Sprite rendering skeleton!

Except that i'm not satisfied. It would appear that we're computing
various distances more-or-less exactly in the sprite rendering
process, but this is at odds with the walls and floors which -- by
virtue of the linear interpolation garbage -- don't agree about where
things are.

The net result is that there are at least two fudge factors:
- to account to for the incorrect height of the floors i shift the
sprites up by 0.2
- to account for the incorrect wall distances i add 1 to the z_buffer
comparison

These fudges are ugly and empirical.

Still to do: for more than one object we have to sort by distance first!

1 files changed, 13 insertions, 1 deletions

diff --git a/src/map.zig b/src/map.zig
index 8093e21..92ca5be 100644
--- a/src/map.zig
+++ b/src/map.zig
@@ -20,6 +20,14 @@ const std = @import("std");
 // Let's pretend that our units are meters
 pub const MAX_HEIGHT: f32 = 2.5;
 
+pub const Object = struct {
+    height : f32,
+    width : f32,
+    texture : u8,
+    pos_x : f32,
+    pos_y : f32,
+};
+
 pub const Cell = struct {
     height: f32,
     wall_texture: u8 = 0,
@@ -34,9 +42,11 @@ pub const Map = struct {
     height: u32,
     size: f32 = 64,
     cells: std.ArrayList(Cell),
+    objects: std.ArrayList(Object),
 
     pub fn deinit(self: Map) void {
         self.cells.deinit();
+        self.objects.deinit();
     }
 
     pub fn new(width: u32, height: u32, alloc: *std.mem.Allocator) !Map {
@@ -44,7 +54,9 @@ pub const Map = struct {
         try cells.ensureTotalCapacity(width * height);
         try cells.appendNTimes(Cell.floor, width * height);
 
-        return Map{ .width = width, .height = height, .cells = cells };
+        var objects = std.ArrayList(Object).init(alloc);
+
+        return Map{ .width = width, .height = height, .cells = cells, .objects = objects };
     }
 
     pub fn inBounds(self: Map, x: i32, y: i32) bool {