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-rw-r--r--src/nvim/vterm/encoding.c271
1 files changed, 271 insertions, 0 deletions
diff --git a/src/nvim/vterm/encoding.c b/src/nvim/vterm/encoding.c
new file mode 100644
index 0000000000..f9061e8e50
--- /dev/null
+++ b/src/nvim/vterm/encoding.c
@@ -0,0 +1,271 @@
+#include "nvim/vterm/encoding.h"
+#include "nvim/vterm/vterm_internal_defs.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "vterm/encoding.c.generated.h"
+#endif
+
+#define UNICODE_INVALID 0xFFFD
+
+#if defined(DEBUG) && DEBUG > 1
+# define DEBUG_PRINT_UTF8
+#endif
+
+struct UTF8DecoderData {
+ // number of bytes remaining in this codepoint
+ int bytes_remaining;
+
+ // number of bytes total in this codepoint once it's finished
+ // (for detecting overlongs)
+ int bytes_total;
+
+ int this_cp;
+};
+
+static void init_utf8(VTermEncoding *enc, void *data_)
+{
+ struct UTF8DecoderData *data = data_;
+
+ data->bytes_remaining = 0;
+ data->bytes_total = 0;
+}
+
+static void decode_utf8(VTermEncoding *enc, void *data_, uint32_t cp[], int *cpi, int cplen,
+ const char bytes[], size_t *pos, size_t bytelen)
+{
+ struct UTF8DecoderData *data = data_;
+
+#ifdef DEBUG_PRINT_UTF8
+ printf("BEGIN UTF-8\n");
+#endif
+
+ for (; *pos < bytelen && *cpi < cplen; (*pos)++) {
+ uint8_t c = (uint8_t)bytes[*pos];
+
+#ifdef DEBUG_PRINT_UTF8
+ printf(" pos=%zd c=%02x rem=%d\n", *pos, c, data->bytes_remaining);
+#endif
+
+ if (c < 0x20) { // C0
+ return;
+ } else if (c >= 0x20 && c < 0x7f) {
+ if (data->bytes_remaining) {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ }
+
+ cp[(*cpi)++] = c;
+#ifdef DEBUG_PRINT_UTF8
+ printf(" UTF-8 char: U+%04x\n", c);
+#endif
+ data->bytes_remaining = 0;
+ } else if (c == 0x7f) { // DEL
+ return;
+ } else if (c >= 0x80 && c < 0xc0) {
+ if (!data->bytes_remaining) {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ continue;
+ }
+
+ data->this_cp <<= 6;
+ data->this_cp |= c & 0x3f;
+ data->bytes_remaining--;
+
+ if (!data->bytes_remaining) {
+#ifdef DEBUG_PRINT_UTF8
+ printf(" UTF-8 raw char U+%04x bytelen=%d ", data->this_cp, data->bytes_total);
+#endif
+ // Check for overlong sequences
+ switch (data->bytes_total) {
+ case 2:
+ if (data->this_cp < 0x0080) {
+ data->this_cp = UNICODE_INVALID;
+ }
+ break;
+ case 3:
+ if (data->this_cp < 0x0800) {
+ data->this_cp = UNICODE_INVALID;
+ }
+ break;
+ case 4:
+ if (data->this_cp < 0x10000) {
+ data->this_cp = UNICODE_INVALID;
+ }
+ break;
+ case 5:
+ if (data->this_cp < 0x200000) {
+ data->this_cp = UNICODE_INVALID;
+ }
+ break;
+ case 6:
+ if (data->this_cp < 0x4000000) {
+ data->this_cp = UNICODE_INVALID;
+ }
+ break;
+ }
+ // Now look for plain invalid ones
+ if ((data->this_cp >= 0xD800 && data->this_cp <= 0xDFFF)
+ || data->this_cp == 0xFFFE
+ || data->this_cp == 0xFFFF) {
+ data->this_cp = UNICODE_INVALID;
+ }
+#ifdef DEBUG_PRINT_UTF8
+ printf(" char: U+%04x\n", data->this_cp);
+#endif
+ cp[(*cpi)++] = (uint32_t)data->this_cp;
+ }
+ } else if (c >= 0xc0 && c < 0xe0) {
+ if (data->bytes_remaining) {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ }
+
+ data->this_cp = c & 0x1f;
+ data->bytes_total = 2;
+ data->bytes_remaining = 1;
+ } else if (c >= 0xe0 && c < 0xf0) {
+ if (data->bytes_remaining) {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ }
+
+ data->this_cp = c & 0x0f;
+ data->bytes_total = 3;
+ data->bytes_remaining = 2;
+ } else if (c >= 0xf0 && c < 0xf8) {
+ if (data->bytes_remaining) {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ }
+
+ data->this_cp = c & 0x07;
+ data->bytes_total = 4;
+ data->bytes_remaining = 3;
+ } else if (c >= 0xf8 && c < 0xfc) {
+ if (data->bytes_remaining) {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ }
+
+ data->this_cp = c & 0x03;
+ data->bytes_total = 5;
+ data->bytes_remaining = 4;
+ } else if (c >= 0xfc && c < 0xfe) {
+ if (data->bytes_remaining) {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ }
+
+ data->this_cp = c & 0x01;
+ data->bytes_total = 6;
+ data->bytes_remaining = 5;
+ } else {
+ cp[(*cpi)++] = UNICODE_INVALID;
+ }
+ }
+}
+
+static VTermEncoding encoding_utf8 = {
+ .init = &init_utf8,
+ .decode = &decode_utf8,
+};
+
+static void decode_usascii(VTermEncoding *enc, void *data, uint32_t cp[], int *cpi, int cplen,
+ const char bytes[], size_t *pos, size_t bytelen)
+{
+ int is_gr = bytes[*pos] & 0x80;
+
+ for (; *pos < bytelen && *cpi < cplen; (*pos)++) {
+ uint8_t c = (uint8_t)(bytes[*pos] ^ is_gr);
+
+ if (c < 0x20 || c == 0x7f || c >= 0x80) {
+ return;
+ }
+
+ cp[(*cpi)++] = c;
+ }
+}
+
+static VTermEncoding encoding_usascii = {
+ .decode = &decode_usascii,
+};
+
+struct StaticTableEncoding {
+ const VTermEncoding enc;
+ const uint32_t chars[128];
+};
+
+static void decode_table(VTermEncoding *enc, void *data, uint32_t cp[], int *cpi, int cplen,
+ const char bytes[], size_t *pos, size_t bytelen)
+{
+ struct StaticTableEncoding *table = (struct StaticTableEncoding *)enc;
+ int is_gr = bytes[*pos] & 0x80;
+
+ for (; *pos < bytelen && *cpi < cplen; (*pos)++) {
+ uint8_t c = (uint8_t)(bytes[*pos] ^ is_gr);
+
+ if (c < 0x20 || c == 0x7f || c >= 0x80) {
+ return;
+ }
+
+ if (table->chars[c]) {
+ cp[(*cpi)++] = table->chars[c];
+ } else {
+ cp[(*cpi)++] = c;
+ }
+ }
+}
+
+// https://en.wikipedia.org/wiki/DEC_Special_Graphics
+static const struct StaticTableEncoding encoding_DECdrawing = {
+ { .decode = &decode_table },
+ {
+ [0x60] = 0x25C6, // BLACK DIAMOND
+ [0x61] = 0x2592, // MEDIUM SHADE (checkerboard)
+ [0x62] = 0x2409, // SYMBOL FOR HORIZONTAL TAB
+ [0x63] = 0x240C, // SYMBOL FOR FORM FEED
+ [0x64] = 0x240D, // SYMBOL FOR CARRIAGE RETURN
+ [0x65] = 0x240A, // SYMBOL FOR LINE FEED
+ [0x66] = 0x00B0, // DEGREE SIGN
+ [0x67] = 0x00B1, // PLUS-MINUS SIGN (plus or minus)
+ [0x68] = 0x2424, // SYMBOL FOR NEW LINE
+ [0x69] = 0x240B, // SYMBOL FOR VERTICAL TAB
+ [0x6a] = 0x2518, // BOX DRAWINGS LIGHT UP AND LEFT (bottom-right corner)
+ [0x6b] = 0x2510, // BOX DRAWINGS LIGHT DOWN AND LEFT (top-right corner)
+ [0x6c] = 0x250C, // BOX DRAWINGS LIGHT DOWN AND RIGHT (top-left corner)
+ [0x6d] = 0x2514, // BOX DRAWINGS LIGHT UP AND RIGHT (bottom-left corner)
+ [0x6e] = 0x253C, // BOX DRAWINGS LIGHT VERTICAL AND HORIZONTAL (crossing lines)
+ [0x6f] = 0x23BA, // HORIZONTAL SCAN LINE-1
+ [0x70] = 0x23BB, // HORIZONTAL SCAN LINE-3
+ [0x71] = 0x2500, // BOX DRAWINGS LIGHT HORIZONTAL
+ [0x72] = 0x23BC, // HORIZONTAL SCAN LINE-7
+ [0x73] = 0x23BD, // HORIZONTAL SCAN LINE-9
+ [0x74] = 0x251C, // BOX DRAWINGS LIGHT VERTICAL AND RIGHT
+ [0x75] = 0x2524, // BOX DRAWINGS LIGHT VERTICAL AND LEFT
+ [0x76] = 0x2534, // BOX DRAWINGS LIGHT UP AND HORIZONTAL
+ [0x77] = 0x252C, // BOX DRAWINGS LIGHT DOWN AND HORIZONTAL
+ [0x78] = 0x2502, // BOX DRAWINGS LIGHT VERTICAL
+ [0x79] = 0x2A7D, // LESS-THAN OR SLANTED EQUAL-TO
+ [0x7a] = 0x2A7E, // GREATER-THAN OR SLANTED EQUAL-TO
+ [0x7b] = 0x03C0, // GREEK SMALL LETTER PI
+ [0x7c] = 0x2260, // NOT EQUAL TO
+ [0x7d] = 0x00A3, // POUND SIGN
+ [0x7e] = 0x00B7, // MIDDLE DOT
+ }
+};
+
+static struct {
+ VTermEncodingType type;
+ char designation;
+ VTermEncoding *enc;
+}
+encodings[] = {
+ { ENC_UTF8, 'u', &encoding_utf8 },
+ { ENC_SINGLE_94, '0', (VTermEncoding *)&encoding_DECdrawing },
+ { ENC_SINGLE_94, 'B', &encoding_usascii },
+ { 0 },
+};
+
+VTermEncoding *vterm_lookup_encoding(VTermEncodingType type, char designation)
+{
+ for (int i = 0; encodings[i].designation; i++) {
+ if (encodings[i].type == type && encodings[i].designation == designation) {
+ return encodings[i].enc;
+ }
+ }
+ return NULL;
+}
generated by cgit (git 2.34.1) at 2025-04-28 20:25:57 +0000