// Sprite-style asset loading.
//
// A JoeyLib asset is a small bitmap with the same 4bpp packed pixel
// format as the rest of the library, plus an optional 16-entry $0RGB
// palette. Assets blit onto SurfaceT via surfaceBlit / surfaceBlitMasked
// (defined in draw.h).
//
// Two production paths:
//
//   1. Embedded -- declare a `const JoeyAssetT` directly in a .c file
//      and bundle it into the executable. No allocation, no I/O. Best
//      for small game assets that always ship with the binary.
//
//   2. File / memory -- joeyAssetLoadFile reads a .jas blob from disk;
//      joeyAssetFromMem parses one already in RAM. Both allocate the
//      JoeyAssetT plus its pixel buffer; release with joeyAssetFree.
//
// .jas binary format (little-endian, byte-stream so endianness of the
// host doesn't matter):
//
//   offset  bytes  field
//   ------  -----  --------------------------------------------
//   0       4      magic "JAS1"
//   4       2      width  in pixels
//   6       2      height in pixels
//   8       1      hasPalette (0 or 1)
//   9       3      reserved (zero)
//   12      32     palette[16] of $0RGB; valid only if hasPalette
//   44      ...    pixels: rowBytes * height where rowBytes = (width+1)/2

#ifndef JOEYLIB_ASSET_H
#define JOEYLIB_ASSET_H

#include "platform.h"
#include "surface.h"
#include "types.h"

typedef struct {
    uint16_t       width;
    uint16_t       height;
    bool           hasPalette;
    uint16_t       palette[16];
    const uint8_t *pixels;
} JoeyAssetT;

// Allocates a new asset by reading a .jas file. Returns NULL if the
// file is missing, malformed, or too large.
JoeyAssetT *joeyAssetLoadFile(const char *path);

// Parses a .jas blob already in memory. Allocates a JoeyAssetT and
// copies the pixel run into a fresh buffer so the caller can free its
// own copy of the bytes after the call returns.
JoeyAssetT *joeyAssetFromMem(const uint8_t *data, uint32_t length);

// Releases an asset previously returned by a loader. Calling free on
// a static / embedded JoeyAssetT is forbidden -- those structs do not
// own their pixels and must not be passed here. NULL is OK.
void joeyAssetFree(JoeyAssetT *asset);

// Copies the asset's 16-entry palette into one of the surface's
// palette slots so that subsequent blits land on the right colors.
// No-op if the asset has no palette.
void joeyAssetApplyPalette(SurfaceT *dst, uint8_t paletteIndex, const JoeyAssetT *asset);

#endif