Refactored texture usage

src/Engine/main.cpp

@@ -8,13 +8,15 @@
 #include <string>
 
 #include "shaders/Shader.h"
+#include "textures/Texture2D.h"
 #include "util/stb_image.h"
 
 // Continue: https://learnopengl.com/Getting-started/Coordinate-Systems
 // Chapter: More Cubes!
 //
 // TODO: look at project->properties->VC++ Directories-> change everything to the Environment var
-// For the "real" Nebulix Engine setup everything so it can be compiled/used with VSCode/CLion and not just VS (so basically having an "external" folder which has open gl, GLAD, etc. in it or something like this)
+// For the "real" Nebulix Engine setup everything so it can be compiled/used with VSCode/CLion and not just VS 
+// (so basically having an "external" folder which has open gl, GLAD, GLM, stb_image etc. in it or something like this)
 
 // 
 // HOW TO redirect error output to file
@@ -42,6 +44,12 @@ void ProcessInput(GLFWwindow* window)
 		glfwSetWindowShouldClose(window, true);
 }
 
+void Configure()
+{
+	stbi_set_flip_vertically_on_load(true); // because an image has 0 at top of y axis and opengl expects it to be on the botton, so if this is omitted, the image will be flipped
+	glEnable(GL_DEPTH_TEST);
+}
+
 int main()
 {
 	glfwInit();
@@ -70,6 +78,8 @@ int main()
 	OnWindowResize(window, WINDOW_WIDTH, WINDOW_HEIGHT);
 	glfwSetFramebufferSizeCallback(window, OnWindowResize);
 
+	Configure();
+
 	float vertices[] = { // object coordinates, uv-coordinates
 	-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
 	 0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
@@ -116,23 +126,8 @@ int main()
 
 	GLuint faces[]{
 		0, 1, 3,
-		1, 2, 3,
+		1, 2, 3
-
+	};
-		4, 5, 6,
-		5, 6, 7,
-
-		8, 9, 10,
-		9, 10, 11,
-
-		12, 13, 14,
-		13, 14, 15,
-
-		16, 17, 18,
-		17, 18, 19,
-
-		20, 21, 22,
-		21, 22, 23
-	}; // 23
 
 	// VBO == all verticies; EBO == connection of vertices (faces) and is optional although it is a bit more efficient than using VBOs; 
 	// VAO == collection of VBOs/EBOs used for rendering
@@ -152,7 +147,7 @@ int main()
 	// position attribute
 	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
 	glEnableVertexAttribArray(0);
-	// uv-coordinates (or more general the third vertex attribute)
+	// uv-coordinates (or more general the third vertex attribute which can be anything not just uv-coordinates)
 	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
 	glEnableVertexAttribArray(2);
 	// I could unbind the VAO, but this is usually not needed because when creating a new VAO we need to bind that to change it anyway, so there shouldn't be a problem
@@ -173,35 +168,8 @@ int main()
 	glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 	
 	// TEXTURES
-	stbi_set_flip_vertically_on_load(true); // because an image has 0 at top of y axis and opengl expects it to be on the botton, so if this is omitted, the image will be flipped
+	Texture2D containerImage("images/container.jpg");
-	int width, height, nrChannels;
+	Texture2D faceImage("images/awesomeface.png", 0, GL_RGBA);
-	unsigned char* image = stbi_load("images/container.jpg", &width, &height, &nrChannels, 0);
-	if (!image)
-	{
-		std::cerr << "ERROR::IO::LOAD_TEXTURE";
-		stbi_image_free(image);
-		return -1; // it would be better to just use a default error image instead and make the error message a warning message instead
-	}
-	unsigned int textureID_container;
-	glGenTextures(1, &textureID_container);
-	glBindTexture(GL_TEXTURE_2D, textureID_container);
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
-	glGenerateMipmap(GL_TEXTURE_2D);
-	stbi_image_free(image);
-
-	image = stbi_load("images/awesomeface.png", &width, &height, &nrChannels, 0);
-	if (!image)
-	{
-		std::cerr << "ERROR::IO::LOAD_TEXTURE";
-		stbi_image_free(image);
-		return -1; // it would be better to just use a default error image instead and make the error message a warning message instead
-	}
-	unsigned int textureID_face;
-	glGenTextures(1, &textureID_face);
-	glBindTexture(GL_TEXTURE_2D, textureID_face);
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image);
-	glGenerateMipmap(GL_TEXTURE_2D);
-	stbi_image_free(image);
 
 	//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
 	//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
@@ -214,7 +182,6 @@ int main()
 	viewMatrix = glm::translate(viewMatrix, vec3(0, 0, -3.0f));
 	mat4 projectionMatrix = glm::perspective(glm::radians(45.0f), 800.0f / 600.0f, 0.1f, 100.0f);
 
-	glEnable(GL_DEPTH_TEST);
 	float timeLastFrame = glfwGetTime();
 	// main loop
 	while(!glfwWindowShouldClose(window))
@@ -235,10 +202,8 @@ int main()
 		shader->SetMatrix("viewMatrix", viewMatrix);
 		shader->SetMatrix("projectionMatrix", projectionMatrix);
 
-		glActiveTexture(GL_TEXTURE0); // before binding texture, activate correct textre Unit (some drivers might show nothing if this is omitted)
+		containerImage.BindTexture();
-		glBindTexture(GL_TEXTURE_2D, textureID_container);
+		faceImage.BindTexture(GL_TEXTURE0 + 1); // GL_TEXTURE0 + 1 == GL_TEXTURE1, this means looping over multiple units is easily possible
-		glActiveTexture(GL_TEXTURE0 + 1); // GL_TEXTURE0 + 1 == GL_TEXTURE1, this means looping over multiple units is easily possible
-		glBindTexture(GL_TEXTURE_2D, textureID_face);
 		
 		glBindVertexArray(vertexArrayObject);
 		//glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0); // for EBOs

src/Engine/textures/Texture2D.h

@@ -1,11 +1,49 @@
 #pragma once
+#include <glad/glad.h>
+#include <string>
+
+#include "../util/stb_image.h"
+#include "../exceptions/IOException.h"
+
 // Maybe make a base "Texture" class and make a Texture2D and Texture3D child class. look into what would make more sense
 class Texture2D
 {
 public:
-	Texture2D();
+	// maybe add a parameter for configuring mipmapping
-	~Texture2D();
+	Texture2D(std::string pathToTexture, int desiredColourChannels = 0, GLenum fileFormat = GL_RGB)
+	{
+		unsigned char* image = stbi_load(pathToTexture.c_str(), &width, &height, &nrChannels, desiredColourChannels);
+		if (!image)
+		{
+			stbi_image_free(image);
+			throw Nebulix::IOException("ERROR::FILE::IO::LOAD_TEXTURE"); // it would be better to just use a default error image instead and make the error message a warning message
+		}
+		glGenTextures(1, &textureId);
+		glBindTexture(GL_TEXTURE_2D, textureId);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, fileFormat, GL_UNSIGNED_BYTE, image);
+		glGenerateMipmap(GL_TEXTURE_2D);
+		stbi_image_free(image);
+	}
+	~Texture2D()
+	{
+		glDeleteTextures(1, &textureId);
+	}
 
+	/// <summary>
+	/// Activate and bind this texture to use it
+	/// </summary>
+	/// <param name="texture">The texture unit of this texture. For example GL_TEXTURE0 (default)</param>
+	void BindTexture(GLenum textureUnit = GL_TEXTURE0)
+	{
+		// TODO: add the interpolation configuration. Make as properties which have default settings kinda like Unity
+		glActiveTexture(textureUnit); // before binding texture, activate correct textre Unit (some drivers might show nothing if this is omitted)
+		glBindTexture(GL_TEXTURE_2D, textureId);
+	}
+
+	int GetWidth() { return width; }
+	int GetHeight() { return height; }
+	int GetNrChannels() { return nrChannels; }
 private:
-
+	GLuint textureId;
+	int width, height, nrChannels;
 };