OPENGL - test 創建兩個三角形，但對它們的數據使用不同的VAO和VBO

// 創建相同的兩個三角形，但對它們的數據使用不同的VAO和VBO：

#include "stdafx.h"

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <iostream>

const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;



int _tmain(int argc, _TCHAR* argv[])
{
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	GLFWwindow *window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
	if (NULL == window)
	{
		std::cout << "Failed to create GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);


	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
	{
		std::cout << "Failed to initialize GLAD" << std::endl;
		return -1;
	}

	float vertices1[] = {
		// first triangle
		-0.9f, -0.5f, 0.0f, 
		-0.0f, -0.5f, 0.0f, 
		-0.45f, 0.5f, 0.0f
	};


	unsigned int VBO1, VAO1;
	glGenVertexArrays(1, &VAO1);
	glGenBuffers(1, &VBO1);
	glBindVertexArray(VAO1);
	glBindBuffer(GL_ARRAY_BUFFER, VBO1);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices1), vertices1, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	float vertices2[] = {
		// first triangle
		0.9f, -0.7f, 0.0f,
		0.0f, -0.7f, 0.0f,
		0.45f, 0.7f, 0.0f
	};

	unsigned int VBO2, VAO2;
	glGenVertexArrays(1, &VAO2);
	glGenBuffers(1, &VBO2);
	glBindVertexArray(VAO2);
	glBindBuffer(GL_ARRAY_BUFFER, VBO2);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices2), vertices2, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	while (!glfwWindowShouldClose(window))
	{
		glClearColor(0.1f, 0.5f, 0.4f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		glBindVertexArray(VAO1);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glBindVertexArray(VAO2);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glfwSwapBuffers(window);
		glfwPollEvents();
	}


	glfwTerminate();
	return 0;
}

 

因爲沒有寫着色器，所以就是黑的

 

【給兩個三角形着色】

// 創建相同的兩個三角形，但對它們的數據使用不同的VAO和VBO：

#include "stdafx.h"

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <iostream>

const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;

const char *vertexShaderCodeSource = "#version 460 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 *fragmentShaderCodeSource = "#version 460 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
"   FragColor = vec4(1.0f, 0.0f, 0.0f, 1.0f);\n"
"}\n\0";


int _tmain(int argc, _TCHAR* argv[])
{
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	GLFWwindow *window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
	if (NULL == window)
	{
		std::cout << "Failed to create GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);


	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
	{
		std::cout << "Failed to initialize GLAD" << std::endl;
		return -1;
	}


	int vertexShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertexShader, 1, &vertexShaderCodeSource, NULL);
	glCompileShader(vertexShader);
	int success;
	char infoLog[512];
	glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
	}

	int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragmentShader, 1, &fragmentShaderCodeSource, NULL);
	glCompileShader(fragmentShader);

	glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
	}


	int 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::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
	}
	// 把着色器對象鏈接到程序對象以後，記得刪除着色器對象
	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);


	float vertices1[] = {
		// first triangle
		-0.9f, -0.5f, 0.0f, 
		-0.0f, -0.5f, 0.0f, 
		-0.45f, 0.5f, 0.0f
	};


	unsigned int VBO1, VAO1;
	glGenVertexArrays(1, &VAO1);
	glGenBuffers(1, &VBO1);
	glBindVertexArray(VAO1);
	glBindBuffer(GL_ARRAY_BUFFER, VBO1);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices1), vertices1, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	float vertices2[] = {
		// first triangle
		0.9f, -0.7f, 0.0f,
		0.0f, -0.7f, 0.0f,
		0.45f, 0.7f, 0.0f
	};

	unsigned int VBO2, VAO2;
	glGenVertexArrays(1, &VAO2);
	glGenBuffers(1, &VBO2);
	glBindVertexArray(VAO2);
	glBindBuffer(GL_ARRAY_BUFFER, VBO2);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices2), vertices2, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	while (!glfwWindowShouldClose(window))
	{
		glClearColor(0.1f, 0.5f, 0.4f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);
		glUseProgram(shaderProgram);
		glBindVertexArray(VAO1);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glBindVertexArray(VAO2);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glfwSwapBuffers(window);
		glfwPollEvents();
	}


	glfwTerminate();
	return 0;
}

 

【給兩個三角形着不同的顏色】

// 創建相同的兩個三角形，但對它們的數據使用不同的VAO和VBO：

#include "stdafx.h"

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <iostream>

const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;

const char *vertexShaderCodeSource = "#version 460 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 *fragmentShaderCodeSource = "#version 460 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
"   FragColor = vec4(1.0f, 0.0f, 0.0f, 1.0f);\n"
"}\n\0";


const char *fragmentShaderCodeSource2 = "#version 460 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
"   FragColor = vec4(1.0f, 0.0f, 1.0f, 1.0f);\n"
"}\n\0";


int _tmain(int argc, _TCHAR* argv[])
{
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	GLFWwindow *window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
	if (NULL == window)
	{
		std::cout << "Failed to create GLFW window" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);


	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
	{
		std::cout << "Failed to initialize GLAD" << std::endl;
		return -1;
	}


	int vertexShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertexShader, 1, &vertexShaderCodeSource, NULL);
	glCompileShader(vertexShader);
	int success;
	char infoLog[512];
	glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
	}

	int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragmentShader, 1, &fragmentShaderCodeSource, NULL);
	glCompileShader(fragmentShader);

	glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
	}


	int 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::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
	}

	int fragmentShader2 = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragmentShader2, 1, &fragmentShaderCodeSource2, NULL);
	glCompileShader(fragmentShader2);

	glGetShaderiv(fragmentShader2, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(fragmentShader2, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
	}

	int shaderProgram2 = glCreateProgram();
	glAttachShader(shaderProgram2, vertexShader);
	glAttachShader(shaderProgram2, fragmentShader2);
	glLinkProgram(shaderProgram2);

	glGetProgramiv(shaderProgram2, GL_LINK_STATUS, &success);
	if (!success)
	{
		glGetProgramInfoLog(shaderProgram2, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
	}

	// 把着色器對象鏈接到程序對象以後，記得刪除着色器對象
	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);


	float vertices1[] = {
		// first triangle
		-0.9f, -0.5f, 0.0f, 
		-0.0f, -0.5f, 0.0f, 
		-0.45f, 0.5f, 0.0f
	};


	unsigned int VBO1, VAO1;
	glGenVertexArrays(1, &VAO1);
	glGenBuffers(1, &VBO1);
	glBindVertexArray(VAO1);
	glBindBuffer(GL_ARRAY_BUFFER, VBO1);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices1), vertices1, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	float vertices2[] = {
		// first triangle
		0.9f, -0.7f, 0.0f,
		0.0f, -0.7f, 0.0f,
		0.45f, 0.7f, 0.0f
	};

	unsigned int VBO2, VAO2;
	glGenVertexArrays(1, &VAO2);
	glGenBuffers(1, &VBO2);
	glBindVertexArray(VAO2);
	glBindBuffer(GL_ARRAY_BUFFER, VBO2);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices2), vertices2, GL_STATIC_DRAW);

	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);

	while (!glfwWindowShouldClose(window))
	{
		glClearColor(0.1f, 0.5f, 0.4f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);
		glUseProgram(shaderProgram);
		glBindVertexArray(VAO1);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glUseProgram(shaderProgram2);
		glBindVertexArray(VAO2);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glfwSwapBuffers(window);
		glfwPollEvents();
	}


	glfwTerminate();
	return 0;
}