[PATCH] d2d1: Partially implement StrokeContainsPoint() for rectangle geometry

[Nikolay Sivov]

On 01.09.2017 1:25, Henri Verbeet wrote:
> On 31 August 2017 at 14:00, Nikolay Sivov <nsivov at codeweavers.com> wrote:
>> -    if (transform)
>> -    {
>> -        if (!d2d_matrix_invert(&g_i, transform))
>> -            return D2DERR_UNSUPPORTED_OPERATION;
>> -        d2d_point_transform(&point, &g_i, point.x, point.y);
>> -    }
>> +    if (FAILED(hr = geometry_inv_transform_point(transform, &point)))
>> +        return hr;
> That's fine in principle, but please do it in a separate commit, and
> please follow the existing conventions. E.g.:
> 
>     if (transform && FAILED(hr = d2d_point_transform_inverse(&point,
> transform, point.x, point.y)))
>         return hr;

Sure.

> 
>> +    stroke_width /= 2.0f;
>> +
>> +    rect = geometry->u.rectangle.rect;
>> +    rect.left -= stroke_width;
>> +    rect.right += stroke_width;
>> +    rect.top -= stroke_width;
>> +    rect.bottom += stroke_width;
>> +
>> +    dx = max(fabsf((rect.right  + rect.left) / 2.0f - point.x) - (rect.right  - rect.left) / 2.0f, 0.0f);
>> +    dy = max(fabsf((rect.bottom + rect.top)  / 2.0f - point.y) - (rect.bottom - rect.top)  / 2.0f, 0.0f);
>> +
>> +    if ((*contains = tolerance * tolerance > (dx * dx + dy * dy)))
>> +    {
>> +        rect = geometry->u.rectangle.rect;
>> +        stroke_width += tolerance;
>> +        rect.left += stroke_width;
>> +        rect.right -= stroke_width;
>> +        rect.top += stroke_width;
>> +        rect.bottom -= stroke_width;
>> +
>> +        *contains = rect.left >= point.x || rect.right <= point.x || rect.top >= point.y || rect.bottom <= point.y;
>> +    }
> I think that looks a little more complicated than it needs to be. How about:
> 
>     D2D1_POINT_2F d, s;
> ...
>     s.x = rect.right - rect.left;
>     s.y = rect.bottom - rect.top;
>     d.x = fabsf((rect.right + rect.left) * 0.5f - point.x);
>     d.y = fabsf((rect.bottom + rect.top) * 0.5f - point.y);
> 
>     if (d.x < (s.x - stroke_width) * 0.5f - tolerance && d.y < (s.y -
> stroke_width) * 0.5f - tolerance)
>     {
>         *contains = FALSE;
>         return S_OK;
>     }
> 
>     d.x = max(d.x - (s.x + stroke_width) * 0.5f, 0.0f);
>     d.y = max(d.y - (s.y + stroke_width) * 0.5f, 0.0f);
>     *contains = (d.x * d.x + d.y * d.y) < tolerance * tolerance;

Ok, I'll take a look.

> 
> I notice you don't have any tests with transformations, is that
> intentional? I think you'd need to transform the stroke width with the
> transformation matrix.
> 

No particular reason, but it's a good point. Also we don't have any
tests for non-invertible case apparently, I'll add some.