src/java.desktop/share/native/libfontmanager/freetypeScaler.c

rev 53953 : 8218854: FontMetrics.getMaxAdvance may be less than the maximum FontMetrics.charWidth
Summary: Consider algorithmic bold in FontMetrics.getMaxAdvance value and update obliqueness.
Reviewed-by: prr, serb

*** 1,7 ****
  /*
!  * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2007, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 403,416 ****
      }
  
      return errCode;
  }
  
! /* ftsynth.c uses (0x10000, 0x06000, 0x0, 0x10000) matrix to get oblique
!    outline.  Therefore x coordinate will change by 0x06000*y.
!    Note that y coordinate does not change. */
! #define OBLIQUE_MODIFIER(y)  (context->doItalize ? ((y)*6/16) : 0)
  
  /*
   * Class:     sun_font_FreetypeFontScaler
   * Method:    getFontMetricsNative
   * Signature: (Lsun/font/Font2D;J)Lsun/font/StrikeMetrics;
--- 403,424 ----
      }
  
      return errCode;
  }
  
! /* ftsynth.c uses (0x10000, 0x0366A, 0x0, 0x10000) matrix to get oblique
!    outline.  Therefore x coordinate will change by 0x0366A*y.
!    Note that y coordinate does not change. These values are based on
!    libfreetype version 2.9.1. */
! #define OBLIQUE_MODIFIER(y)  (context->doItalize ? ((y)*0x366A/0x10000) : 0)
! 
! /* FT_GlyphSlot_Embolden (ftsynth.c) uses FT_MulFix(units_per_EM, y_scale) / 24
!  * strength value when glyph format is FT_GLYPH_FORMAT_OUTLINE. This value has
!  * been taken from libfreetype version 2.6 and remain valid at least up to
!  * 2.9.1. */
! #define BOLD_MODIFIER(units_per_EM, y_scale) \
!     (context->doBold ? FT_MulFix(units_per_EM, y_scale) / 24 : 0)
  
  /*
   * Class:     sun_font_FreetypeFontScaler
   * Method:    getFontMetricsNative
   * Signature: (Lsun/font/Font2D;J)Lsun/font/StrikeMetrics;
*** 493,503 ****
                        (jlong) scalerInfo->face->size->metrics.y_scale))
                    + ay - dy;
      /* max advance */
      mx = (jfloat) FT26Dot6ToFloat(
                       scalerInfo->face->size->metrics.max_advance +
!                      OBLIQUE_MODIFIER(scalerInfo->face->size->metrics.height));
      my = 0;
  
      metrics = (*env)->NewObject(env,
          sunFontIDs.strikeMetricsClass,
          sunFontIDs.strikeMetricsCtr,
--- 501,513 ----
                        (jlong) scalerInfo->face->size->metrics.y_scale))
                    + ay - dy;
      /* max advance */
      mx = (jfloat) FT26Dot6ToFloat(
                       scalerInfo->face->size->metrics.max_advance +
!                      OBLIQUE_MODIFIER(scalerInfo->face->size->metrics.height) +
!                      BOLD_MODIFIER(scalerInfo->face->units_per_EM,
!                              scalerInfo->face->size->metrics.y_scale));
      my = 0;
  
      metrics = (*env)->NewObject(env,
          sunFontIDs.strikeMetricsClass,
          sunFontIDs.strikeMetricsCtr,