vtgl

Commit: 74a07eb867da5ff89d82991b946540bc99610802
Parent: 21f08e5cafd29dae841324424e7debc7f51009c0
Author: Randy Palamar
Date:   Thu, 31 Oct 2024 06:14:43 -0600

fix tab advancement for arbitrary tabstop locations

Diffstat:
M
terminal.c
 | 
19
+++++++++++++++----
M
test.c
 | 
136
+++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------

2 files changed, 107 insertions(+), 48 deletions(-)
diff --git a/terminal.c b/terminal.c
@@ -334,15 +334,26 @@ cursor_step_raw(Term *t, i32 step, i32 rows, i32 cols)
 static i32
 next_tab_position(Term *t, b32 backwards)
 {
+	static_assert(ARRAY_COUNT(t->tabs) == 8 * sizeof(*t->tabs),
+	              "Term.tabs must be same length as the bitwidth of it's type");
 	u32 col  = t->cursor.pos.x;
 	u32 idx  = col / ARRAY_COUNT(t->tabs);
 	u32 bit  = col % ARRAY_COUNT(t->tabs);
 	u32 mask = safe_left_shift(1, bit - backwards) - 1;
 
-	i32 result = 32 * idx;
-	if (backwards) result += 32 - _lzcnt_u32(t->tabs[idx] & mask);
-	else           result += _tzcnt_u32(t->tabs[idx] & ~mask) + 1;
-	ASSERT(ABS(result) < t->size.w);
+	u32 result = 32 * idx, zeroes;
+	if (backwards) zeroes = 32 - _lzcnt_u32(t->tabs[idx++] & mask);
+	else           zeroes = _tzcnt_u32(t->tabs[idx++] & ~mask);
+	result += zeroes;
+
+	/* NOTE we may need to advance across idx boundaries */
+	while (idx < ARRAY_COUNT(t->tabs) && zeroes == 32) {
+		if (backwards) zeroes = 32 - _lzcnt_u32(t->tabs[idx++]);
+		else           zeroes = _tzcnt_u32(t->tabs[idx++]);
+		result += zeroes;
+	}
+	result += !backwards;
+	ASSERT(result < t->size.w);
 
 	return result;
 }
diff --git a/test.c b/test.c
@@ -60,12 +60,13 @@ struct test_result { b32 status; const char *info; };
 #define TEST_FN(name) struct test_result name(Term *term, Arena arena)
 typedef TEST_FN(Test_Fn);
 
-#define TESTS                      \
-	X(csi_embedded_control)    \
-	X(colour_setting)          \
-	X(cursor_at_line_boundary) \
-	X(cursor_movement)         \
-	X(cursor_tabs)             \
+#define TESTS                          \
+	X(csi_embedded_control)        \
+	X(colour_setting)              \
+	X(cursor_at_line_boundary)     \
+	X(cursor_movement)             \
+	X(cursor_tabs)                 \
+	X(cursor_tabs_across_boundary) \
 	X(working_ringbuffer)
 
 #define X(fn) static TEST_FN(fn);
@@ -76,6 +77,7 @@ TESTS
 static Test_Fn *tests[] = {
 	TESTS
 };
+#undef X
 
 #define ESC(a) s8("\x1B"#a)
 #define CSI(a) ESC([a)
@@ -194,43 +196,6 @@ static TEST_FN(colour_setting)
 	return result;
 }
 
-static TEST_FN(cursor_movement)
-{
-	struct test_result result = {.info = __FUNCTION__};
-
-	s8 raw = launder_static_string(term, CSI(17;2H));
-	handle_input(term, arena, raw);
-
-	raw = launder_static_string(term, CSI(7G));
-	handle_input(term, arena, raw);
-
-	result.status = term->cursor.pos.y == 16 && term->cursor.pos.x == 6;
-
-	return result;
-}
-
-static TEST_FN(cursor_tabs)
-{
-	struct test_result result = {.info = __FUNCTION__};
-
-	/* NOTE: first test advancing to a tabstop */
-	s8 raw = launder_static_string(term, s8("123\t"));
-	handle_input(term, arena, raw);
-
-	result.status = term->cursor.pos.x == (g_tabstop);
-
-	/* NOTE: now test negative tabstop movement and tabstop setting */
-	launder_static_string(term, s8("12"));
-	launder_static_string(term, ESC(H));
-	launder_static_string(term, s8("34\t"));
-	raw = launder_static_string(term, CSI(2Z));
-	handle_input(term, arena, raw);
-
-	result.status &= term->cursor.pos.x == (g_tabstop);
-
-	return result;
-}
-
 static TEST_FN(cursor_at_line_boundary)
 {
 	/* NOTE: two tests here
@@ -289,6 +254,83 @@ static TEST_FN(cursor_at_line_boundary)
 	return result;
 }
 
+
+static TEST_FN(cursor_movement)
+{
+	struct test_result result = {.info = __FUNCTION__};
+
+	s8 raw = launder_static_string(term, CSI(17;2H));
+	handle_input(term, arena, raw);
+
+	raw = launder_static_string(term, CSI(7G));
+	handle_input(term, arena, raw);
+
+	result.status = term->cursor.pos.y == 16 && term->cursor.pos.x == 6;
+
+	return result;
+}
+
+static TEST_FN(cursor_tabs)
+{
+	struct test_result result = {.info = __FUNCTION__};
+
+	/* NOTE: first test advancing to a tabstop */
+	s8 raw = launder_static_string(term, s8("123\t"));
+	handle_input(term, arena, raw);
+
+	result.status = term->cursor.pos.x == (g_tabstop);
+
+	/* NOTE: now test negative tabstop movement and tabstop setting */
+	launder_static_string(term, s8("12"));
+	launder_static_string(term, ESC(H));
+	launder_static_string(term, s8("34\t"));
+	raw = launder_static_string(term, CSI(2Z));
+	handle_input(term, arena, raw);
+
+	result.status &= term->cursor.pos.x == (g_tabstop);
+
+	return result;
+}
+
+static TEST_FN(cursor_tabs_across_boundary)
+{
+	struct test_result result = {.info = __FUNCTION__};
+
+	/* NOTE: clear tabstops then set one beyond multiple boundaries */
+	launder_static_string(term, CSI(3g));
+	launder_static_string(term, CSI(1;67H));
+	launder_static_string(term, ESC(H));
+	launder_static_string(term, CSI(1;1H));
+	s8 raw = launder_static_string(term, s8("\t"));
+	handle_input(term, arena, raw);
+
+	result.status = term->cursor.pos.x == 66;
+
+	/* NOTE: now set one exactly on a boundary */
+	launder_static_string(term, CSI(1;34H));
+	launder_static_string(term, ESC(H));
+	launder_static_string(term, CSI(1;1H));
+	raw = launder_static_string(term, s8("\t"));
+	handle_input(term, arena, raw);
+
+	result.status &= term->cursor.pos.x == 33;
+
+	/* NOTE: now set one right before the previous */
+	launder_static_string(term, CSI(1;33H));
+	launder_static_string(term, ESC(H));
+	launder_static_string(term, CSI(1;1H));
+
+	raw = launder_static_string(term, s8("\t"));
+	handle_input(term, arena, raw);
+	result.status &= term->cursor.pos.x == 32;
+
+	raw = launder_static_string(term, s8("\t"));
+	handle_input(term, arena, raw);
+	result.status &= term->cursor.pos.x == 33;
+
+	return result;
+}
+
 static TEST_FN(working_ringbuffer)
 {
 	struct test_result result = {.info = __FUNCTION__};
@@ -331,6 +373,12 @@ main(void)
 	os_alloc_framebuffer(&term.views[0].fb, term.size.h, term.size.w);
 	os_alloc_framebuffer(&term.views[1].fb, term.size.h, term.size.w);
 
+	u32 max_name_len = 0;
+	#define X(name) if (sizeof(#name) - 1 > max_name_len) max_name_len = sizeof(#name) - 1;
+	TESTS
+	#undef X
+	max_name_len += 1;
+
 	for (u32 i = 0; i < ARRAY_COUNT(tests); i++) {
 		buffer_reset(&term);
 		term_reset(&term);
@@ -339,7 +387,7 @@ main(void)
 		stream_push_s8(&log, fn);
 		stream_push_s8(&log, s8(":"));
 		size count = fn.len;
-		while (count < 26) { stream_push_byte(&log, ' '); count++; }
+		while (count < max_name_len) { stream_push_byte(&log, ' '); count++; }
 		if (result.status == 0) {
 			failure_count++;
 			stream_push_s8(&log, failure_string);