[PATCH v2 0/1] MR6843: opengl: Avoid inifinite recursion in bezier_approximate() in case of degraded curve.

[Paul Gofman (＠gofman)]

--
  v2: opengl: Avoid infinite recursion in bezier_approximate() in case of degraded curve.

https://gitlab.winehq.org/wine/wine/-/merge_requests/6843

[PATCH v2 1/1] opengl: Avoid infinite recursion in bezier_approximate() in case of degraded curve.

[Paul Gofman]

From: Paul Gofman

CW-Bug-Id: #24476
---
 dlls/opengl32/wgl.c | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/dlls/opengl32/wgl.c b/dlls/opengl32/wgl.c
index c6414054ff5..01e0e66f0fd 100644
--- a/dlls/opengl32/wgl.c
+++ b/dlls/opengl32/wgl.c
@@ -1176,7 +1176,7 @@ typedef struct _bezier_vector {
     GLdouble y;
 } bezier_vector;

-static double bezier_deviation_squared(const bezier_vector *p)
+static BOOL bezier_fits_deviation(const bezier_vector *p, FLOAT max_deviation)
 {
     bezier_vector deviation;
     bezier_vector vertex;
@@ -1184,25 +1184,36 @@ static double bezier_deviation_squared(const bezier_vector *p)
     double base_length;
     double dot;

+    max_deviation *= max_deviation;
+
     vertex.x = (p[0].x + p[1].x*2 + p[2].x)/4 - p[0].x;
     vertex.y = (p[0].y + p[1].y*2 + p[2].y)/4 - p[0].y;

base.x = p[2].x - p[0].x;
     base.y = p[2].y - p[0].y;

-    base_length = sqrt(base.x*base.x + base.y*base.y);
-    base.x /= base_length;
-    base.y /= base_length;
-
-    dot = base.x*vertex.x + base.y*vertex.y;
-    dot = min(max(dot, 0.0), base_length);
-    base.x *= dot;
-    base.y *= dot;
+    base_length = base.x * base.x + base.y * base.y;
+    if (base_length <= max_deviation)
+    {
+        base.x = 0.0;
+        base.y = 0.0;
+    }
+    else
+    {
+        base_length = sqrt(base_length);
+        base.x /= base_length;
+        base.y /= base_length;
+
+        dot = base.x*vertex.x + base.y*vertex.y;
+        dot = min(max(dot, 0.0), base_length);
+        base.x *= dot;
+        base.y *= dot;
+    }

deviation.x = vertex.x-base.x;
     deviation.y = vertex.y-base.y;

-    return deviation.x*deviation.x + deviation.y*deviation.y;
+    return deviation.x*deviation.x + deviation.y*deviation.y <= max_deviation;
 }

static int bezier_approximate(const bezier_vector *p, bezier_vector *points, FLOAT deviation)
@@ -1212,7 +1223,7 @@ static int bezier_approximate(const bezier_vector *p, bezier_vector *points, FLO
     bezier_vector vertex;
     int total_vertices;

-    if(bezier_deviation_squared(p) <= deviation*deviation)
+    if (bezier_fits_deviation(p, deviation))
     {
         if(points)
             *points = p[2];

[PATCH v2 1/1] opengl: Avoid infinite recursion in bezier_approximate() in case of degraded curve.

[Marvin]

Hi,

It looks like your patch introduced the new failures shown below.
Please investigate and fix them before resubmitting your patch.
If they are not new, fixing them anyway would help a lot. Otherwise
please ask for the known failures list to be updated.

The tests also ran into some preexisting test failures. If you know how
to fix them that would be helpful. See the TestBot job for the details:

The full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=149756

Your paranoid android.

=== debian11b (64 bit WoW report) ===

user32:
input.c:4305: Test succeeded inside todo block: button_down_hwnd_todo 1: got MSG_TEST_WIN hwnd 00000000008200EA, msg WM_LBUTTONDOWN, wparam 0x1, lparam 0x320032
win.c:4070: Test failed: Expected active window 0000000003D90164, got 0000000000000000.
win.c:4071: Test failed: Expected focus window 0000000003D90164, got 0000000000000000.

Report validation errors:
mshtml:script crashed (c0000005)