Advanced Font Cache and Region Testing

This release adds a powerful font-face cache system and new APIs for testing whether a point lies within fill, stroke, or clip regions. It improves font management, enables dynamic font selection by family and style, and supports precise hit-testing for interactive graphics.

New APIs and Features

Font-Face Cache System

A complete API for managing and accessing font faces:

• Creation and Lifecycle

  • plutovg_font_face_cache_create()
  • plutovg_font_face_cache_reference()
  • plutovg_font_face_cache_destroy()
  • plutovg_font_face_cache_reference_count()
  • plutovg_font_face_cache_reset()

• Manual Addition and Retrieval

  • plutovg_font_face_cache_add()
    Adds a font face with a specified family and style.
  • plutovg_font_face_cache_add_file()
    Loads and adds a font face from a specific file.
  • plutovg_font_face_cache_get()
    Retrieves a font face matching a given style.

• Bulk Font Loading

  • plutovg_font_face_cache_load_file()
    Loads all faces from a single file.
  • plutovg_font_face_cache_load_dir()
    Recursively loads fonts from a directory.
  • plutovg_font_face_cache_load_sys()
    Loads system-installed fonts.

Canvas Font Integration

The canvas can now associate and select fonts dynamically using:

• plutovg_canvas_set_font_face_cache()
  Assigns a font cache to the canvas.

• plutovg_canvas_get_font_face_cache()
  Retrieves the current cache from the canvas.

• plutovg_canvas_add_font_face()
  Registers a font face under a family and style.

• plutovg_canvas_add_font_file()
  Loads and registers a font face from a file.

• plutovg_canvas_select_font_face()
  Selects a font face for use in drawing operations.

These APIs allow high-level font selection using family names and style flags (bold, italic), while internally managing font-face lifetimes through the cache.

Point Containment Queries

Three new functions provide hit-testing against rendering regions in user space:

• plutovg_canvas_fill_contains()
  Tests whether a point lies within the current fill region (ignores clip and surface).

• plutovg_canvas_stroke_contains()
  Tests whether a point lies within the stroked path outline.

• plutovg_canvas_clip_contains()
  Tests whether a point lies inside the canvas clipping region.

These APIs allow precise user interaction handling, including mouse hit-tests and visual region queries.

Make plutovg Thread-Safe with Atomic Ops and Mutexes

This release introduces platform-specific implementations of atomic reference counting and mutex primitives, making plutovg objects thread-safe across supported systems.

Key Additions:

• Atomic Reference Counting:

  • On Windows (_WIN32), InterlockedIncrement, InterlockedDecrement, and InterlockedCompareExchange are used for efficient, lock-free atomic operations on reference counts.
  • On C11-compliant platforms with <stdatomic.h>, atomic_fetch_add, atomic_fetch_sub, and atomic_load are used.
  • A fallback implementation using plain int is provided for platforms without atomic support (non-thread-safe).

• Mutex Abstraction:

  • On Windows, CRITICAL_SECTION is used to implement recursive mutexes.
  • On C11 platforms with <threads.h>, mtx_t and mtx_recursive are used.
  • A no-op implementation is included for unsupported platforms, allowing builds to proceed without thread safety.

These changes lay the foundation for making plutovg safe to use in multi-threaded environments, improving robustness for concurrent applications.

• Enforce valid (0 < size < 32K) constraint on surface dimensions
• Clip lines to clip_box using Cyrus-Beck to prevent infinite loops in gray_render_line
• Generate plutovg.pc from cmake @dg0yt

• Adopt Semantic Versioning (SemVer)
• Add PLUTOVG_EMPTY_POINT and PLUTOVG_EMPTY_RECT macros

• Add plutovg_color_init_hsl and plutovg_color_init_hsla.
• Support HSL/HSLA color syntax in plutovg_color_parse.

• Fix comma handling in SVG path and matrix parsing

• Fix endianness problems #43

• Fix incorrect font scaling
• Prevent undefined behavior in memcpy by adding nullptr checks

• Enhanced Gradient Color Interpolation
• Fixed Texture Tile Boundaries

• Implemented all compositing modes:

  • Clear
  • Source
  • Destination
  • Source Over
  • Destination Over
  • Source In
  • Destination In
  • Source Out
  • Destination Out
  • Source Atop
  • Destination Atop
  • XOR

• Resolved issues related to undefined behavior in the RadialGradient functionality.

• Fixed issues related to incomplete stroke rendering.