doodle/level/json.go
Noah Petherbridge bca848d534 Wallpapers and Bounded Levels
Implement the Wallpaper system into the levels and the concept of
Bounded and Unbounded levels.

The first wallpaper image is notepad.png which looks like standard ruled
notebook paper. On bounded levels, the top/left edges of the page look
as you would expect and the blue lines tile indefinitely in the positive
directions. On unbounded levels, you only get the repeating blue lines
but not the edge pieces.

A wallpaper is just a rectangular image file. The image is divided into
four equal quadrants to be the Corner, Top, Left and Repeat textures for
the wallpaper. The Repeat texture is ALWAYS used and fills all the empty
space behind the drawing. (Doodads draw with blank canvases as before
because only levels have wallpapers!)

Levels have four options of a "Page Type":
- Unbounded       (default, infinite space)
- NoNegativeSpace (has a top left edge but can grow infinitely)
- Bounded         (has a top left edge and bounded size)
- Bordered        (bounded with bordered texture; NOT IMPLEMENTED!)

The scrollable viewport of a Canvas will respect the wallpaper and page
type settings of a Level loaded into it. That is, if the level has a top
left edge (not Unbounded) you can NOT scroll to see negative coordinates
below (0,0) -- and if the level has a max dimension set, you can't
scroll to see pixels outside those dimensions.

The Canvas property NoLimitScroll=true will override the scroll locking
and let you see outside the bounds, for debugging.

- Default map settings for New Level are now:
  - Page Type: NoNegativeSpace
  - Wallpaper: notepad.png (default)
  - MaxWidth: 2550  (8.5" * 300 ppi)
  - MaxHeight: 3300 ( 11" * 300 ppi)
2018-10-27 22:35:06 -07:00

64 lines
1.3 KiB
Go

package level
import (
"bytes"
"encoding/json"
"fmt"
"io/ioutil"
"os"
)
// ToJSON serializes the level as JSON.
func (m *Level) ToJSON() ([]byte, error) {
out := bytes.NewBuffer([]byte{})
encoder := json.NewEncoder(out)
encoder.SetIndent("", "\t")
err := encoder.Encode(m)
return out.Bytes(), err
}
// WriteJSON writes a level to JSON on disk.
func (m *Level) WriteJSON(filename string) error {
json, err := m.ToJSON()
if err != nil {
return fmt.Errorf("Level.WriteJSON: JSON encode error: %s", err)
}
err = ioutil.WriteFile(filename, json, 0755)
if err != nil {
return fmt.Errorf("Level.WriteJSON: WriteFile error: %s", err)
}
return nil
}
// LoadJSON loads a map from JSON file.
func LoadJSON(filename string) (*Level, error) {
fh, err := os.Open(filename)
if err != nil {
return nil, err
}
defer fh.Close()
// Decode the JSON file from disk.
m := New()
decoder := json.NewDecoder(fh)
err = decoder.Decode(&m)
if err != nil {
return m, fmt.Errorf("level.LoadJSON: JSON decode error: %s", err)
}
// Fill in defaults.
if m.Wallpaper == "" {
m.Wallpaper = DefaultWallpaper
}
// Inflate the chunk metadata to map the pixels to their palette indexes.
m.Chunker.Inflate(m.Palette)
m.Actors.Inflate()
// Inflate the private instance values.
m.Palette.Inflate()
return m, err
}