Started on the engine proper

core/common.c

@@ -0,0 +1,2 @@
+#include "common.h"
+

core/common.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+//platform exports/imports
+#if defined(__linux__)
+#define CORE_API extern
+#else
+#define CORE_API
+#endif
+

core/engine.c

@@ -0,0 +1,113 @@
+#include "engine.h"
+
+#include <stdio.h>
+
+//errors here should be fatal
+static void error(Engine* engine, char* message) {
+	fprintf(stderr, message);
+	exit(-1);
+}
+
+//exposed functions
+void initEngine(Engine* engine) {
+	//clear
+	engine->root = NULL;
+	engine->running = true;
+
+	//init SDL
+	if (SDL_Init(0) != 0) {
+		error(engine, "Failed to initialize SDL2");
+	}
+
+	//init the window
+	engine->window = SDL_CreateWindow(
+		"Caption",
+		SDL_WINDOWPOS_UNDEFINED,
+		SDL_WINDOWPOS_UNDEFINED,
+		engine->screenWidth,
+		engine->screenHeight,
+		SDL_WINDOW_RESIZABLE
+	);
+
+	if (engine->window == NULL) {
+		error(engine, "Failed to initialize the window");
+	}
+
+	//init the renderer
+	engine->renderer = SDL_CreateRenderer(engine->window, -1, 0);
+
+	if (engine->renderer == NULL) {
+		error(engine, "Failed to initialize the renderer");
+	}
+
+	SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "best");
+	SDL_RenderSetLogicalSize(engine->renderer, engine->screenWidth, engine->screenHeight);
+}
+
+void freeEngine(Engine* engine) {
+	SDL_DestroyRenderer(engine->renderer);
+	SDL_DestroyWindow(engine->window);
+	SDL_Quit();
+
+	engine->renderer = NULL;
+	engine->window = NULL;
+}
+
+static void execStep(Engine* engine) {
+	//DEBUG: for now, just poll events
+	SDL_Event event;
+	while (SDL_PollEvent(&event)) {
+		switch(event.type) {
+			//quit
+			case SDL_QUIT: {
+				engine->running = false;
+			}
+			break;
+
+			//window events are handled internally
+			case SDL_WINDOWEVENT: {
+				switch(event.window.event) {
+					case SDL_WINDOWEVENT_RESIZED:
+						SDL_RenderSetLogicalSize(engine->renderer, event.window.data1, event.window.data2);
+					break;
+				}
+			}
+			break;
+
+			//TODO: input
+		}
+	}
+}
+
+//the heart of the engine
+void execEngine(Engine* engine) {
+	//set up time
+	gettimeofday(&engine->realTime, NULL);
+	engine->simTime = engine->realTime;
+	struct timeval delta = { .tv_sec = 0, .tv_usec = 1000 * 1000 / 60 }; //60 frames per second
+
+	while (engine->running) {
+		//calc the time passed
+		gettimeofday(&engine->realTime, NULL);
+
+		//if not enough time has passed
+		if (engine->simTime.tv_sec < engine->realTime.tv_sec && engine->simTime.tv_usec < engine->realTime.tv_usec) {
+			//while not enough time has passed
+			while(engine->simTime.tv_sec < engine->realTime.tv_sec && engine->simTime.tv_usec < engine->realTime.tv_usec) {
+				//simulate the world
+				execStep(engine);
+
+				//calc the time simulation
+				timeradd(&delta, &engine->simTime, &engine->simTime);
+			}
+		}
+		else {
+			SDL_Delay(10); //let the machine sleep, 10ms
+		}
+
+		//render the world
+		SDL_SetRenderDrawColor(engine->renderer, 0, 0, 0, 255); //NOTE: This line can be disabled later
+		SDL_RenderClear(engine->renderer); //NOTE: This line can be disabled later
+		SDL_RenderPresent(engine->renderer);
+	}
+}

core/engine.h

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+#pragma once
+
+#include "common.h"
+#include "engine_node.h"
+
+#include <SDL2/SDL.h>
+
+#include <sys/time.h>
+
+//the base engine object, which represents the state of the game
+typedef struct _engine {
+	//engine stuff
+	EngineNode* root;
+	struct timeval simTime;
+	struct timeval realTime;
+	bool running;
+
+	//SDL stuff
+	SDL_Window* window;
+	SDL_Renderer* renderer;
+	int screenWidth;
+	int screenHeight;
+} Engine;
+
+//APIs for initializing the engine
+CORE_API void initEngine(Engine* engine);
+CORE_API void freeEngine(Engine* engine);
+
+CORE_API void execEngine(Engine* engine);
+

core/engine_node.c

@@ -0,0 +1,2 @@
+#include "engine_node.h"
+

core/engine_node.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "common.h"
+
+//forward declare
+typedef struct _engineNode EngineNode;
+typedef struct _engine Engine;
+
+//the interface function
+typedef void (*EngineNodeFn)(EngineNode* self, Engine* engine);
+
+//the node object, which forms a tree
+typedef struct _engineNode {
+	//use Toy's memory model
+	void* children;
+	int capacity;
+	int count;
+
+	EngineNodeFn onInit;
+	EngineNodeFn onStep;
+	EngineNodeFn onFree;
+} EngineNode;
+

core/makefile

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+CC=gcc
+
+IDIR+=.
+CFLAGS+=$(addprefix -I,$(IDIR)) -DSDL_MAIN_HANDLED -g -Wall -W -pedantic -Wno-unused-parameter -Wno-unused-function -Wno-unused-variable
+LIBS+=-lSDL2
+
+ODIR = obj
+SRC = $(wildcard *.c)
+OBJ = $(addprefix $(ODIR)/,$(SRC:.c=.o))
+
+OUTNAME=core
+
+ifeq ($(findstring CYGWIN, $(shell uname)),CYGWIN)
+	LIBLINE =-Wl,--out-implib=$(CORE_OUTDIR)/lib$(OUTNAME).dll.a -Wl,--export-all-symbols -Wl,--enable-auto-import -Wl,--whole-archive $(OBJ) -Wl,--no-whole-archive
+	OUT=$(CORE_OUTDIR)/$(OUTNAME).dll
+else ifeq ($(shell uname),Linux)
+# No linux for the time being
+else ifeq ($(OS),Windows_NT)
+	LIBLINE =-Wl,--out-implib=$(CORE_OUTDIR)/lib$(OUTNAME).dll.a -Wl,--export-all-symbols -Wl,--enable-auto-import -Wl,--whole-archive $(OBJ) -Wl,--no-whole-archive
+	OUT=$(CORE_OUTDIR)/$(OUTNAME).dll
+else
+	@echo "Platform test failed - what platform is this?"
+	exit 1
+endif
+
+library: $(OBJ)
+	$(CC) -DCORE_EXPORT $(CFLAGS) -shared -o $(OUT) $(LIBLINE) $(LIBS)
+
+static: $(OBJ)
+	ar crs $(CORE_OUTDIR)/lib$(OUTNAME).a $(OBJ) $(LIBS)
+
+$(OBJ): | $(ODIR)
+
+$(ODIR):
+	mkdir $(ODIR)
+
+$(ODIR)/%.o: %.c
+	$(CC) -c -o $@ $< $(CFLAGS)
+
+.PHONY: clean
+
+clean:
+	$(RM) $(ODIR)