astext(3x) | AfterStep X11 window manager | astext(3x) |
astext - demonstrates antialiased texturized text rendering libAfterImage/tutorials/ASText
libAfterImage application for rendering texturized text.
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. Opening and
closing fonts. ASText.2. Approximating rendered text size. ASText.3.
Rendering texturized text. ASText.4. Merging foreground and background with
bevel.
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.
#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 =
"ã��ã��è¿~没æ��";
/* 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]
Step 1. Opening and closing fonts.
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.
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 );
create_font_manager(), get_asfont(), destroy_font(),
destroy_font_manager()
libAfterImage/tutorials/ASText.2 [7.2]
Step 2. Approximating rendered text size.
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.
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 ;
}
}
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.
get_text_size(), scale_asimage(), tile_asimage(), ASText.3
libAfterImage/tutorials/ASText.3 [7.3]
Step 3. Rendering texturized text.
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.
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 ;
move_asimage_channel() will only work if both images have exactly
the same size. It will do nothing otherwise.
draw_text(), move_asimage_channel()
libAfterImage/tutorials/ASText.4 [7.4]
Step 4. Merging foreground and background with bevel.
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 (remember - 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.
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 );
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.
ASImageLayer, ASImageBevel, merge_layers()
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