codegirl.games/codegirl-games
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

trim atlas of excess transparent pixels

Browse Source
This commit is contained in:
codegirl007
2026-08-01 12:34:11 -07:00
parent 49a3b8a682
commit d488161433
5 changed files with 407 additions and 341 deletions
Download Patch File Download Diff File Expand all files Collapse all files
assetbake/main.odin
+63 -24
View File
@@ -56,10 +56,12 @@ Char_Def :: struct {
// Packed atlas pixels + per-frame rects (indexed like the combined frames list) // Packed atlas pixels + per-frame rects (indexed like the combined frames list)
Atlas :: struct { Atlas :: struct {
pixels: []u8, pixels: []u8,
width: int, width: int,
height: int, height: int,
rects: [][4]int, // [x, y, w, h] per frame; sizes may differ across clips rects: [][4]int,
source_sizes: [][2]int,
trim_offsets: [][2]int,
} }
// Where one clip's frames sit inside the packed atlas frame list // Where one clip's frames sit inside the packed atlas frame list
@@ -95,6 +97,8 @@ bake_character :: proc(in_dir, out_dir: string) {
atlas := pack_atlas(frames) atlas := pack_atlas(frames)
defer delete(atlas.pixels) defer delete(atlas.pixels)
defer delete(atlas.rects) defer delete(atlas.rects)
defer delete(atlas.source_sizes)
defer delete(atlas.trim_offsets)
ensure_dir(out_dir) ensure_dir(out_dir)
@@ -283,22 +287,56 @@ destroy_frames :: proc(frames: []^image.Image) {
delete(frames) delete(frames)
} }
// pack_atlas packs variable-size frames with stb_rect_pack and blits them into one sheet. opaque_bounds :: proc(img: ^image.Image, alpha_min: u8 = 1) -> (x, y, w, h: int) {
// Caller owns atlas.pixels and atlas.rects. iw, ih := int(img.width), int(img.height)
pixels := bytes.buffer_to_bytes(&img.pixels)
min_x, min_y := iw, ih
max_x, max_y := -1, -1
for py in 0 ..< ih {
for px in 0 ..< iw {
i := (py * iw + px) * 4
a := pixels[i + 3]
if a >= alpha_min {
if px < min_x do min_x = px
if py < min_y do min_y = py
if px > max_x do max_x = px
if py > max_y do max_y = py
}
}
}
if max_x < min_x {
return 0, 0, 1, 1
}
return min_x, min_y, max_x - min_x + 1, max_y - min_y + 1
}
pack_atlas :: proc(frames: []^image.Image) -> Atlas { pack_atlas :: proc(frames: []^image.Image) -> Atlas {
PADDING :: 1 // 1px gap to reduce bleeding if filtered later PADDING :: 1
pack_rects := make([]stbrp.Rect, len(frames)) pack_rects := make([]stbrp.Rect, len(frames))
defer delete(pack_rects) defer delete(pack_rects)
trims := make([][4]int, len(frames))
defer delete(trims)
source_sizes := make([][2]int, len(frames))
trim_offsets := make([][2]int, len(frames))
total_area := 0 total_area := 0
max_w := 0 max_w := 0
max_h := 0 max_h := 0
for frame, i in frames { for frame, i in frames {
w := frame.width + PADDING tx, ty, tw, th := opaque_bounds(frame)
h := frame.height + PADDING trims[i] = {tx, ty, tw, th}
source_sizes[i] = {int(frame.width), int(frame.height)}
trim_offsets[i] = {tx, ty}
w := tw + PADDING
h := th + PADDING
pack_rects[i] = stbrp.Rect { pack_rects[i] = stbrp.Rect {
id = c.int(i), // pack_rects may reorder; id maps back to frame index id = c.int(i),
w = stbrp.Coord(w), w = stbrp.Coord(w),
h = stbrp.Coord(h), h = stbrp.Coord(h),
} }
@@ -307,7 +345,6 @@ pack_atlas :: proc(frames: []^image.Image) -> Atlas {
max_h = max(max_h, h) max_h = max(max_h, h)
} }
// Grow a square-ish atlas until everything fits
side := max(max_w, max_h, int(math.ceil(math.sqrt(f64(total_area))))) side := max(max_w, max_h, int(math.ceil(math.sqrt(f64(total_area)))))
atlas_w, atlas_h := 0, 0 atlas_w, atlas_h := 0, 0
packed := false packed := false
@@ -326,10 +363,9 @@ pack_atlas :: proc(frames: []^image.Image) -> Atlas {
os.exit(1) os.exit(1)
} }
pixels := make([]u8, atlas_w * atlas_h * 4) // transparent pixels := make([]u8, atlas_w * atlas_h * 4)
rects := make([][4]int, len(frames)) rects := make([][4]int, len(frames))
// Blit using each rect's id (array order may have changed during packing)
for pr in pack_rects { for pr in pack_rects {
if !pr.was_packed { if !pr.was_packed {
fmt.eprintfln("frame %d was not packed", pr.id) fmt.eprintfln("frame %d was not packed", pr.id)
@@ -337,27 +373,30 @@ pack_atlas :: proc(frames: []^image.Image) -> Atlas {
} }
idx := int(pr.id) idx := int(pr.id)
frame := frames[idx] frame := frames[idx]
fw := frame.width trim := trims[idx]
fh := frame.height tx, ty, tw, th := trim[0], trim[1], trim[2], trim[3]
dst_x := int(pr.x) dst_x := int(pr.x)
dst_y := int(pr.y) dst_y := int(pr.y)
src := bytes.buffer_to_bytes(&frame.pixels) src := bytes.buffer_to_bytes(&frame.pixels)
for y in 0 ..< fh { src_w := int(frame.width)
src_row := src[y * fw * 4:(y + 1) * fw * 4] for y in 0 ..< th {
src_row := src[((ty + y) * src_w + tx) * 4:][:tw * 4]
dst_i := ((dst_y + y) * atlas_w + dst_x) * 4 dst_i := ((dst_y + y) * atlas_w + dst_x) * 4
copy(pixels[dst_i:], src_row) copy(pixels[dst_i:], src_row)
} }
rects[idx] = {dst_x, dst_y, fw, fh} rects[idx] = {dst_x, dst_y, tw, th}
} }
fmt.printfln("packed atlas %dx%d", atlas_w, atlas_h) fmt.printfln("packed atlas %dx%d", atlas_w, atlas_h)
return Atlas { return Atlas {
pixels = pixels, pixels = pixels,
width = atlas_w, width = atlas_w,
height = atlas_h, height = atlas_h,
rects = rects, rects = rects,
source_sizes = source_sizes,
trim_offsets = trim_offsets,
} }
} }
@@ -422,8 +461,8 @@ build_char_def :: proc(
r := atlas.rects[slot] r := atlas.rects[slot]
frame_defs[i] = Frame_Def { frame_defs[i] = Frame_Def {
rect = r, rect = r,
source_size = {r[2], r[3]}, source_size = atlas.source_sizes[slot],
trim_offset = {0, 0}, // no trimming in v1 trim_offset = atlas.trim_offsets[slot],
} }
} }
assets_baked/characters/toad/toad.atlas.png
BIN
View File
Binary file not shown.
Side by Side Swipe Overlay

Before

Width:  |  Height:  |  Size: 1.8 MiB

After

Width:  |  Height:  |  Size: 1.6 MiB

assets_baked/characters/toad/toad.char.json
+295 -295
View File
@@ -14,274 +14,274 @@
"frames": [ "frames": [
{ {
"rect": [ "rect": [
0, 1253,
0, 630,
268, 204,
326 311
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 9,
0 14
] ]
}, },
{ {
"rect": [ "rect": [
269, 1256,
0, 0,
268, 218,
326 314
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 9,
0 10
] ]
}, },
{ {
"rect": [ "rect": [
538, 1458,
0, 630,
268, 231,
326 310
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 9,
0 8
] ]
}, },
{ {
"rect": [ "rect": [
807, 643,
0, 943,
268, 243,
326 295
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 10,
0 7
] ]
}, },
{ {
"rect": [ "rect": [
1076, 881,
0, 1245,
268, 254,
326 278
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 11,
0 8
]
},
{
"rect": [
1345,
0,
268,
326
],
"source_size": [
268,
326
],
"trim_offset": [
0,
0
]
},
{
"rect": [
1614,
0,
268,
326
],
"source_size": [
268,
326
],
"trim_offset": [
0,
0
] ]
}, },
{ {
"rect": [ "rect": [
0, 0,
327, 944,
268, 247,
326 288
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 10,
0 7
] ]
}, },
{ {
"rect": [ "rect": [
269, 1669,
327, 941,
268, 236,
326 305
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 9,
0 8
]
},
{
"rect": [
538,
327,
268,
326
],
"source_size": [
268,
326
],
"trim_offset": [
0,
0
]
},
{
"rect": [
807,
327,
268,
326
],
"source_size": [
268,
326
],
"trim_offset": [
0,
0
]
},
{
"rect": [
1076,
327,
268,
326
],
"source_size": [
268,
326
],
"trim_offset": [
0,
0
]
},
{
"rect": [
1345,
327,
268,
326
],
"source_size": [
268,
326
],
"trim_offset": [
0,
0
]
},
{
"rect": [
1614,
327,
268,
326
],
"source_size": [
268,
326
],
"trim_offset": [
0,
0
] ]
}, },
{ {
"rect": [ "rect": [
0, 0,
654, 316,
268, 223,
326 313
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 9,
0 9
] ]
}, },
{ {
"rect": [ "rect": [
269, 1458,
654, 941,
268, 210,
326 310
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
0, 9,
0 13
] ]
}, },
{ {
"rect": [ "rect": [
538, 224,
654, 316,
268, 211,
326 313
], ],
"source_size": [ "source_size": [
268, 268,
326 326
], ],
"trim_offset": [ "trim_offset": [
11,
11
]
},
{
"rect": [
1032,
630,
220,
311
],
"source_size": [
268,
326
],
"trim_offset": [
13,
7
]
},
{
"rect": [
1032,
942,
228,
302
],
"source_size": [
268,
326
],
"trim_offset": [
16,
4
]
},
{
"rect": [
0, 0,
0 1233,
237,
286
],
"source_size": [
268,
326
],
"trim_offset": [
18,
2
]
},
{
"rect": [
643,
1239,
237,
286
],
"source_size": [
268,
326
],
"trim_offset": [
18,
2
]
},
{
"rect": [
414,
943,
228,
302
],
"source_size": [
268,
326
],
"trim_offset": [
16,
4
]
},
{
"rect": [
1690,
630,
220,
310
],
"source_size": [
268,
326
],
"trim_offset": [
13,
7
]
},
{
"rect": [
436,
316,
210,
313
],
"source_size": [
268,
326
],
"trim_offset": [
11,
11
] ]
} }
] ]
@@ -292,290 +292,290 @@
"frames": [ "frames": [
{ {
"rect": [ "rect": [
807, 414,
654, 630,
213, 205,
319 312
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 6,
0 7
] ]
}, },
{ {
"rect": [ "rect": [
1021, 647,
654, 316,
213, 206,
319 313
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 5,
0 6
] ]
}, },
{ {
"rect": [ "rect": [
1235, 854,
654, 316,
213, 206,
319 313
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 5,
0 6
] ]
}, },
{ {
"rect": [ "rect": [
1449, 1684,
654, 0,
213, 207,
319 314
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 4,
0 5
] ]
}, },
{ {
"rect": [ "rect": [
1663, 1256,
654, 315,
213, 207,
319 314
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 4,
0 5
] ]
}, },
{ {
"rect": [ "rect": [
807, 420,
974, 0,
213, 208,
319 315
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 3,
0 4
] ]
}, },
{ {
"rect": [ "rect": [
1021, 1475,
974, 0,
213, 208,
319 314
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 3,
0 4
] ]
}, },
{ {
"rect": [ "rect": [
1235, 629,
974, 0,
213, 208,
319 315
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 3,
0 3
]
},
{
"rect": [
1449,
974,
213,
319
],
"source_size": [
213,
319
],
"trim_offset": [
0,
0
]
},
{
"rect": [
1663,
974,
213,
319
],
"source_size": [
213,
319
],
"trim_offset": [
0,
0
] ]
}, },
{ {
"rect": [ "rect": [
0, 0,
981, 0,
213, 209,
319 315
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 2,
0 3
] ]
}, },
{ {
"rect": [ "rect": [
214, 210,
981, 0,
213, 209,
319 315
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 2,
0 3
] ]
}, },
{ {
"rect": [ "rect": [
428, 838,
981, 0,
213, 208,
319 315
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 3,
0 3
] ]
}, },
{ {
"rect": [ "rect": [
642, 1047,
1294, 0,
213, 208,
319 315
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 3,
0 4
] ]
}, },
{ {
"rect": [ "rect": [
856, 1464,
1294, 315,
213, 207,
319 314
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 4,
0 5
] ]
}, },
{ {
"rect": [ "rect": [
1070, 1672,
1294, 315,
213, 207,
319 314
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 4,
0 5
] ]
}, },
{ {
"rect": [ "rect": [
1284, 0,
1294, 630,
213, 206,
319 313
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 5,
0 6
] ]
}, },
{ {
"rect": [ "rect": [
1498, 207,
1294, 630,
213, 206,
319 313
], ],
"source_size": [ "source_size": [
213, 213,
319 319
], ],
"trim_offset": [ "trim_offset": [
0, 5,
0 6
]
},
{
"rect": [
620,
630,
205,
312
],
"source_size": [
213,
319
],
"trim_offset": [
6,
7
]
},
{
"rect": [
826,
630,
205,
312
],
"source_size": [
213,
319
],
"trim_offset": [
6,
7
] ]
} }
] ]
engine/character_data.odin
+19 -6
View File
@@ -210,6 +210,22 @@ character_clip :: proc(data: ^Character_Data, clip_name: string) -> (clip: Clip_
return character, true return character, true
} }
character_frame :: proc(
data: ^Character_Data,
clip_name: string,
frame_index: int,
) -> (
frame: Frame_Def,
ok: bool,
) {
if data == nil do return {}, false
clip, found := data.def.clips[clip_name]
if !found || frame_index < 0 || frame_index >= len(clip.frames) {
return {}, false
}
return clip.frames[frame_index], true
}
character_frame_rect :: proc( character_frame_rect :: proc(
data: ^Character_Data, data: ^Character_Data,
clip_name: string, clip_name: string,
@@ -218,10 +234,7 @@ character_frame_rect :: proc(
rect: [4]int, rect: [4]int,
ok: bool, ok: bool,
) { ) {
clip, found := data.def.clips[clip_name] frame, found := character_frame(data, clip_name, frame_index)
if !found || frame_index < 0 || frame_index >= len(clip.frames) { if !found do return {}, false
return {}, false return frame.rect, true
}
return clip.frames[frame_index].rect, true
} }
engine/sprite.odin
+30 -16
View File
@@ -84,7 +84,7 @@ to_clip :: proc(px, py, sw, sh: f32) -> [2]f32 {
draw_sprite :: proc(app: ^App, sprite: ^Sprite) { draw_sprite :: proc(app: ^App, sprite: ^Sprite) {
if app.cmd == nil || app.swapchain_texture == nil { if app.cmd == nil || app.swapchain_texture == nil {
return // begin_frame may have skipped (minimized window, etc.) return
} }
if sprite == nil || sprite.data == nil || sprite.data.texture == nil { if sprite == nil || sprite.data == nil || sprite.data.texture == nil {
return return
@@ -93,37 +93,51 @@ draw_sprite :: proc(app: ^App, sprite: ^Sprite) {
return return
} }
rect, ok := character_frame_rect(sprite.data, sprite.clip, sprite.frame) frame, ok := character_frame(sprite.data, sprite.clip, sprite.frame)
if !ok { if !ok {
return return
} }
fw := f32(rect[2]) src_w := f32(frame.source_size[0])
fh := f32(rect[3]) src_h := f32(frame.source_size[1])
if src_w <= 0 do src_w = f32(frame.rect[2])
if src_h <= 0 do src_h = f32(frame.rect[3])
fw := f32(frame.rect[2])
fh := f32(frame.rect[3])
trim_x := f32(frame.trim_offset[0])
trim_y := f32(frame.trim_offset[1])
pivot := sprite.data.def.pivot pivot := sprite.data.def.pivot
origin := sprite_quad_origin(sprite.position, {fw, fh}, pivot)
x0_px := origin.x canvas_top := sprite.position.y - src_h * pivot[1]
y0_px := origin.y x0_px, y0_px: f32
if sprite.flip_x {
canvas_left := sprite.position.x - (1.0 - pivot[0]) * src_w
x0_px = canvas_left + (src_w - trim_x - fw)
y0_px = canvas_top + trim_y
} else {
canvas_left := sprite.position.x - src_w * pivot[0]
x0_px = canvas_left + trim_x
y0_px = canvas_top + trim_y
}
x1_px := x0_px + fw x1_px := x0_px + fw
y1_px := y0_px + fh y1_px := y0_px + fh
sw := f32(app.swapchain_w) sw := f32(app.swapchain_w)
sh := f32(app.swapchain_h) sh := f32(app.swapchain_h)
p0 := to_clip(x0_px, y0_px, sw, sh) // top-left p0 := to_clip(x0_px, y0_px, sw, sh)
p1 := to_clip(x1_px, y0_px, sw, sh) // top-right p1 := to_clip(x1_px, y0_px, sw, sh)
p2 := to_clip(x1_px, y1_px, sw, sh) // bottom-right p2 := to_clip(x1_px, y1_px, sw, sh)
p3 := to_clip(x0_px, y1_px, sw, sh) // bottom-left p3 := to_clip(x0_px, y1_px, sw, sh)
tex_w := f32(sprite.data.width) tex_w := f32(sprite.data.width)
tex_h := f32(sprite.data.height) tex_h := f32(sprite.data.height)
u0 := f32(rect[0]) / tex_w u0 := f32(frame.rect[0]) / tex_w
v0 := f32(rect[1]) / tex_h v0 := f32(frame.rect[1]) / tex_h
u1 := f32(rect[0] + rect[2]) / tex_w u1 := f32(frame.rect[0] + frame.rect[2]) / tex_w
v1 := f32(rect[1] + rect[3]) / tex_h v1 := f32(frame.rect[1] + frame.rect[3]) / tex_h
if sprite.flip_x do u0, u1 = u1, u0 if sprite.flip_x do u0, u1 = u1, u0
// Two triangles: (0,1,2) and (0,2,3)
verts := [SPRITE_VERT_COUNT]Vertex { verts := [SPRITE_VERT_COUNT]Vertex {
{pos = p0, uv = {u0, v0}}, {pos = p0, uv = {u0, v0}},
{pos = p1, uv = {u1, v0}}, {pos = p1, uv = {u1, v0}},