Add RMODERN build option, main function

Makefile

@@ -65,6 +65,9 @@ AUDIO_API ?= SDL2
 # Controller backends (can have multiple, space separated): SDL2
 CONTROLLER_API ?= SDL2
 
+# Modern rendering system (will eventually replace other backends)
+RMODERN ?= 0
+
 # Misc settings for EXTERNAL_DATA
 
 BASEDIR ?= res
@@ -255,6 +258,14 @@ else
   BUILD_DIR := $(BUILD_DIR_BASE)/$(VERSION)_pc
 endif
 
+ifeq ($(DEBUG),1)
+  BUILD_DIR := $(BUILD_DIR)_debug
+endif
+
+ifeq ($(RMODERN),1)
+  BUILD_DIR := $(BUILD_DIR)_rmodern
+endif
+
 LIBULTRA := $(BUILD_DIR)/libultra.a
 
 ifeq ($(TARGET_WEB),1)
@@ -286,6 +297,10 @@ LEVEL_DIRS := $(patsubst levels/%,%,$(dir $(wildcard levels/*/header.h)))
 SRC_DIRS := src src/engine src/game src/audio src/menu src/buffers actors levels bin data assets src/pc src/pc/gfx src/pc/audio src/pc/controller src/pc/fs src/pc/fs/packtypes
 ASM_DIRS :=
 
+ifeq ($(RMODERN),1)
+  SRC_DIRS += src/pc/rmodern
+endif
+
 ifeq ($(DISCORDRPC),1)
   SRC_DIRS += src/pc/discord
 endif
@@ -478,6 +493,12 @@ SDLCONFIG := $(CROSS)sdl2-config
 # configure backend flags
 
 BACKEND_CFLAGS := -DRAPI_$(RENDER_API)=1 -DWAPI_$(WINDOW_API)=1 -DAAPI_$(AUDIO_API)=1
+
+# rmodern
+ifeq ($(RMODERN),1)
+  BACKEND_CFLAGS += -DRMODERN
+endif
+
 # can have multiple controller APIs
 BACKEND_CFLAGS += $(foreach capi,$(CONTROLLER_API),-DCAPI_$(capi)=1)
 BACKEND_LDFLAGS :=

src/pc/pc_main.c

@@ -171,6 +171,14 @@ static void on_anim_frame(double time) {
 }
 #endif
 
+
+#ifdef RMODERN
+#include "rmodern/rmodern.h"
+void main_func(void)
+{
+    rmodern_init();
+}
+#else
 void main_func(void) {
     static u64 pool[0x165000/8 / 4 * sizeof(void *)];
     main_pool_init(pool, pool + sizeof(pool) / sizeof(pool[0]));
@@ -261,6 +269,7 @@ void main_func(void) {
     }
 #endif
 }
+#endif
 
 int main(int argc, char *argv[]) {
     parse_cli_opts(argc, argv);

src/pc/rmodern/rmodern.h

@@ -0,0 +1,18 @@
+/**
+ * This header file provides the interface between modern rendering functionality,
+ * written in C++, and the rest of the codebase.
+ */
+
+#ifndef RMODERN_H
+#define RMODERN_H
+#ifdef __cplusplus
+    extern "C"
+    {
+#endif
+
+void rmodern_init();
+
+#ifdef __cplusplus
+    }
+#endif
+#endif

src/pc/rmodern/rmodern_main.cpp

@@ -0,0 +1,8 @@
+#include "rmodern.h"
+
+#include <iostream>
+
+void rmodern_init()
+{
+    std::cout << "Hello, world!! ^-^" << std::endl;
+}