在这个环境中,我已经编译了一个在线发布的c++/openGL例子:
- Windows 7操作系统
- Code::Blocks版本为13.12
- MinGW版本为2013年10月构建(版本不确定)
- mingw32-g++版本为4.8.1
来自codeincodeblock.com的代码:
#define GLEW_STATIC
// third-party libraries
#include <windows.h>
#include <GL/glew.h>
#include <GL/glfw.h>
#include <glm/glm.hpp>
#include <cassert>
#include <iostream>
#include <stdexcept>
GLuint gVAO = 0;
GLuint gVBO = 0;
GLuint programId;
const glm::vec2 SCREEN_SIZE(800, 600);
static void LoadTriangle() {
// make and bind the VAO
glGenVertexArrays(1, &gVAO);
glBindVertexArray(gVAO);
// make and bind the VBO
glGenBuffers(1, &gVBO);
glBindBuffer(GL_ARRAY_BUFFER, gVBO);
// Put the three triangle verticies into the VBO
GLfloat vertexData[] = {
// X Y Z
0.0f, 0.8f, 0.0f,
-0.8f,-0.8f, 0.0f,
0.8f,-0.8f, 0.0f,
};
glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW);
// connect the xyz to the "vert" attribute of the vertex shader
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
// unbind the VBO and VAO
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
// draws a single frame
static void Render() {
// clear everything
glClearColor(0, 0, 0, 1); // black
glClear(GL_COLOR_BUFFER_BIT);
// bind the VAO (the triangle)
glBindVertexArray(gVAO);
// draw the VAO
glDrawArrays(GL_TRIANGLES, 0, 3);
// unbind the VAO
glBindVertexArray(0);
// swap the display buffers (displays what was just drawn)
glfwSwapBuffers();
}
// the program starts here
void AppMain() {
// initialise GLFW
if(!glfwInit())
throw std::runtime_error("glfwInit failed");
// open a window with GLFW
glfwOpenWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 3);
glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 2);
glfwOpenWindowHint(GLFW_WINDOW_NO_RESIZE, GL_TRUE);
if(!glfwOpenWindow((int)SCREEN_SIZE.x, (int)SCREEN_SIZE.y, 8, 8, 8, 8, 0, 0, GLFW_WINDOW))
throw std::runtime_error("glfwOpenWindow failed. Can your hardware handle OpenGL 3.2?");
// initialise GLEW
glewExperimental = GL_TRUE; //stops glew crashing on OSX :-/
if(glewInit() != GLEW_OK)
throw std::runtime_error("glewInit failed");
// print out some info about the graphics drivers
std::cout << "OpenGL version: " << glGetString(GL_VERSION) << std::endl;
std::cout << "GLSL version: " << glGetString(GL_SHADING_LANGUAGE_VERSION) << std::endl;
std::cout << "Vendor: " << glGetString(GL_VENDOR) << std::endl;
std::cout << "Renderer: " << glGetString(GL_RENDERER) << std::endl;
// make sure OpenGL version 3.2 API is available
if(!GLEW_VERSION_3_2)
throw std::runtime_error("OpenGL 3.2 API is not available.");
// create buffer and fill it with the points of the triangle
LoadTriangle();
// run while the window is open
while(glfwGetWindowParam(GLFW_OPENED)){
// draw one frame
Render();
}
// clean up and exit
glfwTerminate();
}
int main(int argc, char *argv[]) {
try {
AppMain();
} catch (const std::exception& e){
std::cerr << "ERROR: " << e.what() << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
我将做出适用于glfw3的修改版本:
我对代码进行了修改以适应glfw3:
#define GLEW_STATIC
// third-party libraries
#include <windows.h>
#include <GL/glew.h>
#include <GL/glfw3.h> // --- changed
#include <glm/glm.hpp>
#include <cassert>
#include <iostream>
#include <stdexcept>
GLuint gVAO = 0;
GLuint gVBO = 0;
GLuint programId;
const glm::vec2 SCREEN_SIZE(800, 600);
GLFWwindow *window; // --- added
static void LoadTriangle() {
// make and bind the VAO
glGenVertexArrays(1, &gVAO);
glBindVertexArray(gVAO);
// make and bind the VBO
glGenBuffers(1, &gVBO);
glBindBuffer(GL_ARRAY_BUFFER, gVBO);
// Put the three triangle verticies into the VBO
GLfloat vertexData[] = {
// X Y Z
0.0f, 0.8f, 0.0f,
-0.8f,-0.8f, 0.0f,
0.8f,-0.8f, 0.0f,
};
glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW);
// connect the xyz to the "vert" attribute of the vertex shader
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
// unbind the VBO and VAO
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
// draws a single frame
static void Render(GLFWwindow *win) { // --- changed
// clear everything
glClearColor(0, 0, 0, 1); // black
glClear(GL_COLOR_BUFFER_BIT);
// bind the VAO (the triangle)
glBindVertexArray(gVAO);
// draw the VAO
glDrawArrays(GL_TRIANGLES, 0, 3);
// unbind the VAO
glBindVertexArray(0);
// swap the display buffers (displays what was just drawn)
glfwSwapBuffers(win); // --- changed
}
// the program starts here
void AppMain() {
// initialise GLFW
if(!glfwInit())
throw std::runtime_error("glfwInit failed");
// open a window with GLFW
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // --- changed
glfwWindowHint(GLFW_VERSION_MAJOR, 3); // --- changed
glfwWindowHint(GLFW_VERSION_MINOR, 2); // --- changed
glfwWindowHint(GLFW_RESIZABLE, GL_TRUE); // --- changed
window = glfwCreateWindow((int)SCREEN_SIZE.x, (int)SCREEN_SIZE.y,"Test window",0,0); // --- changed
if(window == NULL)
throw std::runtime_error("glfwOpenWindow failed. Can your hardware handle OpenGL 3.2?");
// initialise GLEWuj
glewExperimental = GL_TRUE; //stops glew crashing on OSX :-/
if(glewInit() != GLEW_OK)
throw std::runtime_error("glewInit failed");
// print out some info about the graphics drivers
std::cout << "OpenGL version: " << glGetString(GL_VERSION) << std::endl;
std::cout << "GLSL version: " << glGetString(GL_SHADING_LANGUAGE_VERSION) << std::endl;
std::cout << "Vendor: " << glGetString(GL_VENDOR) << std::endl;
std::cout << "Renderer: " << glGetString(GL_RENDERER) << std::endl;
// make sure OpenGL version 3.2 API is available
if(!GLEW_VERSION_3_2)
throw std::runtime_error("OpenGL 3.2 API is not available.");
// create buffer and fill it with the points of the triangle
LoadTriangle();
// run while the window is open
while(!glfwWindowShouldClose(window)){ // --- changed
// draw one frame
Render(window); // --- changed
}
// clean up and exit
glfwTerminate();
}
int main(int argc, char *argv[]) {
try {
AppMain();
} catch (const std::exception& e){
std::cerr << "ERROR: " << e.what() << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
我在链接选项中添加了 -mwindows,同时按照 Dinesh 在他的 设置现代OpenGL页面 上的指示设置了我的 OpenGL 环境。
请注意,Dinesh 使用的是早期的 glfw 编译版本,因此我需要进行更改才能使代码编译和执行。
无论如何,该构建会产生以下输出:
=== Build: Debug in OpenGLTest (compiler: GNU GCC Compiler) ===
Warning: corrupt .drectve at end of def file
=== Build finished: 0 error(s), 1 warning(s) (0 minute(s), 5 second(s)) ===
=== Run: Debug in OpenGLTest (compiler: GNU GCC Compiler) ===
所以说,经过这一切,我的问题是:这个警告是什么意思?我应该担心吗?