[Pixman] [PATCH v14 08/22] pixman-filter: rename "scale" to "size" when it is 1/scale
Bill Spitzak
spitzak at gmail.com
Mon Apr 4 18:53:34 UTC 2016
Okay that sounds pretty good. Also 'r' is better than 'i' since 'i' can be
mis-read as "input" or "image". 'r' I think is mostly going to be read as
"reverse" which actually makes sense.
Sorry to be a pain about this but I really find it confusing to use the
same term for different numbers.
On Sun, Apr 3, 2016 at 9:29 AM, Søren Sandmann <soren.sandmann at gmail.com>
wrote:
> I guess I can live with 'rscale' (for reciprocal scale).
>
>
> Søren
>
> On Thu, Mar 24, 2016 at 9:30 PM, Bill Spitzak <spitzak at gmail.com> wrote:
>
>> Would using "iscale" (for inverse scale) work? Another is "tscale"
>> because it is the scale from the transform matrix.
>>
>> I really would like to use two different names for these variables as it
>> is really confusing using the same one.
>>
>>
>> On Fri, Mar 18, 2016 at 8:24 AM, Bill Spitzak <spitzak at gmail.com> wrote:
>>
>>>
>>>
>>> On Thu, Mar 17, 2016 at 10:06 PM, Søren Sandmann <
>>> soren.sandmann at gmail.com> wrote:
>>>
>>>> I suppose it's a little illogical that scale_x and scale_y really are
>>>> the reciprocal values of how much the source image should be scaled. I
>>>> don't remember exactly what I was thinking, but it might have something
>>>> like "this allows you to just pass t[0][0] and t[1][1] if you have a pure
>>>> scaling, which avoids a division". There is also kind of precedence in the
>>>> Pixman API since the transformation given as in the dst->source direction.
>>>>
>>>> I don't really like "size" either though. It's not really the size of
>>>> the filter that we are specifying; it just happens to be proportional to it.
>>>>
>>>> If it comes down to "size" and "scale", I prefer "scale".
>>>>
>>>
>>> I tried "width" but it is not actually the filter width. How about "dx"
>>> and "dy" since it is almost always the derivative of the x and y in the
>>> input (or du,dv or dtx dtx)
>>>
>>>>
>>>>
>>>> Søren
>>>>
>>>>
>>>> On Sun, Mar 6, 2016 at 8:06 PM, <spitzak at gmail.com> wrote:
>>>>
>>>>> From: Bill Spitzak <spitzak at gmail.com>
>>>>>
>>>>> This is to remove some confusion when reading the code. "scale" gets
>>>>> larger
>>>>> as the picture gets larger, while "size" (ie the size of the filter)
>>>>> gets
>>>>> smaller.
>>>>>
>>>>> v14: Removed changes to integral function
>>>>>
>>>>> Signed-off-by: Bill Spitzak <spitzak at gmail.com>
>>>>> Reviewed-by: Oded Gabbay <oded.gabbay at gmail.com>
>>>>> ---
>>>>> pixman/pixman-filter.c | 18 +++++++++---------
>>>>> pixman/pixman.h | 6 +++---
>>>>> 2 files changed, 12 insertions(+), 12 deletions(-)
>>>>>
>>>>> diff --git a/pixman/pixman-filter.c b/pixman/pixman-filter.c
>>>>> index a29116a..c03a7f6 100644
>>>>> --- a/pixman/pixman-filter.c
>>>>> +++ b/pixman/pixman-filter.c
>>>>> @@ -221,7 +221,7 @@ static void
>>>>> create_1d_filter (int width,
>>>>> pixman_kernel_t reconstruct,
>>>>> pixman_kernel_t sample,
>>>>> - double scale,
>>>>> + double size,
>>>>> int n_phases,
>>>>> pixman_fixed_t *p)
>>>>> {
>>>>> @@ -251,8 +251,8 @@ create_1d_filter (int width,
>>>>> double pos = x + 0.5 - frac;
>>>>> double rlow = - filters[reconstruct].width / 2.0;
>>>>> double rhigh = rlow + filters[reconstruct].width;
>>>>> - double slow = pos - scale * filters[sample].width / 2.0;
>>>>> - double shigh = slow + scale * filters[sample].width;
>>>>> + double slow = pos - size * filters[sample].width / 2.0;
>>>>> + double shigh = slow + size * filters[sample].width;
>>>>> double c = 0.0;
>>>>> double ilow, ihigh;
>>>>>
>>>>> @@ -262,7 +262,7 @@ create_1d_filter (int width,
>>>>> ihigh = MIN (shigh, rhigh);
>>>>>
>>>>> c = integral (reconstruct, ilow,
>>>>> - sample, 1.0 / scale, ilow - pos,
>>>>> + sample, 1.0 / size, ilow - pos,
>>>>> ihigh - ilow);
>>>>> }
>>>>>
>>>>> @@ -335,12 +335,12 @@ filter_width (pixman_kernel_t reconstruct,
>>>>> pixman_kernel_t sample, double size)
>>>>> }
>>>>>
>>>>> /* Create the parameter list for a SEPARABLE_CONVOLUTION filter
>>>>> - * with the given kernels and scale parameters
>>>>> + * with the given kernels and size parameters
>>>>> */
>>>>> PIXMAN_EXPORT pixman_fixed_t *
>>>>> pixman_filter_create_separable_convolution (int *n_values,
>>>>> - pixman_fixed_t scale_x,
>>>>> - pixman_fixed_t scale_y,
>>>>> + pixman_fixed_t size_x,
>>>>> + pixman_fixed_t size_y,
>>>>> pixman_kernel_t
>>>>> reconstruct_x,
>>>>> pixman_kernel_t
>>>>> reconstruct_y,
>>>>> pixman_kernel_t sample_x,
>>>>> @@ -348,8 +348,8 @@ pixman_filter_create_separable_convolution (int
>>>>> *n_values,
>>>>> int
>>>>> subsample_bits_x,
>>>>> int
>>>>> subsample_bits_y)
>>>>> {
>>>>> - double sx = fabs (pixman_fixed_to_double (scale_x));
>>>>> - double sy = fabs (pixman_fixed_to_double (scale_y));
>>>>> + double sx = fabs (pixman_fixed_to_double (size_x));
>>>>> + double sy = fabs (pixman_fixed_to_double (size_y));
>>>>> pixman_fixed_t *params;
>>>>> int subsample_x, subsample_y;
>>>>> int width, height;
>>>>> diff --git a/pixman/pixman.h b/pixman/pixman.h
>>>>> index 509ba5e..b012a33 100644
>>>>> --- a/pixman/pixman.h
>>>>> +++ b/pixman/pixman.h
>>>>> @@ -845,12 +845,12 @@ typedef enum
>>>>> } pixman_kernel_t;
>>>>>
>>>>> /* Create the parameter list for a SEPARABLE_CONVOLUTION filter
>>>>> - * with the given kernels and scale parameters.
>>>>> + * with the given kernels and size parameters.
>>>>> */
>>>>> pixman_fixed_t *
>>>>> pixman_filter_create_separable_convolution (int *n_values,
>>>>> - pixman_fixed_t scale_x,
>>>>> - pixman_fixed_t scale_y,
>>>>> + pixman_fixed_t size_x,
>>>>> + pixman_fixed_t size_y,
>>>>> pixman_kernel_t
>>>>> reconstruct_x,
>>>>> pixman_kernel_t
>>>>> reconstruct_y,
>>>>> pixman_kernel_t sample_x,
>>>>> --
>>>>> 1.9.1
>>>>>
>>>>> _______________________________________________
>>>>> Pixman mailing list
>>>>> Pixman at lists.freedesktop.org
>>>>> https://lists.freedesktop.org/mailman/listinfo/pixman
>>>>>
>>>>
>>>>
>>>
>>
>
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