1 files changed, 133 insertions, 0 deletions
diff --git a/escape.h b/escape.h
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+//Types of ANSI Escape Sequences
+
+//C0	[0x07-0x0A|0x0C-0x0D|0x1B]
+//C1/Fe	[ESC][0x40-0x5F]
+//	technically can be represented in 1 byte w/ bytes above 0x80 but
+//	unimplemented b/c of unicode
+//	STring Terminator ESC \
+//CSI	(ESC\[|0x9B)[0-9:;<=>?]*[!"#$%&'()*+,-./]*[&A-Z[\]^_`a-z{|}~]
+//OSC	(ESC\]|0x9D).*(0x9C|0x1B 0x5C)
+//OCS	(ESCP|0x90).*(0x9C|0x1B 0x5C)
+//Fs	ESC[0x60-0x7E]
+//nF	ESC[0x20-02F]*[0x30-0x7E]
+//Fp	ESC[0x30-0x3F] save and clear
+
+//last read key
+enum esc_state {
+	//C0 except BEL or ESC, \n ,\r and \f
+	C0,
+	ESC,
+	CSI_START,
+	CSI_MID,
+	CSI_END,
+	//OSC, DCS, PM APC etc ST terminted C1,
+	C1_START,
+	ST,
+	nF_START,
+	nF_END,
+	//other fixed elngth C1, Fs,
+	C1,
+	//save and clear
+	DECSC,
+	DECRC,
+	NORMAL,
+};
+//global stdin -> pty ESC state
+enum esc_state in_state = NORMAL;
+//global pty -> stdout ESC state
+enum esc_state out_state = NORMAL;
+
+//c0 c1 c2 osc, sf nF sequences
+
+//also ESC 7 and ESC 8 up down bit
+//have a semaphore and above lock, IM will draw if available when input updates
+//or if some time has passed since output has been written
+
+enum esc_state update_esc_state(char * buff,unsigned int buff_len, enum esc_state state) {
+	for (int i = 0; i < buff_len; i++) {
+		char c = buff[i];
+		switch (state) {
+			case CSI_END:
+			case ST:
+			case nF_END:
+			case C0:
+			case C1:
+			case DECSC:
+			case DECRC:
+			//all the sequences that have ended don't have an end
+			//and default to normal
+			case NORMAL:
+				if  (c >= 0x08 && c <= 0x0A) {
+					state = C0;
+				}
+				if (c == 0x1B) {
+					state = ESC;
+				} else {
+					//return to normal
+					state = NORMAL;
+				}
+			break;
+			case ESC:
+				//fix length C1
+				if (c == 'N' || c == 'O') {
+					state = C1;
+				}
+				else if (c == '[') {
+					state = CSI_START;
+				}
+				//ST terminated C1 OSC, DCS, SOS, PM, APC
+				else if (c == ']' || c =='P' || c == '^' || c == 'X' || c == '_') {
+					state = C1_START;
+				}
+				//nF
+				else if (c >= 0x20 && c <= 0x2F) {
+					state = nF_START;
+				}
+				else if (c == '\\') {
+					state - ST;
+				}
+				else if (c == '7') {
+					state = DECSC;
+				}
+				else if (c == '8') {
+					state = DECSC;
+				//deformed escape sequence
+				} else {
+					state = NORMAL;
+				}
+			break;
+			case C1_START:
+				if (c == 0x1B) {
+					state = ESC;
+				}
+				if (c == 0x9C) {
+					state = ST;
+				}
+			break;
+			case CSI_START:
+			case CSI_MID:
+				if (c >= 0x30 && c <= 0x3F) {
+					state = CSI_MID;
+				} else if (c >= 0x20 && c <= 0x2F) {
+					state = CSI_MID;
+				} else if (c >= 0x40 && c <= 0x7E) {
+					state = CSI_END;
+				} else {
+					//malformed CSI sequence
+					state = NORMAL;
+				}
+			break;
+			case nF_START:
+				if (c >= 0x20 && c <= 0x2F) {
+					state = nF_START;
+				} else if (c >= 0x30 && c <= 0x7E) {
+					state = nF_END;
+					//malformed nF sequence
+				} else {
+					state = NORMAL;
+				}
+			break;
+		}
+	}
+	return state;
+}