CI: Test builds with freetype on linux.

.github/workflows/build.yml

@@ -166,7 +166,7 @@ jobs:
     - name: Install Dependencies
       run: |
         sudo apt-get update
-        sudo apt-get install -y libglfw3-dev libsdl2-dev gcc-multilib g++-multilib
+        sudo apt-get install -y libglfw3-dev libsdl2-dev gcc-multilib g++-multilib libfreetype6-dev
 
     - name: Build example_null (extra warnings, gcc 32-bit)
       run: |
@@ -188,6 +188,11 @@ jobs:
         make -C examples/example_null clean
         CXXFLAGS="$CXXFLAGS -m64 -Werror" CXX=clang++ make -C examples/example_null EXTRA_WARNINGS=1
 
+    - name: Build example_null (freetype)
+      run: |
+        make -C examples/example_null clean
+        make -C examples/example_null WITH_FREETYPE=1
+
     - name: Build example_null (single file build)
       run: |
         echo '#define IMGUI_IMPLEMENTATION'                    >  example_single_file.cpp

examples/example_null/Makefile

@@ -5,6 +5,7 @@
 
 EXE = example_null
 EXTRA_WARNINGS ?= 0
+WITH_FREETYPE ?= 0
 SOURCES = main.cpp
 SOURCES += ../../imgui.cpp ../../imgui_demo.cpp ../../imgui_draw.cpp ../../imgui_widgets.cpp
 OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
@@ -19,6 +20,13 @@ ifeq ($(EXTRA_WARNINGS), 1)
 	CXXFLAGS += -Wno-zero-as-null-pointer-constant -Wno-double-promotion -Wno-variadic-macros
 endif
 
+# We use the WITH_FREETYPE flag on our CI setup to test misc/freetype/imgui_freetype.cpp font rasterizer
+ifeq ($(WITH_FREETYPE), 1)
+	SOURCES += ../../misc/freetype/imgui_freetype.cpp
+	CXXFLAGS += $(shell pkg-config --cflags freetype2)
+	LIBS += $(shell pkg-config --libs freetype2)
+endif
+
 ##---------------------------------------------------------------------
 ## BUILD FLAGS PER PLATFORM
 ##---------------------------------------------------------------------
@@ -60,6 +68,9 @@ endif
 %.o:../../%.cpp
 	$(CXX) $(CXXFLAGS) -c -o $@ $<
 
+%.o:../../misc/freetype/%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
 all: $(EXE)
 	@echo Build complete for $(ECHO_MESSAGE)