vtgl

Commit: 8b63ad912b83a4103f5745d979af7c6a19b93228
Parent: bf4d6cd4d7ace61e9aff996f6ab1f00b6cacfd63
Author: Randy Palamar
Date:   Sun, 25 Aug 2024 12:46:33 -0600

CBT: cursor backwards tabulation (move cursor backwards to tabstop)

Diffstat:
M
terminal.c
 | 
19
++++++++++++-------
M
test.c
 | 
54
+++++++++++++++++++++++++++++++++++++++---------------
M
util.h
 | 
6
++++--

3 files changed, 55 insertions(+), 24 deletions(-)
diff --git a/terminal.c b/terminal.c
@@ -247,10 +247,13 @@ cursor_alt(Term *t, b32 save)
 }
 
 
+/* NOTE: advance the cursor by <n> cells; handles reverse movement */
 static void
-cursor_step_column(Term *t, i32 step)
+cursor_step_column(Term *t, i32 n)
 {
-	t->cursor.pos.x += step;
+	t->cursor.pos.x += n;
+	if (t->cursor.pos.x < 0)
+		t->cursor.pos.x = 0;
 	if (t->cursor.pos.x < t->size.w)
 		return;
 	t->cursor.pos.x = 0;
@@ -581,11 +584,12 @@ push_newline(Term *t)
 }
 
 static void
-push_tab(Term *t)
+push_tab(Term *t, i32 n)
 {
-	u32 advance = g_tabstop - (t->cursor.pos.x % g_tabstop);
-	fb_clear_region(t, t->cursor.pos.y, t->cursor.pos.y, t->cursor.pos.x, t->cursor.pos.x + advance);
-	cursor_step_column(t, advance);
+	i32 n_abs   = ABS(n);
+	i32 n_sgn   = SGN(n);
+	i32 advance = n_abs * g_tabstop - (t->cursor.pos.x % g_tabstop);
+	cursor_step_column(t, n_sgn * advance);
 }
 
 static i32
@@ -647,6 +651,7 @@ handle_csi(Term *t, s8 *raw)
 	case 'J': erase_in_display(t, &csi);                           break;
 	case 'K': erase_in_line(t, &csi);                              break;
 	case 'X': erase_characters(t, ORONE(csi.argv[0]));             break;
+	case 'Z': push_tab(t, -(ORONE(csi.argv[0])));                  break;
 	case 'a': cursor_step_raw(t, ORONE(csi.argv[0]),  0,  1);      break;
 	case 'd': cursor_move_to(t, csi.argv[0] - 1, p.x);             break;
 	case 'e': cursor_step_raw(t, ORONE(csi.argv[0]),  1,  0);      break;
@@ -988,7 +993,7 @@ push_line(Term *t, Line *line, Arena a)
 		case 0x1B: handle_escape(t, &l, a); break;
 		case '\r': t->cursor.pos.x = 0;     break;
 		case '\n': push_newline(t);         break;
-		case '\t': push_tab(t);             break;
+		case '\t': push_tab(t, 1);          break;
 		case '\a': /* TODO: ding ding? */   break;
 		case '\b':
 			cursor_move_to(t, t->cursor.pos.y, t->cursor.pos.x - 1);
diff --git a/test.c b/test.c
@@ -20,6 +20,7 @@ typedef TEST_FN(Test_Fn);
 	X(colour_setting)          \
 	X(cursor_at_line_boundary) \
 	X(cursor_movement)         \
+	X(cursor_tabs)             \
 	X(working_ringbuffer)
 
 #define X(fn) static TEST_FN(fn);
@@ -86,6 +87,31 @@ launder_static_string(Term *term, s8 static_str)
 	return raw;
 }
 
+static TEST_FN(colour_setting)
+{
+	struct test_result result = {.info = __FUNCTION__};
+
+	launder_static_string(term, CSI(8m));
+	launder_static_string(term, CSI(4m));
+	launder_static_string(term, CSI(9m));
+	launder_static_string(term, CSI(24m));
+	launder_static_string(term, CSI(33m));
+	launder_static_string(term, CSI(48;2;75;63;42m));
+	s8 raw = launder_static_string(term, s8("A"));
+
+	size parsed_lines = split_raw_input_to_lines(term, raw);
+	blit_lines(term, arena, parsed_lines);
+
+	Cell c = { .cp = 'A', .style = {
+		.bg    = (Colour){.r = 75, .g = 63, .b = 42, .a = 0xFF},
+		.fg    = g_colours.data[3],
+		.attr  = (ATTR_INVISIBLE|ATTR_STRUCK),
+	}};
+	result.status = check_cells_equal(&c, term->views[term->view_idx].fb.rows[0]);
+
+	return result;
+}
+
 static TEST_FN(cursor_movement)
 {
 	struct test_result result = {.info = __FUNCTION__};
@@ -103,27 +129,24 @@ static TEST_FN(cursor_movement)
 	return result;
 }
 
-static TEST_FN(colour_setting)
+static TEST_FN(cursor_tabs)
 {
 	struct test_result result = {.info = __FUNCTION__};
 
-	launder_static_string(term, CSI(8m));
-	launder_static_string(term, CSI(4m));
-	launder_static_string(term, CSI(9m));
-	launder_static_string(term, CSI(24m));
-	launder_static_string(term, CSI(33m));
-	launder_static_string(term, CSI(48;2;75;63;42m));
-	s8 raw = launder_static_string(term, s8("A"));
-
+	/* NOTE: first test advancing to a tabstop */
+	s8 raw            = launder_static_string(term, s8("123\t"));
 	size parsed_lines = split_raw_input_to_lines(term, raw);
 	blit_lines(term, arena, parsed_lines);
 
-	Cell c = { .cp = 'A', .style = {
-		.bg    = (Colour){.r = 75, .g = 63, .b = 42, .a = 0xFF},
-		.fg    = g_colours.data[3],
-		.attr  = (ATTR_INVISIBLE|ATTR_STRUCK),
-	}};
-	result.status = check_cells_equal(&c, term->views[term->view_idx].fb.rows[0]);
+	result.status = term->cursor.pos.x == (g_tabstop);
+
+	/* NOTE: now test negative tabstop movement */
+	launder_static_string(term, s8("\t1234\t"));
+	raw = launder_static_string(term, CSI(2Z));
+	parsed_lines = split_raw_input_to_lines(term, raw);
+	blit_lines(term, arena, parsed_lines);
+
+	result.status &= term->cursor.pos.x == (g_tabstop);
 
 	return result;
 }
@@ -217,6 +240,7 @@ main(void)
 	for (u32 i = 0; i < ARRAY_COUNT(tests); i++) {
 		buffer_reset(&term);
 		cursor_reset(&term);
+		cursor_move_to(&term, 0, 0);
 		struct test_result result = tests[i](&term, memory);
 		if (result.status == 0) {
 			failure_count++;
diff --git a/util.h b/util.h
@@ -24,10 +24,12 @@
 #define MEGABYTE (1024ULL * 1024ULL)
 
 #define ARRAY_COUNT(a)   (sizeof(a) / sizeof(*a))
+#define ABS(a)           ((a) < 0 ? (-a) : (a))
 #define BETWEEN(x, a, b) ((x) >= (a) && (x) <= (b))
-#define MIN(a, b)        ((a) <= (b) ? (a) : (b))
-#define MAX(a, b)        ((a) >= (b) ? (a) : (b))
 #define CLAMP(x, a, b)   ((x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x))
+#define MAX(a, b)        ((a) >= (b) ? (a) : (b))
+#define MIN(a, b)        ((a) <= (b) ? (a) : (b))
+#define SGN(a)           ((a) < 0 ? (-1) : (1))
 
 #define ISSPACE(c)       ((c) == ' ' || (c) == '\n' || (c) == '\t')
 #define ISPRINT(c)       BETWEEN((c), ' ', '~')