From a62eea4aeca62318984065eeb0673293515ac0e3 Mon Sep 17 00:00:00 2001 From: Behdad Esfahbod Date: Sat, 12 Feb 2022 23:28:53 -0600 Subject: [PATCH] [user-font] Implement subpixel-positioning See: https://github.com/harfbuzz/harfbuzz/pull/3411#issuecomment-1033118545 https://github.com/harfbuzz/harfbuzz/pull/3411#issuecomment-1033125311 https://github.com/harfbuzz/harfbuzz/pull/3411#issuecomment-1037765840 Basically the code in cairo-image-compositor.c:composite_glyphs() is flooring glyph positions and putting some phase in the glyph-id. This was being lost in the user-font backend. Fetch that and put it in the recording-surface's device-transform translation, to be applied. --- src/cairo-user-font.c | 3 + test/Makefile.sources | 1 + test/meson.build | 1 + test/reference/user-font-subpixel.ref.png | Bin 0 -> 357 bytes test/reference/user-font-subpixel.svg.ref.png | Bin 0 -> 351 bytes test/reference/user-font-subpixel.xfail.png | Bin 0 -> 323 bytes test/user-font-subpixel.c | 92 ++++++++++++++++++ 7 files changed, 97 insertions(+) create mode 100644 test/reference/user-font-subpixel.ref.png create mode 100644 test/reference/user-font-subpixel.svg.ref.png create mode 100644 test/reference/user-font-subpixel.xfail.png create mode 100644 test/user-font-subpixel.c diff --git a/src/cairo-user-font.c b/src/cairo-user-font.c index 76f64ebfb..b2a05d67d 100644 --- a/src/cairo-user-font.c +++ b/src/cairo-user-font.c @@ -195,8 +195,11 @@ _cairo_user_scaled_glyph_init (void *abstract_font, if (recording_surface) cairo_surface_destroy (recording_surface); recording_surface = _cairo_user_scaled_font_create_recording_surface (scaled_font, FALSE); + recording_surface->device_transform.x0 = .25 * _cairo_scaled_glyph_xphase (scaled_glyph); + recording_surface->device_transform.y0 = .25 * _cairo_scaled_glyph_yphase (scaled_glyph); cr = _cairo_user_scaled_font_create_recording_context (scaled_font, recording_surface, FALSE); + status = face->scaled_font_methods.render_glyph ((cairo_scaled_font_t *)scaled_font, _cairo_scaled_glyph_index(scaled_glyph), cr, &extents); diff --git a/test/Makefile.sources b/test/Makefile.sources index d962a57fb..c180289ab 100644 --- a/test/Makefile.sources +++ b/test/Makefile.sources @@ -392,6 +392,7 @@ test_sources = \ user-font-mask.c \ user-font-proxy.c \ user-font-rescale.c \ + user-font-subpixel.c \ world-map.c \ white-in-noop.c \ xcb-huge-image-shm.c \ diff --git a/test/meson.build b/test/meson.build index b7bda2333..c0be0e086 100644 --- a/test/meson.build +++ b/test/meson.build @@ -392,6 +392,7 @@ test_sources = [ 'user-font-mask.c', 'user-font-proxy.c', 'user-font-rescale.c', + 'user-font-subpixel.c', 'world-map.c', 'white-in-noop.c', 'xcb-huge-image-shm.c', diff --git a/test/reference/user-font-subpixel.ref.png b/test/reference/user-font-subpixel.ref.png new file mode 100644 index 0000000000000000000000000000000000000000..7574c97b7a3608b145b4f4940f6b6b13af13ddf9 GIT binary patch literal 357 zcmeAS@N?(olHy`uVBq!ia0y~yV4MPE>u@ju$+Mm}qk$A#lDE4H!+#K5uy^@npb{xh z7srr_IdAW7u@ju$+Mm}qk$A#lDE4H!+#K5uy^@npb`;J z7srr_IdAV?iM%_cVAsVs#NBC>8g7`t?%Xoo8*%s}?WI)SAh> zB>TDigN(JY+fGegr4(VhTqLLXWQD8 zbNk+_7Q5YDzWw>CS%+-OvU1Pk+5cJ_NK8NZy2S0&Od*nCjMd|cAoxk>Qv REntW-c)I$ztaD0e0sy~>jn)7F literal 0 HcmV?d00001 diff --git a/test/reference/user-font-subpixel.xfail.png b/test/reference/user-font-subpixel.xfail.png new file mode 100644 index 0000000000000000000000000000000000000000..3647b4b8c3ee34be1f4b24cfe1ffd52c5d5ffa55 GIT binary patch literal 323 zcmeAS@N?(olHy`uVBq!ia0y~yV4MPE>u@ju$+Mm}qk$A#lDE4H!+#K5uy^@npvVtT z7srr_IdAVC%xy6caJVRt>wcl0H9+`f!&ITuA2z>_-FfCE|1_OS%k!VP7d-p@j*+3x zc~67NN2WnrCJZ)nIV{mWOv3e^rCY#CC qaSoFz7(E}cs&tA^P$8OgiQn^;u6_J^l?A{sVDNPHb6Mw<&;$TzPk{;m literal 0 HcmV?d00001 diff --git a/test/user-font-subpixel.c b/test/user-font-subpixel.c new file mode 100644 index 000000000..5378c733f --- /dev/null +++ b/test/user-font-subpixel.c @@ -0,0 +1,92 @@ +/* + * Copyright © 2022 Behdad Esfahbod + * + * 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. + * + * Contributor(s): + * Behdad Esfahbod + */ + +/* Test that user-fonts can subpixel positioning. + */ + +#include "cairo-test.h" + + +#define BORDER 10 +#define REPEAT 16 +#define TEXT_SIZE 24 +#define WIDTH (TEXT_SIZE * REPEAT + 2*BORDER) +#define HEIGHT (TEXT_SIZE + 2*BORDER) + + +static cairo_status_t +test_scaled_font_render_glyph (cairo_scaled_font_t *scaled_font, + unsigned long glyph, + cairo_t *cr, + cairo_text_extents_t *metrics) +{ + cairo_rectangle (cr, 0, .45, 1., .1); + cairo_fill (cr); + return CAIRO_STATUS_SUCCESS; +} + +static cairo_font_face_t * +_user_font_face_create (void) +{ + cairo_font_face_t *user_font_face; + + user_font_face = cairo_user_font_face_create (); + cairo_user_font_face_set_render_glyph_func (user_font_face, test_scaled_font_render_glyph); + + return user_font_face; +} + +static cairo_test_status_t +draw (cairo_t *cr, int width, int height) +{ + cairo_font_face_t *font_face; + + cairo_set_source_rgb (cr, 1, 1, 1); + cairo_paint (cr); + + font_face = _user_font_face_create (); + + cairo_set_font_face (cr, font_face); + cairo_font_face_destroy (font_face); + + cairo_set_source_rgb (cr, 0, 0, 0); + cairo_set_font_size (cr, TEXT_SIZE); + + for (unsigned i = 0; i < REPEAT; i++) + { + cairo_move_to (cr, BORDER + TEXT_SIZE * i, BORDER + i * .1); + cairo_show_text (cr, "-"); + } + + return CAIRO_TEST_SUCCESS; +} + +CAIRO_TEST (user_font_subpixel, + "Tests user font subpixel rendering", + "font, user-font", /* keywords */ + "cairo >= 1.17.4", /* requirements */ + WIDTH, HEIGHT, + NULL, draw)