Assertion

Engine/src/Engine/Base.h

@@ -12,3 +12,7 @@
 
 
 #define BIT(x) 1 << x
+
+#define LT_ENGINE_ASSERT(x, ...) { if(!(x)) { LT_ENGINE_CRITICAL(__VA_ARGS__); __debugbreak(); } }
+#define LT_CLIENT_ASSERT(x, ...) { if(!(x)) { LT_CLIENT_CRITICAL(__VA_ARGS__); __debugbreak(); } }
+

Engine/src/Engine/Core/Application.cpp

@@ -26,6 +26,8 @@ namespace Light {
 
 	void Application::GameLoop()
 	{
+		LT_ENGINE_ASSERT(!m_LayerStack.IsEmpty(), "Application::GameLoop: Layerstack is empty");
+
 		while (m_Window->IsOpen())
 		{
 			// Events

Engine/src/Engine/Graphics/GraphicsContext.cpp

@@ -18,26 +18,36 @@ namespace Light {
 			s_Context->m_UserInterface.reset();
 		}
 
+		// determine the default api
+		if (api == GraphicsAPI::Default)
+		{
+#ifdef LIGHT_PLATFORM_WINDOWS
+			api = GraphicsAPI::OpenGL; // TODO: Change to DirectX
+#endif
+		}
+
 		// create gfx context
 		switch (api)
 		{
-		case Light::GraphicsAPI::Default:
 		case Light::GraphicsAPI::OpenGL:
 			s_Context = new glGraphicsContext(windowHandle);
 			break;
+
 		default:
-			break;
+			LT_ENGINE_ASSERT(false, "GraphicsContext::Create: invalid/unsupported GraphicsAPI {}", api);
-			// TODO: ASSERT
+			return nullptr;
 		}
 
 		// create gfx context dependent classes
-		if (s_Context)
-		{
 		s_Context->m_RenderCommand = std::unique_ptr<RenderCommand>(RenderCommand::Create(windowHandle));
 		s_Context->m_UserInterface = std::unique_ptr<UserInterface>(UserInterface::Create(windowHandle));
 		// ...Renderer
 		// ...UserInterface...
-		}
+
+		// sanity check
+		LT_ENGINE_ASSERT(s_Context->m_RenderCommand, "GraphicsContext::Create: RenderCommand creation failed");
+		LT_ENGINE_ASSERT(s_Context->m_UserInterface, "GraphicsContext::Create: UserInterface creation failed");
+
 
 		return s_Context;
 	}

Engine/src/Engine/Graphics/GraphicsContext.h

@@ -2,7 +2,6 @@
 
 #include "Base.h"
 
-
 struct GLFWwindow;
 
 namespace Light {
@@ -12,7 +11,11 @@ namespace Light {
 
 	enum class GraphicsAPI
 	{
-		Default, OpenGL // TODO: Add DirectX, Vulkan, Metal.
+		Default = 0,
+		OpenGL, 
+		DirectX, 
+		Vulkan, 
+		Metal
 	};
 
 	class GraphicsContext

Engine/src/Engine/Graphics/RenderCommand.cpp

@@ -14,7 +14,8 @@ namespace Light {
 			return new glRenderCommand(windowHandle);
 
 		default:
-			return nullptr; // TODO: Add ASSERT
+			LT_ENGINE_ASSERT(false, "RenderCommand::Create: invalid/unsupported GraphicsAPI {}", GraphicsContext::GetGraphicsAPI());
+			return nullptr;
 		}
 	}
 

Engine/src/Engine/Graphics/Shader.cpp

@@ -1,7 +1,22 @@
 #include "ltpch.h"
 #include "Shader.h"
+#include "OpenGL/glShader.h"
+
+#include "GraphicsContext.h"
 
 namespace Light {
 
+	Shader* Shader::Create(const std::string& vertexPath, const std::string& pixelPath)
+	{
+		switch (GraphicsContext::GetGraphicsAPI())
+		{
+		case GraphicsAPI::OpenGL:
+			return new glShader(vertexPath, pixelPath);
+
+		default:
+			LT_ENGINE_ASSERT(false, "Shader::Create: invalid/unsupported GraphicsAPI {}", GraphicsContext::GetGraphicsAPI());
+			return nullptr;
+		}
+	}
 
 }

Engine/src/Engine/Graphics/Shader.h

@@ -6,7 +6,7 @@ namespace Light {
 	{
 	private:
 	public:
-		static Shader* Create();
+		static Shader* Create(const std::string& vertexPath, const std::string& pixelPath);
 
 		virtual ~Shader() = default;
 

Engine/src/Engine/Layer/LayerStack.h

@@ -29,6 +29,8 @@ namespace Light {
 
 		void OnEvent(const Event& event);
 
+		inline bool IsEmpty() { return m_Layers.empty(); }
+
 		std::vector<Layer*>::iterator begin() { return m_Layers.begin(); }
 		std::vector<Layer*>::iterator end() { return m_Layers.end(); }
 

Engine/src/Engine/UserInterface/UserInterface.cpp

@@ -18,6 +18,10 @@ namespace Light {
 		{
 		case GraphicsAPI::OpenGL:
 			return new glUserInterface(windowHandle);
+
+		default:
+			LT_ENGINE_ASSERT(false, "UserInterface::Create: invalid/unsupported GraphicsAPI {}", GraphicsContext::GetGraphicsAPI());
+			return nullptr;
 		}
 	}
 

Engine/src/Platform/GraphicsAPI/OpenGL/glGraphicsContext.cpp

@@ -16,7 +16,8 @@ namespace Light {
 		m_GraphicsAPI = GraphicsAPI::OpenGL;
 
 		glfwMakeContextCurrent(windowHandle);
-		gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
+		LT_ENGINE_ASSERT(gladLoadGLLoader((GLADloadproc)glfwGetProcAddress),
+		                 "glGraphicsContext::glGraphicsContext: gladLoadGLLoader: failed to initialize opengl context");
 
 		LT_ENGINE_INFO("glGraphicsContext:");
 		LT_ENGINE_INFO("        Renderer: {}", glGetString(GL_RENDERER));

Engine/src/Platform/GraphicsAPI/OpenGL/glShader.cpp

@@ -0,0 +1,76 @@
+#include "ltpch.h"
+#include "glShader.h"
+
+#include <GLAD/glad.h>
+
+namespace Light {
+
+	glShader::glShader(const std::string& vertexPath, const std::string& pixelPath)
+	{
+		m_ShaderID = glCreateProgram();
+
+		unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
+		unsigned int pixelShader = glCreateShader(GL_FRAGMENT_SHADER);
+
+		const char* vertexPath_cstr = vertexPath.c_str();
+		const char* pixelPath_cstr = pixelPath.c_str();
+
+		glShaderSource(vertexShader, 1, &vertexPath_cstr, NULL);
+		glShaderSource(pixelShader, 1, &pixelPath_cstr, NULL);
+
+		glCompileShader(vertexShader);
+		glCompileShader(pixelShader);
+
+		// TEMP
+		int isCompiled = 0;
+		glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &isCompiled);
+		if (isCompiled == GL_FALSE)
+		{
+			GLint maxLength = 0;
+			glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength);
+
+			std::vector<char> errorLog(maxLength);
+			glGetShaderInfoLog(vertexShader, maxLength, &maxLength, &errorLog[0]);
+
+			glDeleteShader(vertexShader);
+		}
+
+		glGetShaderiv(pixelShader, GL_COMPILE_STATUS, &isCompiled);
+		if (isCompiled == GL_FALSE)
+		{
+			GLint maxLength = 0;
+			glGetShaderiv(pixelShader, GL_INFO_LOG_LENGTH, &maxLength);
+
+			std::vector<char> errorLog(maxLength);
+			glGetShaderInfoLog(pixelShader, maxLength, &maxLength, &errorLog[0]);
+
+			glDeleteShader(pixelShader);
+		}
+		// TEMP
+
+		glAttachShader(m_ShaderID, vertexShader);
+		glAttachShader(m_ShaderID, pixelShader);
+		glLinkProgram(m_ShaderID);
+	
+		glDeleteShader(vertexShader);
+		glDeleteShader(pixelShader);
+
+		// TODO: validate program
+	}
+
+	glShader::~glShader()
+	{
+		glDeleteProgram(m_ShaderID);
+	}
+
+	void glShader::Bind()
+	{
+		glUseProgram(m_ShaderID);
+	}
+
+	void glShader::UnBind()
+	{
+		glUseProgram(NULL);
+	}
+
+}

Engine/src/Platform/GraphicsAPI/OpenGL/glShader.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "Base.h"
+#include "Graphics/Shader.h"
+
+namespace Light {
+
+	class glShader : public Shader
+	{
+	private:
+		unsigned int m_ShaderID;
+
+	public:
+		glShader(const std::string& vertexPath, const std::string& pixelPath);
+		~glShader();
+
+		void Bind() override;
+		void UnBind() override;
+	};
+
+}

Engine/src/Platform/OS/Windows/wWindow.cpp

@@ -20,14 +20,16 @@ namespace Light {
 	wWindow::wWindow(const WindowProperties& properties, std::function<void(Event&)> callback)
 		: m_Properties(properties), m_EventCallback(callback)
 	{
-		if (!glfwInit()) __debugbreak();
+		LT_ENGINE_ASSERT(glfwInit(), "wWindow::wWindow: glfwInit: failed to initialize glfw");
 
 		m_Handle = glfwCreateWindow(properties.width, properties.height, properties.title.c_str(), nullptr, nullptr);
+		LT_ENGINE_ASSERT(m_Handle, "wWindow::wWindow: glfwCreateWindow: failed to create glfw window");
 
 		glfwSetWindowUserPointer(m_Handle, &m_EventCallback);
 		BindGlfwEvents();
 
 		m_GraphicsContext = std::unique_ptr<GraphicsContext>(GraphicsContext::Create(GraphicsAPI::OpenGL, m_Handle));
+		LT_ENGINE_ASSERT(m_GraphicsContext, "wWindow::wWindow: graphics context creation failed");
 	}
 
 	wWindow::~wWindow()