diff options
Diffstat (limited to 'textscreen')
| -rw-r--r-- | textscreen/txt_gui.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/textscreen/txt_gui.c b/textscreen/txt_gui.c index af1bb0a4..1bcc2e9e 100644 --- a/textscreen/txt_gui.c +++ b/textscreen/txt_gui.c @@ -28,6 +28,51 @@ typedef struct txt_cliparea_s txt_cliparea_t; +// Mapping table that converts from the Extended ASCII codes in the +// CP437 codepage to Unicode character numbers. + +static const uint16_t cp437_unicode[] = { + 0x00c7, 0x00fc, 0x00e9, 0x00e2, // 80-8f + 0x00e4, 0x00e0, 0x00e5, 0x00e6, + 0x00ea, 0x00eb, 0x00e8, 0x00ef, + 0x00ee, 0x00ec, 0x00c4, 0x00c5, + + 0x00c9, 0x00e6, 0x00c6, 0x00f4, // 90-9f + 0x00f6, 0x00f2, 0x00fb, 0x00f9, + 0x00ff, 0x00d6, 0x00dc, 0x00a2, + 0x00a3, 0x00a5, 0x20a7, 0x0192, + + 0x00e1, 0x00ed, 0x00f3, 0x00fa, // a0-af + 0x00f1, 0x00d1, 0x00aa, 0x00ba, + 0x00bf, 0x2310, 0x00ac, 0x00bd, + 0x00bc, 0x00a1, 0x00ab, 0x00bb, + + 0x2591, 0x2592, 0x2593, 0x2502, // b0-bf + 0x2524, 0x2561, 0x2562, 0x2556, + 0x2555, 0x2563, 0x2551, 0x2557, + 0x255D, 0x255C, 0x255B, 0x2510, + + 0x2514, 0x2534, 0x252C, 0x251C, // c0-cf + 0x2500, 0x253C, 0x255E, 0x255F, + 0x255A, 0x2554, 0x2569, 0x2566, + 0x2560, 0x2550, 0x256C, 0x2567, + + 0x2568, 0x2564, 0x2565, 0x2559, // d0-df + 0x2558, 0x2552, 0x2553, 0x256B, + 0x256A, 0x2518, 0x250C, 0x2588, + 0x2584, 0x258C, 0x2590, 0x2580, + + 0x03B1, 0x00DF, 0x0393, 0x03C0, // e0-ef + 0x03A3, 0x03C3, 0x00B5, 0x03C4, + 0x03A6, 0x0398, 0x03A9, 0x03B4, + 0x221E, 0x03C6, 0x03B5, 0x2229, + + 0x2261, 0x00B1, 0x2265, 0x2264, // f0-ff + 0x2320, 0x2321, 0x00F7, 0x2248, + 0x00B0, 0x2219, 0x00B7, 0x221A, + 0x207F, 0x00B2, 0x25A0, 0x00A0, +}; + struct txt_cliparea_s { int x1, x2; @@ -251,6 +296,119 @@ void TXT_DrawString(const char *s) TXT_GotoXY(x + strlen(s), y); } +// Decode UTF-8 character, incrementing *ptr over the decoded bytes. + +static unsigned int DecodeUTF8(const char **ptr) +{ + const char *p = *ptr; + unsigned int c; + + // UTF-8 decode. + + if ((*p & 0x80) == 0) // 1 character (ASCII): + { + c = *p; + *ptr += 1; + } + else if ((p[0] & 0xe0) == 0xc0 // 2 character: + && (p[1] & 0xc0) == 0x80) + { + c = ((p[0] & 0x1f) << 6) + | (p[1] & 0x3f); + *ptr += 2; + } + else if ((p[0] & 0xf0) == 0xe0 // 3 character: + && (p[1] & 0xc0) == 0x80 + && (p[2] & 0xc0) == 0x80) + { + c = ((p[0] & 0x0f) << 12) + | ((p[1] & 0x3f) << 6) + | (p[2] & 0x3f); + *ptr += 3; + } + else if ((p[0] & 0xf8) == 0xf0 // 4 character: + && (p[1] & 0xc0) == 0x80 + && (p[2] & 0xc0) == 0x80 + && (p[3] & 0xc0) == 0x80) + { + c = ((p[0] & 0x07) << 18) + | ((p[1] & 0x3f) << 12) + | ((p[2] & 0x3f) << 6) + | (p[3] & 0x3f); + *ptr += 4; + } + else + { + // Decode failure. + // Don't bother with 5/6 byte sequences. + + c = 0; + } + + return c; +} + +static void PutUnicodeChar(unsigned int c) +{ + unsigned int i; + + if (c < 128) + { + TXT_PutChar(c); + return; + } + + // We can only display this character if it is in the CP437 codepage. + + for (i = 0; i < 128; ++i) + { + if (cp437_unicode[i] == c) + { + TXT_PutChar(128 + i); + return; + } + } + + // Otherwise, print a fallback character (inverted question mark): + + TXT_PutChar('\xa8'); +} + +void TXT_DrawUTF8String(const char *s) +{ + int x, y; + int x1; + const char *p; + unsigned int c; + + TXT_GetXY(&x, &y); + + if (VALID_Y(y)) + { + x1 = x; + + for (p = s; *p != '\0'; ) + { + c = DecodeUTF8(&p); + + if (c == 0) + { + break; + } + + if (VALID_X(x1)) + { + TXT_GotoXY(x1, y); + PutUnicodeChar(c); + } + + x1 += 1; + } + } + + TXT_GotoXY(x + strlen(s), y); +} + void TXT_DrawHorizScrollbar(int x, int y, int w, int cursor, int range) { int x1; |