FlushTools

A single-header C utility library that started as a helper for Raylib games and grew into a general-purpose toolkit for systems and embedded C projects.

Drop flushtools.h into your project and you're done — no build system, no dependencies.

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Features

Module	Description
Lambda macros	Anonymous function helpers for GCC, Clang, and MSVC
Bit packing	Compact bit-level serialization for network packets
Quantization	Float ↔ integer compression for bandwidth-sensitive data
Coordinate compression	16-bit encode/decode for world-space coordinates
Timer	Simple second-resolution timer with callback support
Random	Fast non-cryptographic RNG seeded from a monotonic clock

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Installation

Copy flushtools.h into your project and include it:

#include "flushtools.h"

No linking required. Works with C11 and C17.

Clang lambda support requires the Blocks runtime:

clang -fblocks -lBlocksRuntime main.c -o main

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Usage

Lambda macros

Write inline callbacks without naming a function. Compiler support varies — see the table below.

// Store in a variable
int (*add)(int, int) = LAMBDA(int, (int a, int b), { return a + b; });
printf("%d\n", add(3, 4)); // 7

// Pass directly to a callback
qsort(arr, n, sizeof(int),
    AS_FN(int, (const void* a, const void* b), {
        return *(int*)a - *(int*)b;
    })
);

// Named function-pointer typedef
FN_TYPE(Predicate, int, int);
Predicate is_even = LAMBDA(int, (int x), { return x % 2 == 0; });

MSVC doesn't support anonymous functions in C, so use the two-step helper instead:

DECL_FN(int, my_cmp, (const void* a, const void* b), {
    return *(int*)a - *(int*)b;
});
qsort(arr, n, sizeof(int), FN_PTR(my_cmp));

Macro	GCC	Clang	MSVC
LAMBDA	✅	✅	❌ use DECL_FN
AS_FN	✅	✅	❌ use DECL_FN
FN_TYPE	✅	✅	✅
BLOCK (capture)	❌	✅	❌
DECL_FN / FN_PTR	✅	✅	✅

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Bit packing

Serialize data at the bit level — useful for compact network packets in multiplayer games.

uint8_t buf[16];
net_bit_writer_t writer;
net_writer_init(&writer, buf, sizeof(buf));
net_writer_bits(&writer, 0b101, 3);  // write 3 bits

net_bit_reader_t reader = { buf, 0 };
uint32_t val = net_read_bits(&reader, 3);  // read back → 5

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Quantization

Compress floats into N-bit integers for compact packet representation.

// Encode a float in [0.0, 1.0] using 8 bits
uint32_t q = net_quantize(0.75f, 0.0f, 1.0f, 8);  // → 191

// Decode back
float f = net_dequantize(q, 0.0f, 1.0f, 8);        // → ~0.75

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Coordinate compression

Pack world-space floats into a uint16_t for network transmission.

uint16_t packed = compass_coord(123.4f, 0.0f, 1000.0f);
float    unpacked = decompress_coord(packed, 0.0f, 1000.0f);

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Timer

Second-resolution timer with an optional per-tick callback.

void on_tick(void) { printf("tick\n"); }

Timer t;
timer_init(&t, 5);   // 5 second timer
timer_run(&t, on_tick);

// Or poll manually
timer_init(&t, 10);
while (!timer_is_finished(&t)) {
    printf("elapsed: %.0fs\n", timer_get_elapsed(&t));
}

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Random

Non-cryptographic RNG seeded from the monotonic clock. Good for procedural generation, shuffles, and similar non-security tasks.

unsigned long long roll = random_gen(1, 6);   // simulates a die roll
unsigned long long uid  = random_gen(0, UINT32_MAX);

⚠️ Not cryptographically secure. Do not use for passwords, tokens, or anything security-sensitive.

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Compiler Support

Compiler	Standard	Notes
GCC	C11, C17	Full support
Clang	C11, C17	Full support; -fblocks for capture
MSVC	C11, C17	DECL_FN/FN_PTR instead of LAMBDA

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License

MIT License — Copyright (c) 2026 Austin Clark. See LICENSE for details.