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Fix infinite recursion in bezier stroke hit-testing at extreme zoom #58

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Fix infinite recursion in bezier stroke hit-testing at extreme zoom #58

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20 changes: 16 additions & 4 deletions WineFix/lib/d2d1/src/geometry.c
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Original file line number Diff line number Diff line change
Expand Up @@ -577,12 +577,24 @@ static BOOL d2d_point_on_line_segment(const D2D1_POINT_2F *q, const D2D1_POINT_2
* also done. If neither of those is the case, we subdivide the Bézier segment
* and try again. */
static BOOL d2d_point_on_bezier_segment(const D2D1_POINT_2F *q, const D2D1_POINT_2F *p0,
const D2D1_BEZIER_SEGMENT *b, const D2D1_MATRIX_3X2_F *transform, float stroke_width, float tolerance)
const D2D1_BEZIER_SEGMENT *b, const D2D1_MATRIX_3X2_F *transform, float stroke_width, float tolerance,
unsigned int depth)
{
float d1, d2, d3, d4, d, l, m, w, w2;
D2D1_POINT_2F t[7], start, end, v_p;
D2D1_BEZIER_SEGMENT b0, b1;

/* At extreme zoom levels the transformed coordinates below can exceed the float32
* mantissa's precision (2^23), so the error estimate never shrinks below tolerance
* and this function would otherwise recurse forever. Cap the depth like the sibling
* cubic-to-quadratic subdivision function does, and treat a still-ambiguous result
* at max depth as "not on the curve" rather than looping indefinitely. */
if (depth > 20)
{
WARN("Maximum recursion depth reached for bezier hit-testing - treating as not on curve.\n");
return FALSE;
}

m = 1.0f;
w = stroke_width * 0.5f;

Expand Down Expand Up @@ -733,8 +745,8 @@ static BOOL d2d_point_on_bezier_segment(const D2D1_POINT_2F *q, const D2D1_POINT
d2d_point_lerp(&b0.point2, &t[0], &b0.point1, 0.5f);
d2d_point_lerp(&b0.point3, &b0.point2, &b1.point1, 0.5f);

return d2d_point_on_bezier_segment(q, p0, &b0, transform, stroke_width, tolerance)
|| d2d_point_on_bezier_segment(q, &b0.point3, &b1, transform, stroke_width, tolerance);
return d2d_point_on_bezier_segment(q, p0, &b0, transform, stroke_width, tolerance, depth + 1)
|| d2d_point_on_bezier_segment(q, &b0.point3, &b1, transform, stroke_width, tolerance, depth + 1);
}

static void d2d_rect_union(D2D1_RECT_F *l, const D2D1_RECT_F *r)
Expand Down Expand Up @@ -3856,7 +3868,7 @@ static HRESULT STDMETHODCALLTYPE d2d_path_geometry_StrokeContainsPoint(ID2D1Path
b.point1 = figure->original_bezier_controls[bezier_idx++];
b.point2 = figure->original_bezier_controls[bezier_idx++];
b.point3 = figure->vertices[j];
*contains = d2d_point_on_bezier_segment(&point, &p, &b, transform, stroke_width, tolerance);
*contains = d2d_point_on_bezier_segment(&point, &p, &b, transform, stroke_width, tolerance, 0);
p = b.point3;
break;

Expand Down