Attachment 57075 Details for Bug 36536 – adjust substitute font width using first character in each string

[patch] adjust substitute font width using first character in each string

0001-cairo-adjust-subtitute-font-width-using-first-charac.patch (text/plain), 5.00 KB, created by Adrian Johnson on 2012-02-15 02:57:57 UTC

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Creator: Adrian Johnson

Created: 2012-02-15 02:57:57 UTC

Size: 5.00 KB

patch

obsolete

>From 16b3f69d1c3260b8bdeb8c5058eaf4b6f4f2060a Mon Sep 17 00:00:00 2001
>From: Adrian Johnson <ajohnson@redneon.com>
>Date: Tue, 7 Feb 2012 16:03:45 +1030
>Subject: [PATCH] cairo: adjust subtitute font width using first character in
> each string
>
>instead of the letter 'm'. Bug 36536 has a PDF where the non embedded
>font has bad widths for unused characters included the letter 'm'.
>---
> poppler/CairoFontEngine.cc |   19 ++++++++-----------
> poppler/CairoFontEngine.h  |    2 +-
> poppler/CairoOutputDev.cc  |   35 ++++++++++++++++++++++++++++-------
> 3 files changed, 37 insertions(+), 19 deletions(-)
>
>diff --git a/poppler/CairoFontEngine.cc b/poppler/CairoFontEngine.cc
>index c9d2d0c..7e8ba91 100644
>--- a/poppler/CairoFontEngine.cc
>+++ b/poppler/CairoFontEngine.cc
>@@ -104,21 +104,13 @@ CairoFont::getGlyph(CharCode code,
> }
> 
> double
>-CairoFont::getSubstitutionCorrection(GfxFont *gfxFont)
>+CairoFont::getSubstitutionCorrection(GfxFont *gfxFont, CharCode code)
> {
>   double w1, w2;
>-  CharCode code;
>-  char *name;
> 
>   // for substituted fonts: adjust the font matrix -- compare the
>-  // width of 'm' in the original font and the substituted font
>+  // width of the character in the original font and the substituted font
>   if (isSubstitute() && !gfxFont->isCIDFont()) {
>-    for (code = 0; code < 256; ++code) {
>-      if ((name = ((Gfx8BitFont *)gfxFont)->getCharName(code)) &&
>-	  name[0] == 'm' && name[1] == '\0') {
>-	break;
>-      }
>-    }
>     if (code < 256) {
>       w1 = ((Gfx8BitFont *)gfxFont)->getWidth(code);
>       {
>@@ -129,8 +121,13 @@ CairoFont::getSubstitutionCorrection(GfxFont *gfxFont)
> 	cairo_font_options_set_hint_metrics(options, CAIRO_HINT_METRICS_OFF);
> 	cairo_scaled_font_t *scaled_font = cairo_scaled_font_create(cairo_font_face, &m, &m, options);
> 
>+        cairo_glyph_t glyph;
>+        glyph.index = getGlyph(code, NULL, 0);
>+        glyph.x = 0;
>+        glyph.y = 0;
>+
> 	cairo_text_extents_t extents;
>-	cairo_scaled_font_text_extents(scaled_font, "m", &extents);
>+	cairo_scaled_font_glyph_extents(scaled_font, &glyph, 1, &extents);
> 
> 	cairo_scaled_font_destroy(scaled_font);
> 	cairo_font_options_destroy(options);
>diff --git a/poppler/CairoFontEngine.h b/poppler/CairoFontEngine.h
>index 6335348..5a1a5ca 100644
>--- a/poppler/CairoFontEngine.h
>+++ b/poppler/CairoFontEngine.h
>@@ -53,7 +53,7 @@ public:
>   virtual GBool matches(Ref &other, GBool printing);
>   cairo_font_face_t *getFontFace(void);
>   unsigned long getGlyph(CharCode code, Unicode *u, int uLen);
>-  double getSubstitutionCorrection(GfxFont *gfxFont);
>+  double getSubstitutionCorrection(GfxFont *gfxFont, CharCode code);
> 
>   GBool isSubstitute() { return substitute; }
> protected:
>diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
>index dab1e47..8ae448a 100644
>--- a/poppler/CairoOutputDev.cc
>+++ b/poppler/CairoOutputDev.cc
>@@ -607,15 +607,11 @@ void CairoOutputDev::updateFont(GfxState *state) {
> 
>   use_show_text_glyphs = state->getFont()->hasToUnicodeCMap() &&
>     cairo_surface_has_show_text_glyphs (cairo_get_target (cairo));
>- 
>+
>   double fontSize = state->getFontSize();
>   double *m = state->getTextMat();
>-  /* NOTE: adjusting by a constant is hack. The correct solution
>-   * is probably to use user-fonts and compute the scale on a per
>-   * glyph basis instead of for the entire font */
>-  double w = currentFont->getSubstitutionCorrection(state->getFont());
>-  matrix.xx = m[0] * fontSize * state->getHorizScaling() * w;
>-  matrix.yx = m[1] * fontSize * state->getHorizScaling() * w;
>+  matrix.xx = m[0] * fontSize * state->getHorizScaling();
>+  matrix.yx = m[1] * fontSize * state->getHorizScaling();
>   matrix.xy = -m[2] * fontSize;
>   matrix.yy = -m[3] * fontSize;
>   matrix.x0 = 0;
>@@ -1123,6 +1119,31 @@ void CairoOutputDev::drawChar(GfxState *state, double x, double y,
> 			      CharCode code, int nBytes, Unicode *u, int uLen)
> {
>   if (currentFont) {
>+
>+    /* Adjust width of substitute fonts to match the width of the
>+     * first character in the string. (Bug 36536) */
>+    if (glyphCount == 0 && currentFont->isSubstitute()) {
>+      double w = currentFont->getSubstitutionCorrection(state->getFont(), code);
>+      if (w != 1.0) {
>+        /* NOTE: adjusting by a constant is hack. The correct solution
>+         * is probably to use user-fonts and compute the scale on a per
>+         * glyph basis instead of for the entire font */
>+        double fontSize = state->getFontSize();
>+        double *m = state->getTextMat();
>+        cairo_matrix_t matrix;
>+        matrix.xx = m[0] * fontSize * state->getHorizScaling() * w;
>+        matrix.yx = m[1] * fontSize * state->getHorizScaling() * w;
>+        matrix.xy = -m[2] * fontSize;
>+        matrix.yy = -m[3] * fontSize;
>+        matrix.x0 = 0;
>+        matrix.y0 = 0;
>+
>+        LOG(printf ("substitute font matrix: %f %f %f %f\n", matrix.xx, matrix.yx, matrix.xy, matrix.yy));
>+
>+        cairo_set_font_matrix (cairo, &matrix);
>+      }
>+    }
>+
>     glyphs[glyphCount].index = currentFont->getGlyph (code, u, uLen);
>     glyphs[glyphCount].x = x - originX;
>     glyphs[glyphCount].y = y - originY;
>-- 
>1.7.5.4
>

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