1 files changed, 7 insertions, 4 deletions
diff --git a/src/player.zig b/src/player.zig
index c8fc4df..8fe0002 100644
--- a/src/player.zig
+++ b/src/player.zig
@@ -383,13 +383,16 @@ pub fn Player(PlaneWidth: f32, PlaneHeight: f32) type {
                             if (draw_lower) {
                                 // which texture index?
                                 const t_lower_off = cell.lower_texture * td;
-                                // now we have what we need to draw the face, and
-                                // update the z-buffer
-                                const constrained_top = std.math.min(top_of_floor, lowest_drawn);
+                                // Note the bizarre rounding we have to do to avoid artifacts
+                                const constrained_top = std.math.min(std.math.floor(top_of_floor), std.math.ceil(lowest_drawn));
+                                const stop = @floatToInt(i32, highest_drawn);
                                 var zb_y = @floatToInt(i32, constrained_top);
                                 var pix_y = @floatToInt(usize, std.math.ceil(std.math.max(PlaneHeight - constrained_top, 0)));
                                 var texel_y = (top_of_floor - constrained_top) / nominal_length;
-                                while (zb_y > @floatToInt(i32, highest_drawn)) : ({
+
+                                // now we have what we need to draw the face,
+                                // and update the z-buffer
+                                while (zb_y > stop) : ({
                                     zb_y -= 1;
                                     pix_y += 1;
                                     texel_y += inv_nom_len;