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tdegraphics/kdvi/TeXFont_PFB.cpp

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11 KiB

// TeXFont_PFB.cpp
//
// Part of KDVI - A DVI previewer for the KDE desktop environemt
//
// (C) 2003 Stefan Kebekus
// Distributed under the GPL
// This file is compiled only if the FreeType library is present on
// the system
// Add header files alphabetically
#include <config.h>
#include <kdebug.h>
#include <klocale.h>
#include <tqimage.h>
#include "fontpool.h"
#ifdef HAVE_FREETYPE
#include "glyph.h"
#include "TeXFont_PFB.h"
//#define DEBUG_PFB 1
TeXFont_PFB::TeXFont_PFB(TeXFontDefinition *tqparent, fontEncoding *enc, double slant)
: TeXFont(tqparent)
{
#ifdef DEBUG_PFB
if (enc != 0)
kdDebug(4300) << "TeXFont_PFB::TeXFont_PFB( tqparent=" << tqparent << ", encoding=" << enc->encodingFullName << " )" << endl;
else
kdDebug(4300) << "TeXFont_PFB::TeXFont_PFB( tqparent=" << tqparent << ", encoding=0 )" << endl;
#endif
fatalErrorInFontLoading = false;
int error = FT_New_Face( tqparent->font_pool->FreeType_library, tqparent->filename.local8Bit(), 0, &face );
if ( error == FT_Err_Unknown_File_Format ) {
errorMessage = i18n("The font file %1 could be opened and read, but its font format is unsupported.").tqarg(tqparent->filename);
kdError(4300) << errorMessage << endl;
fatalErrorInFontLoading = true;
return;
} else
if ( error ) {
errorMessage = i18n("The font file %1 is broken, or it could not be opened or read.").tqarg(tqparent->filename);
kdError(4300) << errorMessage << endl;
fatalErrorInFontLoading = true;
return;
}
// Take care of slanting, and transform all characters in the font, if necessary.
if (slant != 0.0) {
// Construct a transformation matrix for vertical shear which will
// be used to transform the characters.
transformationMatrix.xx = 0x10000;
transformationMatrix.xy = (FT_Fixed)(slant * 0x10000);
transformationMatrix.yx = 0;
transformationMatrix.yy = 0x10000;
FT_Set_Transform( face, &transformationMatrix, 0);
}
if (face->family_name != 0)
tqparent->fullFontName = face->family_name;
// Finally, we need to set up the charMap array, which maps TeX
// character codes to glyph indices in the font. (Remark: the
// charMap, and the font encoding procedure is necessary, because
// TeX is only able to address character codes 0-255 while
// e.g. Type1 fonts may contain several thousands of characters)
if (enc != 0) {
tqparent->fullEncodingName = enc->encodingFullName.remove(TQString::tqfromLatin1( "Encoding" ));
tqparent->fullEncodingName = enc->encodingFullName.remove(TQString::tqfromLatin1( "encoding" ));
// An encoding vector is given for this font, i.e. an array of
// character names (such as: 'parenleft' or 'dotlessj'). We use
// the FreeType library function 'FT_Get_Name_Index()' to
// associate glyph indices to those names.
#ifdef DEBUG_PFB
kdDebug(4300) << "Trying to associate glyph indices to names from the encoding vector." << endl;
#endif
for(int i=0; i<256; i++) {
charMap[i] = FT_Get_Name_Index( face, (FT_String *)(enc->glyphNameVector[i].ascii()) );
#ifdef DEBUG_PFB
kdDebug(4300) << i << ": " << enc->glyphNameVector[i] << ", GlyphIndex=" << charMap[i] << endl;
#endif
}
} else {
// If there is no encoding vector available, we check if the font
// itself contains a charmap that could be used. An admissible
// charMap will be stored under platform_id=7 and encoding_id=2.
FT_CharMap found = 0;
for (int n = 0; n<face->num_charmaps; n++ ) {
FT_CharMap charmap = face->charmaps[n];
if ( charmap->platform_id == 7 && charmap->encoding_id == 2 ) {
found = charmap;
break;
}
}
if ((found != 0) && (FT_Set_Charmap( face, found ) == 0)) {
// Feed the charMap array with the charmap data found in the
// previous step.
#ifdef DEBUG_PFB
kdDebug(4300) << "No encoding given: using charmap platform=7, encoding=2 that is contained in the font." << endl;
#endif
for(int i=0; i<256; i++)
charMap[i] = FT_Get_Char_Index( face, i );
} else {
if ((found == 0) && (face->charmap != 0)) {
#ifdef DEBUG_PFB
kdDebug(4300) << "No encoding given: using charmap platform=" << face->charmap->platform_id <<
", encoding=" << face->charmap->encoding_id << " that is contained in the font." << endl;
#endif
for(int i=0; i<256; i++)
charMap[i] = FT_Get_Char_Index( face, i );
} else {
// As a last resort, we use the identity map.
#ifdef DEBUG_PFB
kdDebug(4300) << "No encoding given, no suitable charmaps found in the font: using identity charmap." << endl;
#endif
for(int i=0; i<256; i++)
charMap[i] = i;
}
}
}
}
TeXFont_PFB::~TeXFont_PFB()
{
FT_Done_Face( face );
}
glyph *TeXFont_PFB::getGlyph(TQ_UINT16 ch, bool generateCharacterPixmap, const TQColor& color)
{
#ifdef DEBUG_PFB
kdDebug(4300) << "TeXFont_PFB::getGlyph( ch=" << ch << ", '" << (char)(ch) << "', generateCharacterPixmap=" << generateCharacterPixmap << " )" << endl;
#endif
// Paranoia checks
if (ch >= TeXFontDefinition::max_num_of_chars_in_font) {
kdError(4300) << "TeXFont_PFB::getGlyph(): Argument is too big." << endl;
return glyphtable;
}
// This is the address of the glyph that will be returned.
struct glyph *g = glyphtable+ch;
if (fatalErrorInFontLoading == true)
return g;
if ((generateCharacterPixmap == true) && ((g->shrunkenCharacter.isNull()) || (color != g->color)) ) {
int error;
unsigned int res = (unsigned int)(tqparent->displayResolution_in_dpi/tqparent->enlargement +0.5);
g->color = color;
// Character height in 1/64th of points (reminder: 1 pt = 1/72 inch)
// Only approximate, may vary from file to file!!!! @@@@@
long int characterSize_in_printers_points_by_64 = (long int)((64.0*72.0*tqparent->scaled_size_in_DVI_units*tqparent->font_pool->getCMperDVIunit())/2.54 + 0.5 );
error = FT_Set_Char_Size(face, 0, characterSize_in_printers_points_by_64, res, res );
if (error) {
TQString msg = i18n("FreeType reported an error when setting the character size for font file %1.").tqarg(tqparent->filename);
if (errorMessage.isEmpty())
errorMessage = msg;
kdError(4300) << msg << endl;
g->shrunkenCharacter.resize(1,1);
g->shrunkenCharacter.fill(TQColor(255, 255, 255));
return g;
}
// load glyph image into the slot and erase the previous one
if (tqparent->font_pool->getUseFontHints() == true)
error = FT_Load_Glyph(face, charMap[ch], FT_LOAD_DEFAULT );
else
error = FT_Load_Glyph(face, charMap[ch], FT_LOAD_NO_HINTING );
if (error) {
TQString msg = i18n("FreeType is unable to load glyph #%1 from font file %2.").tqarg(ch).tqarg(tqparent->filename);
if (errorMessage.isEmpty())
errorMessage = msg;
kdError(4300) << msg << endl;
g->shrunkenCharacter.resize(1,1);
g->shrunkenCharacter.fill(TQColor(255, 255, 255));
return g;
}
// convert to an anti-aliased bitmap
error = FT_Render_Glyph( face->glyph, ft_render_mode_normal );
if (error) {
TQString msg = i18n("FreeType is unable to render glyph #%1 from font file %2.").tqarg(ch).tqarg(tqparent->filename);
if (errorMessage.isEmpty())
errorMessage = msg;
kdError(4300) << msg << endl;
g->shrunkenCharacter.resize(1,1);
g->shrunkenCharacter.fill(TQColor(255, 255, 255));
return g;
}
FT_GlyphSlot slot = face->glyph;
if ((slot->bitmap.width == 0) || (slot->bitmap.rows == 0)) {
if (errorMessage.isEmpty())
errorMessage = i18n("Glyph #%1 is empty.").tqarg(ch);
kdError(4300) << i18n("Glyph #%1 from font file %2 is empty.").tqarg(ch).tqarg(tqparent->filename) << endl;
g->shrunkenCharacter.resize( 15, 15 );
g->shrunkenCharacter.fill(TQColor(255, 0, 0));
g->x2 = 0;
g->y2 = 15;
} else {
TQImage imgi(slot->bitmap.width, slot->bitmap.rows, 32);
imgi.setAlphaBuffer(true);
// Do TQPixmaps fully support the alpha channel? If yes, we use
// that. Otherwise, use other routines as a fallback
if (tqparent->font_pool->TQPixmapSupportsAlpha) {
// If the alpha channel is properly supported, we set the
// character glyph to a colored rectangle, and define the
// character outline only using the alpha channel. That
// ensures good quality rendering for overlapping characters.
uchar *srcScanLine = slot->bitmap.buffer;
for(int row=0; row<slot->bitmap.rows; row++) {
uchar *destScanLine = imgi.scanLine(row);
for(int col=0; col<slot->bitmap.width; col++) {
destScanLine[4*col+0] = color.blue();
destScanLine[4*col+1] = color.green();
destScanLine[4*col+2] = color.red();
destScanLine[4*col+3] = srcScanLine[col];
}
srcScanLine += slot->bitmap.pitch;
}
} else {
// If the alpha channel is not supported... QT seems to turn
// the alpha channel into a crude bitmap which is used to tqmask
// the resulting TQPixmap. In this case, we define the
// character outline using the image data, and use the alpha
// channel only to store "maximally opaque" or "completely
// transparent" values. When characters are rendered,
// overlapping characters are no longer correctly drawn, but
// quality is still sufficient for most purposes. One notable
// exception is output from the gftodvi program, which will be
// partially unreadable.
TQ_UINT16 rInv = 0xFF - color.red();
TQ_UINT16 gInv = 0xFF - color.green();
TQ_UINT16 bInv = 0xFF - color.blue();
for(TQ_UINT16 y=0; y<slot->bitmap.rows; y++) {
TQ_UINT8 *srcScanLine = slot->bitmap.buffer + y*slot->bitmap.pitch;
unsigned int *destScanLine = (unsigned int *)imgi.scanLine(y);
for(TQ_UINT16 col=0; col<slot->bitmap.width; col++) {
TQ_UINT16 data = *srcScanLine;
// The value stored in "data" now has the following meaning:
// data = 0 -> white; data = 0xff -> use "color"
*destScanLine = tqRgba(0xFF - (rInv*data + 0x7F) / 0xFF,
0xFF - (gInv*data + 0x7F) / 0xFF,
0xFF - (bInv*data + 0x7F) / 0xFF,
(data > 0x03) ? 0xff : 0x00);
destScanLine++;
srcScanLine++;
}
}
}
g->shrunkenCharacter.convertFromImage (imgi, 0);
g->x2 = -slot->bitmap_left;
g->y2 = slot->bitmap_top;
}
}
// Load glyph width, if that hasn't been done yet.
if (g->dvi_advance_in_units_of_design_size_by_2e20 == 0) {
int error = FT_Load_Glyph(face, charMap[ch], FT_LOAD_NO_SCALE);
if (error) {
TQString msg = i18n("FreeType is unable to load metric for glyph #%1 from font file %2.").tqarg(ch).tqarg(tqparent->filename);
if (errorMessage.isEmpty())
errorMessage = msg;
kdError(4300) << msg << endl;
g->dvi_advance_in_units_of_design_size_by_2e20 = 1;
}
g->dvi_advance_in_units_of_design_size_by_2e20 = (TQ_INT32)(((TQ_INT64)(1<<20) * (TQ_INT64)face->glyph->metrics.horiAdvance) / (TQ_INT64)face->units_per_EM);
}
return g;
}
#endif // HAVE_FREETYPE