Question

我正在尝试使用glutBitmapCharacter()使用OpenGL，FreeGlut进行简单的文本输出。我的问题是，我没有显示任何文字。三角形工作正常。我想问题不是displayText()函数本身，但我可能在错误的地方调用它或重绘/清除文本？我用gcc main.c -lGL -lglut -o filename

编译

#include <stdio.h>
#include <string.h>
#include <GL/freeglut.h>


int WindowHeight = 500;
int WindowWidth = 500;

void displayText(float x, float y, int r, int g, int b, const char *string) {

    int j = strlen(string);
    glColor3f(r, g, b);
    glRasterPos2f(x, y);
    for (int i = 0; i < j; i++) {
        glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, string[i]);
    }
    printf("Lange: %i - Raster: %f %f", j, x, y);

}

void keyboard(unsigned char key, int x, int y) {
    if (key == 27)
        exit(0);
    else
        printf("Sie haben %c gedruckt.\n", key);
}

void display(void) {


    glClearColor(1.0, 1.0, 1.0, 0);
    glClear(GL_COLOR_BUFFER_BIT);

    glLoadIdentity();

    glBegin(GL_LINE_LOOP);
    glVertex3f(-0.3, -0.3, 0);
    glVertex3f(0, 0.3, 0);
    glVertex3f(0.3, -0.3, 0);
    glEnd();

    displayText(200, 200, 0, 0, 255, "test");

    glFlush();
}

int main(int argc, char **argv) {


    glutInit(&argc, argv);
    glutInitWindowSize(WindowWidth, WindowHeight);
    glutInitWindowPosition(0, 0);
    glutCreateWindow("Test");

    glutDisplayFunc(display);
    glutKeyboardFunc(keyboard);

    glutMainLoop();
    return 0;
}

Answer 1

glWindowPos()考虑当前的矩阵堆栈，切换到(200, 200)（直接在窗口坐标中工作，绕过矩阵堆栈和视口变换）或更改模型视图/投影矩阵以生成转换Connector protocol="org.apache.coyote.http11.Http11NioProtocol" port="8443" maxThreads="200" scheme="https" secure="true" SSLEnabled="true" keystoreFile="tomcat.keystore" keystorePass="secret" clientAuth="false" ciphers="TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA" sslProtocol="TLSv1.2"不在屏幕外的地方。

glutBitmapCharacter（）没有显示任何内容？

1 个答案: