API.md

API Reference

Auto-generated from /// doc-comments in the header files. Run .\gen-docs.ps1 from the repository root to regenerate.

• l_os.h — core runtime (strings, I/O, processes, terminal, data structures)
• l_gfx.h — pixel graphics (drawing, fonts, canvas)
• l_svg.h — SVG rasterization
• l_ui.h — immediate-mode UI

For platform support see COMPAT.md. For test coverage see COVERAGE.md.

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Function Reference — l_os.h

Platform column: All = Linux + Windows + WASI; Unix = Linux-only (Windows has no - column equivalent — consult COMPAT.md for WASI stubs).

Function	Description	Platform
String functions
l_wcslen	Returns the length of a wide character string	All
l_strlen	Returns the length of a null-terminated string	All
l_strcpy	Copies src string to dst, returns dst	All
l_strncpy	Copies up to n characters from src to dst, padding with nulls	All
l_strcat	Appends src string to dst, returns dst	All
l_strncat	Appends at most n characters of src to dst, always null-terminates, returns dst	All
l_strchr	Returns pointer to first occurrence of c in s, or NULL	All
l_strrchr	Returns pointer to last occurrence of c in s, or NULL	All
l_strstr	Returns pointer to first occurrence of s2 in s1, or NULL	All
l_strcmp	Compares two strings, returns <0, 0, or >0	All
l_strncmp	Compares up to n characters of two strings	All
l_strcasecmp	Case-insensitive string comparison	All
l_strncasecmp	Case-insensitive comparison of up to n characters	All
l_strspn	Returns length of initial segment of s consisting entirely of bytes in accept	All
l_strcspn	Returns length of initial segment of s consisting entirely of bytes NOT in reject	All
l_strpbrk	Returns pointer to first occurrence in s of any character in accept, or NULL	All
l_strtok_r	Splits str into tokens delimited by any char in delim; saves state in *saveptr (reentrant)	All
l_strsep	Extracts token from *stringp delimited by any char in delim (BSD strsep); advances *stringp past delimiter	All
l_bin2hex	Converts binary data to lowercase hex string. NUL-terminates dst. Returns 2*len.	All
l_hex2bin	Converts hex string to binary data. Returns bytes written, or -1 on invalid input.	All
l_basename	Returns pointer to the filename component of path (after last '/' or '')	All
l_dirname	Writes the directory component of path into buf (up to bufsize), returns buf	All
l_path_join	Joins directory and filename with separator, returns buf	All
l_path_ext	Returns pointer to extension including dot (".txt"), or "" if none	All
l_path_exists	Returns 1 if path exists, 0 if not	All
l_path_isdir	Returns 1 if path is a directory, 0 if not	All
l_reverse	Reverses a string in place	All
Conversion functions
l_isspace	Returns non-zero if c is a whitespace character (space, tab, newline, etc.)	All
l_isdigit	Returns non-zero if c is a digit ('0'-'9')	All
l_isalpha	Returns non-zero if c is an alphabetic character ('A'-'Z' or 'a'-'z')	All
l_isalnum	Returns non-zero if c is alphanumeric (l_isalpha or l_isdigit)	All
l_isupper	Returns non-zero if c is an uppercase letter ('A'-'Z')	All
l_islower	Returns non-zero if c is a lowercase letter ('a'-'z')	All
l_toupper	Converts c to uppercase; returns c unchanged if not a lowercase letter	All
l_tolower	Converts c to lowercase; returns c unchanged if not an uppercase letter	All
l_isprint	Returns non-zero if c is a printable ASCII character (0x20-0x7e)	All
l_isxdigit	Returns non-zero if c is a hexadecimal digit (0-9, a-f, A-F)	All
l_abs	Returns the absolute value of an integer	All
l_labs	Returns the absolute value of a long	All
l_llabs	Returns the absolute value of a long long	All
l_atol	Converts a string to a long integer, skipping leading whitespace	All
l_atoi	Converts a string to an integer	All
l_strtoul	Converts a string to an unsigned long, auto-detecting base when base==0 (0x=hex, 0=octal, else decimal); sets *endptr past last digit	All
l_strtol	Converts a string to a long, auto-detecting base when base==0; handles leading sign; sets *endptr past last digit	All
l_strtoull	Converts a string to an unsigned long long (64-bit); auto-detects base when base==0; sets *endptr past last digit	All
l_strtoll	Converts a string to a long long (64-bit); auto-detects base when base==0; handles leading sign; sets *endptr past last digit	All
l_strtod	Converts a string to a double; skips leading whitespace; handles sign, decimal point, and e/E exponent; sets *endptr past last digit	All
l_atof	Converts a string to a double (convenience wrapper around l_strtod)	All
l_strtof	Converts a string to a float; skips leading whitespace; handles sign, decimal point, and e/E exponent; sets *endptr past last digit	All
Math functions
l_fabs	Returns the absolute value of a double	All
l_floor	Rounds toward negative infinity	All
l_ceil	Rounds toward positive infinity	All
l_fmod	Floating-point remainder of x/y	All
l_sqrt	Square root via Newton-Raphson with IEEE bit hack seed	All
l_sin	Sine via range reduction and Taylor series	All
l_cos	Cosine: l_sin(x + pi/2)	All
l_exp	Exponential function via range reduction and Taylor series	All
l_log	Natural logarithm via mantissa/exponent decomposition	All
l_pow	Power: base^exp via exp(exp * log(base))	All
l_atan2	Two-argument arctangent with quadrant handling	All
l_tan	Tangent: sin(x)/cos(x)	All
l_asin	Inverse sine via Newton's method, valid for [-1,1]	All
l_acos	Inverse cosine: pi/2 - asin(x)	All
l_atan	Inverse tangent: asin(x/sqrt(1+x*x))	All
l_log10	Base-10 logarithm: log(x)/log(10)	All
l_log2	Base-2 logarithm: log(x)/log(2)	All
l_round	Round to nearest integer (halfway rounds away from zero)	All
l_trunc	Truncate toward zero	All
l_hypot	Euclidean distance, overflow-safe: sqrt(xx+yy)	All
l_itoa	Converts an integer to a string in the given radix (2-36)	All
Memory functions
l_memmove	Copies len bytes from src to dst, handling overlapping regions	All
l_memset	Fills len bytes of dst with byte value b	All
l_memcmp	Compares n bytes of s1 and s2, returns <0, 0, or >0	All
l_memcpy	Copies len bytes from src to dst	All
l_memchr	Finds first occurrence of byte c in the first n bytes of s, or NULL	All
l_memrchr	Finds last occurrence of byte c in the first n bytes of s, or NULL	All
l_strnlen	Returns the length of s, but at most maxlen (does not scan past maxlen bytes)	All
l_memmem	Finds first occurrence of needle (needlelen bytes) in haystack (haystacklen bytes), or NULL	All
Random number generation (xorshift32, single-threaded)
l_srand	Seeds the pseudo-random number generator	All
l_rand	Returns a pseudo-random unsigned int (xorshift32)	All
l_rand_ctx_init	Initialize an independent RNG context	All
l_srand_ctx	Seed an independent RNG context	All
l_rand_ctx	Returns a pseudo-random unsigned int from an independent context	All
Formatted output (opt-in: define L_WITHSNPRINTF before including l_os.h)
l_vsnprintf	Formats a string into buf (at most n bytes including NUL); returns number of chars that would have been written	All
l_snprintf	Formats a string into buf (at most n bytes including NUL); returns number of chars that would have been written	All
l_dprintf	Writes formatted output to file descriptor fd. Returns number of bytes written.	All
l_printf	Writes formatted output to stdout. Returns number of bytes written.	All
l_vfprintf	Writes formatted output to file descriptor fd via va_list. Returns number of bytes written.	All
l_vprintf	Writes formatted output to stdout via va_list. Returns number of bytes written.	All
l_fprintf	Writes formatted output to file descriptor fd. Returns number of bytes written.	All
System functions
l_exit	Terminates the process with the given status code	All
l_open	Opens a file with the given flags and mode, returns file descriptor	All
l_close	Closes a file descriptor	All
l_read	Reads up to count bytes from fd into buf	All
l_write	Writes up to count bytes from buf to fd	All
l_read_line	Reads one line from fd into buf (up to bufsz-1 bytes). Strips the newline.	All
l_linebuf_init	Initialise a buffered line reader wrapping fd.	All
l_linebuf_read	Read one line into out (up to outsz-1 bytes). Strips newline. Buffers reads in 4096-byte chunks.	All
l_time	Returns current Unix timestamp (seconds since 1970-01-01). Also writes to *t if non-NULL.	All
l_puts	Writes a string to stdout	All
l_exitif	Exits with code and message if condition is true	All
l_getenv	Returns value of environment variable, or NULL if not found	All
l_getenv_init	Initializes environment variable access (call from main)	All
l_env_start	Begin iterating environment variables. Returns opaque handle (pass to l_env_end).	All
l_env_next	Get next "KEY=VALUE" string. buf/bufsz provide conversion space (Windows).	All
l_env_end	End iteration and free resources.	All
l_find_executable	Finds an executable by name, searching PATH if needed.	All
Option parsing (single-threaded; state in static variables)
l_getopt	Parses command-line options. optstring lists valid option chars; trailing ':' means the option	All
l_getopt_ctx_init	Initialize an independent option parser context	All
l_getopt_ctx	Reentrant getopt using an independent context. Same semantics as l_getopt.	All
Convenience file openers
l_open_read	Opens a file for reading	All
l_open_write	Opens or creates a file for writing	All
l_open_readwrite	Opens or creates a file for reading and writing	All
l_open_append	Opens or creates a file for appending	All
l_open_trunc	Opens or creates a file, truncating to zero length	All
Error reporting
l_errno	Returns the error code from the most recent failed syscall (0 if last call succeeded)	All
l_strerror	Returns a human-readable string for the given error code	All
Terminal and timing functions (cross-platform)
l_sleep_ms	Sleeps for the given number of milliseconds	All
l_term_raw	Sets stdin to raw mode (no echo, no line buffering), returns old mode	All
l_term_restore	Restores terminal mode from value returned by l_term_raw	All
l_read_nonblock	Reads from fd without blocking, returns 0 if no data available	All
l_term_size	Gets terminal size in rows and columns	All
ANSI terminal helpers
l_ansi_move	Writes cursor-move sequence into buf, returns bytes written	All
l_ansi_color	Writes color sequence into buf; fg/bg are 0-7 ANSI colors, -1 for default	All
l_ansi_color_rgb	Writes 24-bit truecolor ANSI sequence into buf; is_bg=0 for foreground, 1 for background	All
File system functions (cross-platform)
l_unlink	Deletes a file, returns 0 on success, -1 on error	All
l_rmdir	Removes an empty directory, returns 0 on success, -1 on error	All
l_rename	Renames (or moves) a file or directory. Returns 0 on success, -1 on error.	All
l_access	Checks access to a file. mode: L_F_OK (exists), L_R_OK, L_W_OK, L_X_OK. Returns 0 if ok, -1 on error.	All
l_chmod	Changes permission bits of a file. Returns 0 on success, -1 on error.	All
l_symlink	Creates a symbolic link at linkpath pointing to target. Returns 0 on success, -1 on error.	All
l_readlink	Reads the target of a symbolic link into buf (up to bufsiz bytes). Returns number of bytes read, or -1 on error.	All
l_realpath	Resolves path to its canonical absolute form into resolved (at least L_PATH_MAX bytes). Returns resolved on success, NULL on error.	All
l_stat	Gets file metadata by path. Returns 0 on success, -1 on error.	All
l_fstat	Gets file metadata by open file descriptor. Returns 0 on success, -1 on error.	All
l_truncate	Truncates a file at the given path to the specified size. Returns 0 on success, -1 on error.	All
l_ftruncate	Truncates an open file descriptor to the specified size. Returns 0 on success, -1 on error.	All
l_file_size	Returns the size of a file in bytes, or -1 on error.	All
l_read_all	Reads exactly count bytes, retrying on short reads. Returns total bytes read, 0 on EOF, or negative on error.	All
l_write_all	Writes exactly count bytes, retrying on short writes. Returns total bytes written, or negative on error.	All
l_opendir	Opens a directory for reading. Returns 0 on success, -1 on error.	All
l_readdir	Reads the next directory entry. Returns pointer to L_DirEntry or NULL when done.	All
l_closedir	Closes a directory handle.	All
l_mmap	Maps a file or anonymous memory into the process address space	All
l_munmap	Unmaps a previously mapped region	All
l_getrandom	Fill buf with len bytes of cryptographic-quality random data (getrandom(2) on Linux, BCryptGenRandom on Windows). Returns 0 on success, -1 on error.	All
Arena function declarations
l_arena_init	Allocate an arena of size bytes via mmap. On failure, base=NULL.	All
l_arena_alloc	Bump-allocate n bytes (8-byte aligned). Returns NULL if arena is full.	All
l_arena_reset	Reset used to 0. Memory is NOT freed — arena can be reused.	All
l_arena_free	Free the backing memory. Sets base=NULL.	All
Buffer function declarations
l_buf_init	Zero-initialize a buffer.	All
l_buf_push	Append n bytes. Returns 0 on success, -1 on failure.	All
l_buf_printf	Formatted append using l_vsnprintf. Returns bytes written or -1.	All
l_buf_clear	Set len=0 (keep allocated memory).	All
l_buf_free	Free backing memory and zero the struct.	All
L_Str — fat string (pointer + length) function declarations
l_str	Wrap a C string (computes strlen).	All
l_str_from	Wrap pointer+length.	All
l_str_null	Return null string {NULL, 0}.	All
l_str_eq	1 if equal, 0 otherwise.	All
l_str_cmp	Lexicographic compare (like strcmp).	All
l_str_startswith	1 if s starts with prefix.	All
l_str_endswith	1 if s ends with suffix.	All
l_str_contains	1 if s contains needle.	All
l_str_sub	Substring (zero-copy).	All
l_str_trim	Trim leading+trailing whitespace (zero-copy).	All
l_str_ltrim	Trim leading whitespace (zero-copy).	All
l_str_rtrim	Trim trailing whitespace (zero-copy).	All
l_str_chr	Find char in string, -1 if not found.	All
l_str_rchr	Find last occurrence of char, -1 if not found.	All
l_str_find	Find substring, -1 if not found.	All
l_str_dup	Copy string into arena.	All
l_str_cat	Concatenate two strings into arena.	All
l_str_cstr	Null-terminated C string copy in arena.	All
l_str_from_cstr	strdup into arena as L_Str.	All
l_str_split	Split string by delimiter. Returns count; *out is arena-allocated array.	All
l_str_join	Join strings with separator.	All
l_str_upper	Uppercase copy in arena (ASCII).	All
l_str_lower	Lowercase copy in arena (ASCII).	All
l_str_replace	Replace all occurrences of find with repl in s. Result is arena-allocated.	All
l_buf_push_str	Append L_Str to buf. Returns 0 on success, -1 on failure.	All
l_buf_push_cstr	Append C string to buf. Returns 0 on success, -1 on failure.	All
l_buf_push_int	Append decimal int to buf. Returns 0 on success, -1 on failure.	All
l_buf_as_str	Return L_Str view of buf contents.	All
I/O multiplexing
l_poll	Poll file descriptors for events. Returns number ready, 0 on timeout, -1 on error.	All
Signal handling
l_signal	Set signal handler. Returns previous handler or L_SIG_DFL on error.	All
Environment manipulation
l_setenv	Set environment variable. Returns 0 on success, -1 on error.	All
l_unsetenv	Unset environment variable. Returns 0 on success, -1 on error.	All
Scatter-gather I/O
l_writev	Write from multiple buffers. Returns bytes written or -1 on error.	All
l_readv	Read into multiple buffers. Returns bytes read or -1 on error.	All
Terminal detection
l_isatty	Returns 1 if fd is a terminal, 0 otherwise.	All
Hash map (arena-backed, fixed capacity)
l_map_init	Initialize a map with given capacity (rounded to power of 2).	All
l_map_get	Get value by key. Returns value pointer or NULL if not found.	All
l_map_put	Put key-value pair. Returns 0 on success, -1 if full (>75% load).	All
l_map_del	Delete key. Returns 0 on success, -1 if not found.	All
Time conversion
l_gmtime	Convert Unix timestamp to UTC broken-down time.	All
l_localtime	Convert Unix timestamp to local broken-down time.	All
l_mktime	Convert UTC broken-down time to Unix timestamp (seconds since 1970-01-01 00:00:00 UTC).	All
l_strftime	Format time into buffer. Returns bytes written (excluding NUL).	All
Glob pattern matching
l_fnmatch	Match pattern against string. Returns 0 if matches, -1 if no match.	All
l_glob	Expand a glob pattern into matching paths. Single-level only (no recursive **).	All
SHA-256
l_sha256_init	Initialize SHA-256 context.	All
l_sha256_update	Feed data into SHA-256.	All
l_sha256_final	Finalize and produce 32-byte hash.	All
l_sha256	One-shot SHA-256.	All
l_base64_encode	Encode len bytes from data into standard Base64. Writes at most outsz bytes (including NUL)	All
l_base64_decode	Decode Base64 text of length inlen into out. Returns decoded byte count, or -1 on invalid input	All
l_getcwd	Gets the current working directory into buf (up to size bytes). Returns buf on success, NULL on error.	All
l_chdir	Changes the current working directory	All
l_pipe	Creates a pipe. fds[0] is the read end, fds[1] is the write end. Returns 0 on success, -1 on error.	All
l_dup	Duplicates fd, returning a new descriptor on success or -1 on error.	All
l_dup2	Duplicates oldfd onto newfd. Returns newfd on success, -1 on error.	All
l_getpid	Returns the current process ID.	All
l_spawn_stdio	Spawns a new process with explicit stdio. Use L_SPAWN_INHERIT to keep the parent's stream.	All
l_spawn	Spawns a new process, inheriting the current stdio descriptors.	All
l_wait	Waits for a spawned process to finish. Returns 0 on success, -1 on error.	All
l_system	Executes a shell command string. Returns the exit code, or -1 on spawn failure.	All
Unix and WASI functions
l_lseek	Repositions the file offset of fd	Unix
l_mkdir	Creates a directory with the given permissions	Unix
l_sched_yield	Yields the processor to other threads	Unix
l_fork	Fork the current process. Returns child pid to parent, 0 to child, -1 on error.	Unix
l_execve	Replace the current process image. Does not return on success.	Unix
l_waitpid	Wait for a child process. Returns child pid on success, -1 on error.	Unix
l_getppid	Returns the parent process ID.	Unix
l_kill	Sends signal sig to process pid. Returns 0 on success, -1 on error.	Unix
Byte order helpers
l_htons	Convert 16-bit value from host to network byte order	All
l_htonl	Convert 32-bit value from host to network byte order	All
l_inet_addr	Parse dotted-quad IP string to network-order u32. Returns 0 on error.	All
l_resolve	Resolve hostname to IPv4 dotted-quad string. ip_out must be at least 16 bytes. If hostname is already IPv4 text, copies it unchanged. Returns 0 on success, -1 on error.	All
TCP socket functions
l_socket_tcp	Create a TCP socket. Returns socket fd or -1 on error.	All
l_socket_connect	Connect to addr:port. Returns 0 on success, -1 on error.	All
l_socket_bind	Bind socket to port on all interfaces. Returns 0/-1.	All
l_socket_listen	Listen for connections. Returns 0/-1.	All
l_socket_accept	Accept connection. Returns new socket or -1.	All
l_socket_send	Send data. Returns bytes sent or -1.	All
l_socket_recv	Receive data. Returns bytes received, 0 on close, -1 on error.	All
l_socket_close	Close socket.	All
UDP socket functions
l_socket_udp	Create a UDP socket. Returns socket fd or -1 on error.	All
l_socket_sendto	Send data to addr:port via UDP. Returns bytes sent or -1.	All
l_socket_recvfrom	Receive data via UDP. addr_out (>=16 bytes) and port_out receive sender info. Returns bytes received or -1.	All
Generic address-based socket API (IPv4 and IPv6)
l_sockaddr_ipv4	Build an IPv4 L_SockAddr from dotted-quad string and port. Returns 0 on success, -1 on error.	All
l_sockaddr_ipv6	Build an IPv6 L_SockAddr from IPv6 text and port. Returns 0 on success, -1 on error.	All
l_parse_ipv6	Parse IPv6 text representation into 16-byte binary. Returns 1 on success, 0 on error.	All
l_format_ipv6	Format 16-byte IPv6 binary to text. buf must be at least L_INET6_ADDRSTRLEN bytes. Returns buf.	All
l_socket_open	Create a socket of the given family (L_AF_INET or L_AF_INET6) and type (L_SOCK_STREAM or L_SOCK_DGRAM). Returns socket fd or -1.	All
l_socket_connect_addr	Connect socket to an L_SockAddr. Returns 0 on success, -1 on error.	All
l_socket_bind_addr	Bind socket to an L_SockAddr. Returns 0 on success, -1 on error.	All
l_socket_sendto_addr	Send data to an L_SockAddr via UDP. Returns bytes sent or -1.	All
l_socket_recvfrom_addr	Receive data via UDP. src receives sender address. Returns bytes received or -1.	All
l_socket_unix_connect	Create a Unix domain socket and connect to the given path. Returns socket fd or -1.	All

---

Function Reference — l_gfx.h

Platform backends:

• Linux: tries X11 first when $DISPLAY is set, falls back to /dev/fb0 (framebuffer console), then falls back to the terminal when both stdin and stdout are TTYs.
• Windows: opens a native GDI window (user32.dll + gdi32.dll) by default. Set L_GFX_TERM=1 to force the terminal backend when stdin and stdout are TTYs.
• Terminal backend: renders the pixel buffer as Unicode half-block characters (▀, U+2580) with 24-bit ANSI truecolor; each terminal cell represents 1×2 pixels.

For framebuffer access on Linux, you may need to grant access first: sudo chmod 666 /dev/fb0. All graphical demos use integer-only math (no floats) for full ARM compatibility.

Function	Description
Color helpers
L_RGB	Composes a 32-bit ARGB color from red, green, blue (0-255).
L_RGBA	Composes a 32-bit ARGB color from red, green, blue, alpha (0-255).
API declarations
l_canvas_open	Opens a canvas. Returns 0 on success, -1 on error (e.g. no display).
l_canvas_close	Closes the canvas and frees resources.
l_canvas_alive	Returns non-zero if the canvas is still alive (window not closed).
l_canvas_flush	Copies the pixel buffer to the screen.
l_canvas_clear	Fills the entire pixel buffer with a single color.
l_canvas_key	Returns the next key press (ASCII or arrow codes), or 0 if none. Non-blocking.
l_canvas_mouse	Returns mouse button bitmask (1=left, 2=right, 4=middle) and writes position to *x, *y.
l_canvas_wheel	Returns and clears the accumulated vertical mouse-wheel delta (positive=up, negative=down,
l_canvas_resized	Returns 1 if the window was resized since the last call, 0 otherwise. Clears the flag.
l_canvas_set_icon	Sets the window / taskbar icon from an ARGB pixel array (0xAARRGGBB).
l_clipboard_set	Copy text to clipboard. Returns 0 on success, -1 on failure.
l_clipboard_get	Get text from clipboard. Returns bytes read (excluding NUL), 0 if empty, -1 on failure.
Drawing primitives (platform-independent, operate on pixels[])
l_pixel	Sets a single pixel at (x, y) to the given color. No-op if out of bounds.
l_get_pixel	Returns the color of the pixel at (x, y), or 0 if out of bounds.
l_line	Draws a line from (x0,y0) to (x1,y1) using Bresenham's algorithm.
l_rect	Draws an outline rectangle at (x,y) with width w and height h.
l_fill_rect	Draws a filled rectangle at (x,y) with width w and height h.
l_circle	Draws an outline circle centered at (cx,cy) with radius r (midpoint algorithm).
l_fill_circle	Draws a filled circle centered at (cx,cy) with radius r.
l_hline	Draws a horizontal line from x0 to x1 at row y (used internally by fill_circle).
Text rendering
l_draw_char	Draws a single character at (x,y) using the embedded 8x8 bitmap font.
l_draw_text	Draws a null-terminated string at (x,y), advancing 8 pixels per character.
l_draw_char_scaled	Draws a single character at (x,y) scaled by (sx,sy) using nearest-neighbor.
l_draw_text_scaled	Draws a string at (x,y) with each glyph scaled by (sx,sy).
Result of l_font_lookup: bitmap pointer (NULL if missing) and pixel advance.
l_utf8_next	Reads one UTF-8 codepoint starting at *p and advances *p past it.
l_font_lookup_raw	Looks up a codepoint in the font. Returns the bitmap pointer and pixel
l_font_lookup	Looks up a codepoint, falling back to fallback_cp once if missing.
l_draw_glyph_f	Draws one codepoint at (x,y) in the given font. Returns its pixel advance.
l_draw_text_f	Draws a UTF-8 string at (x,y) using font f. Returns the total pixel width drawn.
l_draw_glyph_scaled_f	Draws a single codepoint scaled by (sx,sy). Returns scaled advance.
l_draw_text_scaled_f	Draws a UTF-8 string scaled by (sx,sy). Returns total pixel width drawn.
l_text_width_f	Returns the pixel width that would be drawn for a UTF-8 string in font f.
Pixel blitting
l_blit	Blit a rectangle of ARGB pixels onto the canvas at (dx, dy).
l_blit_alpha	Blit with alpha blending (source-over). Assumes pre-multiplied alpha in the A channel.
Shared terminal flush (used by both Windows and Linux backend=2)
l_term_flush_pixels	Renders the pixel buffer as half-block characters with ANSI truecolor.
l_term_canvas_init	Opens a terminal canvas: enters raw mode, gets terminal size, allocates buffers.
l_term_canvas_cleanup	Closes a terminal canvas: shows cursor, resets colors, restores terminal.

---

Function Reference — l_svg.h

Freestanding SVG rasterization powered by a vendored NanoSVG-derived fork. Parses SVG from memory buffers and rasterizes to ARGB pixels. Subset renderer optimized for icons, diagrams, and controlled vector assets. Uses a 256 MB demand-paged bump allocator (same as l_img.h).

Supported elements: <svg>, <g> (groups), <path>, <rect>, <circle>, <ellipse>, <line>, <polyline>, <polygon>, <defs>, <linearGradient> (basic), <radialGradient> (basic).

Unsupported (intentional subset): <text>, <image>, <symbol>, <use>, <clipPath>, <mask>, <filter>, CSS stylesheets, advanced color spaces (ICC profiles), complex gradients with pattern fills.

Sizing behavior:

• If width and height are both 0 in L_SvgOptions, uses the SVG's intrinsic dimensions from viewBox or width/height attributes. If none exist, returns NULL.
• If one dimension is 0 and the other is nonzero, scales preserving aspect ratio.
• If both dimensions are nonzero, rasterizes at that size (may distort).

Function	Description
-- Public API ---------------------------------------------------------------
l_svg_load_mem	Rasterize SVG from a memory buffer. Returns ARGB pixel data or NULL.
l_svg_free_pixels	Free pixel data returned by l_svg_load_mem(). w and h must match the decode.

Type: L_SvgOptions

typedef struct {
    int width;        // requested raster width (0 = use intrinsic/viewBox)
    int height;       // requested raster height (0 = use intrinsic/viewBox)
    float dpi;        // default 96.0f
} L_SvgOptions;

Usage notes:

• Pixels are 32-bit ARGB, compatible with l_blit in l_gfx.h.
• Read SVG file into memory first, then pass the buffer to l_svg_load_mem.
• The internal allocator reserves 256 MB virtual memory (demand-paged).
• #include "l_svg.h" automatically pulls in l_os.h.
• Default DPI is 96; multiply by scale factor (e.g., 144 for 1.5× resolution) as needed.
• Transforms (translate, scale, rotate, skewX, skewY, matrix) are supported; nested transforms accumulate.
• CSS color names are supported; currentColor uses fallback rules; RGB/RGBA hex notation is standard.
• Opacity and stroke/fill attributes follow SVG spec (default fill: black, no stroke).
• SVG backgrounds are transparent. When displaying with l_gfx.h, use l_blit_alpha (not l_blit) and clear to L_WHITE so transparent areas render correctly. See examples/svg_view.c.

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Function Reference — l_ui.h

Immediate-mode UI library built on l_gfx.h. No heap allocation, no widget tree — declare widgets every frame between l_ui_begin/l_ui_end. Widget functions return action state (e.g. l_ui_button returns 1 if clicked).

Function	Description
Frame functions
l_ui_begin	Begins a UI frame. Call once per frame before declaring widgets.
l_ui_end	Ends a UI frame. Handles releasing active widget when mouse released.
l_ui_init	Initializes a UI context with the default dark theme. font_scale is left
Widgets
l_ui_label	Draws a text label at (x,y). Returns 0 always.
l_ui_button	Draws a clickable button at (x,y) with given width and height. Returns 1 if clicked this frame.
l_ui_checkbox	Draws a checkbox at (x,y). *checked is toggled on click. Returns 1 if toggled this frame.
l_ui_slider	Draws a horizontal slider at (x,y) with given width. *value is clamped to [min_val, max_val]. Returns 1 if value changed.
l_ui_textbox	Draws a single-line text input at (x,y) with width w. buf is the text buffer, buf_len is max capacity. Returns 1 if text changed.
l_ui_panel	Draws a panel (filled rectangle with border) at (x,y). Returns 0.
l_ui_separator	Draws a horizontal separator line at (x,y) with width w. Returns 0.
Auto-Layout Helpers
l_ui_column_begin	Begins a vertical (column) auto-layout at (x,y) with given spacing between widgets.
l_ui_row_begin	Begins a horizontal (row) auto-layout at (x,y) with given spacing.
l_ui_next	Advances auto-layout by size pixels. Returns the position before advancing (y for column, x for row).
l_ui_layout_end	Ends the current layout.