Skip to content

Allocate one INT8 for ZStripInfo pbZChange #256

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Asdow merged 1 commit into from
Dec 24, 2023
Merged

Allocate one INT8 for ZStripInfo pbZChange #256

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
38 changes: 30 additions & 8 deletions TileEngine/structure.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2440,10 +2440,14 @@ BOOLEAN AddZStripInfoToVObject( HVOBJECT hVObject, STRUCTURE_FILE_REF * pStructu
// MemAlloc returns a NULL pointer which the code would interpret as
// allocation failing because of no memory.
// I hope this is OK, I don't entirely understand what is done here...
// (ASDOW): Commented out the added conditional, because with an unlucky combination of sti image width and offset, eg 9x16 with x offset of -15
// pCurr->pbZChange would be null, which then crashes the game inside the blitting functions when dereferencing a nullptr
// With Bio experiencing crashes causing him to add the check, I don't know if this is just kicking the can down the road.
// if (pCurr->ubNumberOfZChanges > 0)
// (ASDOW): Adjusted the else branch to prevent DEBUG build hitting an assertion error due to this function returning false and
// preventing crashes in blitter functions due to nullptr dereference as what happened with bio's original solution.
// Allocating one INT8 and setting it to 0 means the Z-value is not adjusted in blitters.
// So far it seems to just work, albeit we're getting a screenmessage of structure not added to the world properly, when
// the game tries to add one in AddMercStructureInfoFromAnimSurface() for said anim when we're missing the actual structureinfo.
// As the game then doesn't do anything besides returning false, it seems to not cause any issues besides the screenmessage in debug build.
// So now we should not suffer from the constant assertion errors in debug build when LOBOT is active. Though this could still use a proper solution..
if (pCurr->ubNumberOfZChanges > 0)
{
pCurr->pbZChange = (INT8 *)MemAlloc(pCurr->ubNumberOfZChanges);
if (pCurr->pbZChange == NULL)
Expand Down Expand Up @@ -2485,10 +2489,28 @@ BOOLEAN AddZStripInfoToVObject( HVOBJECT hVObject, STRUCTURE_FILE_REF * pStructu
pCurr->bInitialZChange = -(ubNumDecreasing);
}
}
// else
// {
// pCurr->pbZChange = NULL;
// }
else
{
pCurr->pbZChange = (INT8*)MemAlloc(1);

// Abort if MemAlloc fails
if (pCurr->pbZChange == NULL)
{
// augh!
for (ubLoop2 = 0; ubLoop2 < uiLoop; ubLoop2++)
{
if (hVObject->ppZStripInfo[ubLoop2] != NULL)
{
MemFree(hVObject->ppZStripInfo[uiLoop]);
}
}
MemFree(hVObject->ppZStripInfo);
hVObject->ppZStripInfo = NULL;
return(FALSE);
}

pCurr->pbZChange[0] = 0;
}
}
}
}
Expand Down