Repository Analysis

nothings/stb

stb single-file public domain libraries for C/C++

6.1 Low AI signal View on GitHub

Analysis Overview

This report presents the forensic synthetic code analysis of nothings/stb, a C project with 34,184 GitHub stars. SynthScan v2.0 examined 109,822 lines of code across 113 source files, recording 882 pattern matches distributed across 6 syntactic categories. The overall adjusted score of 6.1 places this repository in the Low AI signal band.

The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).

6.1
Adjusted Score
6.1
Raw Score
100%
Time Factor
2026-04-15
Last Push
34.2K
Stars
C
Language
109.8K
Lines of Code
113
Files
882
Pattern Hits
2026-07-14
Scan Date
0.02
HC Hit Rate

What These Metrics Mean

Adjusted Score
Primary synthetic code indicator. Raw score normalised per 1,000 lines of code and multiplied by the temporal discount factor. This is the definitive comparative metric — use it to rank repositories by AI authorship density.
Raw Score
The unmodified sum of all severity-weighted, context-multiplied pattern match scores before temporal discounting. Reflects the absolute signal strength independent of when the repository was last active.
Time Factor
The temporal discount multiplier (0–100%) applied to the raw score. Repositories last updated before ChatGPT's launch (Nov 2022) receive a 5% factor. Full signal is only assigned to repositories active in the post-adoption era (Jan 2024+).
Pattern Hits
Total count of individual pattern matches across all files and categories. A high hit count with a low score may indicate a very large codebase with isolated AI snippets; a low count with a high score indicates dense, concentrated AI signatures.
HC Hit Rate
High+Critical pattern hits per file, averaged across the repository. This orthogonal signal catches repositories where a few files are densely packed with high-severity AI tells — a strong indicator even when the normalised score appears moderate due to codebase size.
Lines of Code / Files
Total lines and files analysed. The scanner examines 94 file extensions. These denominators are used to normalise the score, enabling fair comparison between repositories of vastly different sizes.

Score History

This chart maps the temporal evolution of the adjusted synthetic code score across successive scan runs. An upward trajectory indicates ongoing incorporation of AI-generated code or expanding LLM-assisted scaffolding; a stable or declining trajectory may reflect active human refactoring, code removal, or the adoption of stricter authorship policies. The dashed secondary line (right axis) independently tracks total raw pattern hit count, which can diverge from the normalised score when codebase size changes significantly between scans.

Severity Breakdown

Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.

CRITICAL 0HIGH 2MEDIUM 2LOW 878

Directory Score Breakdown

This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.

Pattern Findings

The scanner identified 882 distinct pattern matches across 6 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.

Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.

Over-Commented Block875 hits · 641 pts
SeverityFileLineSnippetContext
LOWstb_c_lexer.h1// stb_c_lexer.h - v0.12 - public domain Sean Barrett 2013COMMENT
LOWstb_c_lexer.h21// 0.04 fix octal parsing bugCOMMENT
LOWstb_c_lexer.h41// github:mundusnine (bugfix)COMMENT
LOWstb_c_lexer.h61#define STB_C_LEX_C_HEX_INTS Y // "0x[0-9a-fA-F]+" CLEX_intlitCOMMENT
LOWstb_c_lexer.h81 // "<<=" CLEX_shleq ">>=" CLEX_shreqCOMMENT
LOWstb_c_lexer.h141extern "C" {COMMENT
LOWstb_c_lexer.h161extern void stb_c_lexer_get_location(const stb_lexer *lexer, const char *where, stb_lex_location *loc);COMMENT
LOWstb_c_lexer.h221typedef double stb__clex_int;COMMENT
LOWstb_c_lexer.h241#define STB__clex_hex_intsCOMMENT
LOWstb_image_write.h201#ifdef _WIN32COMMENT
LOWstb_image_write.h221#elif !defined(STBIW_MALLOC) && !defined(STBIW_FREE) && !defined(STBIW_REALLOC) && !defined(STBIW_REALLOC_SIZED)COMMENT
LOWstb_image_write.h801 } elseCOMMENT
LOWstb_image_write.h881 (bitbuf |= (code) << bitcount, bitcount += (codebits), stbiw__zlib_flush())COMMENT
LOWstb_image_resize2.h401typedef uint32_t stbir_uint32;COMMENT
LOWstb_image_resize2.h421//COMMENT
LOWstb_image_resize2.h541// * Separate input and output data typesCOMMENT
LOWstb_image_resize2.h641STBIRDEF int stbir_set_non_pm_alpha_speed_over_quality( STBIR_RESIZE * resize, int non_pma_alpha_speed_over_quality );COMMENT
LOWstb_image_resize2.h661STBIRDEF int stbir_resize_extended( STBIR_RESIZE * resize );COMMENT
LOWstb_image_resize2.h681// Note that you MUST call stbir_build_samplers_with_splits before stbir_resize_extended_split!COMMENT
LOWstb_image_resize2.h701//COMMENT
LOWstb_image_resize2.h721// return optional_output; // return the optional buffer that we filledCOMMENT
LOWstb_image_resize2.h781#endif // STBIR_INCLUDE_STB_IMAGE_RESIZE2_HCOMMENT
LOWstb_image_resize2.h801#elseCOMMENT
LOWstb_image_resize2.h821#endifCOMMENT
LOWstb_image_resize2.h841#endifCOMMENT
LOWstb_image_resize2.h881 STBIRI_AR_PM = 16,COMMENT
LOWstb_image_resize2.h1161 return (unsigned char) ((bias + scale*t) >> 16);COMMENT
LOWstb_image_resize2.h1181COMMENT
LOWstb_image_resize2.h1201 #define STBIR_AVX2COMMENT
LOWstb_image_resize2.h1221#endifCOMMENT
LOWstb_image_resize2.h1241 #elseCOMMENT
LOWstb_image_resize2.h1261#elseCOMMENT
LOWstb_image_resize2.h1281#endifCOMMENT
LOWstb_image_resize2.h1301#endifCOMMENT
LOWstb_image_resize2.h1321 #define stbir__simdf_load2( out, ptr ) (out) = _mm_castsi128_ps( _mm_loadl_epi64( (__m128i*)(ptr)) ) // top values canCOMMENT
LOWstb_image_resize2.h1361 out1 = _mm_unpackhi_epi16( ireg, zero ); \COMMENT
LOWstb_image_resize2.h1381 #define stbir__simdf_madd1( out, add, mul1, mul2 ) (out) = _mm_fmadd_ss( mul1, mul2, add )COMMENT
LOWstb_image_resize2.h1401COMMENT
LOWstb_image_resize2.h1461 #if defined(_MSC_VER) && !defined(__clang__)COMMENT
LOWstb_image_resize2.h1501 #include <immintrin.h>COMMENT
LOWstb_image_resize2.h1641COMMENT
LOWstb_image_resize2.h1661COMMENT
LOWstb_image_resize2.h1721 #define stbir__simdf_load1( out, ptr ) (out) = vld1q_dup_f32( (float const*)(ptr) ) // top values can be random (not dCOMMENT
LOWstb_image_resize2.h1761 { \COMMENT
LOWstb_image_resize2.h1781 #define stbir__simdf_madd( out, add, mul1, mul2 ) (out) = vfmaq_f32( add, mul1, mul2 )COMMENT
LOWstb_image_resize2.h1921COMMENT
LOWstb_image_resize2.h1981 #define stbir_simdi_castf( reg ) (reg)COMMENT
LOWstb_image_resize2.h2021 v128_t tmp = wasm_u16x8_extend_low_u8x16(ireg); \COMMENT
LOWstb_image_resize2.h2041 #define stbir__simdf_add_mem( out, reg, ptr ) (out) = wasm_f32x4_add( reg, wasm_v128_load( (void const*)(ptr) )COMMENT
LOWstb_image_resize2.h2121 #define STBIR__SIMDF_CONST(var, x) stbir__simdf var = (v128_t)(stbir__f32x4){ x, x, x, x }COMMENT
LOWstb_image_resize2.h2141 return wasm_f32x4_extract_lane( wasm_f32x4_ceil( wasm_f32x4_splat(x) ), 0);COMMENT
LOWstb_image_resize2.h2161 #define stbir__simdfX_madd stbir__simdf8_maddCOMMENT
LOWstb_image_resize2.h2181 static const stbir__simdf8 STBIR_simd_point58 = { 0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5 };COMMENT
LOWstb_image_resize2.h2201 #define stbir__simdfX_1a1a stbir__simdf_1a1aCOMMENT
LOWstb_image_resize2.h2541#define stbir__simdf_0123to0001( out, reg ) (out) = stbir__simdf_swiz( reg, 0,0,0,1 )COMMENT
LOWstb_image_resize2.h2781#define STBIR_PROFILE_START_ll( info, wh ) { stbir_uint64 wh##thiszonetime = STBIR_PROFILE_FUNC(); stbir_uint64 * wh##saCOMMENT
LOWstb_image_resize2.h2801#define STBIR_ONLY_PROFILE_SET_SPLIT_INFOCOMMENT
LOWstb_image_resize2.h2821#define STBIR_CEILF(x) ((float)ceil((float)(x)))COMMENT
LOWstb_image_resize2.h4081#define stbir__decode_swizzleCOMMENT
LOWstb_image_resize2.h4101#define stbir__encode_order1 0COMMENT
815 more matches not shown…
AI Response Leakage2 hits · 15 pts
SeverityFileLineSnippetContext
HIGHtests/prerelease/stb_lib.h1467// ok, so I've added something that generates _two separate_COMMENT
HIGHdeprecated/stb.h3444// ok, so I've added something that generates _two separate_COMMENT
AI Slop Vocabulary2 hits · 6 pts
SeverityFileLineSnippetContext
MEDIUMstb_vorbis.c51// 1.10 - 2017-03-03 - more robust seeking; fix negative ilog(); clear error in open_memoryCOMMENT
MEDIUMstb_voxel_render.h116// everything else should be seamless. (And I'd like to change the APICOMMENT
Verbosity Indicators1 hit · 2 pts
SeverityFileLineSnippetContext
LOWstb_voxel_render.h105// Step 3: define STBVOX_CONFIG_PREFER_TEXBUFFERCOMMENT
Structural Annotation Overuse1 hit · 2 pts
SeverityFileLineSnippetContext
LOWstb_voxel_render.h105// Step 3: define STBVOX_CONFIG_PREFER_TEXBUFFERCOMMENT
Slop Phrases1 hit · 2 pts
SeverityFileLineSnippetContext
LOWstb_tilemap_editor.h71// representation to the game representation. (Don't forget toCOMMENT