1 files changed, 41 insertions, 0 deletions
diff --git a/src/Animation.zig b/src/Animation.zig
new file mode 100644
index 0000000..5201193
--- /dev/null
+++ b/src/Animation.zig
@@ -0,0 +1,41 @@
+const root = @import("root.zig");
+const rl = @cImport(@cInclude("raylib.h"));
+const rlm = @cImport(@cInclude("raymath.h"));
+
+const Animation = @This();
+
+world_from: rl.Vector2,
+world_to: rl.Vector2,
+duration: u32, // TODO frame independent durations
+tick: u32,
+active: bool,
+
+pub fn init() Animation {
+    return Animation{
+        .world_from = .{ .x = 0.0, .y = 0.0 },
+        .world_to = .{ .x = 0.0, .y = 0.0 },
+        .duration = 60, // TODO speed based duration
+        .tick = 0,
+        .active = false,
+    };
+}
+
+pub fn next(self: *Animation) rl.Vector2 {
+    if (self.tick >= self.duration) {
+        self.active = false;
+        return self.world_to;
+    }
+
+    self.tick += 1;
+    return self.lerp();
+}
+
+inline fn lerp(self: *Animation) rl.Vector2 {
+    const t: f32 = @as(f32, @floatFromInt(self.tick)) / @as(f32, @floatFromInt(self.duration));
+    const v1 = self.world_from;
+    const v2 = self.world_to;
+    return .{
+        .x = v1.x + (t * (v2.x - v1.x)),
+        .y = v1.y + (t * (v2.y - v1.y)),
+    };
+}