build: explicitly inject OF include paths to fix cross-compile find() failures

scripts/build.sh

@@ -205,6 +205,28 @@ unset PKG_CONFIG_LIBDIR
 
 ARM64_PKG_CONFIG_PATH="/usr/lib/aarch64-linux-gnu/pkgconfig:/usr/share/pkgconfig"
 
+# OF's config.shared.mk uses $(shell find ...) to discover OF source subdirectory
+# include paths and thirdparty lib headers. This can return empty in Docker
+# cross-compile environments, causing "ofConstants.h: No such file or directory".
+# Work around it by computing the include paths here and injecting them via
+# PLATFORM_CFLAGS (which appears in the project compile command regardless).
+OF_EXTRA_INCLUDES="-I$OF_DIR/libs/openFrameworks"
+# OF source subdirectories (app, utils, math, gl, graphics, events, etc.)
+for d in "$OF_DIR/libs/openFrameworks"/*/; do
+  [ -d "$d" ] && OF_EXTRA_INCLUDES="$OF_EXTRA_INCLUDES -I${d%/}"
+done
+# Thirdparty header-only libs bundled with OF (glm, json, kiss, tess2, utf8, ...)
+for lib in "$OF_DIR/libs"/*/; do
+  libname=$(basename "$lib")
+  [ "$libname" = "openFrameworks" ] && continue
+  [ "$libname" = "openFrameworksCompiled" ] && continue
+  incdir="${lib}include"
+  [ -d "$incdir" ] || continue
+  while IFS= read -r subdir; do
+    OF_EXTRA_INCLUDES="$OF_EXTRA_INCLUDES -I$subdir"
+  done < <(find "$incdir" -type d)
+done
+
 make clean 2>/dev/null || true
 make -j1 \
   PKG_CONFIG="$PKGCFG_WRAPPER" \
@@ -216,7 +238,7 @@ make -j1 \
   CXX=aarch64-linux-gnu-g++ \
   AR=aarch64-linux-gnu-ar \
   LD=aarch64-linux-gnu-ld \
-  PLATFORM_CFLAGS="$GLOBAL_FLAGS -I$ADDON_DIR/src" \
+  PLATFORM_CFLAGS="$GLOBAL_FLAGS $OF_EXTRA_INCLUDES -I$ADDON_DIR/src" \
   USER_CFLAGS="$GLOBAL_FLAGS" \
   USER_CPPFLAGS="-std=c++11" \
   OF_PROJECT_OPTIMIZATION_FLAGS="-O0"