winansi: code shrink

Rework the ANSI emulation code to reduce its size.

- Fetch console attributes when required rather than caching them.
  The init() function is no longer required; the only remaining
  initialisation is now performed in is_console().

- Turning off inverse video (ESC[27m) didn't work properly.  This has
  been improved though it still doesn't work in some unlikely cases
  (ESC[7;27m).

These changes save 180 bytes.

1 files changed, 31 insertions, 37 deletions

diff --git a/win32/winansi.c b/win32/winansi.c
index 0d8cf662a..41ca3ccca 100644
--- a/win32/winansi.c
+++ b/win32/winansi.c
@@ -21,41 +21,35 @@
 #undef read
 #undef getc
 
-static WORD plain_attr;
-static WORD attr;
-static int negative;
+#define FOREGROUND_ALL (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE)
+#define BACKGROUND_ALL (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE)
+
+static WORD plain_attr = 0;
 
 static HANDLE get_console(void)
 {
         return GetStdHandle(STD_OUTPUT_HANDLE);
 }
 
-static void init(void)
+static WORD get_console_attr(void)
 {
-        static int initialised = FALSE;
-        HANDLE console;
         CONSOLE_SCREEN_BUFFER_INFO sbi;
 
-        if (initialised)
-                return;
-        initialised = TRUE;
+        if (GetConsoleScreenBufferInfo(get_console(), &sbi))
+                return sbi.wAttributes;
 
-        console = get_console();
-        if (GetConsoleScreenBufferInfo(console, &sbi)) {
-                attr = plain_attr = sbi.wAttributes;
-                negative = 0;
-        }
+        return FOREGROUND_ALL;
 }
 
 static int is_console(int fd)
 {
-        init();
+        if (!plain_attr)
+                plain_attr = get_console_attr();
         return isatty(fd) && get_console() != INVALID_HANDLE_VALUE;
 }
 
 static int is_console_in(int fd)
 {
-        init();
         return isatty(fd) && GetStdHandle(STD_INPUT_HANDLE) != INVALID_HANDLE_VALUE;
 }
 
@@ -91,11 +85,8 @@ static HANDLE dup_handle(HANDLE h)
 static void use_alt_buffer(int flag)
 {
         static HANDLE console_orig = INVALID_HANDLE_VALUE;
-        CONSOLE_SCREEN_BUFFER_INFO sbi;
         HANDLE console, h;
 
-        init();
-
         console = get_console();
         console_orig = dup_handle(console);
         if (console_orig == INVALID_HANDLE_VALUE)
@@ -103,6 +94,7 @@ static void use_alt_buffer(int flag)
 
         if (flag) {
                 SECURITY_ATTRIBUTES sa;
+                CONSOLE_SCREEN_BUFFER_INFO sbi;
 
                 // handle should be inheritable
                 memset(&sa, 0, sizeof(sa));
@@ -134,31 +126,28 @@ static void use_alt_buffer(int flag)
         _open_osfhandle((intptr_t)console, O_RDWR|O_BINARY);
 }
 
-#define FOREGROUND_ALL (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE)
-#define BACKGROUND_ALL (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE)
-
-static void set_console_attr(void)
+static void set_console_attr(WORD attributes, int invert)
 {
         HANDLE console = get_console();
-        WORD attributes = attr;
-        if (negative) {
+        if (invert) {
+                WORD save = attributes;
                 attributes &= ~FOREGROUND_ALL;
                 attributes &= ~BACKGROUND_ALL;
 
                 /* This could probably use a bitmask
                    instead of a series of ifs */
-                if (attr & FOREGROUND_RED)
+                if (save & FOREGROUND_RED)
                         attributes |= BACKGROUND_RED;
-                if (attr & FOREGROUND_GREEN)
+                if (save & FOREGROUND_GREEN)
                         attributes |= BACKGROUND_GREEN;
-                if (attr & FOREGROUND_BLUE)
+                if (save & FOREGROUND_BLUE)
                         attributes |= BACKGROUND_BLUE;
 
-                if (attr & BACKGROUND_RED)
+                if (save & BACKGROUND_RED)
                         attributes |= FOREGROUND_RED;
-                if (attr & BACKGROUND_GREEN)
+                if (save & BACKGROUND_GREEN)
                         attributes |= FOREGROUND_GREEN;
-                if (attr & BACKGROUND_BLUE)
+                if (save & BACKGROUND_BLUE)
                         attributes |= FOREGROUND_BLUE;
         }
         SetConsoleTextAttribute(console, attributes);
@@ -252,6 +241,9 @@ static char *process_escape(char *pos)
         const char *str, *func;
         char *bel;
         size_t len;
+        WORD attr = get_console_attr();
+        int invert = FALSE;
+        static int inverse = 0;
 
         switch (pos[1]) {
         case '[':
@@ -281,7 +273,7 @@ static char *process_escape(char *pos)
                         switch (val) {
                         case 0: /* reset */
                                 attr = plain_attr;
-                                negative = 0;
+                                inverse = 0;
                                 break;
                         case 1: /* bold */
                                 attr |= FOREGROUND_INTENSITY;
@@ -311,11 +303,13 @@ static char *process_escape(char *pos)
                         case 25: /* no blink */
                                 attr &= ~BACKGROUND_INTENSITY;
                                 break;
-                        case 7:  /* negative */
-                                negative = 1;
+                        case 7:  /* inverse on */
+                                invert = !inverse;
+                                inverse = 1;
                                 break;
-                        case 27: /* positive */
-                                negative = 0;
+                        case 27: /* inverse off */
+                                invert = inverse;
+                                inverse = 0;
                                 break;
                         case 8:  /* conceal */
                         case 28: /* reveal */
@@ -404,7 +398,7 @@ static char *process_escape(char *pos)
                         str++;
                 } while (*(str-1) == ';');
 
-                set_console_attr();
+                set_console_attr(attr, invert);
                 break;
         case 'A': /* up */
                 move_cursor_row(-strtol(str, (char **)&str, 10));