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.sandm...@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 <spit...@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 <spit...@gmail.com> wrote: >> >>> >>> >>> On Thu, Mar 17, 2016 at 10:06 PM, Søren Sandmann < >>> soren.sandm...@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, <spit...@gmail.com> wrote: >>>> >>>>> From: Bill Spitzak <spit...@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 <spit...@gmail.com> >>>>> Reviewed-by: Oded Gabbay <oded.gab...@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@lists.freedesktop.org >>>>> https://lists.freedesktop.org/mailman/listinfo/pixman >>>>> >>>> >>>> >>> >> >
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