Adjusted Godot Atlas exporter to take margins into account

[jdbhartley]

When using the tool as an alternative to Texture Packer in Godot 4 I noticed that the margins were all set to 0 resulting in either a lot of fixing by hand or being left with sprites unusable for animation.

[Gerfalerf]

I think rather than splitting the difference of spriteSourceSize and sourceSize, margin.x and margin.y here should simply be set to spriteSourceSize.x and spriteSourceSize.y. Weird that spriteSourceSize is called a "size" when it has an offset like a rect, but those x/y values appear to be the actual offset of the sprite's subregion that was copied into the atlas.

Otherwise, change looks great. Just ran into this issue myself.

[DmitriiPetukhov]

I also needed this fix, but I ended up creating a custom template based on built-in godot template that also takes margins into account.

I replaced the margin block with:

"margin": {
  "x": {{frame.w | divide : 2 | add : spriteSourceSize.x}},
  "y": {{frame.h | divide : 2 | add : spriteSourceSize.y}},
  "w": {{sourceSize.w}},
  "h": {{sourceSize.h}}
}

End result:

{
  "textures": [
    {
      "image": "{{config.imageFile}}",
      "size": {
        "w": {{config.imageWidth}},
        "h": {{config.imageHeight}}
      },
      "sprites": [
        {{#rects}}
        {
          "filename": "{{name}}",
          "region": {
            "x": {{frame.x}},
            "y": {{frame.y}},
            "w": {{frame.w}},
            "h": {{frame.h}}
          },
          "margin": {
            "x": {{frame.w | divide : 2 | add : spriteSourceSize.x}},
            "y": {{frame.h | divide : 2 | add : spriteSourceSize.y}},
            "w": {{sourceSize.w}},
            "h": {{sourceSize.h}}
          }
        }{{^last}},{{/last}}
        {{/rects}}
      ]
    }
  ],
  "meta": {
    "app": "{{{appInfo.url}}}",
    "version": "{{appInfo.version}}",
    "format": "{{config.format}}",
    "scale": {{config.scale}}
  }
}