Create an abstracted engine class for the programs.

engine.cc

@@ -0,0 +1,73 @@
+#include "engine.hh"
+
+#include <GL/gl.h>
+#include <GL/glkos.h>
+
+#include <cstdio>
+#include <functional>
+
+void Engine::initScreen() {
+	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+	glViewport(0, 0, 640, 480);
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glOrtho(0, 640, 0, 480, -100, 100);
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+}
+
+void Engine::printSystemInformation() {
+	printf("GL_VENDOR: %s\n", glGetString(GL_VENDOR));
+	printf("GL_RENDERER: %s\n", glGetString(GL_RENDERER));
+	printf("GL_VERSION: %s\n", glGetString(GL_VERSION));
+	printf("GL_EXTENSIONS: %s\n", glGetString(GL_EXTENSIONS));
+}
+
+void Engine::initializeEngine() {
+	glKosInit();
+	initScreen();
+	printSystemInformation();
+}
+
+template <typename T>
+void Engine::deltaTimeLoop(T&& callback, struct timeval& beginningOfFrame,
+						   struct timeval& endOfFrame) {
+	gettimeofday(&beginningOfFrame, 0);
+	(this->*callback)();
+	gettimeofday(&endOfFrame, 0);
+	float time = ((float)(endOfFrame.tv_usec) * microSecond) -
+				 ((float)(beginningOfFrame.tv_usec) * microSecond);
+	if (time > 0.0f) {
+		deltaTime = time;
+	}
+}
+
+void Engine::initializeGameLoop() {
+	struct timeval beginningOfFrame, endOfFrame;
+
+	while (1) {
+		deltaTimeLoop(&Engine::gameLoop, beginningOfFrame, endOfFrame);
+	}
+}
+
+void Engine::pressButton(cont_state_t* controller_state, int button,
+						 std::function<void()> callback) {
+	if (controller_state->buttons & button) {
+		if (!(buttonsPressed & button)) {
+			buttonsPressed |= button;
+
+			callback();
+		}
+	} else if ((buttonsPressed & button) &&
+			   ~(controller_state->buttons & button)) {
+		buttonsPressed &= ~button;
+	}
+}
+
+void Engine::glVertex3fNormalized(float x, float y, float z) {
+	int xSize, ySize;
+	xSize = 640;
+	ySize = 480;
+
+	glVertex3f(x * xSize, y * ySize, z);
+}

engine.hh

@@ -0,0 +1,36 @@
+#ifndef ENGINE_HH
+#define ENGINE_HH
+
+#include <kos.h>
+#include <sys/time.h>
+
+#include <functional>
+
+class Engine {
+   protected:
+	const float microSecond = 0.000001f;
+
+	float angle = 0;
+	float deltaTime = 1.0 / 60.0;
+	float speed = 5.0f;
+
+	bool thirtyfps;
+	unsigned int buttonsPressed;
+
+	void initScreen();
+	void printSystemInformation();
+	virtual void gameLoop(){};
+	void pressButton(cont_state_t* controller_state, int button,
+					 std::function<void()> callback);
+	void glVertex3fNormalized(float x, float y, float z);
+
+   private:
+	template <typename T>
+	void deltaTimeLoop(T&& callback, struct timeval& beginningOfFrame,
+					   struct timeval& endOfFrame);
+
+   public:
+	void initializeEngine();
+	void initializeGameLoop();
+};
+#endif

gl.cc

@@ -1,53 +1,22 @@
 #include <GL/gl.h>
 #include <GL/glkos.h>
-#include <kos.h>
-#include <sys/time.h>
 
 #include <algorithm>
 #include <cstdio>
 
-const float microSecond = 0.000001f;
+#include "engine.hh"
 
-float angle = 0;
+class Glcc : public Engine {
-float deltaTime = 1.0 / 60.0;
+	void process_input();
-float speed = 5.0f;
+	void displayStuff();
 
-bool thirtyfps;
+	void gameLoop() override {
-uint32 buttonsPressed;
+		process_input();
-
+		displayStuff();
-template <typename T>
-void pressButton(cont_state_t* controller_state, int button, T&& callback) {
-	if (controller_state->buttons & button) {
-		if (!(buttonsPressed & button)) {
-			buttonsPressed |= button;
-
-			callback();
-		}
-	} else if ((buttonsPressed & button) &&
-			   ~(controller_state->buttons & button)) {
-		buttonsPressed &= ~button;
 	}
-}
+};
 
-void initScreen() {
+void Glcc::displayStuff() {
-	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
-	glViewport(0, 0, 640, 480);
-	glMatrixMode(GL_MODELVIEW);
-	glLoadIdentity();
-	glOrtho(0, 640, 0, 480, -100, 100);
-	glMatrixMode(GL_PROJECTION);
-	glLoadIdentity();
-}
-
-void glVertex3fNormalized(float x, float y, float z) {
-	int xSize, ySize;
-	xSize = 640;
-	ySize = 480;
-
-	glVertex3f(x * xSize, y * ySize, z);
-}
-
-void displayStuff() {
 	glClear(GL_COLOR_BUFFER_BIT);
 
 	// clang-format off
@@ -78,7 +47,7 @@ void displayStuff() {
 	glKosSwapBuffers();
 }
 
-void process_input() {
+void Glcc::process_input() {
 	maple_device_t* controller;
 	cont_state_t* controller_state;
 
@@ -89,12 +58,15 @@ void process_input() {
 
 		if (!controller_state) {
 			printf(
-				"An error has occured while trying to read the controller.\n");
+				"An error has occured while trying to read the "
+				"controller.\n");
 		}
 
-		pressButton(controller_state, CONT_DPAD_LEFT, []() { speed -= 1.0f; });
+		pressButton(controller_state, CONT_DPAD_LEFT, [&]() { speed -= 1.0f; });
-		pressButton(controller_state, CONT_DPAD_RIGHT, []() { speed += 1.0f; });
+		pressButton(controller_state, CONT_DPAD_RIGHT,
-		pressButton(controller_state, CONT_A, []() { thirtyfps = !thirtyfps; });
+					[&]() { speed += 1.0f; });
+		pressButton(controller_state, CONT_A,
+					[&]() { thirtyfps = !thirtyfps; });
 
 		speed = std::clamp(speed, 1.0f, 10.0f);
 
@@ -102,38 +74,8 @@ void process_input() {
 	}
 }
 
-void printSystemInformation() {
-	printf("GL_VENDOR: %s\n", glGetString(GL_VENDOR));
-	printf("GL_RENDERER: %s\n", glGetString(GL_RENDERER));
-	printf("GL_VERSION: %s\n", glGetString(GL_VERSION));
-	printf("GL_EXTENSIONS: %s\n", glGetString(GL_EXTENSIONS));
-}
-
-template <typename T>
-void deltaTimeLoop(T&& callback, struct timeval& beginningOfFrame,
-				   struct timeval& endOfFrame) {
-	gettimeofday(&beginningOfFrame, 0);
-	callback();
-	gettimeofday(&endOfFrame, 0);
-	float time = ((float)(endOfFrame.tv_usec) * microSecond) -
-				 ((float)(beginningOfFrame.tv_usec) * microSecond);
-	if (time > 0.0f) {
-		deltaTime = time;
-	}
-}
-
-void gameLoop() {
-	process_input();
-	displayStuff();
-}
-
 int main() {
-	glKosInit();
+	Glcc* engine = new Glcc;
-	initScreen();
+	engine->initializeEngine();
-	printSystemInformation();
+	engine->initializeGameLoop();
-	struct timeval beginningOfFrame, endOfFrame;
-
-	while (1) {
-		deltaTimeLoop(gameLoop, beginningOfFrame, endOfFrame);
-	}
 }

hello.c

@@ -1,50 +0,0 @@
-#include <kos.h>
-
-#include <GL/gl.h>
-#include <GL/glu.h>
-#include <GL/glkos.h>
-
-void triangle() {
-	// glClearColor(1.0f, 1.0f, 0.0f, 0.0f);
-	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
-	glBegin(GL_TRIANGLES);
-		glColor3f(1.0f, 0.0f, 0.0f);
-		glVertex3f(-1.0f, -1.0f, 0.0f);
-
-		glColor3f(0.0f, 1.0f, 0.0f);
-		glVertex3f(0.0f, 1.0f, 0.0f);
-
-		glColor3f(0.0f, 0.0f, 1.0f);
-		glVertex3f(1.0f, -1.0f, 0.0f);
-	glEnd();
-}
-
-int main(int argc, char *argv[]) {
-	maple_device_t *controller;
-
-	glKosInit();
-	glMatrixMode(GL_PROJECTION);
-	glLoadIdentity();
-	glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
-	// gluPerspective(45.0f, 640.0f/480.0f, 0.1f, 100.0f);
-	// glMatrixMode(GL_MODELVIEW);
-	// glEnable(GL_TEXTURE_2D);
-	// glEnable(GL_DEPTH_TEST);
-
-	// glFrontFace(GL_CW);
-	// glBlendFunc(GL_SRC_ALPHA,  GL_ONE_MINUS_SRC_ALPHA);
-
-	glClearColor(0.3f, 0.4f, 0.5f, 1.0f);
-
-	while (1) {
-		// glLoadIdentity();
-        // glTranslatef(-5.0f, 0.0f, 0.0f);
-        // glEnable(GL_CULL_FACE);
-		triangle();
-
-		glKosSwapBuffers();
-	}
-
-	return 0;
-}

hello.cc

@@ -0,0 +1,34 @@
+#include <GL/gl.h>
+#include <GL/glkos.h>
+#include "engine.hh"
+
+class Hello : public Engine {
+	void triangle();
+
+	void gameLoop() override {
+		triangle();
+		glKosSwapBuffers();
+	}
+};
+
+void Hello::triangle() {
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+	glBegin(GL_TRIANGLES);
+		glColor3f(1.0f, 0.0f, 0.0f);
+		glVertex3fNormalized(-1.0f, -1.0f, 0.0f);
+
+		glColor3f(0.0f, 1.0f, 0.0f);
+		glVertex3fNormalized(0.0f, 1.0f, 0.0f);
+
+		glColor3f(0.0f, 0.0f, 1.0f);
+		glVertex3fNormalized(1.0f, -1.0f, 0.0f);
+	glEnd();
+}
+
+
+int main(int argc, char *argv[]) {
+	Hello* engine = new Hello;
+	engine->initializeEngine();
+	engine->initializeGameLoop();
+}

meson.build

@@ -24,5 +24,5 @@ incdirs = [
 	kosportsinc
 ]
 
-executable('hello.elf', ['hello.c'], dependencies: deps, include_directories: incdirs)
+executable('hello.elf', ['hello.cc', 'engine.cc'], dependencies: deps, include_directories: incdirs)
-executable('gl.elf', ['gl.cc'], dependencies: deps, include_directories: incdirs)
+executable('gl.elf', ['gl.cc', 'engine.cc'], dependencies: deps, include_directories: incdirs)