Optimize font use by only allocating platform font resources for unique fonts

and using aliases of these in the Style objects.
Font measurement is also performed once for each unique font and the results
copied into each style.
No change is needed in callers.
On PLAT_WX, the font ascent is cached in the Font object when Ascent is called
but this is not copied into the aliases as ascent is protected. Therefore the
code that copies the FontID into the alias also calls Ascent to ensure the
ascent value is cached.

1 files changed, 15 insertions, 0 deletions

diff --git a/src/ViewStyle.h b/src/ViewStyle.h
index 6ca488dff..cf45be41f 100644
--- a/src/ViewStyle.h
+++ b/src/ViewStyle.h
@@ -39,6 +39,19 @@ public:
 	const char *Save(const char *name);
 };
 
+class FontRealised : public Font, public FontSpecification, public FontMeasurements {
+	// Private so FontRealised objects can not be copied
+	FontRealised(const FontRealised &);
+	FontRealised &operator=(const FontRealised &);
+public:
+	FontRealised *frNext;
+	FontRealised(const FontSpecification &fs);
+	virtual ~FontRealised();
+	void Realise(Surface &surface, int zoomLevel);
+	FontRealised *Find(const FontSpecification &fs);
+	void FindMaxAscentDescent(unsigned int &maxAscent, unsigned int &maxDescent);
+};
+
 enum IndentView {ivNone, ivReal, ivLookForward, ivLookBoth};
 
 enum WhiteSpaceVisibility {wsInvisible=0, wsVisibleAlways=1, wsVisibleAfterIndent=2};
@@ -48,6 +61,7 @@ enum WhiteSpaceVisibility {wsInvisible=0, wsVisibleAlways=1, wsVisibleAfterInden
 class ViewStyle {
 public:
 	FontNames fontNames;
+	FontRealised *frFirst;
 	size_t stylesSize;
 	Style *styles;
 	LineMarker markers[MARKER_MAX + 1];
@@ -119,6 +133,7 @@ public:
 	ViewStyle(const ViewStyle &source);
 	~ViewStyle();
 	void Init(size_t stylesSize_=64);
+	void CreateFont(const FontSpecification &fs);
 	void RefreshColourPalette(Palette &pal, bool want);
 	void Refresh(Surface &surface);
 	void AllocStyles(size_t sizeNew);