Background images

Editable mapped backgrounds

Open the image browser. Ninety-one resources now have 158 editable image layers using KMP maps or affine TSC frames. For example, OP_05_A.KCG.png is the complete 240×160 picture of Ginta and Babbo. OP_06_A is 240×256; other resources use their own map sizes.

Edit these PNGs directly. The build converts the assembled pixels back into the tile indices, horizontal/vertical flips, and palette banks expected by the map. For KMP resources, the JSON beside each primary image records dimensions and each plane's u16 map entries. Bits 0–9 select a tile, bits 10/11 flip it, and bits 12–15 select its palette bank. Additional nonempty planes have .layer1.png etc. names; these are separate layers, not a claim about their final on-screen priority.

The mapped images replace the old tile-sheet PNGs as build inputs. Small unused/ strips preserve tiles not referenced by the rendered planes; deleting one fails the build. The image compiler reconstructs every tile from the PNGs, without reading the original ROM, compressed tile stream, or a hidden tile sheet. Baseline hashes only distinguish edited copies of shared tiles; hashes cannot recover pixel content. All LZ77 streams are generated from reconstructed pixels by the matching VRAM-safe encoder. No original compressed source is used. Edited streams must fit their fixed ROM spans.

A tile can appear more than once. Editing one occurrence changes that tile wherever the game uses it. Incompatible edits to separate copies are rejected; giving those copies independent artwork would require allocating more tiles and changing the map. Keep each cell's pixels within its assigned palette bank. Edit the linked graphics/palettes/*.pal file to change the game's colors.

Preview the compiled primary layer, including propagated shared-tile edits:

python3 tools/mapped_images.py preview --asset OP_05_A.KCG --output /tmp/OP_05_A.png
make -j4 compare

Map JSON edits are written into the corresponding KMP planes during the build. The raw KMP source retains unknown header and attribute data; this is a partial format reconstruction, not a complete scene engine. Width/height changes are rejected because they require reallocating the map's fixed spans.

Evidence and remaining cases

The renderer at 08002650 selects a plane through KMP+0x9C and uses dimensions at +0x14/+0x18. The loader at 08003178 reads the KCG/KCL names at +0x1C/+0x5C and palette destination/count at +0xB0/+0xB4. The recovered header is in include/kmp.h; viewport initialization and attribute addressing now match in src/kmp.c.

The original KMP migration report listed 27 exceptions. The affine migration resolves five, and the regular TSC migration below resolves nine more. Thirteen resources still need another map profile. These include regular TSC cases, missing same-name KMPs, and unresolved tile or palette references. OP_07_A references tile 1023 outside its own tile resource and remains unresolved. Those resources retain their tile-sheet sources rather than guessed pictures.

tools/exercise_mapped_images.py checks a clean build, an actual PNG edit and an independent map flip in the final ROM, then restores both sources. Run it alone after the unit tests have finished.

Affine TSC frames

NE01, NE13, NE33, SK02 and SK03 now build from 15 individual mapped frames. Their JSON uses format: affine_tsc_u8: each entry is a byte tile index, without flip or palette-bank bits. Each frame names its separate TSC source. Pixels remain 8bpp indices, including the original palette placement; colors come from the named TCL .pal file. Shared tile edit rules apply across frames. Unused tiles remain in the narrow strips so the tile payload rebuilds exactly.

NE01's loader at 080411A4 confirms BG2CNT 188A, a 128×128 affine map, and a 96-byte palette copy to color 192. Other four resources use complete square byte-index planes: 128×128 for NE13/NE33/SK02 and 256×256 for SK03. Those shapes are inferred from their plane sizes and valid references. The earlier claim that every TSC was a 2048-byte screenblock was incorrect.

Regular TSC screenblocks

Nine more resources now have 42 editable 256×256 frames. Their JSON format is regular_tsc_u16; each frame names its TSC member and contains 1024 tilemap words. The map's palette banks 12–14 select the named TCL palette at colors 192–239. Bank-zero entries are allowed only for fully transparent tiles. Per-bank transparent colors are recorded in PNG alpha without changing indices.

See reports/graphics/regular-image-migration.json for the migrated resources. GA60_03 and NE21_01 reference tile 1023 outside their own tile payload; these remain unresolved. GA08, NE32, SN07 and SSN07 use multiple screenblocks and still need the runtime size/orientation traced. Together with the remaining KMP exceptions and unassociated tile source, 13 resources remain tile sheets. Animation ordering and duration are not inferred from filename order.