Add texthook option

`-texthook print` prints text to console, and `-texthook copy`
automatically copies text to clipboard (for use with text hooker tools).

On Windows, copy mode can be toggled from the menu bar.

src/texthook.cpp

@@ -1,9 +1,15 @@
+#include <string>
 #include <stdio.h>
+#include <SDL.h>
 #include "texthook.h"
 
-#ifdef __EMSCRIPTEN__  // ----------------------------------------------
+#ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 
+void texthook_set_mode(TexthookMode m) {
+	// Do nothing
+}
+
 void texthook_character(int page, int character) {
 	EM_ASM_({ xsystem35.texthook.message(String.fromCharCode($0), $1); },
 			character, page);
@@ -21,59 +27,139 @@ EM_JS(void, texthook_keywait, (void), {
 	xsystem35.texthook.keywait();
 });
 
-#elif defined(TEXTHOOK_PRINT)  // --------------------------------------
+#else
 
-static int newlines = 0;
+namespace {
+
+class TextHookHandler {
+public:
+	virtual void character(int page, int c) = 0;
+	virtual void newline(void) = 0;
+	virtual void nextpage(void) = 0;
+	virtual void keywait(void) = 0;
+};
+
+class None : public TextHookHandler {
+public:
+	void character(int page, int c) override {}
+	void newline(void) override {}
+	void nextpage(void) override {}
+	void keywait(void) override {}
+} none;
+
+class Print : public TextHookHandler {
+public:
+	void character(int page, int c) override {
+		if (newlines)
+			printf("%d:", page);
+		newlines = 0;
+
+		if (c <= 0x7f) {
+			putchar(c);
+		} else if (c <= 0x7ff) {
+			putchar(0xc0 | c >> 6);
+			putchar(0x80 | (c & 0x3f));
+		} else {
+			putchar(0xe0 | c >> 12);
+			putchar(0x80 | (c >> 6 & 0x3f));
+			putchar(0x80 | (c & 0x3f));
+		}
+	}
+
+	void newline(void) override {
+		if (newlines < 2) {
+			putchar('\n');
+			fflush(stdout);
+			newlines++;
+		}
+	}
+
+	void nextpage(void) override {
+		while (newlines < 2) {
+			putchar('\n');
+			fflush(stdout);
+			newlines++;
+		}
+	}
+
+	void keywait(void) override {
+		newline();
+	}
+
+private:
+	int newlines = 0;
+} print;
+
+class Copy : public TextHookHandler {
+public:
+	void character(int page, int c) override {
+		if (c <= 0x7f) {
+			buf += c;
+		} else if (c <= 0x7ff) {
+			buf += static_cast<char>(0xc0 | c >> 6);
+			buf += static_cast<char>(0x80 | (c & 0x3f));
+		} else {
+			buf += static_cast<char>(0xe0 | c >> 12);
+			buf += static_cast<char>(0x80 | (c >> 6 & 0x3f));
+			buf += static_cast<char>(0x80 | (c & 0x3f));
+		}
+	}
+
+	void newline(void) override {
+		buf += "\n";
+	}
+
+	void nextpage(void) override {
+		if (!buf.empty())
+			copy_to_clipboard();
+	}
+
+	void keywait(void) override {
+		if (!buf.empty())
+			copy_to_clipboard();
+	}
+
+private:
+	std::string buf;
+
+	void copy_to_clipboard(void) {
+		SDL_SetClipboardText(buf.c_str());
+		buf.clear();
+	}
+} copy;
+
+TextHookHandler *handler = &none;
+
+}  // namespace
+
+void texthook_set_mode(TexthookMode mode) {
+	switch (mode) {
+	case TEXTHOOK_NONE:
+		handler = &none;
+		break;
+	case TEXTHOOK_PRINT:
+		handler = &print;
+		break;
+	case TEXTHOOK_COPY:
+		handler = &copy;
+		break;
+	}
+}
 
 void texthook_character(int page, int c) {
-	if (newlines)
-		printf("%d:", page);
-	newlines = 0;
-
-	if (c <= 0x7f) {
-		putchar(c);
-	} else if (c <= 0x7ff) {
-		putchar(0xc0 | c >> 6);
-		putchar(0x80 | (c & 0x3f));
-	} else {
-		putchar(0xe0 | c >> 12);
-		putchar(0x80 | (c >> 6 & 0x3f));
-		putchar(0x80 | (c & 0x3f));
-	}
+	handler->character(page, c);
 }
 
 void texthook_newline(void) {
-	if (newlines < 2) {
-		putchar('\n');
-		fflush(stdout);
-		newlines++;
-	}
+	handler->newline();
 }
 
 void texthook_nextpage(void) {
-	while (newlines < 2) {
-		putchar('\n');
-		fflush(stdout);
-		newlines++;
-	}
+	handler->nextpage();
 }
 
 void texthook_keywait(void) {
-	texthook_newline();
+	handler->keywait();
 }
 
-#else  // --------------------------------------------------------------
-
-void texthook_character(int page, int c) {
-}
-
-void texthook_newline(void) {
-}
-
-void texthook_nextpage(void) {
-}
-
-void texthook_keywait(void) {
-}
-
-#endif  // -------------------------------------------------------------
+#endif