--- /dev/null
+/*
+
+QOI - The "Quite OK Image" format for fast, lossless image compression
+
+Dominic Szablewski - https://phoboslab.org
+
+
+-- LICENSE: The MIT License(MIT)
+
+Copyright(c) 2021 Dominic Szablewski
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files(the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and / or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions :
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+
+-- About
+
+QOI encodes and decodes images in a lossless format. An encoded QOI image is
+usually around 10--30% larger than a decently optimized PNG image.
+
+QOI outperforms simpler PNG encoders in compression ratio and performance. QOI
+images are typically 20% smaller than PNGs written with stbi_image. Encoding is
+25-50x faster and decoding is 3-4x faster than stbi_image or libpng.
+
+
+-- Synopsis
+
+// Define `QOI_IMPLEMENTATION` in *one* C/C++ file before including this
+// library to create the implementation.
+
+#define QOI_IMPLEMENTATION
+#include "qoi.h"
+
+// Encode and store an RGBA buffer to the file system. The qoi_desc describes
+// the input pixel data.
+qoi_write("image_new.qoi", rgba_pixels, &(qoi_desc){
+ .width = 1920,
+ .height = 1080,
+ .channels = 4,
+ .colorspace = QOI_SRGB
+});
+
+// Load and decode a QOI image from the file system into a 32bbp RGBA buffer.
+// The qoi_desc struct will be filled with the width, height, number of channels
+// and colorspace read from the file header.
+qoi_desc desc;
+void *rgba_pixels = qoi_read("image.qoi", &desc, 4);
+
+
+
+-- Documentation
+
+This library provides the following functions;
+- qoi_read -- read and decode a QOI file
+- qoi_decode -- decode the raw bytes of a QOI image from memory
+- qoi_write -- encode and write a QOI file
+- qoi_encode -- encode an rgba buffer into a QOI image in memory
+
+See the function declaration below for the signature and more information.
+
+If you don't want/need the qoi_read and qoi_write functions, you can define
+QOI_NO_STDIO before including this library.
+
+This library uses malloc() and free(). To supply your own malloc implementation
+you can define QOI_MALLOC and QOI_FREE before including this library.
+
+
+-- Data Format
+
+A QOI file has a 14 byte header, followed by any number of data "chunks".
+
+struct qoi_header_t {
+ char magic[4]; // magic bytes "qoif"
+ uint32_t width; // image width in pixels (BE)
+ uint32_t height; // image height in pixels (BE)
+ uint8_t channels; // must be 3 (RGB) or 4 (RGBA)
+ uint8_t colorspace; // a bitmap 0000rgba where
+ // - a zero bit indicates sRGBA,
+ // - a one bit indicates linear (user interpreted)
+ // colorspace for each channel
+};
+
+The decoder and encoder start with {r: 0, g: 0, b: 0, a: 255} as the previous
+pixel value. Pixels are either encoded as
+ - a run of the previous pixel
+ - an index into a previously seen pixel
+ - a difference to the previous pixel value in r,g,b,a
+ - full r,g,b,a values
+
+A running array[64] of previously seen pixel values is maintained by the encoder
+and decoder. Each pixel that is seen by the encoder and decoder is put into this
+array at the position (r^g^b^a) % 64. In the encoder, if the pixel value at this
+index matches the current pixel, this index position is written to the stream.
+
+Each chunk starts with a 2, 3 or 4 bit tag, followed by a number of data bits.
+The bit length of chunks is divisible by 8 - i.e. all chunks are byte aligned.
+All values encoded in these data bits have the most significant bit (MSB) on the
+left.
+
+The possible chunks are:
+
+ - QOI_INDEX -------------
+| Byte[0] |
+| 7 6 5 4 3 2 1 0 |
+|-------+-----------------|
+| 0 0 | index |
+
+2-bit tag b00
+6-bit index into the color index array: 0..63
+
+
+ - QOI_RUN_8 -------------
+| Byte[0] |
+| 7 6 5 4 3 2 1 0 |
+|----------+--------------|
+| 0 1 0 | run |
+
+3-bit tag b010
+5-bit run-length repeating the previous pixel: 1..32
+
+
+ - QOI_RUN_16 --------------------------------------
+| Byte[0] | Byte[1] |
+| 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 |
+|----------+----------------------------------------|
+| 0 1 1 | run |
+
+3-bit tag b011
+13-bit run-length repeating the previous pixel: 33..8224
+
+
+ - QOI_DIFF_8 ------------
+| Byte[0] |
+| 7 6 5 4 3 2 1 0 |
+|-------+-----+-----+-----|
+| 1 0 | dr | db | bg |
+
+2-bit tag b10
+2-bit red channel difference from the previous pixel between -2..1
+2-bit green channel difference from the previous pixel between -2..1
+2-bit blue channel difference from the previous pixel between -2..1
+
+The difference to the current channel values are using a wraparound operation,
+so "1 - 2" will result in 255, while "255 + 1" will result in 0.
+
+
+ - QOI_DIFF_16 -------------------------------------
+| Byte[0] | Byte[1] |
+| 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 |
+|----------+--------------|------------ +-----------|
+| 1 1 0 | red diff | green diff | blue diff |
+
+3-bit tag b110
+5-bit red channel difference from the previous pixel between -16..15
+4-bit green channel difference from the previous pixel between -8..7
+4-bit blue channel difference from the previous pixel between -8..7
+
+The difference to the current channel values are using a wraparound operation,
+so "10 - 13" will result in 253, while "250 + 7" will result in 1.
+
+
+ - QOI_DIFF_24 ---------------------------------------------------------------
+| Byte[0] | Byte[1] | Byte[2] |
+| 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 |
+|-------------+----------------+--------------+----------------+--------------|
+| 1 1 1 0 | red diff | green diff | blue diff | alpha diff |
+
+4-bit tag b1110
+5-bit red channel difference from the previous pixel between -16..15
+5-bit green channel difference from the previous pixel between -16..15
+5-bit blue channel difference from the previous pixel between -16..15
+5-bit alpha channel difference from the previous pixel between -16..15
+
+The difference to the current channel values are using a wraparound operation,
+so "10 - 13" will result in 253, while "250 + 7" will result in 1.
+
+
+ - QOI_COLOR -------------
+| Byte[0] |
+| 7 6 5 4 3 2 1 0 |
+|-------------+--+--+--+--|
+| 1 1 1 1 |hr|hg|hb|ha|
+
+4-bit tag b1111
+1-bit red byte follows
+1-bit green byte follows
+1-bit blue byte follows
+1-bit alpha byte follows
+
+For each set bit hr, hg, hb and ha another byte follows in this order. If such a
+byte follows, it will replace the current color channel value with the value of
+this byte.
+
+
+The byte stream is padded at the end with 4 zero bytes. Size the longest chunk
+we can encounter is 5 bytes (QOI_COLOR with RGBA set), with this padding we just
+have to check for an overrun once per decode loop iteration.
+
+*/
+
+
+// -----------------------------------------------------------------------------
+// Header - Public functions
+
+#ifndef QOI_H
+#define QOI_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// A pointer to qoi_desc struct has to be supplied to all of qoi's functions. It
+// describes either the input format (for qoi_write, qoi_encode), or is filled
+// with the description read from the file header (for qoi_read, qoi_decode).
+
+// The colorspace in this qoi_desc is a bitmap with 0000rgba where a 0-bit
+// indicates sRGB and a 1-bit indicates linear colorspace for each channel. You
+// may use one of the predefined constants: QOI_SRGB, QOI_SRGB_LINEAR_ALPHA or
+// QOI_LINEAR. The colorspace is purely informative. It will be saved to the
+// file header, but does not affect en-/decoding in any way.
+
+#define QOI_SRGB 0x00
+#define QOI_SRGB_LINEAR_ALPHA 0x01
+#define QOI_LINEAR 0x0f
+
+typedef struct {
+ unsigned int width;
+ unsigned int height;
+ unsigned char channels;
+ unsigned char colorspace;
+} qoi_desc;
+
+#ifndef QOI_NO_STDIO
+
+// Encode raw RGB or RGBA pixels into a QOI image and write it to the file
+// system. The qoi_desc struct must be filled with the image width, height,
+// number of channels (3 = RGB, 4 = RGBA) and the colorspace.
+
+// The function returns 0 on failure (invalid parameters, or fopen or malloc
+// failed) or the number of bytes written on success.
+
+int qoi_write(const char *filename, const void *data, const qoi_desc *desc);
+
+
+// Read and decode a QOI image from the file system. If channels is 0, the
+// number of channels from the file header is used. If channels is 3 or 4 the
+// output format will be forced into this number of channels.
+
+// The function either returns NULL on failure (invalid data, or malloc or fopen
+// failed) or a pointer to the decoded pixels. On success, the qoi_desc struct
+// will be filled with the description from the file header.
+
+// The returned pixel data should be free()d after use.
+
+void *qoi_read(const char *filename, qoi_desc *desc, int channels);
+
+#endif // QOI_NO_STDIO
+
+
+// Encode raw RGB or RGBA pixels into a QOI image in memory.
+
+// The function either returns NULL on failure (invalid parameters or malloc
+// failed) or a pointer to the encoded data on success. On success the out_len
+// is set to the size in bytes of the encoded data.
+
+// The returned qoi data should be free()d after use.
+
+void *qoi_encode(const void *data, const qoi_desc *desc, int *out_len);
+
+
+// Decode a QOI image from memory.
+
+// The function either returns NULL on failure (invalid parameters or malloc
+// failed) or a pointer to the decoded pixels. On success, the qoi_desc struct
+// is filled with the description from the file header.
+
+// The returned pixel data should be free()d after use.
+
+void *qoi_decode(const void *data, int size, qoi_desc *desc, int channels);
+
+
+#ifdef __cplusplus
+}
+#endif
+#endif // QOI_H
+
+
+// -----------------------------------------------------------------------------
+// Implementation
+
+#ifdef QOI_IMPLEMENTATION
+#include <stdlib.h>
+
+#ifndef QOI_MALLOC
+ #define QOI_MALLOC(sz) malloc(sz)
+ #define QOI_FREE(p) free(p)
+#endif
+
+#define QOI_INDEX 0x00 // 00xxxxxx
+#define QOI_RUN_8 0x40 // 010xxxxx
+#define QOI_RUN_16 0x60 // 011xxxxx
+#define QOI_DIFF_8 0x80 // 10xxxxxx
+#define QOI_DIFF_16 0xc0 // 110xxxxx
+#define QOI_DIFF_24 0xe0 // 1110xxxx
+#define QOI_COLOR 0xf0 // 1111xxxx
+
+#define QOI_MASK_2 0xc0 // 11000000
+#define QOI_MASK_3 0xe0 // 11100000
+#define QOI_MASK_4 0xf0 // 11110000
+
+#define QOI_COLOR_HASH(C) (C.rgba.r ^ C.rgba.g ^ C.rgba.b ^ C.rgba.a)
+#define QOI_MAGIC \
+ (((unsigned int)'q') << 24 | ((unsigned int)'o') << 16 | \
+ ((unsigned int)'i') << 8 | ((unsigned int)'f'))
+#define QOI_HEADER_SIZE 14
+#define QOI_PADDING 4
+
+typedef union {
+ struct { unsigned char r, g, b, a; } rgba;
+ unsigned int v;
+} qoi_rgba_t;
+
+void qoi_write_32(unsigned char *bytes, int *p, unsigned int v) {
+ bytes[(*p)++] = (0xff000000 & v) >> 24;
+ bytes[(*p)++] = (0x00ff0000 & v) >> 16;
+ bytes[(*p)++] = (0x0000ff00 & v) >> 8;
+ bytes[(*p)++] = (0x000000ff & v);
+}
+
+unsigned int qoi_read_32(const unsigned char *bytes, int *p) {
+ unsigned int a = bytes[(*p)++];
+ unsigned int b = bytes[(*p)++];
+ unsigned int c = bytes[(*p)++];
+ unsigned int d = bytes[(*p)++];
+ return (a << 24) | (b << 16) | (c << 8) | d;
+}
+
+void *qoi_encode(const void *data, const qoi_desc *desc, int *out_len) {
+ if (
+ data == NULL || out_len == NULL || desc == NULL ||
+ desc->width == 0 || desc->height == 0 ||
+ desc->channels < 3 || desc->channels > 4 ||
+ (desc->colorspace & 0xf0) != 0
+ ) {
+ return NULL;
+ }
+
+ int max_size =
+ desc->width * desc->height * (desc->channels + 1) +
+ QOI_HEADER_SIZE + QOI_PADDING;
+
+ int p = 0;
+ unsigned char *bytes = QOI_MALLOC(max_size);
+ if (!bytes) {
+ return NULL;
+ }
+
+ qoi_write_32(bytes, &p, QOI_MAGIC);
+ qoi_write_32(bytes, &p, desc->width);
+ qoi_write_32(bytes, &p, desc->height);
+ bytes[p++] = desc->channels;
+ bytes[p++] = desc->colorspace;
+
+
+ const unsigned char *pixels = (const unsigned char *)data;
+
+ qoi_rgba_t index[64] = {0};
+
+ int run = 0;
+ qoi_rgba_t px_prev = {.rgba = {.r = 0, .g = 0, .b = 0, .a = 255}};
+ qoi_rgba_t px = px_prev;
+
+ int px_len = desc->width * desc->height * desc->channels;
+ int px_end = px_len - desc->channels;
+ int channels = desc->channels;
+
+ for (int px_pos = 0; px_pos < px_len; px_pos += channels) {
+ if (channels == 4) {
+ px = *(qoi_rgba_t *)(pixels + px_pos);
+ }
+ else {
+ px.rgba.r = pixels[px_pos];
+ px.rgba.g = pixels[px_pos+1];
+ px.rgba.b = pixels[px_pos+2];
+ }
+
+ if (px.v == px_prev.v) {
+ run++;
+ }
+
+ if (
+ run > 0 &&
+ (run == 0x2020 || px.v != px_prev.v || px_pos == px_end)
+ ) {
+ if (run < 33) {
+ run -= 1;
+ bytes[p++] = QOI_RUN_8 | run;
+ }
+ else {
+ run -= 33;
+ bytes[p++] = QOI_RUN_16 | run >> 8;
+ bytes[p++] = run;
+ }
+ run = 0;
+ }
+
+ if (px.v != px_prev.v) {
+ int index_pos = QOI_COLOR_HASH(px) % 64;
+
+ if (index[index_pos].v == px.v) {
+ bytes[p++] = QOI_INDEX | index_pos;
+ }
+ else {
+ index[index_pos] = px;
+
+ int vr = px.rgba.r - px_prev.rgba.r;
+ int vg = px.rgba.g - px_prev.rgba.g;
+ int vb = px.rgba.b - px_prev.rgba.b;
+ int va = px.rgba.a - px_prev.rgba.a;
+
+ if (
+ vr > -17 && vr < 16 &&
+ vg > -17 && vg < 16 &&
+ vb > -17 && vb < 16 &&
+ va > -17 && va < 16
+ ) {
+ if (
+ va == 0 &&
+ vr > -3 && vr < 2 &&
+ vg > -3 && vg < 2 &&
+ vb > -3 && vb < 2
+ ) {
+ bytes[p++] = QOI_DIFF_8 | ((vr + 2) << 4) | (vg + 2) << 2 | (vb + 2);
+ }
+ else if (
+ va == 0 &&
+ vr > -17 && vr < 16 &&
+ vg > -9 && vg < 8 &&
+ vb > -9 && vb < 8
+ ) {
+ bytes[p++] = QOI_DIFF_16 | (vr + 16);
+ bytes[p++] = (vg + 8) << 4 | (vb + 8);
+ }
+ else {
+ bytes[p++] = QOI_DIFF_24 | (vr + 16) >> 1;
+ bytes[p++] = (vr + 16) << 7 | (vg + 16) << 2 | (vb + 16) >> 3;
+ bytes[p++] = (vb + 16) << 5 | (va + 16);
+ }
+ }
+ else {
+ bytes[p++] = QOI_COLOR | (vr ? 8 : 0) | (vg ? 4 : 0) | (vb ? 2 : 0) | (va ? 1 : 0);
+ if (vr) { bytes[p++] = px.rgba.r; }
+ if (vg) { bytes[p++] = px.rgba.g; }
+ if (vb) { bytes[p++] = px.rgba.b; }
+ if (va) { bytes[p++] = px.rgba.a; }
+ }
+ }
+ }
+ px_prev = px;
+ }
+
+ for (int i = 0; i < QOI_PADDING; i++) {
+ bytes[p++] = 0;
+ }
+
+ *out_len = p;
+ return bytes;
+}
+
+void *qoi_decode(const void *data, int size, qoi_desc *desc, int channels) {
+ if (
+ data == NULL || desc == NULL ||
+ (channels != 0 && channels != 3 && channels != 4) ||
+ size < QOI_HEADER_SIZE + QOI_PADDING
+ ) {
+ return NULL;
+ }
+
+ const unsigned char *bytes = (const unsigned char *)data;
+ int p = 0;
+
+ unsigned int header_magic = qoi_read_32(bytes, &p);
+ desc->width = qoi_read_32(bytes, &p);
+ desc->height = qoi_read_32(bytes, &p);
+ desc->channels = bytes[p++];
+ desc->colorspace = bytes[p++];
+
+ if (
+ desc->width == 0 || desc->height == 0 ||
+ desc->channels < 3 || desc->channels > 4 ||
+ header_magic != QOI_MAGIC
+ ) {
+ return NULL;
+ }
+
+ if (channels == 0) {
+ channels = desc->channels;
+ }
+
+ int px_len = desc->width * desc->height * channels;
+ unsigned char *pixels = QOI_MALLOC(px_len);
+ if (!pixels) {
+ return NULL;
+ }
+
+ qoi_rgba_t px = {.rgba = {.r = 0, .g = 0, .b = 0, .a = 255}};
+ qoi_rgba_t index[64] = {0};
+
+ int run = 0;
+ int chunks_len = size - QOI_PADDING;
+ for (int px_pos = 0; px_pos < px_len; px_pos += channels) {
+ if (run > 0) {
+ run--;
+ }
+ else if (p < chunks_len) {
+ int b1 = bytes[p++];
+
+ if ((b1 & QOI_MASK_2) == QOI_INDEX) {
+ px = index[b1 ^ QOI_INDEX];
+ }
+ else if ((b1 & QOI_MASK_3) == QOI_RUN_8) {
+ run = (b1 & 0x1f);
+ }
+ else if ((b1 & QOI_MASK_3) == QOI_RUN_16) {
+ int b2 = bytes[p++];
+ run = (((b1 & 0x1f) << 8) | (b2)) + 32;
+ }
+ else if ((b1 & QOI_MASK_2) == QOI_DIFF_8) {
+ px.rgba.r += ((b1 >> 4) & 0x03) - 2;
+ px.rgba.g += ((b1 >> 2) & 0x03) - 2;
+ px.rgba.b += ( b1 & 0x03) - 2;
+ }
+ else if ((b1 & QOI_MASK_3) == QOI_DIFF_16) {
+ int b2 = bytes[p++];
+ px.rgba.r += (b1 & 0x1f) - 16;
+ px.rgba.g += (b2 >> 4) - 8;
+ px.rgba.b += (b2 & 0x0f) - 8;
+ }
+ else if ((b1 & QOI_MASK_4) == QOI_DIFF_24) {
+ int b2 = bytes[p++];
+ int b3 = bytes[p++];
+ px.rgba.r += (((b1 & 0x0f) << 1) | (b2 >> 7)) - 16;
+ px.rgba.g += ((b2 & 0x7c) >> 2) - 16;
+ px.rgba.b += (((b2 & 0x03) << 3) | ((b3 & 0xe0) >> 5)) - 16;
+ px.rgba.a += (b3 & 0x1f) - 16;
+ }
+ else if ((b1 & QOI_MASK_4) == QOI_COLOR) {
+ if (b1 & 8) { px.rgba.r = bytes[p++]; }
+ if (b1 & 4) { px.rgba.g = bytes[p++]; }
+ if (b1 & 2) { px.rgba.b = bytes[p++]; }
+ if (b1 & 1) { px.rgba.a = bytes[p++]; }
+ }
+
+ index[QOI_COLOR_HASH(px) % 64] = px;
+ }
+
+ if (channels == 4) {
+ *(qoi_rgba_t*)(pixels + px_pos) = px;
+ }
+ else {
+ pixels[px_pos] = px.rgba.r;
+ pixels[px_pos+1] = px.rgba.g;
+ pixels[px_pos+2] = px.rgba.b;
+ }
+ }
+
+ return pixels;
+}
+
+#ifndef QOI_NO_STDIO
+#include <stdio.h>
+
+int qoi_write(const char *filename, const void *data, const qoi_desc *desc) {
+ FILE *f = fopen(filename, "wb");
+ if (!f) {
+ return 0;
+ }
+
+ int size;
+ void *encoded = qoi_encode(data, desc, &size);
+ if (!encoded) {
+ fclose(f);
+ return 0;
+ }
+
+ fwrite(encoded, 1, size, f);
+ fclose(f);
+
+ QOI_FREE(encoded);
+ return size;
+}
+
+void *qoi_read(const char *filename, qoi_desc *desc, int channels) {
+ FILE *f = fopen(filename, "rb");
+ if (!f) {
+ return NULL;
+ }
+
+ fseek(f, 0, SEEK_END);
+ int size = ftell(f);
+ fseek(f, 0, SEEK_SET);
+
+ void *data = QOI_MALLOC(size);
+ if (!data) {
+ fclose(f);
+ return NULL;
+ }
+
+ int bytes_read = fread(data, 1, size, f);
+ fclose(f);
+
+ void *pixels = qoi_decode(data, bytes_read, desc, channels);
+ QOI_FREE(data);
+ return pixels;
+}
+
+#endif // QOI_NO_STDIO
+#endif // QOI_IMPLEMENTATION
+
projects / fishladder.git / blobdiff