[ft-devel] add italic render mode to ftview.c

[Allan Yang, Jian Hua - SH]

Attachment is my code for add italic render mode to ftview.c, hope it can help 
you. :)


Allan

--patch start--

@@ -60,6 +60,7 @@
   {
     RENDER_MODE_ALL = 0,
     RENDER_MODE_EMBOLDEN,
+    RENDER_MODE_ITALIC,
     RENDER_MODE_STROKE,
     RENDER_MODE_TEXT,
     RENDER_MODE_WATERFALL,
@@ -202,6 +203,96 @@
 
 
   static FT_Error
+  Render_Italic( int  num_indices,
+                 int  first_index )
+  {
+    int       start_x, start_y, step_x, step_y, x, y;
+    int       i;
+    FT_Size   size;
+
+
+    error = FTDemo_Get_Size( handle, &size );
+
+    if ( error )
+    {
+      /* probably a non-existent bitmap font size */
+      return error;
+    }
+
+    INIT_SIZE( size, start_x, start_y, step_x, step_y, x, y );
+
+    i = first_index;
+
+    while ( i < num_indices )
+    {
+      int           gindex;
+      FT_Face       face = size->face;
+
+      if ( handle->encoding == FT_ENCODING_NONE )
+        gindex = i;
+      else
+        gindex = FTDemo_Get_Index( handle, i );
+
+      error = FT_Load_Glyph( face, gindex, handle->load_flags );
+      if ( !error )
+      {
+        FT_Matrix      shear;
+        FT_Outline*    outline;
+
+
+        
/**********************************************************************/
+        /*                                                                    
*/
+        /*  2*2 affine transformation matrix, 16.16 fixed float format        
*/
+        /*                                                                    
*/
+        /*  Shear matrix:                                                     
*/
+        /*                                                                    
*/
+        /*         ┌   ┐   ┌      ┐    ┌   ┐                            */
+        /*         │ x'│ = │ 1, k │ × │ x │   <==>    x' = x + ky      */
+        /*         │ y'│   │ 0, 1 │    │ y │           y' = y           */
+        /*         └   ┘   └      ┘    └   ┘                            */
+        /*                                                                    
*/
+        /*         outline'    shear       outline                            
*/
+        /*                                                                    
*/
+        /*                                                                    
*/
+        /*  Shear angle is 12 degree, so:                                     
*/
+        /*                                                                    
*/
+        /*         k = math.tan(math.radians(12))       (Python syntax)       
*/
+        /*           = 0.2126                                                 
*/
+        /*                                                                    
*/
+        
/**********************************************************************/
+               shear.xx = 1 << 16;
+               shear.xy = ( FT_Fixed ) ( 0.2126f * ( 1 << 16 ) );
+               shear.yx = 0;
+               shear.yy = 1 << 16;
+
+        outline  = &( face->glyph )->outline;
+
+        FT_Outline_Transform( outline, &shear );
+
+        error = FTDemo_Draw_Slot( handle, display, face->glyph, &x, &y );
+
+        if ( error )
+          status.Fail++;
+        else if ( X_TOO_LONG( x, size, display ) )
+        {
+          x  = start_x;
+          y += step_y;
+
+          if ( Y_TOO_LONG( y, size, display ) )
+            break;
+        }
+      }
+      else
+        status.Fail++;
+
+      i++;
+    }
+
+    return error;
+  }
+
+
+  static FT_Error
   Render_Embolden( int  num_indices,
                    int  first_index )
   {
@@ -227,6 +318,7 @@
       int           gindex;
       FT_Face       face = size->face;
 
+
       if ( handle->encoding == FT_ENCODING_NONE )
         gindex = i;
       else
@@ -502,7 +594,7 @@
     grLn();
     grWriteln( "  L          : cycle through LCD modes" );
     grWriteln( "  space      : toggle rendering mode" );
-    grWriteln( "  1-5        : select rendering mode" );
+    grWriteln( "  1-6        : select rendering mode" );
     grLn();
     grWriteln( "  G          : show gamma ramp" );
     grWriteln( "  g          : increase gamma by 0.1" );
@@ -665,6 +757,9 @@
     case RENDER_MODE_EMBOLDEN:
       status.header = (char *)"rendering emboldened text";
       break;
+    case RENDER_MODE_ITALIC:
+      status.header = (char *)"rendering italiced text";
+      break;
     case RENDER_MODE_STROKE:
       status.header = (char *)"rendering stroked text";
       break;
@@ -1125,6 +1220,10 @@
 
       case RENDER_MODE_EMBOLDEN:
         error = Render_Embolden( handle->current_font->num_indices, status.Num 
);
+        break;
+
+      case RENDER_MODE_ITALIC:
+        error = Render_Italic( handle->current_font->num_indices, status.Num );
         break;
 
       case RENDER_MODE_STROKE:

--patch end--

ftview.c
Description: ftview.c

ftview_italic_patch.txt
Description: ftview_italic_patch.txt