MAN page from Other AfterStep-2.2.2-20060804.i386.rpm
astext
Section: AfterStep X11 window manager (1)
Updated: AfterStep v.2.2.2
Index NAME
astext - demonstrates antialiased texturized text renderinglibAfterImage/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 alsosurround rendered text with beveled frame, creating an illusion of abutton.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] ); printf( " [-c text_color] [-b background_color]); printf( " [-T foreground_texture] " "[-B background_image]); printf( " [-r foreground_resize_type] " "[-R background_resize_type]); printf( " [-m ]); printf( " Where: font - TrueType font's filename or X font spec or " "alias;); printf( " size - size in points for TrueType fonts;); printf( " text - text to be drawn;); printf( " 3D_style - 3D style of text. " "One of the following:); printf( " 0 - plain 2D tetx, 1 - embossed, 2 - sunken, " "3 - shade above,); printf( " 4 - shade below, 5 - embossed thick, " "6 - sunken thick.); printf( " 7 - ouline above, 8 - ouline below, " "9 - full ouline.); printf( " resize_type - tells how texture/image should be " "transformed to fit); printf( " the text size. Could be: scale or tile." "Default is tile); printf( " -m make font monospaced. );}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 jumpsver The Lazy Fox, "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); } 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 ;} SYNOPSIS
Step 1. Openning and closing fonts.
DESCRIPTION
Before any text can be rendered using libAfterImage - desired fonthas to be opened for use. Font opening process is two-step. At firstwe need to create font manager ( ASFontManager ). That is done once,and same font manager can be used throughout entire application. Itcontains information about used external libraries, hash of openedfonts, 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 seeif the font has been loaded already, and if not - then it will loadthe 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 sizeof the image, that rendered text will occupy, So that window can becreated of appropriate size, and othe interface elements laid outaccordingly. get_text_size() could be used to obtain rendered textsize 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 textureto fit the text. In order to texturize the text - we need to userendered text as an alpha channel on texture image. That can easilybe 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 bylibAfterImage consists of substitution of the alpha channel of thetexture, with rendered text. That is possible since all the text isrendered into alpha channel only. move_asimage_channel() call is usedto accomplish this operation. This call actually removes channeldata from the original image and stores it in destination image. Ifthere was something in destination image's channel already - it willbe destroyed.All kinds of nifty things could be done using this call, actually.Like, for example, rendered text can be moved into green channel ofthe 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 thesame 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 texturizedtext. At this point we need to merge them together by alpha-blendingtext over background (remeber - text is alpha-channel of foregroundtexture). At the same time we would like to add some nice bevel borderaround entire image. To accomplish that task all we have to do is setupASImageLayer structure for both background and foreground, and applymerge_layers on them. When it is done - we no longer need originalimages 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 imagesize, hence we have to use width+BEVEL_ADDON , height+BEVEL_ADDON asdesired image size.
SEE ALSO
ASImageLayer, ASImageBevel, merge_layers()
Index
- NAME
- NAMEASText
- SYNOPSIS
- DESCRIPTION
- SEE ALSO
- SOURCE
- SYNOPSIS
- DESCRIPTION
- EXAMPLE
- SEE ALSO
- SYNOPSIS
- DESCRIPTION
- EXAMPLE
- NOTES
- SEE ALSO
- SYNOPSIS
- DESCRIPTION
- EXAMPLE
- NOTES
- SEE ALSO
- SYNOPSIS
- DESCRIPTION
- EXAMPLE
- NOTES
- SEE ALSO
This document was created byman2html,using the manual pages.
