2017-01-15 8 views
0

私はOpenGLを使い始めています。私はチュートリアルに続き、テクスチャ付きの三角形を作成しようとしました。このコードのシェーダはハードコードされているので、最小限の実行可能ファイルになります。これはスムーズにコンパイルされますが、出力は三角形のない色付きのウィンドウにすぎません。私は間違って何をしていますか?コードは次のとおりです。テクスチャを2D要素に追加

#include <iostream> 

// GLEW 
#define GLEW_STATIC 
#include <GL/glew.h> 

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

// Function prototypes 
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode); 

// Window dimensions 
const GLuint WIDTH = 800, HEIGHT = 600; 

// Texture co-ordinates 
GLfloat texCoords[] = { 
    0.0f, 0.0f, // Lower-left corner 
    1.0f, 0.0f, // Lower-right corner 
    0.5f, 1.0f // Top-center corner 
}; 

// Shaders 
const GLchar* vertexShaderSource = "#version 330 core\n layout (location = 0) in vec3 position;\r\nlayout (location = 1) in vec3 color;\r\nlayout (location = 2) in vec2 texCoord;\r\n\r\nout vec3 ourColor;\r\nout vec2 TexCoord;\r\n\r\nvoid main()\r\n{\r\n gl_Position = vec4(position, 1.0f);\r\n ourColor = color;\r\n TexCoord = texCoord;\r\n}"; 
const GLchar* fragmentShaderSource = "#version 330 core\r\nin vec3 ourColor;\r\nin vec2 TexCoord;\r\n\r\nout vec4 color;\r\n\r\nuniform sampler2D ourTexture;\r\n\r\nvoid main()\r\n{\r\n color = texture(ourTexture, TexCoord);\r\n}"; 

// The MAIN function, from here we start the application and run the game loop 
int main() 
{ 
    // Init GLFW 
    glfwInit(); 
    // Set all the required options for GLFW 
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); 
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); 
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); 
    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE); 

    // Create a GLFWwindow object that we can use for GLFW's functions 
    GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "LearnOpenGL", nullptr, nullptr); 
    glfwMakeContextCurrent(window); 

    // Set the required callback functions 
    glfwSetKeyCallback(window, key_callback); 

    // Set this to true so GLEW knows to use a modern approach to retrieving function pointers and extensions 
    glewExperimental = GL_TRUE; 
    // Initialize GLEW to setup the OpenGL Function pointers 
    glewInit(); 

    // Define the viewport dimensions 
    int width, height; 
    glfwGetFramebufferSize(window, &width, &height); 
    glViewport(0, 0, width, height); 


    // Build and compile our shader program 
    // Vertex shader 
    GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER); 
    glShaderSource(vertexShader, 1, &vertexShaderSource, NULL); 
    glCompileShader(vertexShader); 
    // Check for compile time errors 
    GLint success; 
    GLchar 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; 
    } 
    // Fragment shader 
    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER); 
    glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL); 
    glCompileShader(fragmentShader); 
    // Check for compile time errors 
    glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success); 
    if (!success) 
    { 
     glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog); 
     std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl; 
    } 
    // Link shaders 
    GLuint shaderProgram = glCreateProgram(); 
    glAttachShader(shaderProgram, vertexShader); 
    glAttachShader(shaderProgram, fragmentShader); 
    glLinkProgram(shaderProgram); 
    // Check for linking errors 
    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success); 
    if (!success) { 
     glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog); 
     std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl; 
    } 
    glDeleteShader(vertexShader); 
    glDeleteShader(fragmentShader); 


    // Set up vertex data (and buffer(s)) and attribute pointers 
    GLfloat vertices[] = { 
     -0.5f, -0.5f, 0.0f, // Left 
     0.5f, -0.5f, 0.0f, // Right 
     0.0f, 0.5f, 0.0f // Top 
    }; 
    GLuint VBO, VAO; 
    glGenVertexArrays(1, &VAO); 
    glGenBuffers(1, &VBO); 

    // Bind the Vertex Array Object first, then bind and set vertex buffer(s) and attribute pointer(s). 
    glBindVertexArray(VAO); 

    glBindBuffer(GL_ARRAY_BUFFER, VBO); 
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); 

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (GLvoid*)0); 
    glEnableVertexAttribArray(0); 

    glBindBuffer(GL_ARRAY_BUFFER, 0); // Note that this is allowed, the call to glVertexAttribPointer registered VBO as the currently bound vertex buffer object so afterwards we can safely unbind 

    glBindVertexArray(0); // Unbind VAO (it's always a good thing to unbind any buffer/array to prevent strange bugs) 

    // Attach image to texture 
    int t_width, t_height; 
    unsigned char* image = SOIL_load_image("texm.jpg", &t_width, &t_height, 0, SOIL_LOAD_RGB); 
    GLuint texture; 
    glGenTextures(1, &texture); 
    glBindTexture(GL_TEXTURE_2D, texture); 
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, t_width, t_height, 0, GL_RGB, GL_UNSIGNED_BYTE, image); 
    glGenerateMipmap(GL_TEXTURE_2D); 
    SOIL_free_image_data(image); 
    glBindTexture(GL_TEXTURE_2D, 0); 
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)(6 * sizeof(GLfloat))); 
    glEnableVertexAttribArray(2); 


    // Game loop 
    while (!glfwWindowShouldClose(window)) 
    { 
     // Check if any events have been activiated (key pressed, mouse moved etc.) and call corresponding response functions 
     glfwPollEvents(); 

     // Render 
     // Clear the colorbuffer 
     glClearColor(0.2f, 0.3f, 0.3f, 1.0f); 
     glClear(GL_COLOR_BUFFER_BIT); 

     // Draw our first triangle 
     glUseProgram(shaderProgram); 
     glBindTexture(GL_TEXTURE_2D, texture); 
     glBindVertexArray(VAO); 
     glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0); 
     glBindVertexArray(0); 

     // Swap the screen buffers 
     glfwSwapBuffers(window); 
    } 
    // Properly de-allocate all resources once they've outlived their purpose 
    glDeleteVertexArrays(1, &VAO); 
    glDeleteBuffers(1, &VBO); 
    // Terminate GLFW, clearing any resources allocated by GLFW. 
    glfwTerminate(); 
    return 0; 
} 

// Is called whenever a key is pressed/released via GLFW 
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode) 
{ 
    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) 
     glfwSetWindowShouldClose(window, GL_TRUE); 
} 

ありがとうございました。

答えて

1

glDrawElementsで描画しようとしていますが、その場合には問題があります。まず、巨大な間違いではなく、3頂点を持つ三角形があるので、glDrawElementsの2番目のパラメータは3にする必要があります。また、インデックスバッファがバインドされることも期待しています。したがって、インデックス作成を実装するか、glDrawArraysで描画します。

あなたは(あなたが意志)後でインデックスを使用すると、あなたは精通していない場合は、次の http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-9-vbo-indexing/

関連する問題