change behavior of jumping between maps

1 files changed, 15 insertions, 21 deletions

diff --git a/core.c b/core.c
index 97953b0..b72f104 100644
--- a/core.c
+++ b/core.c
@@ -50,25 +50,18 @@ static void goto_addr(uintptr_t addr) {
 	pos_y -= (double) screen_height / 2 * scale;
 }
 
-static size_t closest_map(struct procfs_map *maps, size_t n, uintptr_t addr) {
-	uintptr_t min = -1;
-	size_t closest;
-	for (size_t i = 0; i < n; i++) {
-		uintptr_t base = maps[i].base;
-		uintptr_t diff = base > addr ? base - addr : addr - base;
-		if (diff < min) {
-			min = diff; closest = i;
-		}
-	}
-	return closest;
-}
+static size_t current_map = 0;
 
 static void next_map() {
 	struct procfs_map *maps;
 	int n = procfs_maps(pid, &maps);
 	if (n < 1) return;
-	size_t m = closest_map(maps, n, current_addr());
-	goto_addr(maps[(m + 1) % n].base);
+	for (int i = 0; i < n; i++) {
+		current_map = (current_map + 1) % n;
+		if (maps[current_map].prot & PROT_READ)
+			break;
+	}
+	goto_addr(maps[current_map].base);
 	free(maps);
 }
 
@@ -76,11 +69,12 @@ static void prev_map() {
 	struct procfs_map *maps;
 	int n = procfs_maps(pid, &maps);
 	if (n < 1) return;
-	size_t m = closest_map(maps, n, current_addr());
-	if (m != 0)
-		goto_addr(maps[m - 1].base);
-	else
-		goto_addr(maps[n - 1].base);
+	for (int i = 0; i < n; i++) {
+		current_map = current_map > 1 ? current_map - 1 : n - 1;
+		if (maps[current_map].prot & PROT_READ)
+			break;
+	}
+	goto_addr(maps[current_map].base);
 	free(maps);
 }
 
@@ -184,12 +178,12 @@ int main(int argc, char *argv[]) {
 
 	char title[1024];
 	snprintf(title, 1024, "%s [%d]", argv[0], pid);
-	init_sdl(argv[0]);
+	init_sdl(title);
 	viewer = create_viewer(mem_fd, renderer);
 	if (!viewer) abort();
 	atexit(cleanup);
 
-	next_map();
+	prev_map();
 
 	int last_time = 0;
 	int current_time = 0;