twn_amalgam.c: a way for single unit compilation, controlled with -DTWN_USE_AMALGAM in cmake

CMakeLists.txt

@@ -24,6 +24,7 @@ set(TWN_ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR} CACHE INTERNAL "")
 
 # feature configuration, set them with -DFEATURE=ON/OFF in cli
 option(TWN_FEATURE_DYNLIB_GAME  "Enable dynamic library loading support" ON)
+option(TWN_USE_AMALGAM  "Enable use of twn_amalgam.c as a single compilation unit" ON)
 
 # todo: figure out how to compile for dynamic linking instead
 if(EMSCRIPTEN)
@@ -88,7 +89,8 @@ set(TWN_THIRD_PARTY_SOURCE_FILES
         third-party/tomlc99/toml.c
         $<$<NOT:$<BOOL:${EMSCRIPTEN}>>:third-party/glad/src/glad.c>)
 
-set(TWN_SOURCE_FILES
+set(TWN_NONOPT_SOURCE_FILES
+        src/twn_stb.c
         src/twn_loop.c
         src/twn_main.c
         src/twn_context.c include/twn_context.h
@@ -104,7 +106,10 @@ set(TWN_SOURCE_FILES
         src/rendering/twn_triangles.c
         src/rendering/twn_circles.c
         src/rendering/twn_skybox.c
-        src/rendering/twn_fog.c
+        src/rendering/twn_fog.c)
+
+set(TWN_SOURCE_FILES
+        $<IF:$<BOOL:${TWN_USE_AMALGAM}>,src/twn_amalgam.c src/twn_stb.c,${TWN_NONOPT_SOURCE_FILES}>
 
         # for dynamic load based solution main is compiled in a separate target
         $<$<NOT:$<BOOL:${TWN_FEATURE_DYNLIB_GAME}>>:src/twn_main.c
@@ -113,6 +118,7 @@ set(TWN_SOURCE_FILES
         ${SYSTEM_SOURCE_FILES})
 
 list(TRANSFORM TWN_SOURCE_FILES PREPEND ${TWN_ROOT_DIR}/)
+source_group(TREE ${TWN_ROOT_DIR} FILES ${TWN_NONOPT_SOURCE_FILES})
 
 add_library(twn_third_parties STATIC ${TWN_THIRD_PARTY_SOURCE_FILES})
 
@@ -123,8 +129,6 @@ else()
         add_library(${TWN_TARGET} STATIC ${TWN_SOURCE_FILES} ${twn_third_parties})
 endif()
 
-source_group(TREE ${TWN_ROOT_DIR} FILES ${TWN_SOURCE_FILES})
-
 set_target_properties(${TWN_TARGET} PROPERTIES
                                     C_STANDARD 11
                                     C_STANDARD_REQUIRED ON

src/twn_amalgam.c

@@ -0,0 +1,19 @@
+/* a technique for faster compilation */
+/* it includes all non-optional .c files directly in a single compilation unit */
+
+#include "twn_audio.c"
+#include "twn_camera.c"
+#include "twn_context.c"
+#include "twn_input.c"
+#include "twn_loop.c"
+#include "twn_main.c"
+#include "twn_textures.c"
+#include "twn_util.c"
+
+#include "rendering/twn_circles.c"
+#include "rendering/twn_draw.c"
+#include "rendering/twn_fog.c"
+#include "rendering/twn_skybox.c"
+#include "rendering/twn_sprites.c"
+#include "rendering/twn_text.c"
+#include "rendering/twn_triangles.c"

src/twn_stb.c

@@ -0,0 +1,24 @@
+/* single compilation unit for every stb implementation */
+
+#define STB_DS_IMPLEMENTATION
+#define STBDS_ASSERT SDL_assert
+#define STBDS_REALLOC(context,ptr,size) ((void)(context), SDL_realloc(ptr, size))
+#define STBDS_FREE(context,ptr) ((void)(context), SDL_free(ptr))
+#include <stb_ds.h>
+
+#define STB_RECT_PACK_IMPLEMENTATION
+#define STBRP_SORT SDL_qsort
+#define STBRP_ASSERT SDL_assert
+#include <stb_rect_pack.h>
+
+#define STB_TRUETYPE_IMPLEMENTATION
+#define STBTT_malloc(x,u) ((void)(u), SDL_malloc(x))
+#define STBTT_free(x,u) ((void)(u), SDL_free(x))
+#define STBTT_assert(x) SDL_assert(x)
+#define STBTT_strlen(x) SDL_strlen(x)
+#define STBTT_memcpy SDL_memcpy
+#define STBTT_memset SDL_memset
+#include <stb_truetype.h>
+
+#define STB_IMAGE_IMPLEMENTATION
+#include <stb_image.h>

src/twn_textures.c

@@ -8,8 +8,6 @@
 #include <physfsrwops.h>
 #include <stb_ds.h>
 #include <stb_rect_pack.h>
-
-#define STB_IMAGE_IMPLEMENTATION
 #include <stb_image.h>
 
 #include <stdbool.h>

src/twn_util.c

@@ -4,23 +4,7 @@
 
 #include <SDL2/SDL.h>
 #include <physfsrwops.h>
-#define STB_DS_IMPLEMENTATION
-#define STBDS_ASSERT SDL_assert
-#define STBDS_REALLOC(context,ptr,size) ((void)(context), SDL_realloc(ptr, size))
-#define STBDS_FREE(context,ptr) ((void)(context), SDL_free(ptr))
 #include <stb_ds.h>
-#define STB_RECT_PACK_IMPLEMENTATION
-#define STBRP_SORT SDL_qsort
-#define STBRP_ASSERT SDL_assert
-#include <stb_rect_pack.h>
-#define STB_TRUETYPE_IMPLEMENTATION
-#define STBTT_malloc(x,u) ((void)(u), SDL_malloc(x))
-#define STBTT_free(x,u) ((void)(u), SDL_free(x))
-#define STBTT_assert(x) SDL_assert(x)
-#define STBTT_strlen(x) SDL_strlen(x)
-#define STBTT_memcpy SDL_memcpy
-#define STBTT_memset SDL_memset
-#include <stb_truetype.h>
 
 #include <stdarg.h>