Fix a bug in vertical line drawing

1 files changed, 2 insertions, 0 deletions

diff --git a/src/renderer.c b/src/renderer.c
index 2cc5758..3072105 100644
--- a/src/renderer.c
+++ b/src/renderer.c
@@ -112,6 +112,7 @@ draw_line(size_t x0, size_t y0, size_t x1, size_t y1, u8 clr) {
             for (size_t i = 0; i < (8 - start_row0); i++, backbuffer++) {
                 backbuffer[0] = (backbuffer[0] & ~row_mask) | row_left;
             }
+            dirty_tiles[tile_y0] |= 1 << tile_x0;
             backbuffer += 8 * 31;
             for (size_t j = 1; j < dy; j++) {
                 for (size_t i = 0; i < 8; i++, backbuffer++) {
@@ -123,6 +124,7 @@ draw_line(size_t x0, size_t y0, size_t x1, size_t y1, u8 clr) {
             for (size_t i = 0; i <= start_row1; i++, backbuffer++) {
                 backbuffer[0] = (backbuffer[0] & ~row_mask) | row_left;
             }
+            dirty_tiles[tile_y1] |= 1 << tile_x0;
         }
     } else {
         // Diagonal line.