[LyX/master] Use real italic slope for slanted caret
Jean-Marc Lasgouttes
lasgouttes at lyx.org
Mon Sep 28 12:06:53 UTC 2020
commit e47092044b0c2e9c475d6d6c4269b2c511b0fed3
Author: Yuriy Skalko <yuriy.skalko at gmail.com>
Date: Wed Sep 23 11:18:08 2020 +0300
Use real italic slope for slanted caret
---
src/frontends/FontMetrics.h | 2 +
src/frontends/qt/GuiFontMetrics.cpp | 28 +++++++++++++++++++++++
src/frontends/qt/GuiFontMetrics.h | 4 +++
src/frontends/qt/GuiWorkArea.cpp | 41 +++++++++++++++++++---------------
4 files changed, 57 insertions(+), 18 deletions(-)
diff --git a/src/frontends/FontMetrics.h b/src/frontends/FontMetrics.h
index 0807a22..d6e6354 100644
--- a/src/frontends/FontMetrics.h
+++ b/src/frontends/FontMetrics.h
@@ -77,6 +77,8 @@ public:
virtual int strikeoutPos() const = 0;
/// return true if font is not upright (italic or oblique)
virtual bool italic() const = 0;
+ /// return slope for italic font
+ virtual double italicSlope() const = 0;
/// return the width of the char in the font
virtual int width(char_type c) const = 0;
diff --git a/src/frontends/qt/GuiFontMetrics.cpp b/src/frontends/qt/GuiFontMetrics.cpp
index ab8815d..77e04a1 100644
--- a/src/frontends/qt/GuiFontMetrics.cpp
+++ b/src/frontends/qt/GuiFontMetrics.cpp
@@ -20,11 +20,15 @@
#include "support/convert.h"
#include "support/lassert.h"
#include "support/lyxlib.h"
+#include "support/debug.h"
#define DISABLE_PMPROF
#include "support/pmprof.h"
#include <QByteArray>
+#include <QRawFont>
+#include <QtEndian>
+#include <QtMath>
using namespace std;
using namespace lyx::support;
@@ -113,6 +117,24 @@ GuiFontMetrics::GuiFontMetrics(QFont const & font)
breakat_cache_(cache_metrics_breakat_size),
qtextlayout_cache_(cache_metrics_qtextlayout_size)
{
+ // Determine italic slope
+ double const defaultSlope = tan(qDegreesToRadians(19.0));
+ QRawFont raw = QRawFont::fromFont(font);
+ QByteArray post(raw.fontTable("post"));
+ if (post.length() == 0) {
+ slope_ = defaultSlope;
+ LYXERR(Debug::FONT, "Screen font doesn't have 'post' table.");
+ } else {
+ // post table description:
+ // https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6post.html
+ int32_t italicAngle = qFromBigEndian(*reinterpret_cast<int32_t *>(post.data() + 4));
+ double angle = italicAngle / 65536.0; // Fixed-point 16.16 to floating-point
+ slope_ = -tan(qDegreesToRadians(angle));
+ // Correct italic fonts with zero slope
+ if (slope_ == 0.0 && font.italic())
+ slope_ = defaultSlope;
+ LYXERR(Debug::FONT, "Italic slope: " << slope_);
+ }
}
@@ -167,6 +189,12 @@ bool GuiFontMetrics::italic() const
}
+double GuiFontMetrics::italicSlope() const
+{
+ return slope_;
+}
+
+
namespace {
int const outOfLimitMetric = -10000;
}
diff --git a/src/frontends/qt/GuiFontMetrics.h b/src/frontends/qt/GuiFontMetrics.h
index d5847a1..c19a3cd 100644
--- a/src/frontends/qt/GuiFontMetrics.h
+++ b/src/frontends/qt/GuiFontMetrics.h
@@ -43,6 +43,7 @@ public:
virtual int underlinePos() const;
virtual int strikeoutPos() const;
virtual bool italic() const;
+ virtual double italicSlope() const;
virtual int width(char_type c) const;
virtual int ascent(char_type c) const;
virtual int descent(char_type c) const;
@@ -85,6 +86,9 @@ private:
/// Metrics on the font
QFontMetrics metrics_;
+ /// Slope of italic font
+ double slope_;
+
/// Cache of char widths
mutable QHash<char_type, int> width_cache_;
/// Cache of string widths
diff --git a/src/frontends/qt/GuiWorkArea.cpp b/src/frontends/qt/GuiWorkArea.cpp
index 064d4cb..7e3b4fb 100644
--- a/src/frontends/qt/GuiWorkArea.cpp
+++ b/src/frontends/qt/GuiWorkArea.cpp
@@ -130,7 +130,7 @@ namespace frontend {
class CaretWidget {
public:
CaretWidget() : rtl_(false), l_shape_(false), completable_(false),
- x_(0), caret_width_(0), slant_(false), ascent_(0)
+ x_(0), caret_width_(0), slant_(false), ascent_(0), slope_(0)
{}
/* Draw the caret. Parameter \c horiz_offset is not 0 when there
@@ -146,18 +146,18 @@ public:
int const lx = rtl_ ? x_ - rect_.left() : rect_.right() - x_;
int const bot = rect_.bottom();
int const dir = rtl_ ? -1 : 1;
- // this is almost equal to tan(14 * PI / 180)
- qreal const slope = 0.25;
// draw caret box
if (slant_ && !rtl_) {
- // slanted (14 degree angle)
+ // slanted
+
QPainterPath path;
- path.moveTo(x + ascent_ * slope, y);
- path.lineTo(x - (rect_.height() - ascent_) * slope, y + rect_.height());
- path.lineTo(x + dir * caret_width_ - (rect_.height() - ascent_) * slope,
+ path.moveTo(x + ascent_ * slope_, y);
+ path.lineTo(x - (rect_.height() - ascent_) * slope_,
+ y + rect_.height());
+ path.lineTo(x + dir * caret_width_ - (rect_.height() - ascent_) * slope_,
y + rect_.height());
- path.lineTo(x + dir * caret_width_ + ascent_ * slope, y);
+ path.lineTo(x + dir * caret_width_ + ascent_ * slope_, y);
painter.setRenderHint(QPainter::Antialiasing, true);
painter.fillPath(path, color_);
painter.setRenderHint(QPainter::Antialiasing, false);
@@ -176,7 +176,7 @@ public:
int const m = y + rect_.height() / 2;
int const d = TabIndicatorWidth - 1;
// offset for slanted carret
- int const sx = (slant_ && !rtl_) ? (ascent_ - (rect_.height() / 2 - d)) * slope : 0;
+ int const sx = (slant_ && !rtl_) ? (ascent_ - (rect_.height() / 2 - d)) * slope_ : 0;
painter.drawLine(x + dir * (caret_width_ + 1) + sx, m - d,
x + dir * (caret_width_ + d + 1) + sx, m);
painter.drawLine(x + dir * (caret_width_ + 1) + sx, m + d,
@@ -185,7 +185,7 @@ public:
}
void update(int x, int y, int h, bool l_shape,
- bool rtl, bool completable, bool slant, int ascent)
+ bool rtl, bool completable, bool slant, int ascent, double slope)
{
color_ = guiApp->colorCache().get(Color_cursor);
l_shape_ = l_shape;
@@ -194,6 +194,7 @@ public:
x_ = x;
slant_ = slant;
ascent_ = ascent;
+ slope_ = slope;
// extension to left and right
int l = 0;
@@ -245,6 +246,8 @@ private:
bool slant_;
/// the fontmetrics ascent for drawing slanted caret
int ascent_;
+ /// the slope for drawing slanted caret
+ double slope_;
};
@@ -644,10 +647,11 @@ void GuiWorkArea::Private::updateCaretGeometry()
Point point;
int h = 0;
buffer_view_->caretPosAndHeight(point, h);
+ Cursor & cur = buffer_view_->cursor();
// RTL or not RTL
bool l_shape = false;
- Font const & realfont = buffer_view_->cursor().real_current_font;
+ Font const & realfont = cur.real_current_font;
FontMetrics const & fm = theFontMetrics(realfont.fontInfo());
BufferParams const & bp = buffer_view_->buffer().params();
bool const samelang = realfont.language() == bp.language;
@@ -661,22 +665,23 @@ void GuiWorkArea::Private::updateCaretGeometry()
l_shape = false;
// show caret on screen
- Cursor & cur = buffer_view_->cursor();
bool completable = cur.inset().showCompletionCursor()
&& completer_->completionAvailable()
&& !completer_->popupVisible()
&& !completer_->inlineVisible();
- caret_->update(point.x_, point.y_, h, l_shape, isrtl, completable,
- // use slanted caret for italics in text edit mode
- fm.italic() && buffer_view_->cursor().inTexted()
- // except for selections because the selection rect does not slant
- && !buffer_view_->cursor().selection(), fm.maxAscent());
+ // use slanted caret for italics in text edit mode
+ // except for selections because the selection rect does not slant
+ int slant = fm.italic() && buffer_view_->cursor().inTexted()
+ && !buffer_view_->cursor().selection();
+ double slope = fm.italicSlope();
+
+ caret_->update(point.x_, point.y_, h, l_shape, isrtl, completable, slant,
+ fm.maxAscent(), slope);
needs_caret_geometry_update_ = false;
}
-
void GuiWorkArea::Private::showCaret()
{
if (caret_visible_)
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