/* See LICENSE file for copyright and license details. */ #ifndef LIBFONTS_H #define LIBFONTS_H #include #include /** * The header file's version of `struct libfonts_context` */ #define LIBFONTS_CONTEXT_VERSION 0 /** * Style-based default fonts */ enum libfonts_default_font { /** * A proportional font without serifs */ LIBFONTS_DEFAULT_SANS_SERIF, /** * A proportional font with serifs */ LIBFONTS_DEFAULT_SERIF, /** * A monospace font, which may escape * the character cell */ LIBFONTS_DEFAULT_MONOSPACE }; /** * Antialiasing algorithm */ enum libfonts_antialiasing { /** * No antialiasing rule specified, use default or if default * is also unspecified: `LIBFONTS_ANTIALIASING_GREYSCALE` */ LIBFONTS_ANTIALIASING_UNSPECIFIED, /** * Do not antialias */ LIBFONTS_ANTIALIASING_NONE, /** * Use greyscale-antialiasing */ LIBFONTS_ANTIALIASING_GREYSCALE, /** * Use greyscale-antialiasing regardless * of other settings */ LIBFONTS_ANTIALIASING_GREYSCALE_FORCED, /** * Use subpixel rendering */ LIBFONTS_ANTIALIASING_SUBPIXEL, /** * Use subpixel rendering regardless of * other settings */ LIBFONTS_ANTIALIASING_SUBPIXEL_FORCED }; /** * Output subpixel colour */ enum libfonts_subpixel_colour { /** * Red primary */ LIBFONTS_SUBPIXEL_COLOUR_RED = 0, /** * Green primary */ LIBFONTS_SUBPIXEL_COLOUR_GREEN = 1, /** * Blue primary */ LIBFONTS_SUBPIXEL_COLOUR_BLUE = 2 }; /** * Output subpixel order class * * Descriptions of relative dimensions for the members * of this enumerated type assume that the monitor's * vertical and horizontal DPI (dots per inch) are equal */ enum libfonts_subpixel_order_class { /** * `LIBFONTS_SUBPIXEL_ORDER_UNKNOWN`, * `LIBFONTS_SUBPIXEL_ORDER_NONRGB`, * `LIBFONTS_SUBPIXEL_ORDER_NONLINEAR`, or * `LIBFONTS_SUBPIXEL_ORDER_OTHER` */ LIBFONTS_SUBPIXEL_ORDER_CLASS_OTHER, /** * A square of horizontally stacked vertical * stripes, numbered from left to right * * ┌───┬───┬───┐ * │ │ │ │ * │ │ │ │ * │ 1 │ 2 │ 3 │ * │ │ │ │ * │ │ │ │ * └───┴───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_CLASS_123, /** * A square of vertically stacked horizontal * stripes, numbered from top to bottom * * ┌───────────┐ * │ 1 │ * ├───────────┤ * │ 2 │ * ├───────────┤ * │ 3 │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_CLASS_1_2_3, /** * A square of two squares with a horizontal * 2:1-oblong rectangle stacked above them; * the rectangle is numbered 1, and the two * squares numbered 2 and 3 from left to right * * ┌───────┐ * │ 1 │ * ├───┬───┤ * │ 2 │ 3 │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_CLASS_11_23, /** * A square of two squares vertically stacked * squares with a vertical 2:1-oblong rectangle * to their right; the rectangle is numbered 1, * and the two squares are numbered 2 and 3 from * top to bottom * * ┌───┬───┐ * │ 2 │ │ * ├───┤ 1 │ * │ 3 │ │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_CLASS_21_31, /** * A square of two squares with a horizontal * 2:1-oblong rectangle stacked beneath them; * the rectangle is numbered 1, and the two * squares numbered 2 and 3 from right to left * * ┌───┬───┐ * │ 3 │ 2 │ * ├───┴───┤ * │ 1 │ * └───────┘ */ LIBFONTS_SUBPIXEL_ORDER_CLASS_32_11, /** * A square of two squares vertically stacked * squares with a vertical 2:1-oblong rectangle * to their left; the rectangle is numbered 1, * and the two squares are numbered 2 and 3 from * bottom to top * * ┌───┬───┐ * │ │ 3 │ * │ 1 ├───┤ * │ │ 2 │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_CLASS_13_12, /** * `LIBFONTS_SUBPIXEL_ORDER_CLASS_11_23` * with the subpixels redimensioned to * balance the subpixels to have equal size * * ┌───────────┐ * │ 1 │ * ├─────┬─────┤ * │ │ │ * │ 2 │ 3 │ * │ │ │ * └─────┴─────┘ * * Cells 2 and 3 have the aspect ratio * (width to height) 3:4 and cell 1 has * the aspect ratio 6:2 */ LIBFONTS_SUBPIXEL_ORDER_CLASS_BALANCED_11_23, /** * `LIBFONTS_SUBPIXEL_ORDER_CLASS_21_21` * with the subpixels redimensioned to * balance the subpixels to have equal size * * ┌───────┬───┐ * │ 2 │ │ * │ │ │ * ├───────┤ 1 │ * │ 3 │ │ * │ │ │ * └───────┴───┘ * * Cells 2 and 3 have the aspect ratio * (width to height) 4:3 and cell 1 has * the aspect ratio 2:6 */ LIBFONTS_SUBPIXEL_ORDER_CLASS_BALANCED_21_31, /** * `LIBFONTS_SUBPIXEL_ORDER_CLASS_32_11` * with the subpixels redimensioned to * balance the subpixels to have equal size * * ┌─────┬─────┐ * │ │ │ * │ 3 │ 2 │ * │ │ │ * ├─────┴─────┤ * │ 1 │ * └───────────┘ * * Cells 2 and 3 have the aspect ratio * (width to height) 3:4 and cell 1 has * the aspect ratio 6:2 */ LIBFONTS_SUBPIXEL_ORDER_CLASS_BALANCED_32_11, /** * `LIBFONTS_SUBPIXEL_ORDER_CLASS_13_12` * with the subpixels redimensioned to * balance the subpixels to have equal size * * ┌───┬───────┐ * │ │ 3 │ * │ │ │ * │ 1 ├───────┤ * │ │ 2 │ * │ │ │ * └───┴───────┘ * * Cells 2 and 3 have the aspect ratio * (width to height) 4:3 and cell 1 has * the aspect ratio 2:6 */ LIBFONTS_SUBPIXEL_ORDER_CLASS_BALANCED_13_12 }; /** * 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 * * This includes the patterns (with disjoint subpixels) * * ┌───┬───┐ (LIBFONTS_SUBPIXEL_ORDER_RG_BR, * │ 1 │ 2 │ LIBFONTS_SUBPIXEL_ORDER_RB_GR, * ├───┼───┤ LIBFONTS_SUBPIXEL_ORDER_GR_BG, * │ 3 │ 1 │ LIBFONTS_SUBPIXEL_ORDER_GB_RG, * └───┴───┘ LIBFONTS_SUBPIXEL_ORDER_BR_GB, * LIBFONTS_SUBPIXEL_ORDER_BG_RB) * and * (LIBFONTS_SUBPIXEL_ORDER_RG_GB, * ┌───┬───┐ LIBFONTS_SUBPIXEL_ORDER_RB_BG, * │ 1 │ 2 │ LIBFONTS_SUBPIXEL_ORDER_GR_RB, * ├───┼───┤ LIBFONTS_SUBPIXEL_ORDER_GB_BR, * │ 2 │ 3 │ LIBFONTS_SUBPIXEL_ORDER_BR_RG, * └───┴───┘ LIBFONTS_SUBPIXEL_ORDER_BG_GR) * * as well trianglar arrangements as found on many * CRT-monitors */ LIBFONTS_SUBPIXEL_ORDER_NONLINEAR, /** * Output is an RGB output device, but the subpixel * order is not one of the supported subpixel orders */ LIBFONTS_SUBPIXEL_ORDER_OTHER, /** * Horizontally stacked vertical stripes, * red to the left, green in the middle, and blue to the right * * ┌───┬───┬───┐ * │ │ │ │ * │ │ │ │ * │ R │ G │ B │ * │ │ │ │ * │ │ │ │ * └───┴───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RGB, /** * Vertically stacked horizontal stripes, * red at the top, green in the middle, and blue at the bottom * * ┌───────────┐ * │ R │ * ├───────────┤ * │ G │ * ├───────────┤ * │ B │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_R_G_B, /** * Horizontally stacked vertical stripes, * blue to the left, green in the middle, and red to the right * * ┌───┬───┬───┐ * │ │ │ │ * │ │ │ │ * │ B │ G │ R │ * │ │ │ │ * │ │ │ │ * └───┴───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BGR, /** * Vertically stacked horizontal stripes, * blue at the top, green in the middle, and red at the bottom * * ┌───────────┐ * │ B │ * ├───────────┤ * │ G │ * ├───────────┤ * │ R │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_B_G_R, /** * Horizontally stacked vertical stripes, * green to the left, blue in the middle, and red to the right * * ┌───┬───┬───┐ * │ │ │ │ * │ │ │ │ * │ G │ B │ R │ * │ │ │ │ * │ │ │ │ * └───┴───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GBR, /** * Vertically stacked horizontal stripes, * green at the top, blue in the middle, and red at the bottom * * ┌───────────┐ * │ G │ * ├───────────┤ * │ B │ * ├───────────┤ * │ R │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_G_B_R, /** * Horizontally stacked vertical stripes, * red to the left, blue in the middle, and green to the right * * ┌───┬───┬───┐ * │ │ │ │ * │ │ │ │ * │ R │ B │ G │ * │ │ │ │ * │ │ │ │ * └───┴───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RBG, /** * Vertically stacked horizontal stripes, * red at the top, blue in the middle, and green at the bottom * * ┌───────────┐ * │ R │ * ├───────────┤ * │ B │ * ├───────────┤ * │ G │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_R_B_G, /** * Horizontally stacked vertical stripes, * blue to the left, red in the middle, and green to the right * * ┌───┬───┬───┐ * │ │ │ │ * │ │ │ │ * │ B │ R │ G │ * │ │ │ │ * │ │ │ │ * └───┴───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BRG, /** * Vertically stacked horizontal stripes, * blue at the top, red in the middle, and green at the bottom * * ┌───────────┐ * │ B │ * ├───────────┤ * │ R │ * ├───────────┤ * │ G │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_B_R_G, /** * Horizontally stacked vertical stripes, * green to the left, red in the middle, and blue to the right * * ┌───┬───┬───┐ * │ │ │ │ * │ │ │ │ * │ G │ R │ B │ * │ │ │ │ * │ │ │ │ * └───┴───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GRB, /** * Vertically stacked horizontal stripes, * green at the top, red in the middle, and blue at the bottom * * ┌───────────┐ * │ G │ * ├───────────┤ * │ R │ * ├───────────┤ * │ B │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_G_R_B, /** * Red subpixel stacked above, having equal height, * green, on the left, and blue, on the right, * square subpixels * * ┌───────┐ * │ R │ * ├───┬───┤ * │ G │ B │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RR_GB, /** * Red subpixel stacked to the right, having * equal width, of green, on the top, and * blue, on the bottom, square subpixels * * ┌───┬───┐ * │ G │ │ * ├───┤ R │ * │ B │ │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GR_BR, /** * Red subpixel stacked beneath, having equal * height, blue, on the left, and green, on * the right, square subpixels * * ┌───┬───┐ * │ B │ G │ * ├───┴───┤ * │ R │ * └───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BG_RR, /** * Red subpixel stacked to the left, having * equal width, of blue, on the top, and * green, on the bottom, square subpixels * * ┌───┬───┐ * │ │ B │ * │ R ├───┤ * │ │ G │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RB_RG, /** * Red subpixel stacked above, having equal height, * blue, on the left, and green, on the right, * square subpixels * * ┌───────┐ * │ R │ * ├───┬───┤ * │ B │ G │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RR_BG, /** * Red subpixel stacked to the right, having * equal width, of blue, on the top, and * green, on the bottom, square subpixels * * ┌───┬───┐ * │ B │ │ * ├───┤ R │ * │ G │ │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BR_GR, /** * Red subpixel stacked beneath, having equal * height, green, on the left, and blue, on * the right, square subpixels * * ┌───┬───┐ * │ G │ B │ * ├───┴───┤ * │ R │ * └───────┘ */ LIBFONTS_SUBPIXEL_ORDER_GB_RR, /** * Red subpixel stacked to the left, having * equal width, of green, on the top, and * blue, on the bottom, square subpixels * * ┌───┬───┐ * │ │ G │ * │ R ├───┤ * │ │ B │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RG_RB, /** * Green subpixel stacked above, having equal height, * red, on the left, and blue, on the right, * square subpixels * * ┌───────┐ * │ G │ * ├───┬───┤ * │ R │ B │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GG_RB, /** * Green subpixel stacked to the right, having * equal width, of red, on the top, and * blue, on the bottom, square subpixels * * ┌───┬───┐ * │ R │ │ * ├───┤ G │ * │ B │ │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RG_BG, /** * Green subpixel stacked beneath, having equal * height, blue, on the left, and red, on * the right, square subpixels * * ┌───┬───┐ * │ B │ R │ * ├───┴───┤ * │ G │ * └───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BR_GG, /** * Green subpixel stacked to the left, having * equal width, of blue, on the top, and * red, on the bottom, square subpixels * * ┌───┬───┐ * │ │ B │ * │ G ├───┤ * │ │ R │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GB_GR, /** * Green subpixel stacked above, having equal height, * blue, on the left, and red, on the right, * square subpixels * * ┌───────┐ * │ G │ * ├───┬───┤ * │ B │ R │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GG_BR, /** * Green subpixel stacked to the right, having * equal width, of blue, on the top, and * red, on the bottom, square subpixels * * ┌───┬───┐ * │ B │ │ * ├───┤ G │ * │ R │ │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BG_RG, /** * Green subpixel stacked beneath, having equal * height, red, on the left, and blue, on * the right, square subpixels * * ┌───┬───┐ * │ R │ B │ * ├───┴───┤ * │ G │ * └───────┘ */ LIBFONTS_SUBPIXEL_ORDER_RB_GG, /** * Green subpixel stacked to the left, having * equal width, of red, on the top, and * blue, on the bottom, square subpixels * * ┌───┬───┐ * │ │ R │ * │ G ├───┤ * │ │ B │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GR_GB, /** * Blue subpixel stacked above, having equal height, * red, on the left, and green, on the right, * square subpixels * * ┌───────┐ * │ B │ * ├───┬───┤ * │ R │ G │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BB_RG, /** * Blue subpixel stacked to the right, having * equal width, of red, on the top, and * green, on the bottom, square subpixels * * ┌───┬───┐ * │ R │ │ * ├───┤ B │ * │ G │ │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_RB_GB, /** * Blue subpixel stacked beneath, having equal * height, green, on the left, and red, on * the right, square subpixels * * ┌───┬───┐ * │ G │ R │ * ├───┴───┤ * │ B │ * └───────┘ */ LIBFONTS_SUBPIXEL_ORDER_GR_BB, /** * Blue subpixel stacked to the left, having * equal width, of green, on the top, and * red, on the bottom, square subpixels * * ┌───┬───┐ * │ │ G │ * │ B ├───┤ * │ │ R │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BG_BR, /** * Blue subpixel stacked above, having equal height, * green, on the left, and red, on the right, * square subpixels * * ┌───────┐ * │ B │ * ├───┬───┤ * │ G │ R │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BB_GR, /** * Blue subpixel stacked to the right, having * equal width, of green, on the top, and * red, on the bottom, square subpixels * * ┌───┬───┐ * │ G │ │ * ├───┤ B │ * │ R │ │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_GB_RB, /** * Blue subpixel stacked beneath, having equal * height, red, on the left, and green, on * the right, square subpixels * * ┌───┬───┐ * │ R │ G │ * ├───┴───┤ * │ B │ * └───────┘ */ LIBFONTS_SUBPIXEL_ORDER_RG_BB, /** * Blue subpixel stacked to the left, having * equal width, of red, on the top, and * green, on the bottom, square subpixels * * ┌───┬───┐ * │ │ R │ * │ B ├───┤ * │ │ G │ * └───┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BR_BG, /** * `LIBFONTS_SUBPIXEL_ORDER_RR_GB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────────┐ * │ R │ * ├─────┬─────┤ * │ │ │ * │ G │ B │ * │ │ │ * └─────┴─────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RR_GB, /** * `LIBFONTS_SUBPIXEL_ORDER_GR_BR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────┬───┐ * │ G │ │ * │ │ │ * ├───────┤ R │ * │ B │ │ * │ │ │ * └───────┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GR_BR, /** * `LIBFONTS_SUBPIXEL_ORDER_BG_RR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌─────┬─────┐ * │ │ │ * │ B │ G │ * │ │ │ * ├─────┴─────┤ * │ R │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BG_RR, /** * `LIBFONTS_SUBPIXEL_ORDER_RB_RG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───┬───────┐ * │ │ B │ * │ │ │ * │ R ├───────┤ * │ │ G │ * │ │ │ * └───┴───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RB_RG, /** * `LIBFONTS_SUBPIXEL_ORDER_RR_BG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────────┐ * │ R │ * ├─────┬─────┤ * │ │ │ * │ B │ G │ * │ │ │ * └─────┴─────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RR_BG, /** * `LIBFONTS_SUBPIXEL_ORDER_BR_GR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────┬───┐ * │ B │ │ * │ │ │ * ├───────┤ R │ * │ G │ │ * │ │ │ * └───────┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BR_GR, /** * `LIBFONTS_SUBPIXEL_ORDER_GB_RR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌─────┬─────┐ * │ │ │ * │ G │ B │ * │ │ │ * ├─────┴─────┤ * │ R │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GB_RR, /** * `LIBFONTS_SUBPIXEL_ORDER_RG_RB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───┬───────┐ * │ │ G │ * │ │ │ * │ R ├───────┤ * │ │ B │ * │ │ │ * └───┴───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RG_RB, /** * `LIBFONTS_SUBPIXEL_ORDER_GG_RB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────────┐ * │ G │ * ├─────┬─────┤ * │ │ │ * │ R │ B │ * │ │ │ * └─────┴─────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GG_RB, /** * `LIBFONTS_SUBPIXEL_ORDER_RG_BG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────┬───┐ * │ R │ │ * │ │ │ * ├───────┤ G │ * │ B │ │ * │ │ │ * └───────┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RG_BG, /** * `LIBFONTS_SUBPIXEL_ORDER_BR_GG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌─────┬─────┐ * │ │ │ * │ B │ R │ * │ │ │ * ├─────┴─────┤ * │ G │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BR_GG, /** * `LIBFONTS_SUBPIXEL_ORDER_GB_GR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───┬───────┐ * │ │ B │ * │ │ │ * │ G ├───────┤ * │ │ R │ * │ │ │ * └───┴───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GB_GR, /** * `LIBFONTS_SUBPIXEL_ORDER_GG_BR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────────┐ * │ G │ * ├─────┬─────┤ * │ │ │ * │ B │ R │ * │ │ │ * └─────┴─────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GG_BR, /** * `LIBFONTS_SUBPIXEL_ORDER_BG_RG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────┬───┐ * │ B │ │ * │ │ │ * ├───────┤ G │ * │ R │ │ * │ │ │ * └───────┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BG_RG, /** * `LIBFONTS_SUBPIXEL_ORDER_RB_GG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌─────┬─────┐ * │ │ │ * │ R │ B │ * │ │ │ * ├─────┴─────┤ * │ G │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RB_GG, /** * `LIBFONTS_SUBPIXEL_ORDER_GR_GB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───┬───────┐ * │ │ R │ * │ │ │ * │ G ├───────┤ * │ │ B │ * │ │ │ * └───┴───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GR_GB, /** * `LIBFONTS_SUBPIXEL_ORDER_BB_RG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────────┐ * │ B │ * ├─────┬─────┤ * │ │ │ * │ R │ G │ * │ │ │ * └─────┴─────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BB_RG, /** * `LIBFONTS_SUBPIXEL_ORDER_RB_GB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────┬───┐ * │ R │ │ * │ │ │ * ├───────┤ B │ * │ G │ │ * │ │ │ * └───────┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RB_GB, /** * `LIBFONTS_SUBPIXEL_ORDER_GR_BB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌─────┬─────┐ * │ │ │ * │ G │ R │ * │ │ │ * ├─────┴─────┤ * │ B │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GR_BB, /** * `LIBFONTS_SUBPIXEL_ORDER_BG_BR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───┬───────┐ * │ │ G │ * │ │ │ * │ B ├───────┤ * │ │ R │ * │ │ │ * └───┴───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BG_BR, /** * `LIBFONTS_SUBPIXEL_ORDER_BB_GR` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────────┐ * │ B │ * ├─────┬─────┤ * │ │ │ * │ G │ R │ * │ │ │ * └─────┴─────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BB_GR, /** * `LIBFONTS_SUBPIXEL_ORDER_GB_RB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───────┬───┐ * │ G │ │ * │ │ │ * ├───────┤ B │ * │ R │ │ * │ │ │ * └───────┴───┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_GB_RB, /** * `LIBFONTS_SUBPIXEL_ORDER_RG_BB` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌─────┬─────┐ * │ │ │ * │ R │ G │ * │ │ │ * ├─────┴─────┤ * │ B │ * └───────────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_RG_BB, /** * `LIBFONTS_SUBPIXEL_ORDER_BR_BG` with * the subpixels stretched to balance * the subpixels to have equal size * * ┌───┬───────┐ * │ │ R │ * │ │ │ * │ B ├───────┤ * │ │ G │ * │ │ │ * └───┴───────┘ */ LIBFONTS_SUBPIXEL_ORDER_BALANCED_BR_BG }; /** * Output transformation structure */ struct libfonts_transformation { /** * Transformation matrix, row-major * * ⎛.m[0][0] .m[0][1] .m[0][2]⎞ * ⎜.m[1][0] .m[1][1] .m[1][2]⎟ * ⎝.m[2][0] .m[2][1] .m[2][2]⎠ * * Let all values be zero if it is unknown */ double m[3][3]; }; /** * Text rendering settings */ struct libfonts_rendering_settings { /** * The output device's horizontal pixel density, * in pixels (not dots) per inch, for the reference * width, without output transformations applied, * 0 if not specified */ double dpi_x; /** * The output device's vertical pixel density, * in pixels (not dots) per inch, for the reference * height, without output transformations applied, * 0 if not specified */ double dpi_y; /** * The width, in pixels, that `.dpi_x` is calculated * for; if 0, `dpi_x` shall apply regardless of * current resolution and transformations */ uint32_t reference_width; /** * The height, in pixels, that `.dpi_y` is calculated * for; if 0, `.dpi_y` shall apply regardless of * current resolution and transformations */ uint32_t reference_height; /** * The output device's physical subpixel order, * when it is not rotated */ enum libfonts_subpixel_order subpixel_order; /** * If the product of the applicable pixel densities * (horizontal and vertical) is less than this * value, the antialiasing mode shall downgrade * to `LIBFONTS_ANTIALIASING_NONE` if it is * `LIBFONTS_ANTIALIASING_GREYSCALE` or * `LIBFONTS_ANTIALIASING_SUBPIXEL` */ double min_dpsqi_for_greyscale; /** * If the product of the applicable pixel densities * (horizontal and vertical) is less than this * value, the antialiasing mode shall downgrade * to `LIBFONTS_ANTIALIASING_GREYSCALE` if it is * `LIBFONTS_ANTIALIASING_SUBPIXEL` */ double min_dpsqi_for_subpixel; /** * Antialiasing mode for horizontal (on unrotated output), grey text */ enum libfonts_antialiasing horizontal_grey_text_antialiasing; /** * Antialiasing mode for vertical (on unrotated output), grey text */ enum libfonts_antialiasing vertical_grey_text_antialiasing; /** * Antialiasing mode for non-horizontal, non-vertical * (on unrotated output), grey text */ enum libfonts_antialiasing diagonal_grey_text_antialiasing; /** * Antialiasing mode for horizontal (on unrotated output), * non-grey text */ enum libfonts_antialiasing horizontal_colour_text_antialiasing; /** * Antialiasing mode for vertical (on unrotated output), * non-grey text */ enum libfonts_antialiasing vertical_colour_text_antialiasing; /** * Antialiasing mode for non-horizontal, non-vertical (on * unrotated output), non-grey text */ enum libfonts_antialiasing diagonal_colour_text_antialiasing; }; /** * 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, on the screen */ uint32_t output_width; /** * The output's height, in pixels, on the screen */ uint32_t output_height; /** * The output's width, in pixels, before transformation is applied */ uint32_t unrotated_output_width; /** * The output's height, in pixels, before transformation is applied */ uint32_t unrotated_output_height; /** * The index of the screen the output belongs to */ int output_screen; /** * Transformation that is applied to the output */ struct libfonts_transformation output_transformation; /** * 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, after transformation * is applied * * This `.unrotated_output_width` divided by the output's * physical width in inches, with inverse of * `.output_transformation` than applied */ double dpi_x; /** * The output's vertical pixel density (pixels per inch), * zero if not applicable or unknown, after transformation * is applied * * This `.unrotated_output_height` divided by the output's * physical height in inches, with inverse of * `.output_transformation` than applied */ 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, * in which case, all following fields will be `NULL`. * This field is normally `NULL`. * * This field will also be used to to store the font name * (including the initial "-") if it is malformated. */ const char *private_font_name; /** * Version if the XLFD used, `NULL` if not included in the font name * (this is normally the case) */ const char *xlfd_version; /** * X-registered foundry name (name of digitaliser, not designer) */ const char *foundry; /** * Human-readable, non-translated, hyphen-free name of the font */ const char *family_name; /** * The nominal blackness of the font, according the the foundry's * judgement. Human-readable and suitable for presentation to the * user. "0" if the font is polymorphic. * * Should not be used for font matching or substitution. */ const char *weight_name; /** * Overall posture * * "R" = Roman * "I" = Italic * "O" = Oblique * "RI" = Reverse italic * "RO" = Reverse oblique * "OT" = Other * numeric = Polymorphic */ const char *slant; /** * The nominal width per horizontal unit of the font, according to the * foundry's judgment. "0" if the font is polymorphic. * * Should not be used for font matching or substitution. * * Example values: * "Normal" * "Condensed" * "Narrow" * "Double Wide" */ const char *setwidth_name; /** * Additional style information. Includes the "[" character if the * font is polymorphic * * Example values: * "" * "Serif" * "Sans Serif" * "Informal" * "Decorated" */ const char *add_style_name; /** * The body size of the font at a particular point size and Y-resolution. * Either an integer-string or (if using matrix transformation) a string * beginning with "[". "0" if the font is scalable. */ const char *pixel_size; /** * The body size the font was designed for. Either an integer-string or * (if using matrix transformation) a string beginning with "[". If the * value is an integer, the body size is expressed in decipoints (72.27 * points equal 1 inch). "0" if the font is scalable. */ const char *point_size; /** * Horizontal resolution (unsigned integer), measured in pixels or dots * per inch (DPI), for which the font was designed. "0" if the font is * scalable. */ const char *resolution_x; /** * Vertical resolution (unsigned integer), measured in pixels or dots * per inch (DPI), for which the font was designed. "0" if the font is * scalable. */ const char *resolution_y; /** * Escapement class of the font * * "P" = Proportional * Logical character widths vary for each glyph * * "M" = Monospace * Logical character widths are constant * * "C" = Character cell * Monospaced font where no glyph have "ink" outside of * the character cell, and there is no kerning and * vertical extents of the font do not exceed the vertical * spacing. The cell height = font-descent + font-ascent, * and the cell width = the average width. */ const char *spacing; /** * Unweighted arithmetic mean of the absolute value of the width of each * glyph, measured in decipixels, and encoded as an integer. Multiplied * by −1 if the dominant writing direction for the font is right-to-left. * "0" if the font is scalable. * * Negative values are encoding with a leading "~", which will be * converted to "-" when parsed. */ const char *average_width; /** * X-registered authority the character set encoding is * standardised by */ const char *charset_registry; /** * The character set encoding * * Unicode shall be represented with the combnation of "iso10646" * (any case) in `.charset_registry` and `1` in `.charset_encoding` */ const char *charset_encoding; /** * Character subset hint, or `NULL` if none * * Will be a sorted, in ascending order, -separated list of * inclusive ranges included the subset. A range will either be a * decimal integer, or an two decimal integers separated by a "-" * (the left-hand side will be strictly less than the right-hand side). * All ranges will be disjunction, and have a non-zero distance. * * The library will take care of converting hexadecimal numbers (prefixed * with "0x") to decimal, removing leading zeroes, converting "_" to "-", * and sorting the range, reducing singleton ranges to single numbers, * and merge mergable ranges. Ranges including negative values and values * 0x80000000 (1 exceeded the maximum value of an unsigned 31-bit integer, * which is less than the smallest number (0xE8D4A51000 = 1000000000000) * whose prefixed hexadecimal representation is shorter than it's decimal * representation) or greater, will be rejected. * * This information is encoded in the character set encoding field, * but the libraries separates out this information to its own * field in this `struct`. */ const char *charset_subset; /** * "-"-separated list of unrecognised fields, `NULL` if none. * Note that the empty string indicates that there was one * unrecognised fields, containing the empty string. * * These fields will not be parsed in any way, meaning * for example that negative values encoded will a leading * "~" will retain the "~" uncoverted. */ const char *unrecognised_fields; /** * For internal use only * * Store the strings in the struct. Limited to 256 * bytes because a font name may only included up * to 255 bytes; add one for NUL-termination. */ char _buf[256]; }; /** * Structure that can be used to spoof the * environment the library is executed in, * as well as the print warnings from the * library */ struct libfonts_context { /** * Set to `LIBFONTS_CONTEXT_VERSION` */ int version; /** * Non-zero to remove all environment * variables that are not included in * `.environ` */ int ignore_process_environ; /** * Environment variables to add or override * * `libfonts_used_environs` can be used to * enumerate the environment variables that * affect the execution of the environment */ char **environ; /** * Whether `.uid` is used */ int use_context_uid; /** * The real user ID of the process * * Only used if `.use_context_uid` is non-zero */ uid_t uid; }; /** * `NULL`-terminated list of environment variables * that affect the execution of the library */ extern const char *const libfonts_used_environs[]; /** * Get the font a default font name aliases to * * @param font The default font * @param ctx Optional `struct libfonts_context` * @return The font the default font is an alias for * (shall be deallocated using free(3) when no * longer used), or `NULL` on failure; in the * case that no font is found, `NULL` with be * returned without modifying `errno` * * @throws EINVAL Unrecognised value on `font` */ char *libfonts_get_default_font(enum libfonts_default_font, struct libfonts_context *); /** * Get the alias for a default font * * @param font The default font * @param index The index of the alias (some default fonts * have multiple aliases) * @param namep Output parameter for the font name * @return If the alias exists, or 0 if `index` is equal to * or greater than the number of aliases, or * -1 on failure * * @throws EINVAL Unrecognised value on `font` */ int libfonts_get_default_font_name(enum libfonts_default_font, size_t, const char **); /** * Get a default font a font name represents * * @param font Output parameter for the default font * @param name The alias for the default font, optionally * with style and size information * @param style Output parameter for the offset in `name` * where the style and size information begins; * will be set to 0 if this information is * excluded from `name` * @return 1 on successful completion, 0 if `name` is not * an alias for a default font */ int libfonts_get_default_font_by_name(enum libfonts_default_font *, const char *, size_t *); /* TODO implement libfonts_get_default_font_by_name */ /** * Encode an X Logical Font Description (XLFD) string * * @param desc The font description to encode * @param out Output buffer for the font description string * @return 0 on successful completion, -1 on failure * * @throws EINVAL Invalid font description */ int libfonts_encode_font_description(const struct libfonts_font_description *, char[static 256]); /** * Decode an X Logical Font Description (XLFD) string * * @param desc Output parameter for the font description * @param in The font description string to decode * @return 0 on successful completion, -1 on failure * * @throws EINVAL Invalid font description */ int libfonts_decode_font_description(struct libfonts_font_description *, const char *); /** * Check if an X Logical Font Description (XLFD) matches * a font specification * * @param desc The font description to test, may not include wildcards * @param spec The specification to test the description against, may include wildcards * @return 1 if the arguments match, 0 if they don't match */ int libfonts_do_font_descriptions_match(const char *, const char *); /* TODO implement libfonts_do_font_descriptions_match */ /** * Check if an X Logical Font Description (XLFD) matches * a font specification * * @param desc The font description to test, may not include wildcards * @param spec The specification to test the description against, may include wildcards * @return 1 if the arguments match, 0 if they don't match */ int libfonts_do_decoded_font_descriptions_match(const struct libfonts_font_description *, const struct libfonts_font_description *); /* TODO implement libfonts_do_decoded_font_descriptions_match */ /** * Get the rendering settings to use for output devices * without any specific rendering settings configured * * Applications that are not output-aware shall use * these settings * * @param settings Output parameter for the rendering settings; * `settings->dpi_x` and `settings->dpi_y` will * have a fallback value assigned if configured to 0 * @param ctx Optional `struct libfonts_context` * @return 1 if rendering settings where found, * 0 otherwise (`*settings` will be filled with fallback values), * -1 on failure */ int libfonts_get_default_rendering_settings(struct libfonts_rendering_settings *, struct libfonts_context *); /** * Get rendering settings specified for a specific output device * * @param settings Output parameter for the rendering settings * @param name The EDID (or other identifier) of the output * @param ctx Optional `struct libfonts_context` * @return 1 if rendering settings where found, * 0 otherwise (`*settings` will be unmodified), * -1 on failure * * @throws EINVAL `name` is `NULL` */ int libfonts_get_output_rendering_settings(struct libfonts_rendering_settings *, const char *, struct libfonts_context *); /** * 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, `.unrotated_output_width`, * `.unrotated_output_height`, and `.output_transformation` 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; * if `NULL`, `output->unrotated_output_width` and * `output->unrotated_output_height` need not be set, instead * `output->dpi_x` and `output->dpi_y` must be set to the pixel * density before the inverse of `output->output_transformation` * is applied * @return 1 if a pixel density was calculated, * 0 otherwise (projector, unsupported EDID, or * non-invertable output transformation) */ int libfonts_get_output_dpi(struct libfonts_output *, const char *); /** * Calculate the subpixel order on an output device after * a transformation is applied on its output * * @param unrotated The device's subpixel order * @param transformation The applied transformation * @return The device's logical subpixel order */ enum libfonts_subpixel_order libfonts_calculate_subpixel_order(enum libfonts_subpixel_order, const struct libfonts_transformation *); /** * Get the general subpixel layout, as well * as which primary is contained in which * cell in the layout, from a specific * subpixel order * * @param order The subpixel order * @param cell1p Output parameter for the primary contained in cell 1 * @param cell2p Output parameter for the primary contained in cell 2 * @param cell3p Output parameter for the primary contained in cell 3 * @return The subpixel layout */ enum libfonts_subpixel_order_class libfonts_get_subpixel_order_class(enum libfonts_subpixel_order, enum libfonts_subpixel_colour *, enum libfonts_subpixel_colour *, enum libfonts_subpixel_colour *); /** * Get a specific subpixel order from the * combination of a general subpixel layout * and the primaries for each cell in the * layout * * @param orderp Output parameter for the subpixel order * @param layout The subpixel layout * @param cell1 The primary contained in cell 1 * @param cell2 The primary contained in cell 2 * @param cell3 The primary contained in cell 3 * @return Normally 1, but 0 if `layout` is `LIBFONTS_SUBPIXEL_ORDER_CLASS_OTHER`; * -1 on failure * * @throws EINVAL Unrecognised value in `layout`, `cell1`, `cell2`, or `cell3` * @throws EINVAL The values of `cell1`, `cell2`, and `cell3` are not unique */ int libfonts_unget_subpixel_order_class(enum libfonts_subpixel_order *, enum libfonts_subpixel_order_class, enum libfonts_subpixel_colour, enum libfonts_subpixel_colour, enum libfonts_subpixel_colour); #endif