test/ft-show-glyphs-positioning.c

   1 /*
   2  * Copyright © 2008 Adrian Johnson
   3  *
   4  * Permission is hereby granted, free of charge, to any person
   5  * obtaining a copy of this software and associated documentation
   6  * files (the "Software"), to deal in the Software without
   7  * restriction, including without limitation the rights to use, copy,
   8  * modify, merge, publish, distribute, sublicense, and/or sell copies
   9  * of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  *
  24  * Author: Adrian Johnson <ajohnson@redneon.com>
  25  */
  26
  27 #include "cairo-test.h"
  28 #include <cairo-ft.h>
  29
  30 #define TEXT_SIZE 12
  31
  32 static cairo_test_draw_function_t draw;
  33
  34 cairo_test_t test = {
  35     "ft-show-glyphs-positioning",
  36     "Test that the PS/PDF glyph positioning optimizations are correct",
  37     235, (TEXT_SIZE + 4)*2,
  38     draw
  39 };
  40
  41 typedef struct {
  42     cairo_glyph_t glyph_list[100];
  43     int num_glyphs;
  44     double x;
  45     double y;
  46 } glyph_array_t;
  47
  48 static void
  49 glyph_array_init (glyph_array_t *glyphs, double x, double y)
  50 {
  51     glyphs->num_glyphs = 0;
  52     glyphs->x = x;
  53     glyphs->y = y;
  54 }
  55
  56 static void
  57 glyph_array_rel_move_to (glyph_array_t *glyphs, double x, double y)
  58 {
  59     glyphs->x += x;
  60     glyphs->y += y;
  61 }
  62
  63 static void
  64 glyph_array_show (glyph_array_t *glyphs, cairo_t *cr)
  65 {
  66     cairo_show_glyphs (cr, glyphs->glyph_list, glyphs->num_glyphs);
  67 }
  68
  69 #define DOUBLE_FROM_26_6(t) ((double)(t) / 64.0)
  70
  71 static void
  72 glyph_array_add_text(glyph_array_t *glyphs, cairo_t *cr, const char *s, double spacing)
  73 {
  74     cairo_scaled_font_t *scaled_font;
  75     FT_Face face;
  76     unsigned long charcode;
  77     unsigned int index;
  78     cairo_text_extents_t extents;
  79     const char *p;
  80     FT_Vector kerning;
  81     double kern_x;
  82     int first = TRUE;
  83
  84     scaled_font = cairo_get_scaled_font (cr);
  85     face = cairo_ft_scaled_font_lock_face (scaled_font);
  86     p = s;
  87     while (*p)
  88     {
  89         charcode = *p;
  90         index = FT_Get_Char_Index (face, charcode);
  91         glyphs->glyph_list[glyphs->num_glyphs].index = index;
  92         if (first) {
  93             first = FALSE;
  94             glyphs->glyph_list[glyphs->num_glyphs].x = glyphs->x;
  95             glyphs->glyph_list[glyphs->num_glyphs].y = glyphs->y;
  96         } else {
  97             cairo_glyph_extents (cr, &glyphs->glyph_list[glyphs->num_glyphs - 1], 1, &extents);
  98             FT_Get_Kerning (face,
  99                             glyphs->glyph_list[glyphs->num_glyphs - 1].index,
 100                             glyphs->glyph_list[glyphs->num_glyphs].index,
 101                             FT_KERNING_UNSCALED,
 102                             &kerning);
 103             kern_x = DOUBLE_FROM_26_6(kerning.x);
 104             glyphs->glyph_list[glyphs->num_glyphs].x =
 105                 glyphs->glyph_list[glyphs->num_glyphs - 1].x + extents.x_advance + kern_x + spacing;
 106             glyphs->glyph_list[glyphs->num_glyphs].y =
 107                 glyphs->glyph_list[glyphs->num_glyphs - 1].y + extents.y_advance;
 108         }
 109
 110         cairo_glyph_extents (cr, &glyphs->glyph_list[glyphs->num_glyphs], 1, &extents);
 111         glyphs->x = glyphs->glyph_list[glyphs->num_glyphs].x + extents.x_advance + spacing;
 112         glyphs->y = glyphs->glyph_list[glyphs->num_glyphs].y + extents.y_advance;
 113         p++;
 114         glyphs->num_glyphs++;
 115     }
 116
 117     cairo_ft_scaled_font_unlock_face (scaled_font);
 118 }
 119
 120 static cairo_test_status_t
 121 draw (cairo_t *cr, int width, int height)
 122 {
 123     glyph_array_t glyphs;
 124     cairo_font_options_t *font_options;
 125
 126     /* paint white so we don't need separate ref images for
 127      * RGB24 and ARGB32 */
 128     cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
 129     cairo_paint (cr);
 130
 131     cairo_select_font_face (cr, "Bitstream Vera Sans",
 132                             CAIRO_FONT_SLANT_NORMAL,
 133                             CAIRO_FONT_WEIGHT_NORMAL);
 134     cairo_set_font_size (cr, TEXT_SIZE);
 135
 136     font_options = cairo_font_options_create ();
 137     cairo_get_font_options (cr, font_options);
 138     cairo_font_options_set_hint_metrics (font_options, CAIRO_HINT_METRICS_OFF);
 139     cairo_set_font_options (cr, font_options);
 140     cairo_font_options_destroy (font_options);
 141
 142     cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
 143
 144     glyph_array_init (&glyphs, 1, TEXT_SIZE);
 145     glyph_array_add_text(&glyphs, cr, "AWAY again", 0.0);
 146     glyph_array_rel_move_to (&glyphs, TEXT_SIZE*1, 0.0);
 147     glyph_array_add_text(&glyphs, cr, "character space", TEXT_SIZE*0.3);
 148     glyph_array_show (&glyphs, cr);
 149
 150     glyph_array_init (&glyphs, 1, TEXT_SIZE*2 + 4);
 151     glyph_array_add_text(&glyphs, cr, "Increasing", 0.0);
 152     glyph_array_rel_move_to (&glyphs, TEXT_SIZE*0.5, 0.0);
 153     glyph_array_add_text(&glyphs, cr, "space", 0.0);
 154     glyph_array_rel_move_to (&glyphs, TEXT_SIZE*1.0, 0.0);
 155     glyph_array_add_text(&glyphs, cr, "between", 0.0);
 156     glyph_array_rel_move_to (&glyphs, TEXT_SIZE*1.5, 0.0);
 157     glyph_array_add_text(&glyphs, cr, "words", 0.0);
 158     glyph_array_show (&glyphs, cr);
 159
 160     return CAIRO_TEST_SUCCESS;
 161 }
 162
 163 int
 164 main (void)
 165 {
 166     return cairo_test (&test);
 167 }