Bartosz Kosiorek : gdiplus/graphicspath: Avoid computation overflow and underflow by using hypotf.
Module: wine Branch: master Commit: 08653cf36870e595f4cda3012c42e8f417a3a354 URL: https://gitlab.winehq.org/wine/wine/-/commit/08653cf36870e595f4cda3012c42e8f...
Author: Bartosz Kosiorek gang65@poczta.onet.pl Date: Fri Nov 24 17:22:16 2023 +0100
gdiplus/graphicspath: Avoid computation overflow and underflow by using hypotf.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=45123
By using sqrt(a * a + b * b), for large (or small) a or b, there is a possibility of overflow (underflow), although the result itself is not that big to cause overflow.
To overcome this problem, there are implementations of hypotenuse that do not use power of 2, and use other methods to calculate the result. To calculate a ⊕ b, you can easily use hypotf(a,b).
https://en.cppreference.com/w/cpp/numeric/math/hypot
---
dlls/gdiplus/graphicspath.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/dlls/gdiplus/graphicspath.c b/dlls/gdiplus/graphicspath.c index 63f120a6aba..32edf408d9d 100644 --- a/dlls/gdiplus/graphicspath.c +++ b/dlls/gdiplus/graphicspath.c @@ -201,7 +201,7 @@ static BOOL flatten_bezier(path_list_node_t *start, REAL x2, REAL y2, REAL x3, R * x0(y2 - y1) + y0(x1 - x2) + (x2*y1 - x1*y2) */ area_triangle = (pt.Y - pt_st.Y)*mp[2].X + (pt_st.X - pt.X)*mp[2].Y + (pt_st.Y*pt.X - pt_st.X*pt.Y); - distance_start_end = sqrtf(powf(pt.Y - pt_st.Y, 2.0) + powf(pt_st.X - pt.X, 2.0)); + distance_start_end = hypotf(pt.Y - pt_st.Y, pt_st.X - pt.X); if(fabs(area_triangle) <= (0.5 * flatness * distance_start_end)){ continue; } @@ -1867,7 +1867,7 @@ static void add_bevel_point(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y-endpoint->Y; REAL segment_dx = nextpoint->X-endpoint->X; - REAL segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL distance = pen_width / 2.0; REAL bevel_dx, bevel_dy;
@@ -1903,8 +1903,8 @@ static void widen_joint(const GpPointF *p1, const GpPointF *p2, const GpPointF * if ((p2->X - p1->X) * (p3->Y - p1->Y) > (p2->Y - p1->Y) * (p3->X - p1->X)) { float distance = pen_width / 2.0; - float length_0 = sqrtf((p2->X-p1->X)*(p2->X-p1->X)+(p2->Y-p1->Y)*(p2->Y-p1->Y)); - float length_1 = sqrtf((p3->X-p2->X)*(p3->X-p2->X)+(p3->Y-p2->Y)*(p3->Y-p2->Y)); + float length_0 = hypotf(p2->X - p1->X, p2->Y - p1->Y); + float length_1 = hypotf(p3->X - p2->X, p3->Y - p2->Y); float dx0 = distance * (p2->X - p1->X) / length_0; float dy0 = distance * (p2->Y - p1->Y) / length_0; float dx1 = distance * (p3->X - p2->X) / length_1; @@ -1954,7 +1954,7 @@ static void widen_cap(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y-endpoint->Y; REAL segment_dx = nextpoint->X-endpoint->X; - REAL segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL distance = pen_width / 2.0; REAL bevel_dx, bevel_dy; REAL extend_dx, extend_dy; @@ -1989,7 +1989,7 @@ static void widen_cap(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y-endpoint->Y; REAL segment_dx = nextpoint->X-endpoint->X; - REAL segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL distance = pen_width / 2.0; REAL dx, dy, dx2, dy2; const REAL control_point_distance = 0.5522847498307935; /* 4/3 * (sqrt(2) - 1) */ @@ -2034,7 +2034,7 @@ static void widen_cap(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y-endpoint->Y; REAL segment_dx = nextpoint->X-endpoint->X; - REAL segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL distance = pen_width / 2.0; REAL dx, dy;
@@ -2074,7 +2074,7 @@ static void add_anchor(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y-endpoint->Y; REAL segment_dx = nextpoint->X-endpoint->X; - REAL segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL distance = pen_width / sqrtf(2.0); REAL par_dx, par_dy; REAL perp_dx, perp_dy; @@ -2099,7 +2099,7 @@ static void add_anchor(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y-endpoint->Y; REAL segment_dx = nextpoint->X-endpoint->X; - REAL segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL dx, dy, dx2, dy2; const REAL control_point_distance = 0.55228475; /* 4/3 * (sqrt(2) - 1) */
@@ -2151,7 +2151,7 @@ static void add_anchor(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y-endpoint->Y; REAL segment_dx = nextpoint->X-endpoint->X; - REAL segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL par_dx, par_dy; REAL perp_dx, perp_dy;
@@ -2175,7 +2175,7 @@ static void add_anchor(const GpPointF *endpoint, const GpPointF *nextpoint, { REAL segment_dy = nextpoint->Y - endpoint->Y; REAL segment_dx = nextpoint->X - endpoint->X; - REAL segment_length = sqrtf(segment_dy * segment_dy + segment_dx * segment_dx); + REAL segment_length = hypotf(segment_dy, segment_dx); REAL par_dx = pen_width * segment_dx / segment_length; REAL par_dy = pen_width * segment_dy / segment_length; REAL perp_dx = -par_dy; @@ -2407,7 +2407,7 @@ static void widen_dashed_figure(GpPath *path, int start, int end, int closed,
segment_dy = path->pathdata.Points[j].Y - path->pathdata.Points[i].Y; segment_dx = path->pathdata.Points[j].X - path->pathdata.Points[i].X; - segment_length = sqrtf(segment_dy*segment_dy + segment_dx*segment_dx); + segment_length = hypotf(segment_dy, segment_dx); segment_pos = 0.0;
while (1)
-
Alexandre Julliard