opengl

glfw/Makefile

@@ -0,0 +1,13 @@
+CC=g++
+CFLAGS= -Wall
+
+LDLIBS = -lglfw
+
+TARGET := test
+
+build:
+	$(CC) $(LDLIBS) src/*.c src/*.cpp -o $(TARGET)
+
+.PHONY: clean
+clean:
+	rm -rf $(BUILD_DIR)

glfw/src/main.cpp

@@ -0,0 +1,199 @@
+#include "include/glad.h"
+#include <GLFW/glfw3.h>
+#include <iostream>
+
+const char* vertexShaderSource = "#version 330 core\n"
+	"layout (location = 0) in vec3 aPos;\n"
+	"void main()\n"
+	"{\n"
+	"	gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
+	"}\0";
+
+const char* fragmentShaderSource = "#version 330 core\n"
+	"out vec4 FragColor;\n"
+	"void main()\n"
+	"{\n"
+	"	FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+	"}\0";
+
+
+void framebuffer_size_callback(GLFWwindow* window, int width, int height);
+void processInput(GLFWwindow* window);
+void compileShaders(unsigned int* shader, bool fragment);
+void createShaderProgram(unsigned int* shaderProgram);
+void setupGLFW(GLFWwindow** window);
+
+/** SINGLE TRIANGLE VERTICES
+float vertices[] = {
+	-0.5f, -0.5f, 0.0f,
+	0.5f, -0.5f, 0.0f,
+	0.0f, 0.5f, 0.0f
+};
+*/
+
+/** RECTANGLE VERTICES
+ * notice how some of these duplicate? solved below...
+float vertices[] = {
+	//first triangle
+	0.5f, 0.5f, 0.0f, // top right
+	0.5f, -0.5f, 0.0f, // bottom right
+	-0.5f, 0.5f, 0.0f, //top left
+	//second triangle
+	0.5f, -0.5f, 0.0f, // bottom right
+	-0.5f, -0.5f, 0.0f, // bottom left
+	-0.5f, 0.5f, 0.0f // top left
+}
+*/
+
+float vertices[] = {
+	0.5f, 0.5f, 0.0f, // top right
+	0.5f, -0.5f, 0.0f, // bottom right
+	-0.5f, -0.5f, 0.0f, // bottom left
+	-0.5f, 0.5f, 0.0f, // top left
+};
+
+unsigned int indices[] = { // note, starts from zero
+	0, 1, 3, // first triangle
+	1, 2, 3 // second triangle
+};
+
+bool wireframe = false;
+
+int main()
+{
+	GLFWwindow* window;
+	unsigned int shaderProgram;
+	setupGLFW(&window);
+
+
+	createShaderProgram(&shaderProgram);
+	
+	unsigned int VAO;
+	glGenVertexArrays(1, &VAO);
+
+	unsigned int VBO;
+	glGenBuffers(1, &VBO);
+
+	unsigned int EBO;
+	glGenBuffers(1, &EBO);
+
+	// bind Vertex Array Object
+	glBindVertexArray(VAO);
+	// copy our vertices into a buffer for opengl to use
+	glBindBuffer(GL_ARRAY_BUFFER, VBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	// copy our indexes 
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
+	
+	// set the vertex attributes pointers
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*) 0);
+	glEnableVertexAttribArray(0);
+
+
+
+	while(!glfwWindowShouldClose(window)) {
+		//input
+		processInput(window);
+
+		//rendering
+		glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT);
+	
+
+		glUseProgram(shaderProgram);
+		glBindVertexArray(VAO);
+		//glDrawArrays(GL_TRIANGLES, 0, 3);
+		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+		glBindVertexArray(0); // unbinds the VAO so its ready to be bound again for the next render
+
+		// check and call events and swap buffers
+		glfwSwapBuffers(window);
+		glfwPollEvents();
+	}
+
+	glfwTerminate();
+	return 0;
+}
+
+void setupGLFW(GLFWwindow** window)
+{
+	glfwInit();
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+	*window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
+	if (window == NULL) {
+		std::cout << "Failed to create GLFW window\n";
+		glfwTerminate();
+		exit(-1);
+	}
+	glfwMakeContextCurrent(*window);
+
+	if (!gladLoadGLLoader((GLADloadproc) glfwGetProcAddress)) {
+		std::cout << "Failed to init GLAD\n";
+		exit(-1);
+	}
+
+	glViewport(0, 0, 800, 600);
+	glfwSetFramebufferSizeCallback(*window, framebuffer_size_callback);
+}
+
+
+void framebuffer_size_callback(GLFWwindow* window, int width, int height)
+{
+	glViewport(0, 0, width, height);
+}
+
+void processInput(GLFWwindow* window)
+{
+	if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
+		glfwSetWindowShouldClose(window, true);
+	if (glfwGetKey(window, GLFW_KEY_ENTER) == GLFW_PRESS) // triggers wireframe mode
+		glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+	if (glfwGetKey(window, GLFW_KEY_BACKSPACE) == GLFW_PRESS) // disables wireframe mode
+		glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
+}
+
+void compileShaders(unsigned int* shader, bool fragment, const char** source)
+{
+	int success;
+	char infoLog[512];
+
+	*shader = glCreateShader(fragment ? GL_FRAGMENT_SHADER : GL_VERTEX_SHADER);
+
+	glShaderSource(*shader, 1, &(*source), NULL);
+
+	glCompileShader(*shader);
+
+	glGetShaderiv(*shader, GL_COMPILE_STATUS, &success);
+	if (!success) {
+		glGetShaderInfoLog(*shader, 512, NULL, infoLog);
+		std::cout << "ERROR::SHADER::" << (fragment ? "FRAGMENT" : "VERTEX") << "::COMPILATION_FAILED\n" << infoLog << "\n";
+	}
+}
+
+void createShaderProgram(unsigned int* shaderProgram) {
+	int success;
+	char infoLog[512];
+	unsigned int vertexShader, fragmentShader;
+
+	compileShaders(&vertexShader, false, &vertexShaderSource);
+	compileShaders(&fragmentShader, true, &fragmentShaderSource);
+
+	*shaderProgram = glCreateProgram();
+	glAttachShader(*shaderProgram, vertexShader);
+	glAttachShader(*shaderProgram, fragmentShader);
+	glLinkProgram(*shaderProgram);
+
+	glGetProgramiv(*shaderProgram, GL_LINK_STATUS, &success);
+	if (!success) {
+		glGetProgramInfoLog(*shaderProgram, 512, NULL, infoLog);
+		std::cout << "ERROR::SHADER::LINK_FAILED\n" << infoLog << "\n";
+	}
+
+	glDeleteShader(vertexShader);
+	glDeleteShader(fragmentShader);
+}