c++ - 如何在OpenGL中输出变量号？

我正在OpenGL中编写一个游戏，其中有3个大盒子和1个小盒子。小盒子隐藏在其中一个大盒子下面，用户必须按A，B或C才能显示小盒子在哪里。我想跟踪用户做出了多少猜测，玩了几轮等等，但是我不确定如何在OpenGL中输出递增的数字。每当发生与数字有关的事情时，我都想增加数字，但是我无法弄清楚。有人可以指出我正确的方向吗？非常感谢！

main.cpp：

#include "Box.h"
#include "Font.h"
#include "Camera.h"
#include "Time.h"
#include <vector>
using namespace std;

#include "vgl.h"
using namespace glm;
#define SPACEBAR_KEY 32
#define ESCAPE_KEY 033

vector<Box * > boxes;
Camera* camera;
Font* font;
int numGenerator, guesses, totalGuesses, rounds, averageGuesses;
bool win;

void closeApp()
{
    delete camera;
    delete font;



    for (auto it = boxes.begin(); it != boxes.end(); ++it)
        delete (*it);


}

void startNewGame()
{
    rounds++;
    win = false;
    guesses = 0;
    numGenerator = rand() % 3;

    boxes[1]->Visible = true;
    boxes[2]->Visible = true;
    boxes[3]->Visible = true;

    if (numGenerator == 0)
    {
        boxes[0]->Position = vec3(0.0f, -3.0f, 0.0f);
    }
    else if (numGenerator == 1)
    {
        boxes[0]->Position = vec3(0.0f, 0.0f, 0.0f);
    }
    else
    {
        boxes[0]->Position = vec3(0.0f, 3.0f, 0.0f);
    }

}

void keyboard(unsigned char key, int x, int y)
{
    switch (key)
    {
        case ESCAPE_KEY:  // ASCII Escape Key Code
            closeApp();
            exit(EXIT_SUCCESS);
            break;
        case 'a':
            boxes[1]->Visible = false;
            if (boxes[0]->Position != vec3(0.0f, -3.0f, 0.0f))
            {
                guesses++;
                totalGuesses++;
            }
            else
            {
                win = true;
            }
            glutPostRedisplay();
            break;
        case 'b':
            boxes[2]->Visible = false;
            if (boxes[0]->Position != vec3(0.0f, 0.0f, 0.0f))
            {
                guesses++;
                totalGuesses++;
            }
            else
            {
                win = true;
            }
            glutPostRedisplay();
            break;
        case 'c':
            boxes[3]->Visible = false;
            if (boxes[0]->Position != vec3(0.0f, 3.0f, 0.0f))
            {
                guesses++;
                totalGuesses++;
            }
            else
            {
                win = true;
            }
            glutPostRedisplay();
            break;
        case 'r':
            startNewGame();
            glutPostRedisplay();
            break;
    }
}



void display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    font->printText("Guessing Game!", 260, 500, 20);
    font->printText("Press 1, 2, or 3 to make one of the boxes disappear!", 10, 480, 15);
    font->printText("Try to find the small cube! Press 'r' to restart!", 30, 460, 15);
    if (win)
    {
        font->printText("You win!", 20, 200, 30);
    }
    font->printText("Guesses: ", 20, 350, 15);
    font->printText("Rounds played: ", 20, 330, 15);
    font->printText("Total guesses: ", 20, 310, 15);
    font->printText("Average guesses: ", 20, 290, 15);



    boxes[0]->Draw(camera->ProjectionMatrix, camera->ViewMatrix);
    boxes[1]->Draw(camera->ProjectionMatrix, camera->ViewMatrix);
    boxes[2]->Draw(camera->ProjectionMatrix, camera->ViewMatrix);
    boxes[3]->Draw(camera->ProjectionMatrix, camera->ViewMatrix);


    glutSwapBuffers();
}

void init()
{
    glClearColor(0.0f, 0.0f, 0.4f, 0.0f);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glEnable(GL_CULL_FACE);

    srand(time(NULL));

    font = new Font();

    camera = new Camera();
    camera->ViewMatrix = glm::lookAt(glm::vec3(0, 0, 20), glm::vec3(0, 0, 0), glm::vec3(0, 1, 0));


    VertexBufferData vertexBufferData = VertexBufferData("Data\\Models\\Objects.xml");

    boxes.push_back(new Box(vertexBufferData, glm::vec3(0.0f, 0.0f, 0.0f), "data/images/wood.bmp", "Data\\Shaders\\Vertex.shader", "Data\\Shaders\\Fragment.shader", vec3(0.4f, 0.4f, 0.4f), true));
    boxes.push_back(new Box(vertexBufferData, glm::vec3(0.0f, -3.0f, 0.0f), "data/images/ground.tga", "Data\\Shaders\\Vertex.shader", "Data\\Shaders\\Fragment.shader", vec3(1.0f, 1.0f, 1.0f), true));
    boxes.push_back(new Box(vertexBufferData,glm::vec3(0.0f, 0.0f, 0.0f), "data/images/metal.bmp", "Data\\Shaders\\Vertex.shader", "Data\\Shaders\\Fragment.shader", vec3(1.0f, 1.0f, 1.0f), true));
    boxes.push_back(new Box(vertexBufferData, glm::vec3(0.0f, 3.0f, 0.0f), "data/images/brick.bmp", "Data\\Shaders\\Vertex.shader", "Data\\Shaders\\Fragment.shader", vec3(1.0f, 1.0f, 1.0f), true));

    startNewGame();
}



int main(int argc, char** argv)
{
    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH);
    glutInitWindowSize(1024, 768);
    glutInitContextProfile(GLUT_CORE_PROFILE);
    glutCreateWindow("Satterwhite_Project_5");


    if (glewInit())
    {
        cerr << "Unable to init glew" << endl;
        exit(EXIT_FAILURE);
    }

    init();
    glutDisplayFunc(display);
    glutKeyboardFunc(keyboard);
    glutMainLoop();
    return 0;
}

最佳答案

您有一个font->printText方法，这很重要，因此打印字符串对您来说不是问题！这意味着，您只需要准备带数字的字符串，然后使用printText打印即可。

在C ++中执行此操作的一种简单方法是使用字符串流。在您的display函数中，而不是font->printText("Guesses: ", 20, 350, 15);中，输入：

std::stringstream ss;
ss << "Guesses: " << guesses;
font->printText(ss.str().c_str(), 20, 350, 15);

并对所有其余数字执行相同的操作。

不要忘记在<sstream>类中包含stringstream。

关于c++ - 如何在OpenGL中输出变量号？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/40393136/