Fix many texture bugs, access memory in increasing order everywhere

- switch z_buffer to use screen space coordinates (why does y increase
  downward!)
- extract pointless (re)calculations from inside hot loops, in
  particular from object drawing but also to the extent allowed by
  applicable law from floor and ceiling drawing

1 files changed, 2 insertions, 2 deletions

diff --git a/src/main.zig b/src/main.zig
index c3647b4..1211529 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -67,11 +67,11 @@ pub fn main() !void {
 
     map.cells.items[16 * 7 + 7] = level.Cell{
         .floor_height = 0.5,
-        .ceiling_height = 2,
+        .ceiling_height = 2.2,
         .lower_texture = 1,
         .upper_texture = 1,
         .floor_texture = 1,
-        .ceiling_texture = 2,
+        .ceiling_texture = 1,
         .draw_down = true,
     };