Parameter buffer (#6)

README.md

@@ -79,6 +79,10 @@ File (read/write):
 * `w`: write (save) level  
 *See `kbleformat.md` for technical informations.*
 
+Parameter buffer (change default value of verb calls):
+* `p`: set parameter buffer to current parameter (defaults to 1)
+* `P`: set the tile ID the keyboard cursor is on as parameter buffer
+
 Modes:
 * `<return>`: normal mode, default
 * `i`: free selection mode

src/actions.zig

@@ -7,6 +7,7 @@ const std = @import("std");
 const expect = std.testing.expect;
 
 const Parameter = @import("parameter.zig");
+const parameter_buffer = @import("parameter_buffer.zig");
 const movement = @import("movement.zig");
 const scaling = @import("scaling.zig");
 const verbs = @import("verbs.zig");
@@ -21,6 +22,7 @@ pub const ActionCat = enum {
     verb, // do stuff with selection
     scale, // change draw scaling
     file, // load/save, file related stuff
+    pbuf, // modify the parameter buffer
     mode, // change mode
 };
 
@@ -32,6 +34,7 @@ pub const Action = struct {
     function_verb: fn (*Level, Parameter.buffer_type) void = verbs.delete,
     function_scale: fn (scaling.scale_type, Parameter.buffer_type) scaling.scale_type = scaling.scale_reset,
     function_file: fn (*Level, *std.mem.Allocator, [*:0]const u8) void = Level.action_write,
+    function_pbuf: fn (Level, Vec2, Parameter.buffer_type) Parameter.buffer_type = parameter_buffer.set,
     next_mode: Mode = Mode.normal,
 };
 
@@ -120,7 +123,7 @@ pub const ActionsDef = .{
         .function_scale = scaling.scale_down,
     },
 
-    // File
+    // File.
     .file_read = Action{
         .category = ActionCat.file,
         .function_file = Level.action_read,
@@ -130,6 +133,16 @@ pub const ActionsDef = .{
         .function_file = Level.action_write,
     },
 
+    // Parameter buffer.
+    .pbuf_set = Action{
+        .category = ActionCat.pbuf,
+        .function_pbuf = parameter_buffer.set,
+    },
+    .pbuf_pick = Action{
+        .category = ActionCat.pbuf,
+        .function_pbuf = parameter_buffer.pick,
+    },
+
     // Mode change.
     .mode_normal = Action{
         .category = ActionCat.mode,

src/level.zig

@@ -256,6 +256,16 @@ pub fn select_rect(self: *Self, rect: Rect, state: bool) void {
     }
 }
 
+pub fn get_tile_at(self: Self, pos: Vec2) cell_type {
+    const target: u32 = @intCast(u32, pos.y) * self.width + @intCast(u32, pos.x);
+    if (pos.x < self.width and pos.y < self.height and
+        target < self.width * self.height and target >= 0)
+    {
+        return self.content[target];
+    } else
+        return 0;
+}
+
 /// Apply selection update to selection *kof*.
 pub fn apply_selection_update(self: *Self, selection_update: SelectionUpdate) void {
     // Apply changes.

src/main.zig

@@ -76,6 +76,9 @@ pub fn main() void {
     // Parameter buffer.
     var parameter: Parameter = Parameter{};
 
+    // Yank/paste for parameters.
+    var parameter_buffer: Parameter.buffer_type = 1;
+
     // Create binding "table".
     var bindings = [_]*const actions.Action{&actions.ActionsDef.none} ** char_range;
     comptime {
@@ -107,6 +110,9 @@ pub fn main() void {
         // File.
         default_bindings['e'] = &ActionsDef.file_read;
         default_bindings['w'] = &ActionsDef.file_write;
+        // Parameter buffer.
+        default_bindings['p'] = &ActionsDef.pbuf_set;
+        default_bindings['P'] = &ActionsDef.pbuf_pick;
         // Mode.
         default_bindings['\n'] = &ActionsDef.mode_normal;
         default_bindings['i'] = &ActionsDef.mode_select;
@@ -175,7 +181,7 @@ pub fn main() void {
                     }
                 },
                 .verb => {
-                    action.function_verb(&level, parameter.pop(1));
+                    action.function_verb(&level, parameter.pop(parameter_buffer));
                 },
                 .scale => {
                     scale = action.function_scale(scale, parameter.pop(1));
@@ -183,6 +189,9 @@ pub fn main() void {
                 .file => {
                     action.function_file(&level, allocator, level_path);
                 },
+                .pbuf => {
+                    parameter_buffer = action.function_pbuf(level, cursor, parameter.pop(1));
+                },
                 .mode => {
                     // Rectangle selection!
                     if (mode == .rectangle or mode == .unrectangle) {

src/parameter_buffer.zig

@@ -0,0 +1,17 @@
+// 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.
+//! Parameter buffer related operations.
+const buffer_type = @import("parameter.zig").buffer_type;
+const Level = @import("level.zig");
+const Vec2 = @import("vec2.zig");
+
+pub fn set(level: Level, cursor: Vec2, arg: buffer_type) buffer_type {
+    return arg;
+}
+
+pub fn pick(level: Level, cursor: Vec2, arg: buffer_type) buffer_type {
+    return level.get_tile_at(cursor);
+}