dany/pdfio
1
0
Fork 0
mirror of https://github.com/michaelrsweet/pdfio.git synced 2025-08-29 15:22:06 +02:00
Code Issues Packages Projects Releases Wiki Activity

Add support for measuring base fonts (Issue #84)

Browse Source 
Update md2pdf example code to support using embedded TrueType or PDF base
fonts.
This commit is contained in:
Michael R Sweet
2024-12-13 17:39:16 -05:00
parent 0d08dd5f1b
commit d3d6683041
4 changed files with 439 additions and 61 deletions
Download Patch File Download Diff File Expand all files Collapse all files

169
pdfio-content.c
View File

@@ -1,7 +1,7 @@
//
// Content helper functions for PDFio.
//
// Copyright © 2021-2023 by Michael R Sweet.
// Copyright © 2021-2024 by Michael R Sweet.
//
// Licensed under Apache License v2.0. See the file "LICENSE" for more
// information.
@@ -9,6 +9,7 @@
#include "pdfio-private.h"
#include "pdfio-content.h"
#include "pdfio-base-font-widths.h"
#include "ttf.h"
#include <math.h>
#ifndef M_PI
@@ -1074,7 +1075,7 @@ pdfioContentTextMeasure(
const char *s, // I - UTF-8 string
double size) // I - Font size/height
{
const char *subtype; // Font sub-type
const char *basefont; // Base font name
ttf_t *ttf = (ttf_t *)_pdfioObjGetExtension(font);
// TrueType font data
ttf_rect_t extents; // Text extents
@@ -1083,75 +1084,124 @@ pdfioContentTextMeasure(
*tempptr; // Pointer into temporary string
if ((subtype = pdfioObjGetSubtype(font)) == NULL || strcmp(subtype, "Type0"))
if (!ttf && (basefont = pdfioDictGetName(pdfioObjGetDict(font), "BaseFont")) != NULL)
{
// Map non-CP1282 characters to '?', everything else as-is...
tempptr = temp;
// Measure the width using the compiled-in base font tables...
const short *widths; // Widths
int width = 0; // Current width
while (*s && tempptr < (temp + sizeof(temp) - 3))
if (strcmp(basefont, "Symbol") && strcmp(basefont, "Zapf-Dingbats"))
{
if ((*s & 0xe0) == 0xc0)
{
// Two-byte UTF-8
ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
s += 2;
}
else if ((*s & 0xf0) == 0xe0)
{
// Three-byte UTF-8
ch = ((s[0] & 0x0f) << 12) | ((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
s += 3;
}
else if ((*s & 0xf8) == 0xf0)
{
// Four-byte UTF-8
ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) | ((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
s += 4;
}
else
{
ch = *s++;
}
// Map non-CP1282 characters to '?', everything else as-is...
tempptr = temp;
if (ch > 255)
while (*s && tempptr < (temp + sizeof(temp) - 3))
{
// Try mapping from Unicode to CP1252...
size_t i; // Looping var
for (i = 0; i < (sizeof(_pdfio_cp1252) / sizeof(_pdfio_cp1252[0])); i ++)
if ((*s & 0xe0) == 0xc0)
{
if (ch == _pdfio_cp1252[i])
break;
// Two-byte UTF-8
ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
s += 2;
}
else if ((*s & 0xf0) == 0xe0)
{
// Three-byte UTF-8
ch = ((s[0] & 0x0f) << 12) | ((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
s += 3;
}
else if ((*s & 0xf8) == 0xf0)
{
// Four-byte UTF-8
ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) | ((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
s += 4;
}
else
{
ch = *s++;
}
if (i >= (sizeof(_pdfio_cp1252) / sizeof(_pdfio_cp1252[0])))
ch = '?'; // Unsupported chars map to ?
if (ch > 255)
{
// Try mapping from Unicode to CP1252...
size_t i; // Looping var
for (i = 0; i < (sizeof(_pdfio_cp1252) / sizeof(_pdfio_cp1252[0])); i ++)
{
if (ch == _pdfio_cp1252[i])
break;
}
if (i >= (sizeof(_pdfio_cp1252) / sizeof(_pdfio_cp1252[0])))
ch = '?'; // Unsupported chars map to ?
}
if (ch < 128)
{
// ASCII
*tempptr++ = (char)ch;
}
else if (ch < 2048)
{
// 2-byte UTF-8
*tempptr++ = (char)(0xc0 | ((ch >> 6) & 0x1f));
*tempptr++ = (char)(0x80 | (ch & 0x3f));
}
else
{
// 3-byte UTF-8
*tempptr++ = (char)(0xe0 | ((ch >> 12) & 0x0f));
*tempptr++ = (char)(0x80 | ((ch >> 6) & 0x3f));
*tempptr++ = (char)(0x80 | (ch & 0x3f));
}
}
if (ch < 128)
{
// ASCII
*tempptr++ = (char)ch;
}
else if (ch < 2048)
{
// 2-byte UTF-8
*tempptr++ = (char)(0xc0 | ((ch >> 6) & 0x1f));
*tempptr++ = (char)(0x80 | (ch & 0x3f));
}
else
{
// 3-byte UTF-8
*tempptr++ = (char)(0xe0 | ((ch >> 12) & 0x0f));
*tempptr++ = (char)(0x80 | ((ch >> 6) & 0x3f));
*tempptr++ = (char)(0x80 | (ch & 0x3f));
}
*tempptr = '\0';
s = temp;
}
*tempptr = '\0';
s = temp;
// Choose the appropriate table...
if (!strcmp(basefont, "Courier"))
widths = courier_widths;
else if (!strcmp(basefont, "Courier-Bold"))
widths = courier_bold_widths;
else if (!strcmp(basefont, "Courier-BoldOblique"))
widths = courier_boldoblique_widths;
else if (!strcmp(basefont, "Courier-Oblique"))
widths = courier_oblique_widths;
else if (!strcmp(basefont, "Helvetica"))
widths = helvetica_widths;
else if (!strcmp(basefont, "Helvetica-Bold"))
widths = helvetica_bold_widths;
else if (!strcmp(basefont, "Helvetica-BoldOblique"))
widths = helvetica_boldoblique_widths;
else if (!strcmp(basefont, "Helvetica-Oblique"))
widths = helvetica_oblique_widths;
else if (!strcmp(basefont, "Symbol"))
widths = symbol_widths;
else if (!strcmp(basefont, "Times-Bold"))
widths = times_bold_widths;
else if (!strcmp(basefont, "Times-BoldItalic"))
widths = times_bolditalic_widths;
else if (!strcmp(basefont, "Times-Italic"))
widths = times_italic_widths;
else if (!strcmp(basefont, "Times-Roman"))
widths = times_roman_widths;
else if (!strcmp(basefont, "Zapf-Dingbats"))
widths = zapf_dingbats_widths;
else
return (0.0);
// Calculate the width using the corresponding table...
while (*s)
{
width += widths[*s & 255];
s ++;
}
return (size * 0.001 * width);
}
// If we get here then we need to measure using the TrueType library...
ttfGetExtents(ttf, (float)size, s, &extents);
return (extents.right - extents.left);
@@ -1421,8 +1471,9 @@ pdfioContentTextShowJustified(
// - "Times-Roman"
// - "ZapfDingbats"
//
// Base fonts always use the Windows CP1252 (ISO-8859-1 with additional
// characters such as the Euro symbol) subset of Unicode.
// Aside from "Symbol" and "Zapf-Dingbats", Base fonts use the Windows CP1252
// (ISO-8859-1 with additional characters such as the Euro symbol) subset of
// Unicode.
//
pdfio_obj_t * // O - Font object