[freetype2-demos] GSoC-2020-anuj 8169d8c 2/5: [ftsdf] Added all the events.

[Anuj Verma]

branch: GSoC-2020-anuj
commit 8169d8c0aecc374b8f9e3d365b555c60da8d13bd
Author: Anuj Verma <anujv@iitbhilai.ac.in>
Commit: Anuj Verma <anujv@iitbhilai.ac.in>

    [ftsdf] Added all the events.
    
    * src/ftsdf.c (event_): Added all the events that are triggered during the 
demo.
---
 src/ftsdf.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

diff --git a/src/ftsdf.c b/src/ftsdf.c
index d1726b6..3f1d50b 100644
--- a/src/ftsdf.c
+++ b/src/ftsdf.c
@@ -72,4 +72,120 @@
     /* edge              */ 0.2f
   };
 
+  static FT_Error
+  event_font_update()
+  {
+    /* This event is triggered when the prooperties of the rasterizer */
+    /* is updated or the glyph index / size is updated.               */
+    FT_Error  error = FT_Err_Ok;
+    clock_t   start, end;
+
+    /* Set various properties of the renderers. */
+    FT_CALL( FT_Property_Set( handle->library, "bsdf", "spread", 
&status.spread ) );
+    FT_CALL( FT_Property_Set( handle->library, "sdf", "spread", &status.spread 
) );
+    FT_CALL( FT_Property_Set( handle->library, "sdf", "overlaps", 
&status.overlaps ) );
+
+    /* Set pixel size and load the glyph index. */
+    FT_CALL( FT_Set_Pixel_Sizes( status.face, 0, status.ptsize ) );
+    FT_CALL( FT_Load_Glyph( status.face, status.glyph_index, FT_LOAD_DEFAULT ) 
);
+
+    /* This is just to measure the generation time. */
+    start = clock();
+
+    /* Finally render the glyph. To force the `bsdf' renderer (i.e. to */
+    /* generate SDF from bitmap) we must render the glyph first using  */
+    /* the smooth or the monochrome FreeType rasterizer.               */
+    if ( status.use_bitmap )
+      FT_CALL( FT_Render_Glyph( status.face->glyph, FT_RENDER_MODE_NORMAL ) );
+    FT_CALL( FT_Render_Glyph( status.face->glyph, FT_RENDER_MODE_SDF ) );
+
+    /* Compute and print the generation time. */
+    end = clock();
+
+    status.generation_time = ( (float)( end - start ) / (float)CLOCKS_PER_SEC 
) * 1000.0f;
+
+    printf( "Generation Time: %.0f ms\n", status.generation_time );
+
+  Exit:
+    return error;
+  }
+
+  static void
+  event_color_change()
+  {
+    /* This event is triggered when we create a new display, */
+    /* in this event we set various colors for the display   */ 
+    /* buffer.                                               */
+    display->back_color = grFindColor( display->bitmap,  0,  0,  0, 0xff );
+    display->fore_color = grFindColor( display->bitmap, 255, 255, 255, 0xff );
+    display->warn_color = grFindColor( display->bitmap,  0, 255, 255, 0xff );
+  }
+
+  static void
+  event_help()
+  {
+    /* This event is triggered when the user presses the help */
+    /* screen button that is either '?' or F1. It basically   */
+    /* prints the list of keys along with thier usage to the  */
+    /* display window.                                        */
+
+    grEvent  dummy;
+
+    /* For help screen we use a slightly gray color instead of */
+    /* completely black background.                            */
+    display->back_color = grFindColor( display->bitmap, 30, 30, 30, 0xff );
+    FTDemo_Display_Clear( display );
+    display->back_color = grFindColor( display->bitmap,  0,  0,  0, 0xff );
+
+    /* Set some properties. */
+    grSetLineHeight( 10 );
+    grGotoxy( 0, 0 );
+    grSetMargin( 2, 1 );
+
+    /* Set the text color. (kind of purple) */
+    grGotobitmapColor( display->bitmap, 204, 153, 204, 255 );
+
+    /* Print the keys and usage. */
+    grWriteln( "Signed Distnace Field Viewer" );
+    grLn();
+    grWriteln( "Use the following keys:" );
+    grWriteln( "-----------------------" );
+    grLn();
+    grWriteln( "  F1 or ? or /       : display this help screen" );
+    grLn();
+    grWriteln( "  b                  : Toggle between bitmap/outline to be 
used for generating" );
+    grLn();
+    grWriteln( "  z, x               : Zoom/Scale Up and Down" );
+    grLn();
+    grWriteln( "  Up, Down Arrow     : Adjust glyph's point size by 1" );
+    grWriteln( "  PgUp, PgDn         : Adjust glyph's point size by 25" );
+    grLn();
+    grWriteln( "  Left, Right Arrow  : Adjust glyph index by 1" );
+    grWriteln( "  F5, F6             : Adjust glyph index by 50" );
+    grWriteln( "  F7, F8             : Adjust glyph index by 500" );
+    grLn();
+    grWriteln( "  o, l               : Adjust spread size by 1" );
+    grLn();
+    grWriteln( "  w, s               : Move glyph Up/Down" );
+    grWriteln( "  a, d               : Move glyph Left/right" );
+    grLn();
+    grWriteln( "  f                  : Toggle between bilinear/nearest 
filtering" );
+    grLn();
+    grWriteln( "  m                  : Toggle overlapping support" );
+    grLn();
+    grWriteln( "Reconstructing Image from SDF" );
+    grWriteln( "-----------------------------" );
+    grWriteln( "  r                  : Toggle between reconstruction/raw view" 
);
+    grWriteln( "  i, k               : Adjust width by 1 (makes the text 
bolder/thinner)" );
+    grWriteln( "  u, j               : Adjust edge by 1 (makes the text 
smoother/sharper)" );
+    grLn();
+    grWriteln( "press any key to exit this help screen" );
+
+    /* Now wait till any key press, otherwise the help screen */
+    /* will only blink and disappear.                         */
+    grRefreshSurface( display->surface );
+    grListenSurface( display->surface, gr_event_key, &dummy );
+  }
+
+
 /* END */