122 lines
2.7 KiB
122 lines
2.7 KiB
module mqoi;
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macro rgb_hash(Rgb px) => ((px.r * 3 + px.g * 5 + px.b * 7) & 0b00111111);
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macro mqoi_rgba_hash(Rgba px) => ((px.r * 3 + px.g * 5 + px.b * 7 + px.a * 11) & 0b00111111);
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const uint MQOI_HEADER_SIZE = 14;
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const char MQOI_MASK_OP_2B = 0b11000000;
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const char MQOI_MASK_OP_8B = 0b11111111;
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const char MQOI_MASK_OP_LUMA_DG = 0b00111111;
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const char MQOI_MASK_OP_RUN = 0b00111111;
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// basic types
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enum DescErr : uint (uint value) {
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MQOI_DESC_OK = 0, // The descriptor is valid
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MQOI_DESC_INVALID_MAGIC = 1, // The magic value isn't correct
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MQOI_DESC_INVALID_CHANNELS = 2, // The channel number isn't valid
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MQOI_DESC_INVALID_COLORSPACE = 3, // The colorspace isn't valid
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}
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enum Op : char (char value) {
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MQOI_OP2_INDEX = (0b00 << 6),
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MQOI_OP2_DIFF = (0b01 << 6),
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MQOI_OP2_LUMA = (0b10 << 6),
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MQOI_OP2_RUN = (0b11 << 6),
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MQOI_OP8_RUN_RGB = (0b11111110),
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MQOI_OP8_RUN_RGBA = (0b11111111),
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}
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enum Channels : char (char value) {
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MQOI_CHANNELS_RGB = 3,
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MQOI_CHANNELS_RGBA = 4,
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}
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enum Colorspace : char (char value) {
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MQOI_COLORSPACE_SRGB = 0,
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MQOI_COLORSPACE_LINEAR = 1,
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}
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union Rgb {
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struct { char r, g, b; }
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char[3] value;
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}
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union Rgba{
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struct { char r, g, b, a; }
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char[4] value;
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}
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struct Desc {
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char head;
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char[4] magic;
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char[4] width; // big-endian width
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char[4] height; // big-endian height
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char channels;
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char colorspace;
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}
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// ==== chunks ====
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union Chunk {
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struct {
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char head;
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union {
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Rgb rgb;
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Rgba rgba;
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char drdb;
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}
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}
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char[5] value;
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}
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// ==== codecs ====
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struct Encoding {
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Rgba[64] hashtable;
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Rgba prev_px;
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Chunk working_chunk;
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char working_chunk_size;
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}
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struct Dec {
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Rgba[64] hashtable;
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Rgba prev_px;
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Chunk curr_chunk;
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bitstruct : char {
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char curr_chunk_head : 0..3;
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char curr_chunk_size : 4..7;
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}
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uint pix_left;
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}
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// ==== utilities ====
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fn void u32_write(uint * n, char * dest) @extern("mqoi_u32_write");
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fn void u32_read(char * src, uint * n) @extern("mqoi_u32_read");
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// ==== Desc ====
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fn void desc_init(Desc* desc) @extern("mqoi_desc_init");
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fn void desc_push(Desc* desc, char byte) @extern("mqoi_desc_push");
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fn char* desc_pop(Desc* desc) @extern("mqoi_desc_pop");
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fn char desc_verify(Desc* desc, uint* w, uint* h) @extern("mqoi_desc_verify");
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fn bool desc_done(Desc* desc) @extern("mqoi_desc_done");
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/* the encoder is still WIP
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void mqoi_enc_init(mqoi_enc_t * enc);
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void mqoi_enc_push(mqoi_enc_t * enc, Rgba * pix)
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Chunk * mqoi_enc_pop(mqoi_enc_t * enc, char * size);
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*/
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// ==== Dec ====
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fn void dec_init(Dec* dec, uint n_pix) @extern("mqoi_dec_init");
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fn void dec_push(Dec* dec, char byte) @extern("mqoi_dec_push");
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fn char dec_take(Dec* dec, char* bytes) @extern("mqoi_dec_take");
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fn Rgba* dec_pop(Dec* dec) @extern("mqoi_dec_pop");
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fn bool dec_done(Dec* dec) @extern("mqoi_dec_done");
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