dear-implot-sys

Low-level FFI bindings for ImPlot via the cimplot C API. This crate pairs with dear-imgui-sys (cimgui C API) and exposes ImPlot_* functions/types for higher-level crates (dear-implot).

Features

prebuilt: allow the build script to auto-download a release archive when available (the env toggle IMPLOT_SYS_USE_PREBUILT=1 requires this feature).
build-from-source: force building native sources with cc even if a prebuilt could be linked.
freetype: passthrough to dear-imgui-sys/freetype to enable FreeType in the workspace.
package-bin: enable an internal bin/package helper to produce release artifacts.

Build Modes

Prebuilt artifacts must match the release train, target, CRT, source revisions, binding identity, feature profile, and shared Dear ImGui core recorded in their manifest. Bare remote .lib/.a downloads do not supply that manifest. build-from-source (or IMPLOT_SYS_FORCE_BUILD) forces source compilation. Choose one prebuilt route at a time: clear IMPLOT_SYS_LIB_DIR before using IMPLOT_SYS_PREBUILT_URL; a local directory override takes precedence. Source builds are the default and do not require libclang unless binding regeneration is explicitly requested. wasm uses import bindings for the fixed imgui-sys-v1 provider and skips C++ compilation in Cargo; build the provider separately with Emscripten.

Native and WebAssembly providers share the implot-imgui-193-v2 correction: line textures use physical thickness at the active viewport's framebuffer density, while geometry remains in local coordinates. Lines widened to one physical pixel retain their original alpha coverage. Artifact identity includes this correction. It also normalizes digital/heatmap rectangle bounds and the demo's candlestick coordinates.

This crate supports three ways to obtain the native dear_implot static library:

Source build (default)
- Compiles cimplot.cpp and embedded implot/*.cpp with cc.
- Inherits include paths and preprocessor defines from dear-imgui-sys.
System/prebuilt library
- Links an existing static library from a directory you provide.
Docs.rs
- Uses validated checked-in Rust bindings; native code is not compiled.

Environment Variables

IMPLOT_SYS_LIB_DIR
- Directory containing the matching static library and its packaged manifest.
- Expected names: dear_implot.lib (Windows/MSVC), libdear_implot.a (Unix).
IMPLOT_SYS_PREBUILT_URL
- Local path or URL to a matching .tar.gz package containing the library and manifest (HTTP(S) and archive extraction require prebuilt). A local bare library path is accepted only when the matching manifest is beside it.
- Downloads/extractions are reused from the prebuilt cache; IMPLOT_SYS_CACHE_DIR overrides its root.
IMPLOT_SYS_SKIP_CC
- If set, skips native C/C++ compilation. Typically used with one of the above.

The build script also consumes the include paths and defines exported by dear-imgui-sys:

DEP_DEAR_IMGUI_IMGUI_INCLUDE_PATH, DEP_DEAR_IMGUI_CIMGUI_INCLUDE_PATH
DEP_DEAR_IMGUI_DEFINE_*

Examples

Default (source build):

cargo build -p dear-implot-sys -p dear-implot

System/prebuilt library (Windows):

$env:IMPLOT_SYS_LIB_DIR = "C:\prebuilt\implot"
cargo build -p dear-implot-sys

System/prebuilt library (Unix):

export IMPLOT_SYS_LIB_DIR=/opt/implot/lib
cargo build -p dear-implot-sys

Remote prebuilt download (choose the block for your shell):

$env:IMPLOT_SYS_LIB_DIR = $null
$env:IMPLOT_SYS_PREBUILT_URL = "https://example.com/dear_implot-matching-profile.tar.gz"
cargo build -p dear-implot-sys --features prebuilt

unset IMPLOT_SYS_LIB_DIR
export IMPLOT_SYS_PREBUILT_URL=https://example.com/dear_implot-matching-profile.tar.gz
cargo build -p dear-implot-sys --features prebuilt

Replace the illustrative URL with an archive for your exact profile. Clear the URL override before switching back to automatic release lookup or source builds.

Notes