Fixes for MacOS, make libpng optional, make SDL2 optional

CMakeLists.txt

@@ -1,46 +1,92 @@
-cmake_minimum_required(VERSION 3.6)
+cmake_minimum_required(VERSION 3.16)
 
 project(Tilengine)
 
+# set an option to use libpng from the system, otherwise use bundled stb_image
+option(TLN_OPTION_LIBPNG "Use the system libpng" ON)
+option(TLN_OPTION_BUILD_LIBPNG "Build libpng from source" OFF)
+
+# set an option to make the examples
+option(TLN_OPTION_SAMPLES "Build the examples" OFF)
 
 file(GLOB SOURCES
      "src/*.c"
 )
 
-
 # main library
 list(REMOVE_ITEM SOURCES "src/Test.c")
 add_library(${PROJECT_NAME} ${SOURCES})
 
 if (UNIX AND NOT APPLE)
 	set(CMAKE_C_FLAGS "-m64 -msse2")
-elseif (UNIX AND APPLE)
-    target_link_libraries(${PROJECT_NAME} PRIVATE "framework")
+endif()
+
+if (TLN_OPTION_LIBPNG)
+    # this project needs png, if png is not found, let's use fetch content
+    find_package(PNG QUIET)
+    if (NOT PNG_FOUND AND TLN_OPTION_BUILD_LIBPNG)
+        include(FetchContent)
+        FetchContent_Declare(
+            libpng
+            GIT_REPOSITORY https://github.com/pnggroup/libpng.git
+            GIT_TAG v1.6.44
+        )
+        FetchContent_MakeAvailable(libpng)
+        set(PNG_LIBRARIES png_static)
+        add_definitions(-DTLN_HAVE_PNG)
+        target_link_libraries(${PROJECT_NAME} PRIVATE ${PNG_LIBRARIES})
+    endif()
+    if (NOT PNG_FOUND AND NOT TLN_OPTION_BUILD_LIBPNG)
+        # clear the PNG_LIBRARY variable
+        unset(PNG_LIBRARY CACHE)
+    endif()
+    if (PNG_FOUND)
+        add_definitions(-DTLN_HAVE_PNG)
+        target_include_directories(${PROJECT_NAME} PRIVATE ${PNG_INCLUDE_DIRS})
+        target_link_libraries(${PROJECT_NAME} PRIVATE ${PNG_LIBRARIES})
+    endif()
 endif()
 
 target_link_libraries(${PROJECT_NAME} PRIVATE "c")
 target_link_libraries(${PROJECT_NAME} PRIVATE "z")
-target_link_libraries(${PROJECT_NAME} PRIVATE "png")
 
-find_package(SDL2 REQUIRED)
-target_link_libraries(${PROJECT_NAME} PRIVATE ${SDL2_LIBRARIES})
+if (TILENGINE_SAMPLES)
+    find_package(SDL2 REQUIRED)
+    target_link_libraries(${PROJECT_NAME} PRIVATE ${SDL2_LIBRARIES})
+    add_definitions(-DTLN_HAVE_SDL2)
+else()
+    add_definitions(-DTLN_EXCLUDE_WINDOW)
+endif()
 
 target_include_directories(${PROJECT_NAME} PRIVATE include)
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -O2 -fpic -DLIB_EXPORTS")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-result -Wno-format-truncation")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-result")
+
+# gcc specific
+if (UNIX AND NOT APPLE)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-format-truncation")
+endif()
 
 file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/include/Tilengine.h
      DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 
-# test executable
-add_executable(Test src/Test.c)
-target_include_directories(Test PRIVATE include)
-target_link_libraries(Test PRIVATE "Tilengine")
-target_link_libraries(Test PRIVATE "c")
-target_link_libraries(Test PRIVATE "z")
-target_link_libraries(Test PRIVATE "png")
-target_link_libraries(Test PRIVATE "m")
-
-# samples
-add_subdirectory(samples)
+if (TILENGINE_SAMPLES)
+    # test executable
+    add_executable(Test src/Test.c)
+    target_include_directories(Test PRIVATE include)
+    target_link_libraries(Test PRIVATE "Tilengine")
+    target_link_libraries(Test PRIVATE "c")
+    target_link_libraries(Test PRIVATE "z")
+    if (TLN_OPTION_LIBPNG)
+        target_include_directories(Test PRIVATE ${PNG_INCLUDE_DIRS})
+        target_link_libraries(Test PRIVATE ${PNG_LIBRARIES})
+    endif()
+    target_link_libraries(Test PRIVATE ${PNG_LIBRARIES})
+    target_link_libraries(Test PRIVATE "m")
+endif()
+
+if (TLN_OPTION_SAMPLES)
+    # samples
+    add_subdirectory(samples)
+endif()

README.md

@@ -5,6 +5,13 @@
 
 Tilengine is an open source, cross-platform 2D graphics engine for creating classic/retro games with tile maps, sprites and palettes. Its unique scanline-based rendering algorithm makes raster effects a core feature, a technique used by many games running on real 2D graphics chips.
 
+# This fork
+
+This fork, in the macos branch, 
+- allows the use of a bundled stb_image instead of libpng via -DTLN_OPTION_LIBPNG=ON
+- only uses SDL2 if the -DTLN_OPTION_SAMPLES=ON flag is set
+- fixes macOS setting issues in the CMakeLists.txt
+
 http://www.tilengine.org
 
 # Contents

samples/Actor.c

@@ -6,7 +6,7 @@
 /* local variables */
 static Actor* actors;
 static int count = 0;
-static unsigned int time;
+static unsigned int actor_time;
 
 /* local prototypes */
 static void TasksActor (Actor* actor);
@@ -112,7 +112,7 @@ void TasksActors (unsigned int t)
 	if (!actors)
 		return;
 
-	time = t;
+    actor_time = t;
 
 	for (c=0; c<count; c++)
 	{
@@ -135,13 +135,13 @@ bool CheckActorCollision (Actor* actor1, Actor* actor2)
 /* sets generic timeout */
 void SetActorTimeout (Actor* actor, int timer, int timeout)
 {
-	actor->timers[timer] = time + timeout;
+	actor->timers[timer] = actor_time + timeout;
 }
 
 /* gets generic timeout ended */
 bool GetActorTimeout (Actor* actor, int timer)
 {
-	return time >= actor->timers[timer];
+	return actor_time >= actor->timers[timer];
 }
 
 /* TasksActor */

samples/CMakeLists.txt

@@ -19,7 +19,12 @@ find_package(SDL2 REQUIRED)
 link_libraries(${SDL2_LIBRARIES})
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -O2 -fpic -DLIB_EXPORTS")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-result -Wno-format-truncation")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-unused-result")
+
+# gcc specific
+if (UNIX AND NOT APPLE)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-format-truncation")
+endif()
 
 file(COPY assets DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 

samples/Racer.c

@@ -50,7 +50,7 @@ int pos;
 int speed;
 int last_tree;
 unsigned int frame;
-unsigned int time;
+unsigned int racer_time;
 int pan = 0;
 
 static void raster_callback (int line);
@@ -81,7 +81,7 @@ int main (int argc, char* argv[])
 	while (TLN_ProcessWindow ())
 	{
 		/* timekeeper */
-		time = frame;
+		racer_time = frame;
 
 		TLN_SetLayerPosition (LAYER_PLAYFIELD, 56,72);
 		if (pos - last_tree >= 100)
@@ -92,7 +92,7 @@ int main (int argc, char* argv[])
 		}
 
 		/* input */
-		if ((time & 0x07) == 0)
+		if ((racer_time & 0x07) == 0)
 		{
 			if (TLN_GetInput (INPUT_UP) && speed < MAX_SPEED)
 				speed++;
@@ -107,10 +107,10 @@ int main (int argc, char* argv[])
 
 		/* actores */
 		pos += speed;
-		TasksActors (time);
+		TasksActors (racer_time);
 
 		/* render to window */
-		TLN_DrawFrame (time);
+		TLN_DrawFrame (racer_time);
 
 		frame++;
 	}