Implementing Back Color Erase (BCE).

diff --git a/st.c b/st.c
index 769de8b..5f75c39 100644 (file)
--- a/st.c
+++ b/st.c
@@ -152,7 +152,7 @@ typedef struct {
        uchar state; /* state flags    */
 } Glyph;
 
-typedef Glyph* Line;
+typedef Glyph *Line;
 
 typedef struct {
        Glyph attr;      /* current char attributes */
@@ -303,7 +303,7 @@ static void strhandle(void);
 static void strparse(void);
 static void strreset(void);
 
-static void tclearregion(int, int, int, int);
+static void tclearregion(int, int, int, int, int);
 static void tcursor(int);
 static void tdeletechar(int);
 static void tdeleteline(int);
@@ -1113,7 +1113,7 @@ treset(void) {
        term.bot = term.row - 1;
        term.mode = MODE_WRAP;
 
-       tclearregion(0, 0, term.col-1, term.row-1);
+       tclearregion(0, 0, term.col-1, term.row-1, 0);
        tmoveto(0, 0);
        tcursor(CURSOR_SAVE);
 }
@@ -1157,7 +1157,7 @@ tscrolldown(int orig, int n) {
 
        LIMIT(n, 0, term.bot-orig+1);
 
-       tclearregion(0, term.bot-n+1, term.col-1, term.bot);
+       tclearregion(0, term.bot-n+1, term.col-1, term.bot, 0);
 
        for(i = term.bot; i >= orig+n; i--) {
                temp = term.line[i];
@@ -1177,7 +1177,7 @@ tscrollup(int orig, int n) {
        Line temp;
        LIMIT(n, 0, term.bot-orig+1);
 
-       tclearregion(0, orig, term.col-1, orig+n-1);
+       tclearregion(0, orig, term.col-1, orig+n-1, 0);
 
        for(i = orig; i <= term.bot-n; i++) {
                 temp = term.line[i];
@@ -1305,7 +1305,7 @@ tsetchar(char *c, Glyph *attr, int x, int y) {
 }
 
 void
-tclearregion(int x1, int y1, int x2, int y2) {
+tclearregion(int x1, int y1, int x2, int y2, int bce) {
        int x, y, temp;
 
        if(x1 > x2)
@@ -1320,8 +1320,15 @@ tclearregion(int x1, int y1, int x2, int y2) {
 
        for(y = y1; y <= y2; y++) {
                term.dirty[y] = 1;
-               for(x = x1; x <= x2; x++)
-                       term.line[y][x].state = 0;
+               for(x = x1; x <= x2; x++) {
+                       if(bce) {
+                               term.line[y][x] = term.c.attr;
+                               memcpy(term.line[y][x].c, " ", 2);
+                               term.line[y][x].state |= GLYPH_SET;
+                       } else {
+                               term.line[y][x].state = 0;
+                       }
+               }
        }
 }
 
@@ -1334,13 +1341,13 @@ tdeletechar(int n) {
        term.dirty[term.c.y] = 1;
 
        if(src >= term.col) {
-               tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
+               tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 0);
                return;
        }
 
        memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src],
                        size * sizeof(Glyph));
-       tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
+       tclearregion(term.col-n, term.c.y, term.col-1, term.c.y, 0);
 }
 
 void
@@ -1352,13 +1359,13 @@ tinsertblank(int n) {
        term.dirty[term.c.y] = 1;
 
        if(dst >= term.col) {
-               tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
+               tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 0);
                return;
        }
 
        memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src],
                        size * sizeof(Glyph));
-       tclearregion(src, term.c.y, dst - 1, term.c.y);
+       tclearregion(src, term.c.y, dst - 1, term.c.y, 0);
 }
 
 void
@@ -1542,8 +1549,10 @@ tsetmode(bool priv, bool set, int *args, int narg) {
                        case 47:
                        case 1047: {
                                alt = IS_SET(MODE_ALTSCREEN);
-                               if(alt)
-                                       tclearregion(0, 0, term.col-1, term.row-1);
+                               if(alt) {
+                                       tclearregion(0, 0, term.col-1,
+                                                       term.row-1, 0);
+                               }
                                if(set ^ alt)           /* set is always 1 or 0 */
                                        tswapscreen();
                                if(*args != 1049)
@@ -1662,17 +1671,19 @@ csihandle(void) {
                sel.bx = -1;
                switch(csiescseq.arg[0]) {
                case 0: /* below */
-                       tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
-                       if(term.c.y < term.row-1)
-                               tclearregion(0, term.c.y+1, term.col-1, term.row-1);
+                       tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 1);
+                       if(term.c.y < term.row-1) {
+                               tclearregion(0, term.c.y+1, term.col-1,
+                                               term.row-1, 1);
+                       }
                        break;
                case 1: /* above */
                        if(term.c.y > 1)
-                               tclearregion(0, 0, term.col-1, term.c.y-1);
-                       tclearregion(0, term.c.y, term.c.x, term.c.y);
+                               tclearregion(0, 0, term.col-1, term.c.y-1, 1);
+                       tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
                        break;
                case 2: /* all */
-                       tclearregion(0, 0, term.col-1, term.row-1);
+                       tclearregion(0, 0, term.col-1, term.row-1, 1);
                        break;
                default:
                        goto unknown;
@@ -1681,13 +1692,14 @@ csihandle(void) {
        case 'K': /* EL -- Clear line */
                switch(csiescseq.arg[0]) {
                case 0: /* right */
-                       tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
+                       tclearregion(term.c.x, term.c.y, term.col-1,
+                                       term.c.y, 1);
                        break;
                case 1: /* left */
-                       tclearregion(0, term.c.y, term.c.x, term.c.y);
+                       tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
                        break;
                case 2: /* all */
-                       tclearregion(0, term.c.y, term.col-1, term.c.y);
+                       tclearregion(0, term.c.y, term.col-1, term.c.y, 1);
                        break;
                }
                break;
@@ -1712,7 +1724,8 @@ csihandle(void) {
                break;
        case 'X': /* ECH -- Erase <n> char */
                DEFAULT(csiescseq.arg[0], 1);
-               tclearregion(term.c.x, term.c.y, term.c.x + csiescseq.arg[0], term.c.y);
+               tclearregion(term.c.x, term.c.y, term.c.x + csiescseq.arg[0],
+                               term.c.y, 0);
                break;
        case 'P': /* DCH -- Delete <n> char */
                DEFAULT(csiescseq.arg[0], 1);
@@ -2505,6 +2518,7 @@ xinit(void) {
                xw.fy = 0;
        }
 
+       /* Events */
        attrs.background_pixel = dc.col[defaultbg].pixel;
        attrs.border_pixel = dc.col[defaultbg].pixel;
        attrs.bit_gravity = NorthWestGravity;
@@ -2898,6 +2912,7 @@ drawregion(int x1, int y1, int x2, int y2) {
                                        ox = x;
                                        base = new;
                                }
+
                                sl = utf8size(new.c);
                                memcpy(buf+ib, new.c, sl);
                                ib += sl;

diff --git a/st.info b/st.info
index fcaa024..1c83dc1 100644 (file)
--- a/st.info
+++ b/st.info
@@ -3,7 +3,7 @@
 st| simpleterm,
        acsc=``aaffggiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,
        am,
-#      bce,
+       bce,
        bel=^G,
 #      blink=\E[5m,
        bold=\E[1m,