astext(1)                AfterStep X11 window manager                astext(1)



NAME
       astext - demonstrates antialiased texturized text rendering
       libAfterImage/tutorials/ASText

NAMEASText
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
       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] 0);
           printf( "                  [-c text_color] [-b background_color]0);
           printf( "                  [-T foreground_texture] "
                   "[-B background_image]0);
           printf( "                  [-r foreground_resize_type] "
                   "[-R background_resize_type]0);
           printf( "                  [-m ]0);
           printf( "  Where: font - TrueType font's filename or X font spec or "
                   "alias;0);
           printf( "         size - size in points for TrueType fonts;0);
           printf( "         text - text to be drawn;0);
           printf( "         3D_style - 3D style of text. "
                   "One of the following:0);
           printf( "             0 - plain 2D tetx, 1 - embossed, 2 - sunken, "
                   "3 - shade above,0);
           printf( "             4 - shade below, 5 - embossed thick, "
                   "6 - sunken thick.0);
           printf( "             7 - ouline above, 8 - ouline below, "
                   "9 - full ouline.0);
           printf( "         resize_type - tells how texture/image should be "
                   "transformed to fit0);
           printf( "         the text size. Could be: scale or tile."
                   "Default is tile0);
           printf( "         -m make font monospaced. 0);


       }

       int main(int argc, char* argv[])
       {
           Display *dpy = NULL;
           ASVisual *asv = NULL ;
           int screen = 0, depth = 0;
           char *font_name = "test.ttf";
           int size = 32 ;
       #if 0
           char *text = "aaecae2iae";  /* chinese */
       #else
           char *text = "Smart Brown Dog jumps0ver The Lazy Fox,0
                        "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
                           "Falling back to
               font = get_asfont( fontman, "fixed", 0, size, ASF_GuessWho );
               if( font == NULL )
               {
                   show_error("font
                   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);
                   dpy = NULL;
       #else
                   /* writing result into the file */
                   ASImage2file( rendered_im, NULL, "astext.jpg", ASIT_Jpeg,
                                 NULL );
                   destroy_asimage( &rendered_im );
       #endif
               }
           }
           return 0 ;
       }

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
                                   Aborting.");
                   return 1;
               }
           }
           ...
           destroy_font( font );
           destroy_font_manager( fontman, False );

SEE ALSO
       create_font_manager(), get_asfont(), destroy_font(),
       destroy_font_manager()

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

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()

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()



3rd Berkeley Distribution      AfterStep v.2.2.9                     astext(1)
