/* * Copyright © 2004 Red Hat, Inc. * * Permission to use, copy, modify, distribute, and sell this software * and its documentation for any purpose is hereby granted without * fee, provided that the above copyright notice appear in all copies * and that both that copyright notice and this permission notice * appear in supporting documentation, and that the name of * Red Hat, Inc. not be used in advertising or publicity pertaining to * distribution of the software without specific, written prior * permission. Red Hat, Inc. makes no representations about the * suitability of this software for any purpose. It is provided "as * is" without express or implied warranty. * * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL, * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Author: Carl D. Worth <cworth@cworth.org> */ /* Bug history * * 2004-11-03 Steve Chaplin <stevech1097@yahoo.com.au> * * Reported bug on mailing list: * * From: Steve Chaplin <stevech1097@yahoo.com.au> * To: cairo@cairographics.org * Date: Thu, 04 Nov 2004 00:00:17 +0800 * Subject: [cairo] Rotated text bug on drawable target * * The attached file draws text rotated 90 degrees first to a PNG file and * then to a drawable. The PNG file looks fine, the text on the drawable is * unreadable. * * Steve * * 2004-11-03 Carl Worth <cworth@cworth.org> * * Looks like the major problems with this bug appeared in the great * font rework between 0.1.23 and 0.2.0. And it looks like we need * to fix the regression test suite to test the xlib target (since * the bug does not show up in the png backend). * * Hmm... Actually, things don't look perfect even in the PNG * output. Look at how that 'o' moves around. It's particularly off * in the case where it's rotated by PI. * * And I'm still not sure about what to do for test cases with * text--a new version of freetype will change everything. We may * need to add a simple backend for stroked fonts and add a simple * builtin font to cairo for pixel-perfect tests with text. * * 2005-08-23 * * It appears that the worst placement and glyph selection problems * have now been resolved. In the past some letters were noticeably * of a different size at some rotations, and there was a lot of * drift away from the baseline. These problems do not appear * anymore. * * Another thing that helps is that we now have font options which * we can use to disable hinting in order to get more repeatable * results. I'm doing that in this test now. * * There are still some subtle positioning problems which I'm * assuming are due to the lack of finer-than-whole-pixel glyph * positioning. I'm generating a reference image now by replacing * cairo_show_text with cairo_text_path; cairo_fill. This will let * us look more closely at the remaining positioning problems. (In * particular, I want to make sure we're rounding as well as * possible). * * 2007-02-21 * * Seems like all the "bugs" have been fixed and all remaining is * missing support for subpixel glyph positioning. Removing from * XFAIL now. */ #include "cairo-test.h" #define WIDTH 150 #define HEIGHT 150 #define NUM_TEXT 20 #define TEXT_SIZE 12 /* Draw the word cairo at NUM_TEXT different angles. * We separate the circle into quadrants to reduce * numerical errors i.e. so each quarter is pixel-aligned. */ static void draw_quadrant (cairo_t *cr, const char *text, const cairo_text_extents_t *extents, const cairo_matrix_t *transform, int x_off, int y_off) { int i; for (i = 0; i < NUM_TEXT/4; i++) { cairo_save (cr); cairo_rotate (cr, 2*M_PI*i/NUM_TEXT); cairo_transform (cr, transform); cairo_set_line_width (cr, 1.0); cairo_rectangle (cr, x_off - 0.5, y_off - 0.5, extents->width + 1, extents->height + 1); cairo_set_source_rgb (cr, 1, 0, 0); cairo_stroke (cr); cairo_move_to (cr, x_off - extents->x_bearing, y_off - extents->y_bearing); cairo_set_source_rgb (cr, 0, 0, 0); #if CAIRO_TEST_GENERATE_REFERENCE_IMAGE cairo_text_path (cr, text); cairo_fill (cr); #else cairo_show_text (cr, text); #endif cairo_restore (cr); } } static cairo_test_status_t draw (cairo_t *cr, int width, int height) { cairo_text_extents_t extents; cairo_font_options_t *font_options; const char text[] = "cairo"; int x_off, y_off; cairo_matrix_t m; /* paint white so we don't need separate ref images for * RGB24 and ARGB32 */ cairo_set_source_rgb (cr, 1., 1., 1.); cairo_paint (cr); cairo_select_font_face (cr, CAIRO_TEST_FONT_FAMILY " Sans", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL); cairo_set_font_size (cr, TEXT_SIZE); font_options = cairo_font_options_create (); cairo_get_font_options (cr, font_options); cairo_font_options_set_hint_metrics (font_options, CAIRO_HINT_METRICS_OFF); cairo_set_font_options (cr, font_options); cairo_font_options_destroy (font_options); cairo_set_source_rgb (cr, 0, 0, 0); cairo_translate (cr, WIDTH/2.0, HEIGHT/2.0); cairo_text_extents (cr, text, &extents); if (NUM_TEXT == 1) { x_off = y_off = 0; } else { y_off = - floor (0.5 + extents.height / 2.0); x_off = floor (0.5 + (extents.height+1) / (2 * tan (M_PI/NUM_TEXT))); } cairo_save (cr); cairo_matrix_init_identity (&m); draw_quadrant (cr, text, &extents, &m, x_off, y_off); cairo_matrix_init (&m, 0, 1, -1, 0, 0, 0); draw_quadrant (cr, text, &extents, &m, x_off, y_off); cairo_restore (cr); cairo_save (cr); cairo_scale (cr, -1, -1); cairo_matrix_init_identity (&m); draw_quadrant (cr, text, &extents, &m, x_off, y_off); cairo_matrix_init (&m, 0, 1, -1, 0, 0, 0); draw_quadrant (cr, text, &extents, &m, x_off, y_off); cairo_restore (cr); return CAIRO_TEST_SUCCESS; } CAIRO_TEST (text_rotate, "Tests show_text under various rotations", "text, transform", /* keywords */ NULL, /* requirements */ WIDTH, HEIGHT, NULL, draw)