From 5aba9b539f3d043c3831c7d679cdf7011e20f2f5 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Fri, 24 Feb 2023 16:24:02 -0800
Subject: [PATCH] Revert font spacing/tabs to the v6 model

While convoluted, this model matches as best we have found so far, the
alignment with scintilla.  The spacing is character size for N-1 of the
characters in the 4-space tab stops.  The final character is sized for
the actual space character in the stroke font (0.761905)

Fixes https://gitlab.com/kicad/code/kicad/issues/13791

(cherry picked from commit bce402a01c9e4b475ba52cd2ef1192d3ff01f5f1)
---
 common/font/stroke_font.cpp                   | 27 ++++--
 qa/unittests/common/CMakeLists.txt            |  1 +
 .../common/test_kicad_stroke_font.cpp         | 82 +++++++++++++++++++
 3 files changed, 101 insertions(+), 9 deletions(-)
 create mode 100644 qa/unittests/common/test_kicad_stroke_font.cpp

diff --git a/common/font/stroke_font.cpp b/common/font/stroke_font.cpp
index 83e2636ba6..ec5f583dc4 100644
--- a/common/font/stroke_font.cpp
+++ b/common/font/stroke_font.cpp
@@ -226,11 +226,8 @@ VECTOR2I STROKE_FONT::GetTextAsGlyphs( BOX2I* aBBox, std::vector<std::unique_ptr
                                        bool aMirror, const VECTOR2I& aOrigin,
                                        TEXT_STYLE_FLAGS aTextStyle ) const
 {
-    constexpr double SPACE_WIDTH = 0.6;
+    constexpr int    TAB_WIDTH = 4;
     constexpr double INTER_CHAR = 0.2;
-    constexpr double TAB_WIDTH = 4 * 0.82;  // Not quite as wide as 5.1/6.0 tab formatting, but
-                                            // a better match for Scintilla, and closer to the
-                                            // nominal SPACE_WIDTH + INTER_CHAR
     constexpr double SUPER_SUB_SIZE_MULTIPLIER = 0.7;
     constexpr double SUPER_HEIGHT_OFFSET = 0.5;
     constexpr double SUB_HEIGHT_OFFSET = 0.3;
@@ -238,6 +235,8 @@ VECTOR2I STROKE_FONT::GetTextAsGlyphs( BOX2I* aBBox, std::vector<std::unique_ptr
     VECTOR2I cursor( aPosition );
     VECTOR2D glyphSize( aSize );
     double   tilt = ( aTextStyle & TEXT_STYLE::ITALIC ) ? ITALIC_TILT : 0.0;
+    double   space_width = m_glyphBoundingBoxes->front().GetWidth(); // First char is space
+    int      char_count = 0;
 
     if( aTextStyle & TEXT_STYLE::SUBSCRIPT || aTextStyle & TEXT_STYLE::SUPERSCRIPT )
     {
@@ -251,18 +250,26 @@ VECTOR2I STROKE_FONT::GetTextAsGlyphs( BOX2I* aBBox, std::vector<std::unique_ptr
 
     for( wxUniChar c : aText )
     {
-        // Handle tabs as locked to the nearest 4th column (in space-widths).
+        // Handle tabs as locked to the next 4th column (in base-widths).
         if( c == '\t' )
         {
-            int tabWidth = KiROUND( glyphSize.x * TAB_WIDTH );
-            int currentIntrusion = ( cursor.x - aOrigin.x ) % tabWidth;
+            char_count = ( char_count / TAB_WIDTH + 1 ) * TAB_WIDTH - 1;
 
-            cursor.x += tabWidth - currentIntrusion;
+            int new_cursor = aPosition.x + aSize.x * char_count
+                    + aSize.x * space_width;
+
+            while( new_cursor <= cursor.x )
+            {
+                char_count += TAB_WIDTH;
+                new_cursor += aSize.x * TAB_WIDTH;
+            }
+
+            cursor.x = new_cursor;
         }
         else if( c == ' ' )
         {
             // 'space' character - draw nothing, advance cursor position
-            cursor.x += KiROUND( glyphSize.x * SPACE_WIDTH );
+            cursor.x += KiROUND( glyphSize.x * space_width );
         }
         else
         {
@@ -293,6 +300,8 @@ VECTOR2I STROKE_FONT::GetTextAsGlyphs( BOX2I* aBBox, std::vector<std::unique_ptr
 
             cursor.x += KiROUND( glyphExtents.x );
         }
+
+        ++char_count;
     }
 
     VECTOR2D barOffset( 0.0, 0.0 );
diff --git a/qa/unittests/common/CMakeLists.txt b/qa/unittests/common/CMakeLists.txt
index 9eef86107b..8fb63a90ed 100644
--- a/qa/unittests/common/CMakeLists.txt
+++ b/qa/unittests/common/CMakeLists.txt
@@ -38,6 +38,7 @@ set( QA_COMMON_SRCS
     test_lib_table.cpp
     test_markup_parser.cpp
     test_kicad_string.cpp
+    test_kicad_stroke_font.cpp
     test_kiid.cpp
     test_property.cpp
     test_refdes_utils.cpp
diff --git a/qa/unittests/common/test_kicad_stroke_font.cpp b/qa/unittests/common/test_kicad_stroke_font.cpp
new file mode 100644
index 0000000000..49a1c1d5ce
--- /dev/null
+++ b/qa/unittests/common/test_kicad_stroke_font.cpp
@@ -0,0 +1,82 @@
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2018 KiCad Developers, see AUTHORS.TXT for contributors.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+/**
+ * @file
+ * Test suite for general string functions
+ */
+
+#include <qa_utils/wx_utils/unit_test_utils.h>
+
+// Code under test
+#include <vector>
+#include <font/stroke_font.h>
+
+/**
+ * Declare the test suite
+ */
+BOOST_AUTO_TEST_SUITE( KicadStrokeFont )
+
+
+/**
+ * Test the tab spacing.
+ */
+BOOST_AUTO_TEST_CASE( TabCheck )
+{
+    using CASE = std::pair<wxString, wxString>;
+
+    KIFONT::STROKE_FONT* font = KIFONT::STROKE_FONT::LoadFont( wxEmptyString );
+
+    const std::vector<CASE> cases = {
+        { "v34_STM23G491\t\tController STM32\t(column 3)",
+          "v34_LPC1758\t\t\tController NXP\t\t(column 3)" },
+        { "1\td9c1892a\t\t\tMOLEX\t\t\t1053071202\t\t\t\t\t12\t\tCONNECTOR",
+          "REF\tPART NUMBER\t\t\tMANUFACTURER\tMANUFACTURER PART NUMBER\tQTY\t\tCONNECTOR" },
+        { "5\tC-000208\t\t\tMCMASTER/CARR\t8054T13 BLUE\t\t\t\t3960MM\tCONNECTOR",
+          "REF\tPART NUMBER\t\t\tMANUFACTURER\tMANUFACTURER PART NUMBER\tQTY\t\tCONNECTOR" },
+        { "0\t\t\t\tlinvA\t\t\tL",
+          "3\t\t\t\tlloadA\t\t\tL" },
+        { "6\t\t\t\tVpccA\t\t\tL",
+          "14\t\t\t\t--\t\t\t\tL" },
+    };
+
+    for( const auto& c : cases )
+    {
+        std::vector<std::unique_ptr<KIFONT::GLYPH>> glyphs;
+        BOX2I bbox;
+        wxString text1 = wxString::Format( c.first );
+        wxString text2 = wxString::Format( c.second );
+
+            VECTOR2I output1 = font->GetTextAsGlyphs( &bbox, &glyphs, text1,
+                    VECTOR2I( 1000, 1000 ), VECTOR2I( 0, 0 ), EDA_ANGLE::m_Angle0, false,
+                    VECTOR2I( 0, 0 ), 0 );
+            VECTOR2I output2 = font->GetTextAsGlyphs( &bbox, &glyphs, text2,
+                    VECTOR2I( 1000, 1000 ), VECTOR2I( 0, 0 ), EDA_ANGLE::m_Angle0, false,
+                    VECTOR2I( 0, 0 ), 0 );
+
+        BOOST_CHECK_MESSAGE( output1.x == output2.x, "Incorrect tab size for \n\t'" << text1.ToStdString() << "' and\n\t'" << text2.ToStdString() << "'" );
+    }
+}
+
+
+BOOST_AUTO_TEST_SUITE_END()