void text(string str)
{
    for (int i = 0; i < str.length(); i++)
    {
        glColor3f(0.0f, 0.0f, 0.0f);
        glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24, str[i]);
    }
}

void render(void)
{
    int width  = glutGet(GLUT_WINDOW_WIDTH);
    int height = glutGet(GLUT_WINDOW_HEIGHT);
    if (height == 0) height = 1;
    GLfloat aspect = (GLfloat)width / (GLfloat)height;

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_SCISSOR_TEST);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0f, aspect, 0.1f, 100.0f);

    // Top view - top left
    glViewport(0, 0, width/2, height/2);
    glScissor(0, 0, width/2, height/2);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    PilotView(0.0f, 0.0f, -5.0f, 0.0f, 0.0f, 0.0f, 1.0f);
    glRasterPos3f(-0.1f, -0.1f, 4.0f);
    text("Front");
    diode();

    // Corner view - top right
    glViewport(width/2, 0, width/2, height/2);
    glScissor(width/2, 0, width/2, height/2);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    PilotView(0.0f, 0.0f, -5.0f, 0.0f, -90.0f, 0.0f, 1.0f);
    glRasterPos3f(4.0f, -0.1f, 0.1f);
    text("Right");
    diode();

    // Front view - bottom left
    glViewport(0, height/2, width/2, height/2);
    glScissor(0, height/2, width/2, height/2);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    PilotView(0.0f, 0.0f, -5.0f, 90.0f, 0.0f, 0.0f, 1.0f);
    glRasterPos3f(-0.1f, 4.0f, 0.0f);
    text("Top");
    diode();

    // Right view - bottom right
    glViewport(width/2, height/2, width/2, height/2);
    glScissor(width/2, height/2, width/2, height/2);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    PilotView(0.0f, 0.0f, -5.0f, 20.0f, 0.0f, 0.0f, 1.0f);
    glRasterPos3f(-0.1f, 4.0f, 0.0f);
    text("Fro4nt");
    diode();

    glDisable(GL_SCISSOR_TEST);
    glutSwapBuffers();
}

我不确定白色“前”和黄色“上” /“右”的来源(就颜色而言)。他们都应该是黑色的。有人知道这个问题是什么吗?

输出如下所示:

最佳答案

令人怀疑,这可能会令人震惊,但是当您调用该函数时,glRasterPos (...)实际上会跟踪“当前”颜色。也就是说,在调用glRasterPos (...)之前设置的任何颜色都将用作该位置上绘制操作的“当前颜色”。我将在下面解释,将其几乎视为光栅化器与glVertex (...)的类似物。

为此,您需要先设置当前颜色,然后再调用glRasterPos (...),为此,您应该从glColor3f (...)函数中完全删除text (...)调用,或者修改该函数以同时执行这两种操作-设置颜色,然后设置栅格pos,然后绘制文本。

glRasterPos — specify the raster position for pixel operations:

关于c++ - 文字颜色不正确,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/20365304/

10-12 17:24
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