Mighty zoom is back (scale system)

src/actions.zig

@@ -7,6 +7,7 @@ const std = @import("std");
 const expect = std.testing.expect;
 
 const movement = @import("movement.zig");
+const scaling = @import("scaling.zig");
 const Vec2 = @import("vec2.zig");
 const Level = @import("level.zig");
 
@@ -23,6 +24,7 @@ pub const Action = struct {
     // Only one of these should be set, and only one should be used.
     function_move: fn (*Vec2, u32, bool) movement.SelectionUpdate = movement.move_left,
     function_verb: fn (*Level) void = Level.action_delete,
+    function_scale: fn (scaling.scale_type) scaling.scale_type = scaling.scale_reset,
 };
 
 pub const ActionsDef = .{
@@ -110,4 +112,18 @@ pub const ActionsDef = .{
         .category = ActionCat.movement,
         .function_move = movement.move_down_right,
     },
+
+    // Scale.
+    .scale_reset = Action{
+        .category = ActionCat.scale,
+        .function_scale = scaling.scale_reset,
+    },
+    .scale_up = Action{
+        .category = ActionCat.scale,
+        .function_scale = scaling.scale_up,
+    },
+    .scale_down = Action{
+        .category = ActionCat.scale,
+        .function_scale = scaling.scale_down,
+    },
 };

src/main.zig

@@ -15,6 +15,7 @@ const maxInt = std.math.maxInt;
 const Level = @import("level.zig");
 const Vec2 = @import("vec2.zig");
 const movement = @import("movement.zig");
+const scaling = @import("scaling.zig");
 const actions = @import("actions.zig");
 const ActionsDef = actions.ActionsDef;
 const ActionCat = actions.ActionCat;
@@ -42,17 +43,16 @@ pub fn main() !void {
     // Create camera.
     var camera: Vec2 = Vec2.init(0, 0);
 
-    // Scale, used by drawing code.
-    const scale_type = u16;
-    const scale_default = 16;
-    var scale: scale_type = scale_default;
+    // Init scale, used by drawing code.
+    var scale: scaling.scale_type = scaling.scale_default;
 
     // Create cursor.
     var cursor: Vec2 = Vec2.init(0, 0);
 
     // Create binding "table".
     var bindings = [_]*const actions.Action{&actions.ActionsDef.none} ** char_range;
-    // Set default bindings
+    // Set default bindings.
+    // Movement.
     bindings['h'] = &ActionsDef.move_left;
     bindings['H'] = &ActionsDef.move_LEFT;
     bindings['j'] = &ActionsDef.move_down;
@@ -69,8 +69,12 @@ pub fn main() !void {
     bindings['B'] = &ActionsDef.move_DOWN_LEFT;
     bindings['n'] = &ActionsDef.move_down_right;
     bindings['N'] = &ActionsDef.move_DOWN_RIGHT;
+    // Scale.
+    bindings['='] = &ActionsDef.scale_reset;
+    bindings['+'] = &ActionsDef.scale_up;
+    bindings['-'] = &ActionsDef.scale_down;
 
-    // Create input buffer (ASCII).
+    // Create input buffer.
     const input_buffer_len = 255;
     var input_buffer: [input_buffer_len]u32 = undefined;
     comptime {
@@ -122,17 +126,7 @@ pub fn main() !void {
                     action.function_verb(&level);
                 },
                 .scale => {
-                    // TODO: move this to functions, doesn't make any sense here
-                    // Zoom (pog feature).
-                    if (scale > 3) {
-                        scale -= 1;
-                    }
-                    if (scale < comptime maxInt(scale_type)) {
-                        scale += 1;
-                    }
-                    // Reset zoom.
-                    scale = scale_default;
-                    log("No action for {} key.", .{action});
+                    scale = action.function_scale(scale);
                 },
             }
         }

src/scaling.zig

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 KikooDX
+// This file is part of [KBLE](https://sr.ht/~kikoodx/kble), which is
+// MIT licensed. The MIT license requires this copyright notice to be
+// included in all copies and substantial portions of the software.
+//! Operates on a scale value used by drawing code.
+const std = @import("std");
+const expect = std.testing.expect;
+const maxInt = std.math.maxInt;
+
+pub const scale_type = u16;
+pub const scale_default: comptime_int = 16;
+const scale_min: comptime_int = 3;
+const scale_max: comptime_int = maxInt(scale_type);
+
+pub fn scale_reset(current_scale: scale_type) scale_type {
+    return scale_default;
+}
+
+pub fn scale_up(current_scale: scale_type) scale_type {
+    if (current_scale < scale_max) {
+        return current_scale + 1;
+    } else return current_scale;
+}
+
+pub fn scale_down(current_scale: scale_type) scale_type {
+    if (current_scale > scale_min) {
+        return current_scale - 1;
+    } else return current_scale;
+}
+
+test "scale reset" {
+    expect(scale_reset(42) == scale_default);
+}
+
+test "scale up" {
+    expect(scale_up(42) == 43);
+    expect(scale_up(scale_max) == scale_max);
+}
+
+test "scale down" {
+    expect(scale_down(42) == 41);
+    expect(scale_down(scale_min) == scale_min);
+}
+