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# AFTERImage example 7: Text rendering

demonstrates antialiased texturized text rendering

libAfterImage/tutorials/ASText

- NAME

  ASText

- SYNOPSIS

      libAfterImage application for rendering texturized text.

- DESCRIPTION

      In this tutorial we will attempt to render arbitrary text in window,
      with optional texturized background and foreground. We shall also
      surround rendered text with beveled frame, creating an illusion of a
      button.

      New steps described in this tutorial are :
      ASText.1. Openning and closing fonts.
      ASText.2. Approximating rendered text size.
      ASText.3. Rendering texturized text.
      ASText.4. Merging foreground and background with bevel.

- SEE ALSO

      Tutorial 1: ASView  - explanation of basic steps needed to use
                            libAfterImage and some other simple things.
      Tutorial 2: ASScale - image scaling basics.
      Tutorial 3: ASTile  - image tiling and tinting.
      Tutorial 4: ASMerge - scaling and blending of arbitrary number of
                            images.
      Tutorial 5: ASGrad  - drawing multipoint linear gradients.
      Tutorial 6: ASFlip  - image rotation.

- SOURCE

      #include "../afterbase.h"
      #include "../afterimage.h"
      #include "common.h"

      /* Usage:  astext [-f font] [-s size] [-t text] [-S 3D_style]
                        [-c text_color] [-b background_color]
                        [-T foreground_texture] [-B background_image]
                        [-r foreground_resize_type] [-R background_resize_type]
       */

      #define BEVEL_HI_WIDTH 20
      #define BEVEL_LO_WIDTH 30
      #define BEVEL_ADDON    (BEVEL_HI_WIDTH+BEVEL_LO_WIDTH)

      void usage()
      {
          printf( "  Usage:   astext [-h] [-f font] [-s size] [-t text] "
                  "[-S 3D_style] \n");
          printf( "                  [-c text_color] [-b background_color]\n");
          printf( "                  [-T foreground_texture] "
                  "[-B background_image]\n");
          printf( "                  [-r foreground_resize_type] "
                  "[-R background_resize_type]\n");
          printf( "                  [-m ]\n");
          printf( "  Where: font - TrueType font's filename or X font spec or "
                  "alias;\n");
          printf( "         size - size in points for TrueType fonts;\n");
          printf( "         text - text to be drawn;\n");
          printf( "         3D_style - 3D style of text. "
                  "One of the following:\n");
          printf( "             0 - plain 2D tetx, 1 - embossed, 2 - sunken, "
                  "3 - shade above,\n");
          printf( "             4 - shade below, 5 - embossed thick, "
                  "6 - sunken thick.\n");
          printf( "             7 - ouline above, 8 - ouline below, "
                  "9 - full ouline.\n");
          printf( "         resize_type - tells how texture/image should be "
                  "transformed to fit\n");
          printf( "         the text size. Could be: scale or tile."
                  "Default is tile\n");
          printf( "         -m make font monospaced. \n");

      }

      int main(int argc, char* argv[])
      {
          ASVisual *asv = NULL ;
          int screen = 0, depth = 0;
          char *font_name = "test.ttf";
          int size = 32 ;
      #if 0
          char *text = "　　还没有";  /* chinese */
      #else
          char *text = "Smart Brown Dog jumps\nOver The Lazy Fox,\n"
                       "and falls into the ditch.";
      #endif
          ARGB32 text_color = ARGB32_White, back_color = ARGB32_Black;
          char *text_color_name = "#FFFFFFFF", *back_color_name = "#FF000000";
          char *fore_image_file = "fore.xpm" ;
          char *back_image_file = "back.xpm" ;
          Bool scale_fore_image = False, scale_back_image = False ;
          ASImage *fore_im = NULL, *back_im = NULL;
          ASImage *text_im = NULL ;
          struct ASFontManager *fontman = NULL;
          struct ASFont  *font = NULL;
          unsigned int width, height ;
          int i ;
          int text_margin = size/2 ;
          Bool monospaced = False ;
          char * font_path = NULL;
          ASTextAttributes attr = {ASTA_VERSION_1, ASTA_UseTabStops,
                                   AST_ShadeBelow, ASCT_UTF8, 8, 0,
                                   NULL, 0, ARGB32_White };

          /* see ASView.1 : */
          set_application_name( argv[0] );
      #if (HAVE_AFTERBASE_FLAG==1)
          set_output_threshold(OUTPUT_LEVEL_DEBUG);
      #endif

          if( argc == 1 )
              usage();
          else for( i = 1 ; i < argc ; i++ )
          {
              if( strncmp( argv[i], "-h", 2 ) == 0 )
              {
                  usage();
                  return 0;
              }
              if( strncmp( argv[i], "-m", 2 ) == 0 )
              {
                  monospaced = True ;
              }else if( i+1 < argc )
              {
                  if( strncmp( argv[i], "-f", 2 ) == 0 )
                      font_name = argv[i+1] ;
                  else if( strncmp( argv[i], "-s", 2 ) == 0 )
                  {
                      size = atoi(argv[i+1]);
                      text_margin = size/2 ;
                  }else if( strncmp( argv[i], "-t", 2 ) == 0 )
                      text = argv[i+1] ;
                  else if( strncmp( argv[i], "-S", 2 ) == 0 )
                  {
                      attr.type = atoi(argv[i+1]);
                      if( attr.type >= AST_3DTypes )
                      {
                          show_error( "3D type is wrong. "
                                      "Using 2D Plain instead.");
                          attr.type = AST_Plain ;
                      }

                  }else if( strncmp( argv[i], "-c", 2 ) == 0 )
                      text_color_name = argv[i+1] ;
                  else if( strncmp( argv[i], "-b", 2 ) == 0 )
                      back_color_name = argv[i+1] ;
                  else if( strncmp( argv[i], "-T", 2 ) == 0 )
                      fore_image_file = argv[i+1] ;
                  else if( strncmp( argv[i], "-B", 2 ) == 0 )
                      back_image_file = argv[i+1] ;
                  else if( strncmp( argv[i], "-r", 2 ) == 0 )
                      scale_fore_image = (strcmp( argv[i+1], "scale") == 0);
                  else if( strncmp( argv[i], "-R", 2 ) == 0 )
                      scale_back_image = (strcmp( argv[i+1], "scale") == 0);
              }
          }

      #ifndef X_DISPLAY_MISSING
          dpy = XOpenDisplay(NULL);
          _XA_WM_DELETE_WINDOW = XInternAtom( dpy, "WM_DELETE_WINDOW", False);
          screen = DefaultScreen(dpy);
          depth = DefaultDepth( dpy, screen );
      #endif

          /* see ASText.1 : */
          if( getenv("FONT_PATH") != NULL )
          {
              font_path = safemalloc( strlen(getenv("FONT_PATH"))+1+2+1);
              sprintf( font_path, "%s:./", getenv("FONT_PATH") );

          }
          if( (fontman = create_font_manager( dpy, font_path, NULL )) != NULL )
              font = get_asfont( fontman, font_name, 0, size,
                                 ASF_GuessWho|(monospaced?ASF_Monospaced:0) );

          if( font == NULL )
          {
              show_error( "unable to load requested font \"%s\". "
                          "Falling back to \"fixed\".", font_name );
              font = get_asfont( fontman, "fixed", 0, size, ASF_GuessWho );
              if( font == NULL )
              {
                  show_error("font \"fixed\" is not available either. Aborting.");
                  return 1;
              }
          }

          /*for( i = 0 ; i < 128 ; ++i )
              print_asglyph( stderr, font, i); */

          parse_argb_color( text_color_name, &text_color );
          parse_argb_color( back_color_name, &back_color );

          attr.fore_color = text_color ;
          if( attr.type >= AST_OutlineAbove )
              fore_image_file = NULL ;

          /* see ASView.3 : */
          asv = create_asvisual( dpy, screen, depth, NULL );

          /* see ASText.2 : */
          /*set_asfont_glyph_spacing( font, 10, 40 );*/
          /*Simple way:get_text_size( text, font, attr.type, &width, &height ); */
          /*Fancy way : */
          get_fancy_text_size( text, font, &attr, &width, &height, 0, NULL );
      /* show_progress( "extimated text size = %dx%d", width, height ); */

          if( fore_image_file )
          {
              ASImage *tmp = file2ASImage( fore_image_file, 0xFFFFFFFF,
                                           SCREEN_GAMMA, 0, getenv("IMAGE_PATH"), NULL );
              if( tmp )
              {
                  if( tmp->width != width || tmp->height != height )
                  {   /* see ASScale.2 : */
                      if( scale_fore_image )
                          fore_im = scale_asimage( asv, tmp, width, height,
                                                   ASA_ASImage, 0,
                                                   ASIMAGE_QUALITY_DEFAULT );
                      else
                          fore_im = tile_asimage( asv, tmp, 0, 0,
                                                  width, height, 0,
                                                  ASA_ASImage, 0,
                                                  ASIMAGE_QUALITY_DEFAULT );
                      destroy_asimage( &tmp );
                  }else
                      fore_im = tmp ;
              }else
                  fore_im = NULL ;
          }
          width  += text_margin*2 + BEVEL_ADDON;
          height += text_margin*2 + BEVEL_ADDON;
          if( back_image_file )
          { /* see ASView.2 : */
              ASImage *tmp = file2ASImage( back_image_file, 0xFFFFFFFF,
                                          SCREEN_GAMMA, 0, getenv("IMAGE_PATH"), NULL );
              if( tmp )
              {
                  if( scale_back_image &&
                      (tmp->width != width || tmp->height != height) )
                  {   /* see ASScale.2 : */
                      back_im = scale_asimage( asv, tmp, width, height,
                                               ASA_ASImage, 0,
                                               ASIMAGE_QUALITY_DEFAULT );
                      destroy_asimage( &tmp );
                  }else
                      back_im = tmp ;
              }else
                  back_im = NULL ;
          }

          /* see ASText.3 : */
          /* simple way : text_im = draw_text( text, font, attr.type, 0 ); */
          text_im = draw_fancy_text( text, font, &attr, 0, 0 );
          if( fore_im )
          {
              move_asimage_channel( fore_im, IC_ALPHA, text_im, IC_ALPHA );
              destroy_asimage( &text_im );
          }else
              fore_im = text_im ;

          /* see ASText.1 : */
          release_font( font );
          destroy_font_manager( fontman, False );

          if( fore_im )
          {
              ASImage *rendered_im ;
              ASImageLayer layers[2] ;
              ASImageBevel bevel = {0/*BEVEL_SOLID_INLINE*/, 0xFFDDDDDD,
                                    0xFF555555, 0xFFFFFFFF,
                                    0xFF777777, 0xFF222222,
                                    BEVEL_HI_WIDTH, BEVEL_HI_WIDTH,
                                    BEVEL_LO_WIDTH, BEVEL_LO_WIDTH,
                                    BEVEL_HI_WIDTH, BEVEL_HI_WIDTH,
                                    BEVEL_LO_WIDTH, BEVEL_LO_WIDTH } ;

              /* see ASText.4 : */
              init_image_layers( &(layers[0]), 2 );
              if( back_im )
                  back_im->back_color = back_color ;
              if( fore_im )
                  fore_im->back_color = text_color ;
              layers[0].im = back_im ;
              layers[0].dst_x = 0 ;
              layers[0].dst_y = 0 ;
              layers[0].clip_width = width ;
              layers[0].clip_height = height ;
              layers[0].bevel = &bevel ;
              layers[1].im = fore_im ;
              layers[1].dst_x = text_margin+BEVEL_HI_WIDTH*2 ;
              layers[1].dst_y = text_margin+
                                  MIN( (int)text_margin,
                                      ((int)font->max_height-
                                       (int)font->max_ascend))/2+
                                       BEVEL_HI_WIDTH*2;
              if( fore_im )
              {
                  layers[1].clip_width = fore_im->width ;
                  layers[1].clip_height = fore_im->height ;
              }
              rendered_im = merge_layers( asv, &(layers[0]), 2,
                                          width+BEVEL_ADDON, height+BEVEL_ADDON,
      #ifndef X_DISPLAY_MISSING
                                          ASA_XImage,
      #else
                                          ASA_ASImage,
      #endif
                                          0, ASIMAGE_QUALITY_DEFAULT);
              destroy_asimage( &fore_im );
              destroy_asimage( &back_im );

              if( rendered_im )
              {
      #ifndef X_DISPLAY_MISSING
                  Window w;
                  /* see ASView.4 : */
                  w = create_top_level_window( asv, DefaultRootWindow(dpy),
                                               32, 32,
                                               width+BEVEL_ADDON,
                                               height+BEVEL_ADDON,
                                               1, 0, NULL,
                                               "ASText", text );
                  if( w != None )
                  {
                      Pixmap p ;

                      XMapRaised   (dpy, w);

                      /* see ASView.5 : */
                      p = asimage2pixmap( asv, DefaultRootWindow(dpy),
                                          rendered_im, NULL, True );
                      destroy_asimage( &rendered_im );
                      /* see common.c: set_window_background_and_free() : */
                      p = set_window_background_and_free( w, p );
                      /* see common.c: wait_closedown() : */
                      wait_closedown(w);
                  }
                  if( dpy )
                      XCloseDisplay (dpy);
      #else
                  /* writing result into the file */
                  ASImage2file( rendered_im, NULL, "astext.jpg", ASIT_Jpeg,
                                NULL );
                  destroy_asimage( &rendered_im );
      #endif
              }
          }
          return 0 ;
      }

libAfterImage/tutorials/ASText.1 [7.1]

- SYNOPSIS

      Step 1. Openning and closing fonts.

- DESCRIPTION

      Before any text can be rendered using libAfterImage - desired font
      has to be opened for use. Font opening process is two-step. At first
      we need to create font manager ( ASFontManager ). That is done once,
      and same font manager can be used throughout entire application. It
      contains information about used external libraries, hash of opened
      fonts, and some other info.

      When ASFontManager is created it could be used to obtain actuall fonts.
      get_asfont() call is used to query cahce of the ASFontManager, to see
      if the font has been loaded already, and if not - then it will load
      the font and prepare it for drawing.

- EXAMPLE

          if( (fontman = create_font_manager( dpy, NULL, NULL )) != NULL )
              font = get_asfont( fontman, font_name, 0, size, ASF_GuessWho);
          if( font == NULL )
          {
              font = get_asfont( fontman, "fixed", 0, size, ASF_GuessWho );
              if( font == NULL )
              {
                  show_error( "font \"fixed\" is not available either.
                                  Aborting.");
                  return 1;
              }
          }
          ...
          destroy_font( font );
          destroy_font_manager( fontman, False );

- SEE ALSO

      create_font_manager(), get_asfont(), destroy_font(),
      destroy_font_manager()

libAfterImage/tutorials/ASText.2 [7.2]

- SYNOPSIS

      Step 2. Approximating rendered text size.

- DESCRIPTION

      Prior to actually drawing the text it is usefull to estimate the size
      of the image, that rendered text will occupy, So that window can be
      created of appropriate size, and othe interface elements laid out
      accordingly. get_text_size() could be used to obtain rendered text
      size without actually drawing it.

- EXAMPLE

          get_text_size( text, font, type_3d, &width, &height );
          if( fore_image_file )
          {
              ASImage *tmp = file2ASImage( fore_image_file, 0xFFFFFFFF,
                                           SCREEN_GAMMA, 0, NULL );
              if( tmp )
              {
                  if( tmp->width != width || tmp->height != height )
                  {
                      if( scale_fore_image )
                          fore_im = scale_asimage( asv, tmp, width, height,
                                                   ASA_ASImage, 0,
                                                   ASIMAGE_QUALITY_DEFAULT );
                      else
                          fore_im = tile_asimage( asv, tmp, 0, 0,
                                                  width, height, 0,
                                                  ASA_ASImage, 0,
                                                  ASIMAGE_QUALITY_DEFAULT );
                      destroy_asimage( &tmp );
                  }else
                      fore_im = tmp ;
              }
          }

- NOTES

      In this particular example we either tile or scale foreground texture
      to fit the text. In order to texturize the text  - we need to use
      rendered text as an alpha channel on texture image. That can easily
      be done only if both images are the same size.

- SEE ALSO

      get_text_size(), scale_asimage(), tile_asimage(), ASText.3

libAfterImage/tutorials/ASText.3 [7.3]

- SYNOPSIS

      Step 3. Rendering texturized text.

- DESCRIPTION

      The most effective text texturization technique provided by
      libAfterImage consists of substitution of the alpha channel of the
      texture, with rendered text. That is possible since all the text is
      rendered into alpha channel only. move_asimage_channel() call is used
      to accomplish this operation. This call actually removes channel
      data from the original image and stores it in destination image. If
      there was something in destination image's channel  already - it will
      be destroyed.
      All kinds of nifty things could be done using this call, actually.
      Like, for example, rendered text can be moved into green channel of
      the texture, creating funky effect.

- EXAMPLE

          text_im = draw_text( text, font, 0 );
          if( fore_im )
          {
              move_asimage_channel( fore_im, IC_ALPHA, text_im, IC_ALPHA );
              destroy_asimage( &text_im );
          }else
              fore_im = text_im ;

- NOTES

      move_asimage_channel() will only work if both images have exactly the
      same size. It will do nothing otherwise.

- SEE ALSO

      draw_text(), move_asimage_channel()

libAfterImage/tutorials/ASText.4 [7.4]

- SYNOPSIS

      Step 4. Merging foreground and background with bevel.

- DESCRIPTION

      On this step we have 2 images ready for us - background and texturized
      text. At this point we need to merge them together by alpha-blending
      text over background (remeber - text is alpha-channel of foreground
      texture). At the same time we would like to add some nice bevel border
      around entire image. To accomplish that task all we have to do is setup
      ASImageLayer structure for both background and foreground, and apply
      merge_layers on them. When it is done - we no longer need original
      images and we destroy them to free up some memory.

- EXAMPLE

          ASImageLayer layers[2] ;
          ASImageBevel bevel = {0, 0xFFDDDDDD, 0xFF555555,
                                   0xFFFFFFFF, 0xFF777777, 0xFF444444,
                                BEVEL_HI_WIDTH, BEVEL_HI_WIDTH,
                                BEVEL_LO_WIDTH, BEVEL_LO_WIDTH,
                                BEVEL_HI_WIDTH, BEVEL_HI_WIDTH,
                                BEVEL_LO_WIDTH, BEVEL_LO_WIDTH } ;
          memset( &(layers[0]), 0x00, sizeof(layers) );
          layers[0].im = back_im ;
          layers[0].clip_width = width ;
          layers[0].clip_height = height ;
          layers[0].merge_scanlines = alphablend_scanlines ;
          layers[0].bevel = &bevel ;
          layers[1].im = fore_im ;
          layers[1].dst_x = TEXT_MARGIN ;
          layers[1].dst_y = TEXT_MARGIN ;
          layers[1].clip_width = fore_im->width ;
          layers[1].clip_height = fore_im->height ;
          layers[1].back_color = text_color ;
          layers[1].merge_scanlines = alphablend_scanlines ;
          rendered_im = merge_layers( asv, &(layers[0]), 2,
                                      width+BEVEL_ADDON, height+BEVEL_ADDON,
                                      ASA_XImage, 0, ASIMAGE_QUALITY_DEFAULT);
          destroy_asimage( &fore_im );
          destroy_asimage( &back_im );

- NOTES

      We have to remember that outside bevel border will addup to the image
      size, hence we have to use width+BEVEL_ADDON , height+BEVEL_ADDON as
      desired image size.

- SEE ALSO

      ASImageLayer, ASImageBevel, merge_layers()

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