[Pixman] [PATCH v14 08/22] pixman-filter: rename "scale" to "size" when it is 1/scale
Søren Sandmann
soren.sandmann at gmail.com
Sun Apr 3 16:29:20 UTC 2016
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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