diff options
| -rw-r--r-- | LICENSE | 2 | ||||
| -rw-r--r-- | libfonts.h | 182 |
2 files changed, 181 insertions, 3 deletions
@@ -1,6 +1,6 @@ ISC License -© 2021 Mattias Andrée <maandree@kth.se> +© 2021, 2022 Mattias Andrée <maandree@kth.se> Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above @@ -12,10 +12,34 @@ enum libfonts_antialiasing { LIBFONTS_ANTIALIASING_SUBPIXEL_FORCED }; + +/** + * Output subpixel order + */ enum libfonts_subpixel_order { + /** + * Unknown subpixel order + */ LIBFONTS_SUBPIXEL_ORDER_UNKNOWN, + + /** + * Output is not an RGB output device + */ LIBFONTS_SUBPIXEL_ORDER_NONRGB, + + /** + * Output is an RGB output device, but + * the subpixels are not ordered in a + * grid of rectangles or subpixels are + * disjoint + */ LIBFONTS_SUBPIXEL_ORDER_NONLINEAR, + + /** + * Output is an RGB output device, but + * the subpixel is non of the supported + * subpixel orders + */ LIBFONTS_SUBPIXEL_ORDER_OTHER, /* For any value V, a rotation of 90⋅R degrees, R integer, @@ -77,42 +101,171 @@ enum libfonts_subpixel_order { LIBFONTS_SUBPIXEL_ORDER_BR_BG }; + +/** + * Device rotation + */ enum libfonts_orientation { + /** + * Unknown rotation + */ LIBFONTS_ORIENTATION_UNKNOWN, + + /** + * Not rotated + */ LIBFONTS_ORIENTATION_0_DEGREES_CLOCKWISE, + + /** + * Rotated 90 degrees clockwise + */ LIBFONTS_ORIENTATION_90_DEGREES_CLOCKWISE, + + /** + * Rotated 180 degrees + */ LIBFONTS_ORIENTATION_180_DEGREES_CLOCKWISE, + + /** + * Rotated 90 degrees counter-clockwise + */ LIBFONTS_ORIENTATION_270_DEGREES_CLOCKWISE, + + /** + * Not rotated by a multiple of 90 degrees + */ LIBFONTS_ORIENTATION_OTHER }; +/* TODO use affine transformations instead to account for scaling and mirroring */ + +/** + * Text rendering settings + */ struct libfonts_rendering_settings { - double dpi_x; /* actually pixels rather than dots */ + /** + * The output device's horizontal pixel density, + * in pixels (not dots) per inch, without output + * rotation applied, zero if not applicable or unknown + */ + double dpi_x; + + /** + * The output device's vertical pixel density, + * in pixels (not dots) per inch, without output + * rotation applied, zero if not applicable or unknown + */ double dpi_y; + + /** + * Antialiasing mode for horizontal, grey text + */ enum libfonts_antialiasing horizontal_grey_text_antialiasing; + + /** + * Antialiasing mode for vertical, grey text + */ enum libfonts_antialiasing vertical_grey_text_antialiasing; + + /** + * Antialiasing mode for non-horizontal, non-vertical, grey text + */ enum libfonts_antialiasing diagonal_grey_text_antialiasing; + + /** + * Antialiasing mode for horizontal, non-grey text + */ enum libfonts_antialiasing horizontal_colour_text_antialiasing; + + /** + * Antialiasing mode for vertical, non-grey text + */ enum libfonts_antialiasing vertical_colour_text_antialiasing; + + /** + * Antialiasing mode for non-horizontal, non-vertical, non-grey text + */ enum libfonts_antialiasing diagonal_colour_text_antialiasing; + + /** + * TODO + */ enum libfonts_subpixel_order unrotated_subpixel_order; + + /** + * TODO + */ enum libfonts_orientation default_physical_screen_orientation; }; + +/** + * Output device information structure + */ struct libfonts_output { + /** + * The output's X-location on the screen (pixels left) + */ int32_t output_x; + + /** + * The output's Y-location on the screen (pixels down) + */ int32_t output_y; + + /** + * The output's width, in pixels + */ uint32_t output_width; + + /** + * The output's height, in pixels + */ uint32_t output_height; + + /** + * The index of the screen the output belongs to + */ int output_screen; + + /** + * The rotation of the output + */ enum libfonts_orientation physical_screen_orientation; + + /** + * The output's subpixel order, disregarding applied rotation + */ enum libfonts_subpixel_order unrotated_subpixel_order; + + /** + * The output's horizontal pixel density (pixels per inch), + * zero if not applicable or unknown + * + * This `.output_width` divided by the output's physical + * width in inches + */ double dpi_x; + + /** + * The output's vertical pixel density (pixels per inch), + * zero if not applicable or unknown + * + * This `.output_height` divided by the output's physical + * height in inches + */ double dpi_y; + + /** + * Text renderings settings for the output device + */ struct libfonts_rendering_settings *rendering_settings; }; +/** + * Font description structure + */ struct libfonts_font_description { /** * The font name unless the foundry is registered with X, @@ -315,8 +468,33 @@ int libfonts_do_decoded_font_descriptions_match(const struct libfonts_font_descr int libfonts_get_default_rendering_settings(struct libfonts_rendering_settings *); int libfonts_get_output_rendering_settings(struct libfonts_rendering_settings *, const char *); -int libfonts_get_output_dpi(struct libfonts_output *, const char *); +/** + * Get an approximate pixel density for an output device + * + * The returned pixel density applied to the applied + * screen resolution, but without any rotation + * + * The output pixel density is only approximate because + * the EDID has limited dimension resolution + * + * @param output Output device information, `.output_width` and `.output_height` + * must already be set; this function will set `.dpi_x` and `.dpi_y` + * (both will be set to zero if the function returns zero) + * @param edid The output device's EDID, in hexadecimal representation + * @return 1 if a pixel density was calculated, + * 0 otherwise (projector or unsupported EDID) + */ +int libfonts_get_output_dpi(struct libfonts_output *, const char *); +/* TODO should take rotation into account */ + +/** + * Calculate the subpixel order on an output device after a rotation is applied + * + * @param unrotated The device's subpixel order + * @param rotation The applied rotation + * @return The device's logical subpixel order + */ enum libfonts_subpixel_order libfonts_calculate_subpixel_order(enum libfonts_subpixel_order, enum libfonts_orientation); |