feat: add on-screen keyboard with layout/hit detection tests

1 files changed, 47 insertions, 0 deletions

diff --git a/main/keyboard.h b/main/keyboard.h
new file mode 100644
index 0000000..d7b3400
--- /dev/null
+++ b/main/keyboard.h
@@ -0,0 +1,47 @@
+#ifndef KEYBOARD_H
+#define KEYBOARD_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#define KB_INPUT_MAX     64
+#define KB_KEY_W         28
+#define KB_KEY_H         36
+#define KB_KEY_GAP       2
+#define KB_ROW_COUNT     4
+#define KB_START_Y       310
+
+typedef enum {
+    KB_ALPHA_LOWER,
+    KB_ALPHA_UPPER,
+    KB_NUMSYM
+} kb_layer_t;
+
+typedef enum {
+    KB_ACTION_NONE = 0,
+    KB_ACTION_CHAR,
+    KB_ACTION_SHIFT,
+    KB_ACTION_BACKSPACE,
+    KB_ACTION_DONE,
+    KB_ACTION_LAYER,
+    KB_ACTION_SPACE
+} kb_action_t;
+
+typedef struct {
+    kb_action_t action;
+    char ch;
+} kb_result_t;
+
+typedef struct {
+    char input[KB_INPUT_MAX + 1];
+    int cursor;
+    bool reveal;
+    kb_layer_t layer;
+} kb_state_t;
+
+void kb_state_init(kb_state_t *st);
+int kb_get_row_keys(int row, kb_layer_t layer, const char **keys_out);
+kb_result_t kb_hit_test(int tx, int ty, kb_layer_t layer);
+void kb_apply(kb_state_t *st, kb_result_t result);
+
+#endif