Variable height ceilings!

Plus bonus graphical artefacts around the edges of such! In the end
the majority of this code was rather easy: take the upwards floor
drawing code and reflect it.

However, there were many edge-cases and plenty of off-by-one pixels
and rounding issues that didn't quite work the same way going down as
they do going up. Also the object drawing code used to take advantage
of the fact that the z-buffer was painted bottom-up only, so that
required change too.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/level.zig b/src/level.zig
index 1d61a02..a5d7330 100644
--- a/src/level.zig
+++ b/src/level.zig
@@ -27,12 +27,17 @@ pub const Object = struct {
 };
 
 pub const Cell = struct {
-    height: f32,
-    wall_texture: u8 = 0,
+    floor_height: f32 = 0,
+    ceiling_height : f32 = DEFAULT_HEIGHT,
+    draw_down: bool = false,
+    lower_texture: u8 = 0,
+    upper_texture: u8 = 0,
     floor_texture: u8 = 0,
     ceiling_texture: u8 = 2,
 
-    const floor = Cell{ .height = 0 };
+    pub const floor = Cell{ };
+
+    pub const DEFAULT_HEIGHT : f32 = 4;
 };
 
 pub const Map = struct {