From ad3eb77af098f34c1ea8cb50f468a8b75fb7d61c Mon Sep 17 00:00:00 2001 From: eunhhu Date: Sun, 27 Sep 2026 15:03:45 +0100 Subject: Take keyboards, mice and touch screens on the display (evdev) vega display --live reads the kernel's input events with no library: keys become Pure's key names and the text they type on a US layout, going through the TUI's own handling (the input line takes text, else the app takes keys); a mouse moves an outlined pointer and clicks, a touch screen presses where it is touched, scaled from the device's range; the line pressed is the row. --input FILE reads recorded events to their end and prints the last frame, which is how this screenless Pi checks it: after typing two items with Shift, Enter, Tab, Space and a touch on a row, the display's last frame is the TUI's after the same keys and click, and came back from the display controller as drawn. --- surfaces/input.c | 190 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 surfaces/input.c (limited to 'surfaces/input.c') diff --git a/surfaces/input.c b/surfaces/input.c new file mode 100644 index 0000000..b358d47 --- /dev/null +++ b/surfaces/input.c @@ -0,0 +1,190 @@ +#define _DEFAULT_SOURCE +#include "vega.h" +#include +#include +#include +#include +#include +#include +#include +#include + +/* Input from evdev (the kernel's input events): keyboards, mice and touch + * screens, read without a library. Keys come out as Pure's key names (as + * KeyboardEvent.code spells them) and the text they type on a US layout; + * pointers as presses at a pixel. */ + +enum { DEVICES = 32 }; + +typedef struct { + int fd; + bool touch; /* absolute positions, scaled to the screen */ + int min[2], max[2]; /* the device's range on x and y */ +} Device; + +struct VegaInput { + Device devices[DEVICES]; + unsigned count; + unsigned width, height; /* the screen, for pointers */ + int x, y; /* the pointer */ + bool shift, touched, moved; +}; + +/* Key names by code, with what a key types on a US layout (unshifted, shifted). */ +static const struct { unsigned short code; const char *name; char plain, shifted; } keys[] = { + {KEY_ESC, "Escape", 0, 0}, {KEY_1, "Digit1", '1', '!'}, {KEY_2, "Digit2", '2', '@'}, {KEY_3, "Digit3", '3', '#'}, + {KEY_4, "Digit4", '4', '$'}, {KEY_5, "Digit5", '5', '%'}, {KEY_6, "Digit6", '6', '^'}, {KEY_7, "Digit7", '7', '&'}, + {KEY_8, "Digit8", '8', '*'}, {KEY_9, "Digit9", '9', '('}, {KEY_0, "Digit0", '0', ')'}, {KEY_MINUS, "Minus", '-', '_'}, + {KEY_EQUAL, "Equal", '=', '+'}, {KEY_BACKSPACE, "Backspace", 0, 0}, {KEY_TAB, "Tab", 0, 0}, + {KEY_Q, "KeyQ", 'q', 'Q'}, {KEY_W, "KeyW", 'w', 'W'}, {KEY_E, "KeyE", 'e', 'E'}, {KEY_R, "KeyR", 'r', 'R'}, + {KEY_T, "KeyT", 't', 'T'}, {KEY_Y, "KeyY", 'y', 'Y'}, {KEY_U, "KeyU", 'u', 'U'}, {KEY_I, "KeyI", 'i', 'I'}, + {KEY_O, "KeyO", 'o', 'O'}, {KEY_P, "KeyP", 'p', 'P'}, {KEY_LEFTBRACE, "BracketLeft", '[', '{'}, + {KEY_RIGHTBRACE, "BracketRight", ']', '}'}, {KEY_ENTER, "Enter", 0, 0}, {KEY_A, "KeyA", 'a', 'A'}, + {KEY_S, "KeyS", 's', 'S'}, {KEY_D, "KeyD", 'd', 'D'}, {KEY_F, "KeyF", 'f', 'F'}, {KEY_G, "KeyG", 'g', 'G'}, + {KEY_H, "KeyH", 'h', 'H'}, {KEY_J, "KeyJ", 'j', 'J'}, {KEY_K, "KeyK", 'k', 'K'}, {KEY_L, "KeyL", 'l', 'L'}, + {KEY_SEMICOLON, "Semicolon", ';', ':'}, {KEY_APOSTROPHE, "Quote", '\'', '"'}, {KEY_GRAVE, "Backquote", '`', '~'}, + {KEY_BACKSLASH, "Backslash", '\\', '|'}, {KEY_Z, "KeyZ", 'z', 'Z'}, {KEY_X, "KeyX", 'x', 'X'}, + {KEY_C, "KeyC", 'c', 'C'}, {KEY_V, "KeyV", 'v', 'V'}, {KEY_B, "KeyB", 'b', 'B'}, {KEY_N, "KeyN", 'n', 'N'}, + {KEY_M, "KeyM", 'm', 'M'}, {KEY_COMMA, "Comma", ',', '<'}, {KEY_DOT, "Period", '.', '>'}, + {KEY_SLASH, "Slash", '/', '?'}, {KEY_SPACE, "Space", ' ', ' '}, {KEY_F1, "F1", 0, 0}, {KEY_F2, "F2", 0, 0}, + {KEY_F3, "F3", 0, 0}, {KEY_F4, "F4", 0, 0}, {KEY_F5, "F5", 0, 0}, {KEY_F6, "F6", 0, 0}, {KEY_F7, "F7", 0, 0}, + {KEY_F8, "F8", 0, 0}, {KEY_F9, "F9", 0, 0}, {KEY_F10, "F10", 0, 0}, {KEY_F11, "F11", 0, 0}, {KEY_F12, "F12", 0, 0}, + {KEY_HOME, "Home", 0, 0}, {KEY_UP, "ArrowUp", 0, 0}, {KEY_PAGEUP, "PageUp", 0, 0}, {KEY_LEFT, "ArrowLeft", 0, 0}, + {KEY_RIGHT, "ArrowRight", 0, 0}, {KEY_END, "End", 0, 0}, {KEY_DOWN, "ArrowDown", 0, 0}, + {KEY_PAGEDOWN, "PageDown", 0, 0}, {KEY_INSERT, "Insert", 0, 0}, {KEY_DELETE, "Delete", 0, 0}, +}; + +static bool has(int fd, unsigned type, unsigned code) { + unsigned long bits[KEY_MAX / (8 * sizeof(long)) + 1] = {0}; + if (ioctl(fd, EVIOCGBIT(type, sizeof(bits)), bits) < 0) return false; + return bits[code / (8 * sizeof(long))] >> (code % (8 * sizeof(long))) & 1; +} + +/* A device worth reading: one with keys, a relative pointer, or touch. */ +static bool add(VegaInput *input, int fd, bool probe) { + Device device = {.fd = fd}; + if (probe) { + bool keys_ = has(fd, EV_KEY, KEY_A) || has(fd, EV_KEY, KEY_ENTER), mouse = has(fd, EV_REL, REL_X); + device.touch = has(fd, EV_ABS, ABS_MT_POSITION_X) || has(fd, EV_ABS, ABS_X); + if (!keys_ && !mouse && !device.touch) return false; + for (int axis = 0; device.touch && axis < 2; ++axis) { + struct input_absinfo range; + unsigned code = has(fd, EV_ABS, ABS_MT_POSITION_X) ? (axis ? ABS_MT_POSITION_Y : ABS_MT_POSITION_X) + : (axis ? ABS_Y : ABS_X); + if (ioctl(fd, EVIOCGABS(code), &range) < 0 || range.maximum <= range.minimum) device.touch = false; + else device.min[axis] = range.minimum, device.max[axis] = range.maximum; + } + } else device.touch = true, device.min[0] = device.min[1] = 0, device.max[0] = device.max[1] = 0; /* raw: screen pixels */ + if (input->count == DEVICES) return false; + input->devices[input->count++] = device; + return true; +} + +VegaInput *vega_input_open(const char *const *paths, unsigned count, unsigned width, unsigned height) { + VegaInput *input = calloc(1, sizeof(*input)); + if (!input) return NULL; + input->width = width, input->height = height, input->x = (int)width / 2, input->y = (int)height / 2; + if (count) { /* files of recorded events, positions already in screen pixels */ + for (unsigned i = 0; i < count; ++i) { + int fd = open(paths[i], O_RDONLY | O_CLOEXEC); + if (fd < 0 || !add(input, fd, false)) { if (fd >= 0) close(fd); vega_input_close(input); return NULL; } + } + return input; + } + DIR *directory = opendir("/dev/input"); + struct dirent *entry; + while (directory && (entry = readdir(directory))) { + if (strncmp(entry->d_name, "event", 5)) continue; + char path[300]; + snprintf(path, sizeof(path), "/dev/input/%s", entry->d_name); + int fd = open(path, O_RDONLY | O_NONBLOCK | O_CLOEXEC); + if (fd >= 0 && !add(input, fd, true)) close(fd); + } + if (directory) closedir(directory); + return input; +} + +unsigned vega_input_fds(const VegaInput *input, struct pollfd *out, unsigned max) { + unsigned n = 0; + for (unsigned i = 0; i < input->count && n < max; ++i) out[n++] = (struct pollfd){input->devices[i].fd, POLLIN, 0}; + return n; +} + +static int scaled(const Device *device, int axis, int value, unsigned size) { + if (device->max[axis] <= device->min[axis]) return value; /* already in screen pixels */ + long long span = device->max[axis] - device->min[axis]; + return (int)((long long)(value - device->min[axis]) * (long long)(size - 1) / span); +} + +static unsigned emit(VegaEvent *out, unsigned n, unsigned max, VegaEvent event) { + if (n < max) out[n++] = event; + return n; +} + +/* One event of a device into what it means; returns the new count. */ +static unsigned translate(VegaInput *input, const Device *device, const struct input_event *e, VegaEvent *out, unsigned n, + unsigned max) { + if (e->type == EV_KEY && (e->code == KEY_LEFTSHIFT || e->code == KEY_RIGHTSHIFT)) { + input->shift = e->value != 0; + return n; + } + if (e->type == EV_KEY && (e->code == BTN_LEFT || e->code == BTN_TOUCH) && e->value == 1) { + if (e->code == BTN_TOUCH) input->touched = true; + return emit(out, n, max, (VegaEvent){VEGA_EVENT_PRESS, "", "", input->x, input->y, 0}); + } + if (e->type == EV_KEY && e->value != 0) { /* a press or its repeat */ + for (size_t i = 0; i < sizeof(keys) / sizeof(*keys); ++i) + if (keys[i].code == e->code) { + VegaEvent event = {VEGA_EVENT_KEY, "", "", input->x, input->y, 0}; + snprintf(event.name, sizeof(event.name), "%s", keys[i].name); + char c = input->shift ? keys[i].shifted : keys[i].plain; + if (c) event.kind = VEGA_EVENT_TEXT, event.text[0] = c; + return emit(out, n, max, event); + } + return n; + } + if (e->type == EV_REL && (e->code == REL_X || e->code == REL_Y)) { + int *at = e->code == REL_X ? &input->x : &input->y, limit = (int)(e->code == REL_X ? input->width : input->height); + *at += e->value; + *at = *at < 0 ? 0 : *at >= limit ? limit - 1 : *at; + input->moved = true; + return n; + } + if (e->type == EV_REL && e->code == REL_WHEEL && e->value) + return emit(out, n, max, (VegaEvent){VEGA_EVENT_WHEEL, "", "", input->x, input->y, e->value > 0 ? -1 : 1}); + if (e->type == EV_ABS && (e->code == ABS_MT_POSITION_X || e->code == ABS_X)) { + input->x = scaled(device, 0, e->value, input->width); + input->moved = true; + } else if (e->type == EV_ABS && (e->code == ABS_MT_POSITION_Y || e->code == ABS_Y)) { + input->y = scaled(device, 1, e->value, input->height); + input->moved = true; + } + return n; +} + +unsigned vega_input_read(VegaInput *input, int fd, VegaEvent *out, unsigned max, bool *ended) { + Device *device = NULL; + for (unsigned i = 0; i < input->count; ++i) if (input->devices[i].fd == fd) device = &input->devices[i]; + *ended = false; + if (!device) return 0; + struct input_event events[64]; + ssize_t got = read(fd, events, sizeof(events)); + if (got <= 0) { + *ended = got == 0 || (errno != EAGAIN && errno != EINTR); + return 0; + } + unsigned n = 0; + for (size_t i = 0; i < (size_t)got / sizeof(*events); ++i) n = translate(input, device, &events[i], out, n, max); + return n; +} + +void vega_input_pointer(const VegaInput *input, int *x, int *y, bool *shown) { + *x = input->x, *y = input->y; + *shown = input->moved && !input->touched; /* a mouse has a pointer to see; a finger does not */ +} + +void vega_input_close(VegaInput *input) { + if (!input) return; + for (unsigned i = 0; i < input->count; ++i) close(input->devices[i].fd); + free(input); +} -- cgit v1.2.3