Add installation support to Makefile

Signed-off-by: Marcin Serwin <marcin@serwin.dev>

Author: marcin-serwin

Makefile

@@ -7,6 +7,10 @@ LFLAGS_CONV ?= $(LDFLAGS)
 TARGET_BENCH ?= qoibench
 TARGET_CONV ?= qoiconv
 
+PREFIX ?= /usr/local
+BINDIR ?= $(PREFIX)/bin
+INCLUDEDIR ?= $(PREFIX)/include
+
 all: $(TARGET_BENCH) $(TARGET_CONV)
 
 bench: $(TARGET_BENCH)
@@ -17,6 +21,18 @@ conv: $(TARGET_CONV)
 $(TARGET_CONV):$(TARGET_CONV).c qoi.h
 	$(CC) $(CFLAGS_CONV) $(CFLAGS) $(TARGET_CONV).c -o $(TARGET_CONV) $(LFLAGS_CONV)
 
+.PHONY: install
+install: install-tools install-header
+
+.PHONY: install-tools
+install-tools: all
+	install -Dm 755 $(TARGET_CONV) $(DESTDIR)$(BINDIR)/$(TARGET_CONV)
+	install -Dm 755 $(TARGET_BENCH) $(DESTDIR)$(BINDIR)/$(TARGET_BENCH)
+
+.PHONY: install-header
+install-header: qoi.h qoi.pc
+	install -Dm 644 qoi.h $(DESTDIR)$(INCLUDEDIR)/qoi.h
+
 .PHONY: clean
 clean:
 	$(RM) $(TARGET_BENCH) $(TARGET_CONV)