(svn r25470) -Feature-ish: use ICU's layout engine when that's available

2 files changed, 134 insertions, 1 deletions

diff --git a/src/gfx_layout.cpp b/src/gfx_layout.cpp
index caa06fc29..861f390a9 100644
--- a/src/gfx_layout.cpp
+++ b/src/gfx_layout.cpp
@@ -12,9 +12,14 @@
 #include "stdafx.h"
 #include "gfx_layout.h"
 #include "string_func.h"
+#include "strings_func.h"
 
 #include "table/control_codes.h"
 
+#ifdef WITH_ICU
+#include <unicode/ustring.h>
+#endif /* WITH_ICU */
+
 /**
  * Construct a new font.
  * @param size   The font size to use for this font.
@@ -26,6 +31,103 @@ Font::Font(FontSize size, TextColour colour) :
 	assert(size < FS_END);
 }
 
+#ifdef WITH_ICU
+/* Implementation details of LEFontInstance */
+
+le_int32 Font::getUnitsPerEM() const
+{
+	return this->fc->GetUnitsPerEM();
+}
+
+le_int32 Font::getAscent() const
+{
+	return this->fc->GetAscender();
+}
+
+le_int32 Font::getDescent() const
+{
+	return -this->fc->GetDescender();
+}
+
+le_int32 Font::getLeading() const
+{
+	return this->fc->GetHeight();
+}
+
+float Font::getXPixelsPerEm() const
+{
+	return (float)this->fc->GetHeight();
+}
+
+float Font::getYPixelsPerEm() const
+{
+	return (float)this->fc->GetHeight();
+}
+
+float Font::getScaleFactorX() const
+{
+	return 1.0f;
+}
+
+float Font::getScaleFactorY() const
+{
+	return 1.0f;
+}
+
+const void *Font::getFontTable(LETag tableTag) const
+{
+	return this->fc->GetFontTable(tableTag);
+}
+
+LEGlyphID Font::mapCharToGlyph(LEUnicode32 ch) const
+{
+	if (IsTextDirectionChar(ch)) return 0;
+	return this->fc->MapCharToGlyph(ch);
+}
+
+void Font::getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const
+{
+	advance.fX = glyph == 0xFFFF ? 0 : this->fc->GetGlyphWidth(glyph);
+	advance.fY = 0;
+}
+
+le_bool Font::getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const
+{
+	return FALSE;
+}
+
+size_t Layouter::AppendToBuffer(UChar *buff, const UChar *buffer_last, WChar c)
+{
+	/* Transform from UTF-32 to internal ICU format of UTF-16. */
+	int32 length = 0;
+	UErrorCode err = U_ZERO_ERROR;
+	u_strFromUTF32(buff, buffer_last - buff, &length, (UChar32*)&c, 1, &err);
+	return length;
+}
+
+ParagraphLayout *Layouter::GetParagraphLayout(UChar *buff)
+{
+	int32 length = buff - this->buffer;
+
+	if (length == 0) {
+		/* ICU's ParagraphLayout cannot handle empty strings, so fake one. */
+		this->buffer[0] = ' ';
+		length = 1;
+		this->fonts.End()[-1].first++;
+	}
+
+	/* Fill ICU's FontRuns with the right data. */
+	FontRuns runs(this->fonts.Length());
+	for (FontMap::iterator iter = this->fonts.Begin(); iter != this->fonts.End(); iter++) {
+		runs.add(iter->second, iter->first);
+	}
+
+	LEErrorCode status = LE_NO_ERROR;
+	return new ParagraphLayout(this->buffer, length, &runs, NULL, NULL, NULL, _current_text_dir == TD_RTL ? UBIDI_DEFAULT_RTL : UBIDI_DEFAULT_LTR, false, status);
+}
+
+#else /* WITH_ICU */
+
 /*** Paragraph layout ***/
 
 /**
@@ -276,6 +378,7 @@ ParagraphLayout *Layouter::GetParagraphLayout(WChar *buff_end)
 {
 	return new ParagraphLayout(this->buffer, buff_end - this->buffer, this->fonts);
 }
+#endif /* !WITH_ICU */
 
 /**
  * Create a new layouter.
diff --git a/src/gfx_layout.h b/src/gfx_layout.h
index 7960bf2a2..f66559e22 100644
--- a/src/gfx_layout.h
+++ b/src/gfx_layout.h
@@ -16,20 +16,45 @@
 #include "gfx_func.h"
 #include "core/smallmap_type.hpp"
 
+#ifdef WITH_ICU
+#include "layout/ParagraphLayout.h"
+#define ICU_FONTINSTANCE : public LEFontInstance
+#else /* WITH_ICU */
+#define ICU_FONTINSTANCE
+#endif /* WITH_ICU */
+
 /**
  * Container with information about a font.
  */
-class Font {
+class Font ICU_FONTINSTANCE {
 public:
 	FontCache *fc;     ///< The font we are using.
 	TextColour colour; ///< The colour this font has to be.
 
 	Font(FontSize size, TextColour colour);
+
+#ifdef WITH_ICU
+	/* Implementation details of LEFontInstance */
+
+	le_int32 getUnitsPerEM() const;
+	le_int32 getAscent() const;
+	le_int32 getDescent() const;
+	le_int32 getLeading() const;
+	float getXPixelsPerEm() const;
+	float getYPixelsPerEm() const;
+	float getScaleFactorX() const;
+	float getScaleFactorY() const;
+	const void *getFontTable(LETag tableTag) const;
+	LEGlyphID mapCharToGlyph(LEUnicode32 ch) const;
+	void getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const;
+	le_bool getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const;
+#endif /* WITH_ICU */
 };
 
 /** Mapping from index to font. */
 typedef SmallMap<int, Font *> FontMap;
 
+#ifndef WITH_ICU
 /**
  * Class handling the splitting of a paragraph of text into lines and
  * visual runs.
@@ -85,6 +110,7 @@ public:
 	ParagraphLayout(WChar *buffer, int length, FontMap &runs);
 	Line *nextLine(int max_width);
 };
+#endif /* !WITH_ICU */
 
 /**
  * The layouter performs all the layout work.
@@ -92,7 +118,11 @@ public:
  * It also accounts for the memory allocations and frees.
  */
 class Layouter : public AutoDeleteSmallVector<ParagraphLayout::Line *, 4> {
+#ifdef WITH_ICU
+	typedef UChar CharType; ///< The type of character used within the layouter.
+#else /* WITH_ICU */
 	typedef WChar CharType; ///< The type of character used within the layouter.
+#endif /* WITH_ICU */
 
 	size_t AppendToBuffer(CharType *buff, const CharType *buffer_last, WChar c);
 	ParagraphLayout *GetParagraphLayout(CharType *buff);