Defcon Draw

Defcon Draw is a C vector graphics library for Linux with a Vulkan backend and a CRT-inspired rendering style for retro games, tools, and UI.

Screenshot Gallery

Meters / Dashboard

Debug UI

Wireframe Cube

Surface Plot

Features

• Public C API in include/vg.h
• Built-in image stylization API in include/vg_image.h (mono scanline rendering)
• Text layout API in include/vg_text_layout.h (build + draw wrapped/aligned text layouts)
• Text effects helpers in include/vg_text_fx.h (typewriter reveal + optional beep callbacks + marquee-in-box)
• Vulkan backend with alpha/additive batching
• CPU fallback raster path (vg_debug_rasterize_rgba8)
• Retro CRT profile system with tunable bloom, persistence, jitter, flicker, scanlines, vignette, and barrel distortion
• Stroke text + boxed text + wrapped text helpers
• Stroke and fill primitives (polyline, path, rect, convex fill, circle fill)
• Reusable immediate-style debug UI (vg_ui)
• Extended widgets (vg_ui_ext): meters, line graphs, bar graphs, histogram, pie/donut charts, history buffers
• Multi-scene Vulkan demo with teletype effect, profile save/load, and live parameter tuning
• Image FX demo scene (8) using nick.jpg with scanline/thickness controls

Documents

• API reference: docs/api.md
• Architecture notes: docs/architecture.md
• Image support plan: docs/image_support_plan.md
• Brainstorm / roadmap notes: brainstorm.md

Build Instructions

cmake -S . -B build
cmake --build build -j

Run demos:

./build/vg_demo
./build/vg_demo_sdl
./build/vg_demo_vk_sdl

Vulkan demo controls:

• TAB: show/hide debug UI
• 1..8: switch scene
• UP/DOWN: select UI row
• LEFT/RIGHT: adjust selected value (key-hold repeat supported)
• R: replay teletype message
• F5: save profile
• F9: load profile

Scene 8 uses a dedicated image debug panel (shown with TAB) for image parameter adjustment.