[freetype2-demos] master f4f64fa: [ftstring, ftview] Loosely match bitmap font sizes.

[Alexei Podtelezhnikov]

branch: master
commit f4f64fa9fb824a9ad2a2c083da42e33270b40759
Author: Alexei Podtelezhnikov <address@hidden>
Commit: Alexei Podtelezhnikov <address@hidden>

    [ftstring, ftview] Loosely match bitmap font sizes.
    
    * src/ftcommon.c (FTDemo_Set_Current_Size,
    FTDemo_Set_Current_Charsize): Round requested size to the closest
    available ppem for bitmap fonts.
    
    * src/ftview.c (Render_Waterfall): Simplify accordingly.
    (write_header): Highlight ppem that does not match the point size.
    
    * src/ftstring.c (write_header): Report ppem.
---
 ChangeLog      | 13 +++++++++++++
 src/ftcommon.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/ftstring.c | 13 +++++++++++--
 src/ftview.c   | 34 ++++++++++------------------------
 4 files changed, 87 insertions(+), 26 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index adf9fea..89debc1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,18 @@
 2017-05-14  Alexei Podtelezhnikov  <address@hidden>
 
+       [ftstring, ftview] Loosely match bitmap font sizes.
+
+       * src/ftcommon.c (FTDemo_Set_Current_Size,
+       FTDemo_Set_Current_Charsize): Round requested size to the closest
+       available ppem for bitmap fonts.
+
+       * src/ftview.c (Render_Waterfall): Simplify accordingly.
+       (write_header): Highlight ppem that does not match the point size.
+
+       * src/ftstring.c (write_header): Report ppem.
+
+2017-05-14  Alexei Podtelezhnikov  <address@hidden>
+
        * src/ftview.c (Render_Stroke): Fix segmentation fault.
 
 2017-05-13  Werner Lemberg  <address@hidden>
diff --git a/src/ftcommon.c b/src/ftcommon.c
index 68c9b33..0c19127 100644
--- a/src/ftcommon.c
+++ b/src/ftcommon.c
@@ -554,9 +554,35 @@
   FTDemo_Set_Current_Size( FTDemo_Handle*  handle,
                            int             pixel_size )
   {
+    FT_Face  face;
+
+
     if ( pixel_size > 0xFFFF )
       pixel_size = 0xFFFF;
 
+    error = FTC_Manager_LookupFace( handle->cache_manager,
+                                    handle->scaler.face_id, &face );
+
+    if ( !error && !FT_IS_SCALABLE ( face ) )
+    {
+      int  i, j = 0;
+      int  c, d = abs( (int)face->available_sizes[j].y_ppem - pixel_size * 64 
);
+
+
+      for ( i = 1; i < face->num_fixed_sizes; i++ )
+      {
+        c = abs( (int)face->available_sizes[i].y_ppem - pixel_size * 64 );
+
+        if ( c < d )
+        {
+          d = c;
+          j = i;
+        }
+      }
+
+      pixel_size = face->available_sizes[j].y_ppem / 64 ;
+    }
+
     handle->scaler.width  = (FT_UInt)pixel_size;
     handle->scaler.height = (FT_UInt)pixel_size;
     handle->scaler.pixel  = 1;                  /* activate integer format */
@@ -572,10 +598,37 @@
                                int             char_size,
                                int             resolution )
   {
+    FT_Face  face;
+
+
     /* in 26.6 format, corresponding to (almost) 0x4000ppem */
     if ( char_size > 0xFFFFF )
       char_size = 0xFFFFF;
 
+    error = FTC_Manager_LookupFace( handle->cache_manager,
+                                    handle->scaler.face_id, &face );
+
+    if ( !error && !FT_IS_SCALABLE ( face ) )
+    {
+      int  pixel_size = char_size * resolution / 72;
+      int  i, j = 0;
+      int  c, d = abs( (int)face->available_sizes[j].y_ppem - pixel_size );
+
+
+      for ( i = 1; i < face->num_fixed_sizes; i++ )
+      {
+        c = abs( (int)face->available_sizes[i].y_ppem - pixel_size );
+
+        if ( c < d )
+        {
+          d = c;
+          j = i;
+        }
+      }
+
+      char_size = face->available_sizes[j].y_ppem * 72 / resolution;
+    }
+
     handle->scaler.width  = (FT_UInt)char_size;
     handle->scaler.height = (FT_UInt)char_size;
     handle->scaler.pixel  = 0;                     /* activate 26.6 format */
diff --git a/src/ftstring.c b/src/ftstring.c
index 6f89e05..4d46a7a 100644
--- a/src/ftstring.c
+++ b/src/ftstring.c
@@ -526,6 +526,7 @@
   {
     FT_Face      face;
     const char*  basename;
+    double       ppem = 0.0;
 
 
     error = FTC_Manager_LookupFace( handle->cache_manager,
@@ -543,6 +544,13 @@
         sprintf( status.header_buffer,
                  "%.50s %.50s (file `%.100s')", face->family_name,
                  face->style_name, basename );
+
+       if ( FT_IS_SCALABLE( face ) )
+          ppem = FT_MulFix( face->units_per_EM,
+                            face->size->metrics.y_scale ) / 64.0;
+        else
+          ppem = (double)face->size->metrics.y_ppem;
+
         break;
 
       case FT_Err_Invalid_Pixel_Size:
@@ -567,8 +575,9 @@
     grWriteCellString( display->bitmap, 0, 0,
                        status.header, display->fore_color );
 
-    sprintf( status.header_buffer, "at %g points, angle = %d, gamma = %g",
-             status.ptsize / 64.0, status.angle, status.gamma );
+    sprintf( status.header_buffer,
+             "at %g points (%.4g ppem), angle = %d, gamma = %g",
+             status.ptsize / 64.0, ppem, status.angle, status.gamma );
     grWriteCellString( display->bitmap, 0, CELLSTRING_HEIGHT,
                        status.header_buffer, display->fore_color );
 
diff --git a/src/ftview.c b/src/ftview.c
index d377f9d..0809d31 100644
--- a/src/ftview.c
+++ b/src/ftview.c
@@ -579,7 +579,6 @@
     int      start_x, start_y, step_y, x, y;
     int      pt_size, max_size = 100000;
     FT_Size  size;
-    FT_Face  face;
     int      have_topleft, start;
 
     char         text[256];
@@ -587,27 +586,6 @@
     const char*  pEnd;
 
 
-    error = FTC_Manager_LookupFace( handle->cache_manager,
-                                    handle->scaler.face_id, &face );
-    if ( error )
-    {
-      /* can't access the font file: do not render anything */
-      fprintf( stderr, "can't access font file %p\n",
-               (void*)handle->scaler.face_id );
-      return 0;
-    }
-
-    if ( !FT_IS_SCALABLE( face ) )
-    {
-      int  i;
-
-
-      max_size = 0;
-      for ( i = 0; i < face->num_fixed_sizes; i++ )
-        if ( face->available_sizes[i].height >= max_size / 64 )
-          max_size = face->available_sizes[i].height * 64;
-    }
-
     start_x = START_X;
     start_y = START_Y;
 
@@ -699,6 +677,7 @@
     }
 
     FTDemo_Set_Current_Charsize( handle, first_size, status.res );
+    FTDemo_Get_Size( handle, &size );
 
     return FT_Err_Ok;
   }
@@ -1421,8 +1400,14 @@
 
     if ( error_code == FT_Err_Ok )
     {
+      int  highlight;
+
+
+      highlight = abs( status.ptsize * status.res -
+                       face->size->metrics.y_ppem * 72 * 64 ) > 36 * 64;
+
       /* ppem */
-      if ( face->face_flags & FT_FACE_FLAG_SCALABLE )
+      if ( FT_IS_SCALABLE( face ) )
         sprintf( buf, "(%.4gppem)",
                       FT_MulFix( face->units_per_EM,
                                  face->size->metrics.y_scale ) / 64.0 );
@@ -1430,7 +1415,8 @@
         sprintf( buf, "(%dppem)",
                       face->size->metrics.y_ppem );
       grWriteCellString( display->bitmap, 8 * x , (line++) * HEADER_HEIGHT,
-                         buf, display->fore_color );
+                         buf, highlight ? display->warn_color
+                                        : display->fore_color );
     }
     else
     {