Cleanup: return gasmix by value

Currently, get_gasmix_from_event() and get_gasmix() return pointers
to either static or to (possibly changing) dive data. This seems like
a dangerous practice and the returned data should be used immediately.

Instead, return the gasmix by value. This is in preparation of
const-ifying input parameters of a number of core functions, which
will ultimately let the merge() function take const-arguments in
preparation of undo of dive-merging.

On common 64-bit systems gasmix (two "int"s) is the size of a pointer
and can be returned in a register.

On 32-bit systems a pointer to the struct to be filled out will be
passed.

Since get_gasmix() now returns a value, the first invocation is
tested by a NULL-initialized "struct event *". Document this in
a comment.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
This commit is contained in:
Berthold Stoeger 2018-08-16 13:35:14 +02:00 committed by Dirk Hohndel
parent b6187f73aa
commit f5b11daffd
10 changed files with 65 additions and 55 deletions

View file

@ -410,11 +410,11 @@ void DivePercentageItem::paint(QPainter *painter, const QStyleOptionGraphicsItem
for (int i = 1, modelDataCount = dataModel->rowCount(); i < modelDataCount; i++) {
if (i < poly.count()) {
double value = dataModel->index(i, vDataColumn).data().toDouble();
struct gasmix *gasmix = NULL;
struct gasmix gasmix = { 0 };
struct event *ev = NULL;
int sec = dataModel->index(i, DivePlotDataModel::TIME).data().toInt();
gasmix = get_gasmix(&displayed_dive, displayed_dc, sec, &ev, gasmix);
int inert = 1000 - get_o2(gasmix);
gasmix = get_gasmix(&displayed_dive, displayed_dc, sec, &ev, &gasmix);
int inert = 1000 - get_o2(&gasmix);
mypen.setBrush(QBrush(ColorScale(value, inert)));
painter->setPen(mypen);
painter->drawLine(poly[i - 1], poly[i]);