Installation

Linking blitcurve (Xcode)

1. Add a dependency on blitcurve. File->Swift Packages->Add Package Dependencies...
2. In your target settings, add blitcurve to your "Frameworks, Libraries, and Embedded Content".

Linking the metal version

Blitcurve is cross-compiled: there's a C version and a metal shader version, so you can use it from inside metal shaders. To add the metal shader version, you need to perform some additional steps.

1. First, you need to add a build setting. Scroll down to the "Metal Compiler - Build Options" heading and set MTL_HEADER_SEARCH_PATHS to be ${HEADER_SEARCH_PATHS}.

2. Now you need to add some custom build settings. You can do this by opening the project settings, and then choosing Edit -> Add Build Setting -> Add User Defined Setting.

   • Set BLITCURVE_DIR to the path to blitcurve on disk. This is typically ${BUILD_ROOT}/../../SourcePackages/Checkouts/blitcurve if your dependency is managed by Xcode.
   • Set MTLLINKER_FLAGS to -L ${BUILT_PRODUCTS_DIR} -l blitcurve-metal.
     

3. Create a "run script" phase for your target.

   • The phase should be before the "Compile Sources" phase in your target settings. You may need to drag it earlier in the list.
   • The phase should have the following contents:

     if [ -z ${BLITCURVE_DIR+x} ]; then 
     echo "error: set BLITCURVE_DIR"
     exit 1
     fi
     (
         . "${BLITCURVE_DIR}/makemetal.sh"
     )

   • The "Input file lists" should contain one entry, ${BLITCURVE_DIR}/inputfiles.txt. This improves incremental compile speeds.
   • The "Output file lists" should contain one entry, ${BLITCURVE_DIR}/outputfiles.txt This improves incremental compile speeds.