixman mailing list
> Pixman@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/pixman

I get the big picture of this feature, and it seems useful, but we
need write this according to standards.
I would like to see the following changes:

1. We can do something more nice than a hard-coded #define. Let's add
a flag to configure.ac called "enable-gnuplot-output". For something
similar, see "enable-timers" in configure.ac. The default will be
"no".

2. Take your code and put it in a new function in pixman-utils.c, and
make sure the code inside the function is encompassed with
#ifdef/#endif around it. In case enable-gluplot-output wasn't called,
the function will be an empty function.

3. Call that function from compute_image_info. I guess you will want
to call it only if:
((flags & FAST_PATH_SEPARABLE_CONVOLUTION_FILTER) &&
image->common.filter_params)
is true.
However, we don't need to put #ifdef around the call itself.

I think the above steps will create two patches:
- Step 1&2 should be the first patch (Adding the utility).
- Step 3 should be the second patch (Using the utility).

Is using this is simple as:
./ | gnuplot ?

or is it more complicated than that ?
If so, put an example of how to use it in the second commit message.

Thanks,

Oded
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Re: [Pixman] [PATCH 03/13] pixman-image: Added GNUPLOT_OUTPUT compile-time option to view filters in gnuplot

[Bill Spitzak]

On Mon, Jan 4, 2016 at 3:25 AM, Oded Gabbay  wrote:

> On Mon, Jan 4, 2016 at 5:12 AM,   wrote:
> > From: Bill Spitzak 
> >
> > If GNUPLOT_OUTPUT is set, 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
> > ---
> >  pixman/pixman-image.c | 40 
> >  1 file changed, 40 insertions(+)
> >
> > diff --git a/pixman/pixman-image.c b/pixman/pixman-image.c
> > index 1ff1a49..69743c4 100644
> > --- a/pixman/pixman-image.c
> > +++ b/pixman/pixman-image.c
> > @@ -531,6 +531,46 @@ compute_image_info (pixman_image_t *image)
> >
> >  image->common.flags = flags;
> >  image->common.extended_format_code = code;
> > +/* If GNUPLOT_OUTPUT is set, 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
> > + */
> > +/* #define GNUPLOT_OUTPUT 1 */
> > +#if GNUPLOT_OUTPUT
> > +if ((flags & FAST_PATH_SEPARABLE_CONVOLUTION_FILTER) &&
> image->common.filter_params) {
> > +   const pixman_fixed_t* p = image->common.filter_params;
> > +   int width = pixman_fixed_to_int(p[0]);
> > +   int samples = 1 << pixman_fixed_to_int(p[2]);
> > +   int x,y;
> > +   p += 4;
> > +   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 * .5 + (y + .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
> >  }
> >
> >  void
> > --
> > 1.9.1
> >
> > ___
> > Pixman mailing list
> > Pixman@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/pixman
>
> I get the big picture of this feature, and it seems useful, but we
> need write this according to standards.
> I would like to see the following changes:
>
> 1. We can do something more nice than a hard-coded #define. Let's add
> a flag to configure.ac called "enable-gnuplot-output". For something
> similar, see "enable-timers" in configure.ac. The default will be
> "no".
>

That makes sense. I actually gave up trying to figure out how to set the
CFLAGS and was forced to edit the source code to turn this on/off, which
meant I often mistakenly checked the code in with it turned on. I guess
configure is the way to go.


> 2. Take your code and put it in a new function in pixman-utils.c, and
> make sure the code inside the function is encompassed with
> #ifdef/#endif around it. In case enable-gluplot-output wasn't called,
> the function will be an empty function.
>
> 3. Call that function from compute_image_info. I guess you will want
> to call it only if:
> ((flags & FAST_PATH_SEPARABLE_CONVOLUTION_FILTER) &&
> image->common.filter_params)
> is true.
> However, we don't need to put #ifdef around the call itself.
>

I would prefer that there not be a call to the empty function there, and
that instead the config option removes the call to it here. In addition the
arguments may be non-trivial as I would like this to be able to print
filters from a future mulit-resolution data structure, to extract this from
the current structure I need to pass the width, subsamples, and pointer to
array.


> I think the above steps will create two patches:
> - Step 1&2 should be the first patch (Adding the utility).
> - Step 3 should be the second patch (Using the utility).
>

Ok.


> Is using this is simple as:
> ./ | gnuplot ?
>

[Pixman] [PATCH 03/13] pixman-image: Added GNUPLOT_OUTPUT compile-time option to view filters in gnuplot

[spitzak]

From: Bill Spitzak 

If GNUPLOT_OUTPUT is set, 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
---
 pixman/pixman-image.c | 40 
 1 file changed, 40 insertions(+)

diff --git a/pixman/pixman-image.c b/pixman/pixman-image.c
index 1ff1a49..69743c4 100644
--- a/pixman/pixman-image.c
+++ b/pixman/pixman-image.c
@@ -531,6 +531,46 @@ compute_image_info (pixman_image_t *image)
 
 image->common.flags = flags;
 image->common.extended_format_code = code;
+/* If GNUPLOT_OUTPUT is set, 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
+ */
+/* #define GNUPLOT_OUTPUT 1 */
+#if GNUPLOT_OUTPUT
+if ((flags & FAST_PATH_SEPARABLE_CONVOLUTION_FILTER) && 
image->common.filter_params) {
+   const pixman_fixed_t* p = image->common.filter_params;
+   int width = pixman_fixed_to_int(p[0]);
+   int samples = 1 << pixman_fixed_to_int(p[2]);
+   int x,y;
+   p += 4;
+   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 * .5 + (y + .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
 }
 
 void
-- 
1.9.1

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