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don't crash if out of memory allocating a new active edge (assert in debug)

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Sean Barrett 2015-11-08 00:54:49 -08:00
parent 0615df6c9b
commit 6382e49063
1 changed files with 26 additions and 20 deletions
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46
stb_truetype.h
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@ -49,7 +49,7 @@
//
// VERSION HISTORY
//
// 1.09 (????-??-??) warning fix
// 1.09 (????-??-??) warning fix; avoid crash on outofmem
// 1.08 (2015-09-13) document stbtt_Rasterize(); fixes for vertical & horizontal edges
// 1.07 (2015-08-01) allow PackFontRanges to accept arrays of sparse codepoints;
// variant PackFontRanges to pack and render in separate phases;
@ -1674,6 +1674,7 @@ static stbtt__active_edge *stbtt__new_active(stbtt__hheap *hh, stbtt__edge *e, i
{
stbtt__active_edge *z = (stbtt__active_edge *) stbtt__hheap_alloc(hh, sizeof(*z), userdata);
float dxdy = (e->x1 - e->x0) / (e->y1 - e->y0);
STBTT_assert(z != NULL);
if (!z) return z;
// round dx down to avoid overshooting
@ -1695,6 +1696,7 @@ static stbtt__active_edge *stbtt__new_active(stbtt__hheap *hh, stbtt__edge *e, i
{
stbtt__active_edge *z = (stbtt__active_edge *) stbtt__hheap_alloc(hh, sizeof(*z), userdata);
float dxdy = (e->x1 - e->x0) / (e->y1 - e->y0);
STBTT_assert(z != NULL);
//STBTT_assert(e->y0 <= start_point);
if (!z) return z;
z->fdx = dxdy;
@ -1819,21 +1821,23 @@ static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e,
while (e->y0 <= scan_y) {
if (e->y1 > scan_y) {
stbtt__active_edge *z = stbtt__new_active(&hh, e, off_x, scan_y, userdata);
// find insertion point
if (active == NULL)
active = z;
else if (z->x < active->x) {
// insert at front
z->next = active;
active = z;
} else {
// find thing to insert AFTER
stbtt__active_edge *p = active;
while (p->next && p->next->x < z->x)
p = p->next;
// at this point, p->next->x is NOT < z->x
z->next = p->next;
p->next = z;
if (z != NULL) {
// find insertion point
if (active == NULL)
active = z;
else if (z->x < active->x) {
// insert at front
z->next = active;
active = z;
} else {
// find thing to insert AFTER
stbtt__active_edge *p = active;
while (p->next && p->next->x < z->x)
p = p->next;
// at this point, p->next->x is NOT < z->x
z->next = p->next;
p->next = z;
}
}
}
++e;
@ -2103,10 +2107,12 @@ static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e,
while (e->y0 <= scan_y_bottom) {
if (e->y0 != e->y1) {
stbtt__active_edge *z = stbtt__new_active(&hh, e, off_x, scan_y_top, userdata);
STBTT_assert(z->ey >= scan_y_top);
// insert at front
z->next = active;
active = z;
if (z != NULL) {
STBTT_assert(z->ey >= scan_y_top);
// insert at front
z->next = active;
active = z;
}
}
++e;
}