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Fix draw halting when using NaN argument #3467

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Fix draw halting when using NaN argument #3467

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21eefb2
Fix draw halting when using NaN argument
MightyJosip Jun 3, 2025
dcaa37f
Fix draw halting when using NaN argument
MightyJosip Jun 3, 2025
de6024c
Fix draw halting when using NaN argument
MightyJosip Jun 3, 2025
22c280d
Fix draw halting when using NaN argument
MightyJosip Jun 3, 2025
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117 changes: 71 additions & 46 deletions src_c/draw.c
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Original file line number Diff line number Diff line change
Expand Up @@ -113,6 +113,8 @@ draw_round_rect(SDL_Surface *surf, SDL_Rect surf_clip_rect, int x1, int y1,
return NULL; \
}

#define CHECK_NAN(value) ((unsigned int)value == 0x80000000)
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I'd rather have something like isnan from math.h instead of this


/* Definition of functions that get called in Python */

/* Draws an antialiased line on the given surface.
Expand Down Expand Up @@ -183,6 +185,10 @@ aaline(PyObject *self, PyObject *arg, PyObject *kwargs)
return pgRect_New4((int)startx, (int)starty, 0, 0);
}

if (CHECK_NAN(startx)) {
return pgRect_New4((int)startx, (int)starty, 0, 0);
}

if (!pgSurface_Lock(surfobj)) {
return RAISE(PyExc_RuntimeError, "error locking surface");
}
Expand Down Expand Up @@ -270,6 +276,11 @@ line(PyObject *self, PyObject *arg, PyObject *kwargs)
return pgRect_New4(startx, starty, 0, 0);
}

if (CHECK_NAN(startx) || CHECK_NAN(starty) || CHECK_NAN(endx) ||
CHECK_NAN(endy)) {
return pgRect_New4(startx, starty, 0, 0);
}

if (!pgSurface_Lock(surfobj)) {
return RAISE(PyExc_RuntimeError, "error locking surface");
}
Expand Down Expand Up @@ -421,15 +432,17 @@ aalines(PyObject *self, PyObject *arg, PyObject *kwargs)
extra_px = steep_prev > steep_curr;
disable_endpoints =
!((roundf(pts[2]) == pts[2]) && (roundf(pts[3]) == pts[3]));
if (closed) {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0], pts[1],
pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
}
else {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0], pts[1],
pts[2], pts[3], drawn_area, 0, disable_endpoints,
extra_px);
if (!CHECK_NAN(pts[0])) {
if (closed) {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0],
pts[1], pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
}
else {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0],
pts[1], pts[2], pts[3], drawn_area, 0,
disable_endpoints, extra_px);
}
}

for (loop = 2; loop < length - 1; ++loop) {
Expand All @@ -440,19 +453,21 @@ aalines(PyObject *self, PyObject *arg, PyObject *kwargs)

/* Comparing previous and current line.
* If one is steep and other is not, extra pixel must be drawn.*/
steep_prev =
fabs(pts_prev[2] - pts_prev[0]) < fabs(pts_prev[3] - pts_prev[1]);
steep_curr = fabs(pts[2] - pts[0]) < fabs(pts[3] - pts[1]);
extra_px = steep_prev != steep_curr;
disable_endpoints =
!((roundf(pts[2]) == pts[2]) && (roundf(pts[3]) == pts[3]));
pts_prev[0] = pts[0];
pts_prev[1] = pts[1];
pts_prev[2] = pts[2];
pts_prev[3] = pts[3];
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0], pts[1],
pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
if (!CHECK_NAN(pts[0])) {
steep_prev = fabs(pts_prev[2] - pts_prev[0]) <
fabs(pts_prev[3] - pts_prev[1]);
steep_curr = fabs(pts[2] - pts[0]) < fabs(pts[3] - pts[1]);
extra_px = steep_prev != steep_curr;
disable_endpoints =
!((roundf(pts[2]) == pts[2]) && (roundf(pts[3]) == pts[3]));
pts_prev[0] = pts[0];
pts_prev[1] = pts[1];
pts_prev[2] = pts[2];
pts_prev[3] = pts[3];
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0],
pts[1], pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
}
}

/* Last line - if open, add endpoint pixels. */
Expand All @@ -470,31 +485,35 @@ aalines(PyObject *self, PyObject *arg, PyObject *kwargs)
pts_prev[1] = pts[1];
pts_prev[2] = pts[2];
pts_prev[3] = pts[3];
if (closed) {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0], pts[1],
pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
}
else {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0], pts[1],
pts[2], pts[3], drawn_area, disable_endpoints, 0,
extra_px);
if (!CHECK_NAN(pts[0])) {
if (closed) {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0],
pts[1], pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
}
else {
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0],
pts[1], pts[2], pts[3], drawn_area, disable_endpoints,
0, extra_px);
}
}

if (closed && length > 2) {
pts[0] = xlist[length - 1];
pts[1] = ylist[length - 1];
pts[2] = xlist[0];
pts[3] = ylist[0];
steep_prev =
fabs(pts_prev[2] - pts_prev[0]) < fabs(pts_prev[3] - pts_prev[1]);
steep_curr = fabs(pts[2] - pts[0]) < fabs(pts[3] - pts[1]);
extra_px = steep_prev != steep_curr;
disable_endpoints =
!((roundf(pts[2]) == pts[2]) && (roundf(pts[3]) == pts[3]));
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0], pts[1],
pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
if (!CHECK_NAN(pts[0])) {
steep_prev = fabs(pts_prev[2] - pts_prev[0]) <
fabs(pts_prev[3] - pts_prev[1]);
steep_curr = fabs(pts[2] - pts[0]) < fabs(pts[3] - pts[1]);
extra_px = steep_prev != steep_curr;
disable_endpoints =
!((roundf(pts[2]) == pts[2]) && (roundf(pts[3]) == pts[3]));
draw_aaline(surf, surf_clip_rect, surf_format, color, pts[0],
pts[1], pts[2], pts[3], drawn_area, disable_endpoints,
disable_endpoints, extra_px);
}
}

PyMem_Free(points_buf);
Expand Down Expand Up @@ -615,15 +634,21 @@ lines(PyObject *self, PyObject *arg, PyObject *kwargs)
}

for (loop = 1; loop < length; ++loop) {
draw_line_width(surf, surf_clip_rect, color, xlist[loop - 1],
ylist[loop - 1], xlist[loop], ylist[loop], width,
drawn_area);
if (!CHECK_NAN(xlist[loop - 1]) && !CHECK_NAN(ylist[loop - 1]) &&
!CHECK_NAN(xlist[loop]) && !CHECK_NAN(ylist[loop])) {
draw_line_width(surf, surf_clip_rect, color, xlist[loop - 1],
ylist[loop - 1], xlist[loop], ylist[loop], width,
drawn_area);
}
}

if (closed && length > 2) {
draw_line_width(surf, surf_clip_rect, color, xlist[length - 1],
ylist[length - 1], xlist[0], ylist[0], width,
drawn_area);
if (!CHECK_NAN(xlist[length - 1]) && !CHECK_NAN(ylist[length - 1]) &&
!CHECK_NAN(xlist[0]) && !CHECK_NAN(ylist[0])) {
draw_line_width(surf, surf_clip_rect, color, xlist[length - 1],
ylist[length - 1], xlist[0], ylist[0], width,
drawn_area);
}
}

PyMem_Free(xlist);
Expand Down
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