[tools] [eraser advanced] resize eraser and remove shape based with history method

[LeVuMinhHuy]

Apr 06, 2023

Eraser Advanced

Resize [-/=]

Idea: besides the default size eraser, it will have 3 other size: small(s: 3x3), medium(m: 5x5), large(l: 9x9)

Solution:

// > src/tools/mod.rs > impl ToolControl
// add this interface, which means it will be apply for all tools

fn resize(&mut self, option: ResizeOption) {
    self.available_tools[self.current].resize(option);
}

// > src/widgets/grid.rs > impl Widget
// only apply for EraserTool at the moment
// -/= instead of -/+

if win_data.mode == DrawingTools::Eraser {
    match keycode {
        Code::Minus => {
            self.tool_manager.resize(ResizeOption::Decrease);
        }
        Code::Equal => {
            self.tool_manager.resize(ResizeOption::Increase);
        }
        _ => {}
    }
}

// define ToolsSize
pub enum ToolsSize {
    Default = 0,
    Small = 1 << 0,
    Medium = 1 << 1,
    Large = 1 << 2,
}

// > src/tools/eraser.rs
// two fn and an algo function for removing k-neighbors chars in 1D vec
pub fn increase_size {}
pub fn decrease_size {}

Progress:

• users also can use - to decrease size or = to increase size of eraser
• when use hover the eraser button in the ui, a popup will open with [s,m,l]

Problems:

• still don't know how to trigger a hover or a popup
• apply resize interface for all tools seems ...
• the history vec seems not right after erasing

Shape-based

Idea: besides erasing cell by cell, user can also hold Ctrl and click to remove the whole shape. each shape wrapped around number will be erased just with a single Ctrl+Click

            ┌────────────────[8]──────────────────┐
            │                                     │
            │                                     │
            │                                    [7]
            │                                     │
            │                                     │
           [9]                                    │
            │                    ┌────────────────┴────[5]──────────────┐
            │                    │                                      │
            │                    │                                      │
            │                    │                                      │
  ┌─────────▼─[1]──────┐         │                                      │
  │                    │         │                                      │
  │                    │         │                                     [5]
  │                    │         │                                      │
  │                    │         │                                      │
 [1]                  [1]        │                     ┌───────────[6]──┼───────┐
  │                    │        [5]                    │                │       │
  │                    │         │                     │                │       │
  │                    │         │                     │                │       │
  │                    │         │                     │                │       │
  │                    │         │                     │                │       │
  └────────[1]─────────┘         │                    [6]               │      [6]
            │                    │                     │                │       │
            │                    │                     │                │       │
            │                    │                     │                │       │
           [2]                   └───────[5]──────▲────┼────────────────┘       │
            │                                     │    │                        │
            │                                     │    │                        │
            │                                    [4]   └───────────[6]──────────┘
            │                                     │
            │                                     │
            └───────────────[3]───────────────────┘

Solution:

I first implemented this feature based on HISTORY_MANAGER, trying to erase the shape that each history version saved, following the logic:

• get current cursor position: pos
• loop to history.versions vector
• loop to each version.edits vector
• check if edit.index == pos, return the whole index in that edits
• update grid_list[index] = CHAR_SPACE
• HISTORY_MANAGER.save_version()

Although, I believe this shouldn't be the right way to implement this. shouldn't mess up with the HISTORY_MANAGER

Progress:

• Able to erase shapes, but not really 😧
• Able to undo/redo after erasing, but not really 😧
• Try another method, but a bit afraid of the algorithm 😧

Problems:

• Overlapping shaped after being erased will miss some strokes

  ┌────────────────┐
  │                │
  │                │
  │                │
  │                │                   ┌─────────── ──────┐
  │     ┌──────────┼──────┐            │                  │
  │     │          │      │─────────▶  │    ┌────── ───┐  │
  │     │   ┌──────┼──┐   │            │    │          │  │
  │     │   │      │  │   │            │    │          │  │
  │     │   │      │  │   │            │    │          │  │
  └─────┼───┼──────┘  │   │                            │  │
        │   │         │   │            │    │          │  │
        │   │         │   │            │    └──────────┘  │
        │   └─────────┘   │            │                  │
        └─────────────────┘            └──────────────────┘

• After user select the whole area and remove that with Selection tool, everything inside that area will be treated as one shape (because edit.index always == pos at this point) <--- I'm trying to bypass with by specifing the tool stored the version and ignore the tool == Selection

// > src/data/history.rs
pub struct Edit {
    index: usize,
    from: char,
    to: char,
    tool: DrawingTools, // <------ this code sucks !!!
}

• When we copy/paste a combination of shapes, that will be grouped too 🙉

• If we still keeping this method, the code need to be compatible with another method by just one change