/*
 * Derived from:
 *   ft-text-vertical-layout-type1.c
 *   cairo_snippets_image.c
 *   cairo_snippets_pdf.c
 *   cairo_snippets_ps.c
 * Original Author:
 *   Jinghua Luo
 *   Carl D. Worth
 *   Øyvind Kolås

 * Usage:
   gcc `pkg-config --cflags cairo freetype2` `pkg-config --libs cairo freetype2` cairo_bitmap_font_scale.c -o cairo_bitmap_font_scale
 */

#define WIDTH  600
#define HEIGHT 400
#define TEXT "Text"

#include <cairo.h>
#include <cairo-ft.h>
#include <cairo-pdf.h>
#include <cairo-ps.h>
#include <math.h>

static cairo_status_t
create_scaled_font (cairo_t * cr,
		    cairo_scaled_font_t **out)
{
    FcPattern *pattern, *resolved;
    FcResult result;
    cairo_font_face_t *font_face;
    cairo_scaled_font_t *scaled_font;
    cairo_font_options_t *font_options;
    cairo_matrix_t font_matrix, ctm;
    cairo_status_t status;
    double pixel_size;

    font_options = cairo_font_options_create ();

    cairo_get_font_options (cr, font_options);

    pattern = FcPatternCreate ();
    if (pattern == NULL)
	return CAIRO_STATUS_NO_MEMORY;

    FcPatternAddString (pattern, FC_FAMILY, (FcChar8 *)"Courier");
    FcPatternAddDouble (pattern, FC_PIXEL_SIZE, 30);
    FcConfigSubstitute (NULL, pattern, FcMatchPattern);

    cairo_ft_font_options_substitute (font_options, pattern);

    FcDefaultSubstitute (pattern);
    resolved = FcFontMatch (NULL, pattern, &result);
    if (resolved == NULL) {
	FcPatternDestroy (pattern);
	return CAIRO_STATUS_NO_MEMORY;
    }

    /* set layout to vertical */
    FcPatternDel (resolved, FC_VERTICAL_LAYOUT);
    FcPatternAddBool (resolved, FC_VERTICAL_LAYOUT, FcTrue);

    FcPatternGetDouble (resolved, FC_PIXEL_SIZE, 0, &pixel_size);

    font_face = cairo_ft_font_face_create_for_pattern (resolved);

    cairo_matrix_init_translate (&font_matrix, 10, 30);
    cairo_matrix_rotate (&font_matrix, M_PI_2/3);
    cairo_matrix_scale (&font_matrix, pixel_size, pixel_size);

    cairo_get_matrix (cr, &ctm);

    scaled_font = cairo_scaled_font_create (font_face,
					    &font_matrix,
					    &ctm,
					    font_options);

    cairo_font_options_destroy (font_options);
    cairo_font_face_destroy (font_face);
    FcPatternDestroy (pattern);
    FcPatternDestroy (resolved);

    status = cairo_scaled_font_status (scaled_font);
    if (status) {
	cairo_scaled_font_destroy (scaled_font);
	return status;
    }

    *out = scaled_font;
    return CAIRO_STATUS_SUCCESS;
}

void
show_text (cairo_t *cr, double x, double y, double scale)
{
    double line_width;
    cairo_text_extents_t extents;
    line_width = cairo_get_line_width (cr);

    cairo_save (cr);
    cairo_scale(cr, scale, scale);
    cairo_move_to (cr, x,  y);
    cairo_show_text (cr, TEXT);
    cairo_text_extents (cr, TEXT, &extents);
    cairo_rectangle (cr,
		     x + extents.x_bearing - line_width / 2,
		     y + extents.y_bearing - line_width / 2,
                     extents.width  + line_width,
                     extents.height + line_width);
    cairo_stroke (cr);
    cairo_restore (cr);
}

void
draw (cairo_t *cr)
{
    cairo_scaled_font_t *scaled_font;
    cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
    cairo_paint (cr);

    create_scaled_font (cr, &scaled_font);
    cairo_set_scaled_font (cr, scaled_font);

    cairo_set_source_rgb (cr, 0, 0, 0); /* black */

    show_text(cr, 100.0, 0.0, 1.0);
    show_text(cr, 100.0, 0.0, 2.0);
    show_text(cr, 1000.0, 0.0, 0.3);
 
    cairo_scaled_font_destroy (scaled_font);
}

int
main ()
{
    cairo_t *cr;
    cairo_surface_t *surface;

    surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
					  WIDTH, HEIGHT);
    cr = cairo_create (surface);
    cairo_save (cr);
    draw (cr);
    cairo_surface_write_to_png (surface, "mytest.png");
    cairo_restore (cr);
    cairo_destroy (cr);
    cairo_surface_destroy (surface);

    surface = cairo_pdf_surface_create ("mytest.pdf", WIDTH, HEIGHT);
    cr = cairo_create (surface); 
    cairo_save (cr);
    draw (cr);
    cairo_show_page (cr);
    cairo_restore (cr);
    cairo_destroy (cr);
    cairo_surface_destroy (surface);

    surface = cairo_ps_surface_create ("mytest.ps", WIDTH, HEIGHT);
    cr = cairo_create (surface); 
    cairo_save (cr);
    draw (cr);
    cairo_show_page (cr);
    cairo_restore (cr);
    cairo_destroy (cr);
    cairo_surface_destroy (surface);

    return 0;
}