| /* im_text |
| * |
| * Written on: 20/5/04 |
| * 29/7/04 |
| * - !HAVE_PANGOFT2 was broken, thanks Kenneth |
| * 15/11/04 |
| * - gah, still broken, thanks Stefan |
| * 5/4/06 |
| * - return an error for im_text( "" ) rather than trying to make an |
| * empty image |
| * 2/2/10 |
| * - gtkdoc |
| */ |
| |
| /* |
| |
| This file is part of VIPS. |
| |
| VIPS is free software; you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| */ |
| |
| /* |
| |
| These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk |
| |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif /*HAVE_CONFIG_H*/ |
| #include <vips/intl.h> |
| |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef HAVE_PANGOFT2 |
| #include <pango/pango.h> |
| #include <pango/pangoft2.h> |
| #endif /*HAVE_PANGOFT2*/ |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| #ifdef HAVE_PANGOFT2 |
| |
| static PangoLayout * |
| text_layout_new( PangoContext *context, |
| const char *text, const char *font, int width, int alignment, int dpi ) |
| { |
| PangoLayout *layout; |
| PangoFontDescription *font_description; |
| |
| layout = pango_layout_new( context ); |
| pango_layout_set_markup( layout, text, -1 ); |
| |
| font_description = pango_font_description_from_string( font ); |
| pango_layout_set_font_description( layout, font_description ); |
| pango_font_description_free( font_description ); |
| |
| if( width > 0 ) |
| pango_layout_set_width( layout, width * PANGO_SCALE ); |
| |
| if( alignment < 0 || alignment > 2 ) |
| alignment = PANGO_ALIGN_RIGHT; |
| pango_layout_set_alignment( layout, (PangoAlignment) alignment ); |
| |
| return( layout ); |
| } |
| |
| static int |
| text_ft_to_vips( FT_Bitmap *bitmap, IMAGE *out ) |
| { |
| int y; |
| |
| if( im_outcheck( out ) ) |
| return( -1 ); |
| im_initdesc( out, bitmap->width, bitmap->rows, 1, |
| IM_BBITS_BYTE, IM_BANDFMT_UCHAR, |
| IM_CODING_NONE, IM_TYPE_B_W, 1.0, 1.0, 0, 0 ); |
| if( im_setupout( out ) ) |
| return( -1 ); |
| |
| for( y = 0; y < bitmap->rows; y++ ) |
| if( im_writeline( y, out, |
| (PEL *) bitmap->buffer + y * bitmap->pitch ) ) |
| return( -1 ); |
| |
| return( 0 ); |
| } |
| |
| static int |
| text_layout_render_to_image( PangoLayout *layout, IMAGE *out ) |
| { |
| PangoRectangle logical_rect; |
| FT_Bitmap bitmap; |
| int left; |
| int top; |
| int width; |
| int height; |
| |
| pango_layout_get_extents( layout, NULL, &logical_rect ); |
| |
| #ifdef DEBUG |
| printf( "logical left = %d, top = %d, width = %d, height = %d\n", |
| PANGO_PIXELS( logical_rect.x ), |
| PANGO_PIXELS( logical_rect.y ), |
| PANGO_PIXELS( logical_rect.width ), |
| PANGO_PIXELS( logical_rect.height ) ); |
| #endif /*DEBUG*/ |
| |
| left = PANGO_PIXELS( logical_rect.x ); |
| top = PANGO_PIXELS( logical_rect.y ); |
| width = PANGO_PIXELS( logical_rect.width ); |
| height = PANGO_PIXELS( logical_rect.height ); |
| |
| /* Can happen for "", for example. |
| */ |
| if( width == 0 || height == 0 ) { |
| im_error( "im_text", |
| "%s", _( "no text to render" ) ); |
| return( -1 ); |
| } |
| |
| bitmap.width = width; |
| bitmap.pitch = (bitmap.width + 3) & ~3; |
| bitmap.rows = height; |
| if( !(bitmap.buffer = im_malloc( NULL, bitmap.pitch * bitmap.rows )) ) |
| return( -1 ); |
| bitmap.num_grays = 256; |
| bitmap.pixel_mode = ft_pixel_mode_grays; |
| memset( bitmap.buffer, 0x00, bitmap.pitch * bitmap.rows ); |
| |
| if( pango_layout_get_width( layout ) != -1 ) |
| pango_ft2_render_layout( &bitmap, layout, -left, -top ); |
| else |
| pango_ft2_render_layout( &bitmap, layout, 0, 0 ); |
| if( text_ft_to_vips( &bitmap, out ) ) { |
| im_free( bitmap.buffer ); |
| return( -1 ); |
| } |
| |
| im_free( bitmap.buffer ); |
| |
| return( 0 ); |
| } |
| |
| static int |
| text_render_to_image( PangoContext *context, IMAGE *out, |
| const char *text, const char *font, int width, int alignment, int dpi ) |
| { |
| PangoLayout *layout; |
| |
| if( !(layout = text_layout_new( context, text, font, |
| width, alignment, dpi )) ) |
| return( -1 ); |
| |
| if( text_layout_render_to_image( layout, out ) ) { |
| g_object_unref( layout ); |
| return( -1 ); |
| } |
| |
| g_object_unref( layout ); |
| |
| return( 0 ); |
| } |
| |
| /** |
| * im_text: |
| * @out: output image |
| * @text: utf-8 text string to render |
| * @font: font to render with |
| * @width: render within this many pixels across |
| * @alignment: left/centre/right alignment |
| * @dpi: render at this resolution |
| * |
| * Draw the string @text to an image. @out is a one-band 8-bit |
| * unsigned char image, with 0 for no text and 255 for text. Values inbetween |
| * are used for anti-aliasing. |
| * |
| * @text is the text to render as a UTF-8 string. It can contain Pango markup, |
| * for example "<i>The</i>Guardian". |
| * |
| * @font is the font to render with, selected by fontconfig. Examples might be |
| * "sans 12" or perhaps "bitstream charter bold 10". |
| * |
| * @width is the maximum number of pixels across to draw within. If the |
| * generated text is wider than this, it will wrap to a new line. In this |
| * case, @alignment can be used to set the alignment style for multi-line |
| * text. 0 means left-align, 1 centre, 2 right-align. |
| * |
| * @dpi sets the resolution to render at. "sans 12" at 72 dpi draws characters |
| * approximately 12 pixels high. |
| * |
| * See also: im_make_xy(), im_black(), im_gaussnoise(). |
| * |
| * Returns: 0 on success, -1 on error |
| */ |
| int |
| im_text( IMAGE *out, const char *text, const char *font, |
| int width, int alignment, int dpi ) |
| { |
| static PangoFontMap *fontmap = NULL; |
| PangoContext *context; |
| |
| if( !pango_parse_markup( text, -1, 0, NULL, NULL, NULL, NULL ) ) { |
| im_error( "im_text", |
| "%s", _( "invalid markup in text" ) ); |
| return( -1 ); |
| } |
| |
| /* Just have one of these, ever. It doesn't close properly when we |
| * _unref(), so keep it around for reuse. |
| */ |
| if( !fontmap ) |
| fontmap = pango_ft2_font_map_new(); |
| |
| pango_ft2_font_map_set_resolution( PANGO_FT2_FONT_MAP( fontmap ), |
| dpi, dpi ); |
| context = pango_ft2_font_map_create_context( |
| PANGO_FT2_FONT_MAP( fontmap ) ); |
| |
| if( text_render_to_image( context, out, text, font, |
| width, alignment, dpi ) ) { |
| g_object_unref( context ); |
| return( -1 ); |
| } |
| |
| g_object_unref( context ); |
| |
| return( 0 ); |
| } |
| |
| #else /*!HAVE_PANGOFT2*/ |
| |
| int |
| im_text( IMAGE *out, const char *text, const char *font, |
| int width, int alignment, int dpi ) |
| { |
| im_error( "im_text", |
| "%s", _( "pangoft2 support disabled" ) ); |
| |
| return( -1 ); |
| } |
| |
| #endif /*HAVE_PANGOFT2*/ |
