commit 2e1863b704fe5260dcf40c19c8679756c0f1a409
Author: Jean-Marc Lasgouttes <[email protected]>
Date: Mon Dec 4 10:44:49 2017 +0100
Implement display of roots more faithfully
This is a follow-up to 758de957.
- unify the metrics and drawing of \sqrt and \root using helper
functions mathed_root_metrics and mathed_draw_root.
- compute the vertical spacing above the nucleus of the root following
rule 11 of the TeXbook. In particular, it is different in inline and
display style.
- draw the root glyph without hard-coded pixel values. Make the line
width depend on the zoom.
more work is needed to implement properly rule 11:
- Ideally, we should use sqrt glyphs from the math fonts. Note that
then we would get rule thickness from there.
- The positioning of the root MathData is arbitrary. It should
follow the definition of \root...\of... in The Texbook in
Apprendix B page 360.
Fixes bug #10814.
(cherry picked from commit 16af6e7c5067fff0873587af30833e0b8006c435)
(cherry picked from commit 6cb6f78ae9050140c75af089350cd7cccc0b58e1)
---
src/mathed/InsetMathRoot.cpp | 101 ++++++++++++++++++++++++++++++------------
src/mathed/InsetMathRoot.h | 5 ++
src/mathed/InsetMathSqrt.cpp | 25 +---------
src/mathed/MathSupport.cpp | 6 +++
src/mathed/MathSupport.h | 2 +
status.23x | 2 +
6 files changed, 91 insertions(+), 50 deletions(-)
diff --git a/src/mathed/InsetMathRoot.cpp b/src/mathed/InsetMathRoot.cpp
index 8b86c59..348b4e9 100644
--- a/src/mathed/InsetMathRoot.cpp
+++ b/src/mathed/InsetMathRoot.cpp
@@ -13,7 +13,6 @@
#include "InsetMathRoot.h"
-#include "MathData.h"
#include "MathStream.h"
#include "MathSupport.h"
@@ -28,6 +27,7 @@ using namespace std;
namespace lyx {
+using namespace frontend;
InsetMathRoot::InsetMathRoot(Buffer * buf)
: InsetMathNest(buf, 2)
@@ -40,56 +40,101 @@ Inset * InsetMathRoot::clone() const
}
-void InsetMathRoot::metrics(MetricsInfo & mi, Dimension & dim) const
+void mathed_root_metrics(MetricsInfo & mi, MathData const & nucleus,
+ MathData const * root, Dimension & dim)
{
Changer dummy = mi.base.changeEnsureMath();
- Dimension dim0;
- {
+ Dimension dimr;
+ if (root) {
Changer script = mi.base.font.changeStyle(LM_ST_SCRIPTSCRIPT);
- cell(0).metrics(mi, dim0);
+ root->metrics(mi, dimr);
// make sure that the dim is high enough for any character
Dimension fontDim;
math_font_max_dim(mi.base.font, fontDim.asc, fontDim.des);
- dim0 += fontDim;
+ dimr += fontDim;
}
- Dimension dim1;
- cell(1).metrics(mi, dim1);
+ Dimension dimn;
+ nucleus.metrics(mi, dimn);
// make sure that the dim is high enough for any character
- Dimension fontDim;
- math_font_max_dim(mi.base.font, fontDim.asc, fontDim.des);
- dim1 += fontDim;
+ // Dimension fontDim;
+ // math_font_max_dim(mi.base.font, fontDim.asc, fontDim.des);
+ // dimn += fontDim;
+
+ // Some room for the decoration
+ // The width of left decoration was 9 pixels with a 10em font
+ int const w = 9 * mathed_font_em(mi.base.font) / 10;
+ /* See rule 11 in Appendix G of Rhe TeXbook for the computation of the
spacing
+ * above nucleus.
+ * FIXME more work is needed to implement properly rule 11.
+ * * Ideally, we should use sqrt glyphs from the math fonts. Note
+ that then we would get rule thickness from there.
+ * * The positioning of the root MathData is arbitrary. It should
+ * follow the definition of \root...\of... in The Texbook in
+ * Apprendix B page 360.
+ *
+ */
+ int const t = mi.base.solidLineThickness();
+ int const x_height = mathed_font_x_height(mi.base.font);
+ int const phi = (mi.base.font.style() == LM_ST_DISPLAY) ? x_height : t;
+ // first part is the spacing, second part is the line width
+ // itself, and last one is the spacing above.
+ int const space_above = (t + phi / 4) + t + t;
+ int const a = dimn.ascent();
+ int const d = dimn.descent();
+ // Not sure what the 1 stands for, it is needed to have some spacing at
small sizes.
+ dim.asc = max(dimr.ascent() + (d - a) / 2, a + space_above) + 1;
+ dim.des = max(dimr.descent() - (d - a) / 2, d);
+ dim.wid = max(dimr.width() + 3 * w / 8, w) + dimn.width();
+}
+
- dim.asc = max(dim0.ascent() + 5, dim1.ascent()) + 1;
- dim.des = max(dim0.descent() - 5, dim1.descent());
- dim.wid = dim0.width() + dim1.width() + 4;
+void InsetMathRoot::metrics(MetricsInfo & mi, Dimension & dim) const
+{
+ mathed_root_metrics(mi, cell(1), &cell(0), dim);
}
-void InsetMathRoot::draw(PainterInfo & pi, int x, int y) const
+void mathed_draw_root(PainterInfo & pi, int x, int y, MathData const & nucleus,
+ MathData const * root, Dimension const & dim)
{
Changer dummy = pi.base.changeEnsureMath();
- Dimension const dim = dimension(*pi.base.bv);
+ // The width of left decoration was 9 pixels with a 10em font
+ int const w = 9 * mathed_font_em(pi.base.font) / 10;
+ // the height of the hook was 5 with a 10em font
+ int const h = 5 * mathed_font_em(pi.base.font) / 10;
int const a = dim.ascent();
int const d = dim.descent();
- Dimension const & dim0 = cell(0).dimension(*pi.base.bv);
- int const w = dim0.width();
+ int const t = pi.base.solidLineThickness();
+ Dimension const dimn = nucleus.dimension(*pi.base.bv);
+ // the width of the left part of the root
+ int const wl = dim.width() - dimn.width();
// the "exponent"
- {
+ if (root) {
Changer script = pi.base.font.changeStyle(LM_ST_SCRIPTSCRIPT);
- cell(0).draw(pi, x, y + (d - a)/2 - dim0.descent());
+ Dimension const dimr = root->dimension(*pi.base.bv);
+ int const root_offset = wl - 3 * w / 8 - dimr.width();
+ root->draw(pi, x + root_offset, y + (d - a)/2);
}
// the "base"
- cell(1).draw(pi, x + w + 4, y);
+ nucleus.draw(pi, x + wl, y);
int xp[4];
int yp[4];
- pi.pain.line(x + dim.width(), y - a + 1,
- x + w + 4, y - a + 1, pi.base.font.color());
- xp[0] = x + w + 4; yp[0] = y - a + 1;
- xp[1] = x + w; yp[1] = y + d;
- xp[2] = x + w - 2; yp[2] = y + (d - a)/2 + 2;
- xp[3] = x + w - 5; yp[3] = y + (d - a)/2 + 4;
- pi.pain.lines(xp, yp, 4, pi.base.font.color());
+ pi.pain.line(x + dim.width(), y - a + 2 * t,
+ x + wl, y - a + 2 * t, pi.base.font.color(),
+ Painter::line_solid, t);
+ xp[0] = x + wl; yp[0] = y - a + 2 * t + 1;
+ xp[1] = x + wl - w / 2; yp[1] = y + d;
+ xp[2] = x + wl - w + h / 4; yp[2] = y + d - h;
+ xp[3] = x + wl - w; yp[3] = y + d - h + h / 4;
+ pi.pain.lines(xp, yp, 4, pi.base.font.color(),
+ Painter::fill_none, Painter::line_solid, t);
+}
+
+
+void InsetMathRoot::draw(PainterInfo & pi, int x, int y) const
+{
+ mathed_draw_root(pi, x, y, cell(1), &cell(0), dimension(*pi.base.bv));
}
diff --git a/src/mathed/InsetMathRoot.h b/src/mathed/InsetMathRoot.h
index 18bacbb..923e9a5 100644
--- a/src/mathed/InsetMathRoot.h
+++ b/src/mathed/InsetMathRoot.h
@@ -54,6 +54,11 @@ private:
virtual Inset * clone() const;
};
+void mathed_root_metrics(MetricsInfo & mi, MathData const & nucleus,
+ MathData const * root, Dimension & dim);
+
+void mathed_draw_root(PainterInfo & pi, int x, int y, MathData const & nucleus,
+ MathData const * root, Dimension const & dim);
} // namespace lyx
diff --git a/src/mathed/InsetMathSqrt.cpp b/src/mathed/InsetMathSqrt.cpp
index a7385cc..7416c33 100644
--- a/src/mathed/InsetMathSqrt.cpp
+++ b/src/mathed/InsetMathSqrt.cpp
@@ -12,6 +12,7 @@
#include "InsetMathSqrt.h"
+#include "InsetMathRoot.h"
#include "MathData.h"
#include "MathStream.h"
#include "MathSupport.h"
@@ -38,33 +39,13 @@ Inset * InsetMathSqrt::clone() const
void InsetMathSqrt::metrics(MetricsInfo & mi, Dimension & dim) const
{
- Changer dummy = mi.base.changeEnsureMath();
- cell(0).metrics(mi, dim);
- // make sure that the dim is high enough for any character
- Dimension fontDim;
- math_font_max_dim(mi.base.font, fontDim.asc, fontDim.des);
- dim += fontDim;
- // Some room for the decoration
- dim.asc += 1;
- dim.wid += 7;
+ mathed_root_metrics(mi, cell(0), nullptr, dim);
}
void InsetMathSqrt::draw(PainterInfo & pi, int x, int y) const
{
- Changer dummy = pi.base.changeEnsureMath();
- cell(0).draw(pi, x + 9, y);
- Dimension const dim = dimension(*pi.base.bv);
- int const a = dim.ascent();
- int const d = dim.descent();
- int xp[3];
- int yp[3];
- pi.pain.line(x + dim.width(), y - a + 1,
- x + 7, y - a + 1, pi.base.font.color());
- xp[0] = x + 7; yp[0] = y - a + 1;
- xp[1] = x + 4; yp[1] = y + d - 1;
- xp[2] = x; yp[2] = y + (d - a)/2;
- pi.pain.lines(xp, yp, 3, pi.base.font.color());
+ mathed_draw_root(pi, x, y, cell(0), nullptr, dimension(*pi.base.bv));
}
diff --git a/src/mathed/MathSupport.cpp b/src/mathed/MathSupport.cpp
index bb6a21c..57eca6e 100644
--- a/src/mathed/MathSupport.cpp
+++ b/src/mathed/MathSupport.cpp
@@ -513,6 +513,12 @@ int mathed_font_em(FontInfo const & font)
return theFontMetrics(font).em();
}
+
+int mathed_font_x_height(FontInfo const & font)
+{
+ return theFontMetrics(font).ascent('x');
+}
+
/* The math units. Quoting TeX by Topic, p.205:
*
* Spacing around mathematical objects is measured in mu units. A mu
diff --git a/src/mathed/MathSupport.h b/src/mathed/MathSupport.h
index 3e5f67d..d930145 100644
--- a/src/mathed/MathSupport.h
+++ b/src/mathed/MathSupport.h
@@ -32,6 +32,8 @@ class LaTeXFeatures;
int mathed_font_em(FontInfo const &);
+int mathed_font_x_height(FontInfo const & font);
+
int mathed_mu(FontInfo const & font, double mu);
int mathed_thinmuskip(FontInfo const & font);
diff --git a/status.23x b/status.23x
index 7f57277..d1e5abf 100644
--- a/status.23x
+++ b/status.23x
@@ -46,6 +46,8 @@ What's new
- Improve Undo for operations that act on several buffers (bug 10823).
+- Improve rendering of square roots in math editor (bug 10814).
+
* INTERNALS
