astext.3x

Langue: en

Version: AfterStep v.2.2.9 (ubuntu - 24/10/10)

Section: 3 (Bibliothèques de fonctions)

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

 #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[])
 {
     Display *dpy = NULL;
     ASVisual *asv = NULL ;
     int screen = 0, depth = 0;
     char *font_name = "test.ttf";
     int size = 32 ;
 #if 0
     char *text = "  è¿~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);
             dpy = NULL;
 #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 useful 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()