more advanced build script, refactor eqprocessor.cpps functions: process and recomputeBiquad, which were not nice to read. now nicer to read. no need to compile, compile at more major change

build.sh

@@ -1,6 +1,45 @@
-rm -rf build
-mkdir build
-cd build
-cmake ..
-make -j$(nproc)
-./SubWave
+#!/usr/bin/env bash
+set -e
+
+clean() {
+    echo "cleaning build dir"
+    rm -rf build
+}
+
+incremental_build() {
+    mkdir -p ../build
+    cd build
+    cmake ..
+    make -j"$(nproc)"
+}
+
+clean_build() {
+    clean
+    mkdir build
+    cd build
+    cmake ..
+    make -j"$(nproc)"
+}
+
+run_executable() {
+    ./build/SubWave
+}
+
+case "${1:-build}" in
+    clean|c)
+        clean
+        ;;
+    build|incremental|ib)
+        incremental_build
+        ;;
+    cleanbuild|cb)
+        clean_build
+        ;;
+    run|exec|r)
+        run_executable
+        ;;
+    *)
+        echo "Usage: $0 {build|clean|cleanbuild|cb}"
+        exit 1
+        ;;
+esac