claude
23135a96d1
- .sprite format: single-char palette keys (hex/rgb()/CSS names/none), grid rows, '.' transparent by default, max 256x256 per sprite - render/sheet/info/preview subcommands; sheets name themselves <base>_<cellW>x<cellH>_<cols>x<rows>.<ext> (row-major) - SVG output RLE-merges pixel runs; JPG composites over --bg - go tests for parser, colors, scaling, svg, sheet layout Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MmdG9GqfSWCzts7AkDwRDh
59 lines
1.9 KiB
Go
59 lines
1.9 KiB
Go
package sprite
|
|
|
|
import (
|
|
"fmt"
|
|
"image/color"
|
|
)
|
|
|
|
// Sheet lays out several equally sized sprites in a row-major grid:
|
|
// index 0 is top-left, then left-to-right, then next row. A 1D strip is
|
|
// simply a sheet with one row (or one column).
|
|
type Sheet struct {
|
|
Sprites []*Sprite
|
|
Cols, Rows int
|
|
CellW, CellH int
|
|
}
|
|
|
|
// NewSheet composes sprites into a sheet with the given number of columns.
|
|
// cols <= 0 puts everything in a single row. Every sprite must have the
|
|
// same dimensions so the sheet can be indexed cell by cell.
|
|
func NewSheet(sprites []*Sprite, cols int) (*Sheet, error) {
|
|
if len(sprites) == 0 {
|
|
return nil, fmt.Errorf("a sheet needs at least one sprite")
|
|
}
|
|
w, h := sprites[0].Bounds()
|
|
for _, sp := range sprites[1:] {
|
|
sw, sh := sp.Bounds()
|
|
if sw != w || sh != h {
|
|
return nil, fmt.Errorf("sprite %q is %dx%d but %q is %dx%d — all sprites in a sheet must be the same size",
|
|
sp.Name, sw, sh, sprites[0].Name, w, h)
|
|
}
|
|
}
|
|
if cols <= 0 || cols > len(sprites) {
|
|
cols = len(sprites)
|
|
}
|
|
rows := (len(sprites) + cols - 1) / cols
|
|
return &Sheet{Sprites: sprites, Cols: cols, Rows: rows, CellW: w, CellH: h}, nil
|
|
}
|
|
|
|
// Bounds returns the total sheet size in pixels.
|
|
func (sh *Sheet) Bounds() (w, h int) { return sh.Cols * sh.CellW, sh.Rows * sh.CellH }
|
|
|
|
// At returns the pixel at (x, y). Cells past the last sprite (when the
|
|
// sprite count doesn't fill the grid) are transparent.
|
|
func (sh *Sheet) At(x, y int) color.NRGBA {
|
|
col, row := x/sh.CellW, y/sh.CellH
|
|
idx := row*sh.Cols + col
|
|
if idx >= len(sh.Sprites) {
|
|
return Transparent
|
|
}
|
|
return sh.Sprites[idx].At(x%sh.CellW, y%sh.CellH)
|
|
}
|
|
|
|
// FileBase appends the layout to an output name so the file itself
|
|
// documents cell size and orientation: <base>_<cellW>x<cellH>_<cols>x<rows>
|
|
// e.g. walk_16x16_4x2 = 16x16 cells, 4 columns, 2 rows, read row by row.
|
|
func (sh *Sheet) FileBase(base string) string {
|
|
return fmt.Sprintf("%s_%dx%d_%dx%d", base, sh.CellW, sh.CellH, sh.Cols, sh.Rows)
|
|
}
|