whytofly
/
qt6-bb10
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

QFont: replace a QVLA with a C array 

QVarLengthArray doesn't allocate, but is nevertheless dynamically
initialized, incl. thread-safe static overhead.

Turn the QVLA<QPair<int,int>> into a std::array<int,2>[] instead. This
container has constant initialization and the use of array<int>
instead of pair<int, int> means we can use the bool inverted argument
as an index into the array instead of having to switch over .first and
.second.

Saves ~600B in text size and ~100B in BSS on optimized Clang 15 AMD64
Linux builds, and the copying, under mutex protection, of the data at
runtime.

Amends 3558704ed5.

Pick-to: 6.4
Change-Id: Iad48eca4eef77011d4094125670ea302e8beae46
Reviewed-by: Jonas Karlsson <jonas.karlsson@qt.io>
bb10
Marc Mutz 2022-12-05 14:44:49 +01:00
parent 20d1477c14
commit 1501f45c33
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/gui/text/qfont.cpp
View File

@ -31,6 +31,8 @@
#include <QtCore/QMutexLocker>
#include <QtCore/QMutex>
#include <array>
// #define QFONTCACHE_DEBUG
#ifdef QFONTCACHE_DEBUG
# define FC_DEBUG qDebug
@ -140,7 +142,7 @@ Q_GUI_EXPORT int qt_defaultDpi()
/* Helper function to convert between legacy Qt and OpenType font weights. */
static int convertWeights(int weight, bool inverted)
{
static const QVarLengthArray<QPair<int, int>, 9> legacyToOpenTypeMap = {
static constexpr std::array<int, 2> legacyToOpenTypeMap[] = {
{ 0, QFont::Thin }, { 12, QFont::ExtraLight }, { 25, QFont::Light },
{ 50, QFont::Normal }, { 57, QFont::Medium }, { 63, QFont::DemiBold },
{ 75, QFont::Bold }, { 81, QFont::ExtraBold }, { 87, QFont::Black },
@ -151,8 +153,8 @@ static int convertWeights(int weight, bool inverted)
// Go through and find the closest mapped value
for (auto mapping : legacyToOpenTypeMap) {
const int weightOld = inverted ? mapping.second : mapping.first;
const int weightNew = inverted ? mapping.first : mapping.second;
const int weightOld = mapping[ inverted];
const int weightNew = mapping[!inverted];
const int dist = qAbs(weightOld - weight);
if (dist < closestDist) {
result = weightNew;