OpenGLES 2球体不会绘制

Question

我正试图在iOS上用OpenGL绘制一个球体。我在下面创建了一个球类。然后我设置并绘制球体。但是，根本没有任何吸引力。

我试过不使用VBO，仍然无法正常工作。我检查了我的VBO是否已创建，它是。

没有崩溃或错误。它只是没有画。我做错了什么？

class Sphere
{
private:
    std::vector<GLVertex> vertices;
    GLuint vbo;
    GLuint count;

public:
    Sphere(float radius, float step)
    {
        #define DEGREES_TO_RADIANS(value) (value * M_PI / 180.0)

        GLfloat uStep = DEGREES_TO_RADIANS(step);
        GLfloat vStep = uStep;

        for (GLfloat u = 0.0f; u <= (2 * M_PI); u += uStep) {
            for (GLfloat v = -M_PI_2; v <= M_PI_2; v += vStep) {
                float x = radius * cosf(v) * cosf(u);
                float y = radius * cosf(v) * sinf(u);
                float z = radius * sinf(v);
                vertices.push_back({{x, y, z}, {1, 0, 0, 1}});

                x = radius * cosf(v) * cosf(u + uStep);
                y = radius * cosf(v) * sinf(u + uStep);
                z = radius * sinf(v);
                vertices.push_back({{x, y, z}, {1, 0, 0, 1}});



                x = radius * cosf(v + vStep) * cosf(u);
                y = radius * cosf(v + vStep) * sinf(u);
                z = radius * sinf(v + vStep);
                vertices.push_back({{x, y, z}, {1, 0, 0, 1}});

                x = radius * cosf(v + vStep) * cosf(u + uStep);
                y = radius * cosf(v + vStep) * sinf(u + uStep);
                z = radius * sinf(v + vStep);
                vertices.push_back({{x, y, z}, {1, 0, 0, 1}});
            }
        }

        count = vertices.size();
        glGenBuffers(1, &vbo);
        glBindBuffer(GL_ARRAY_BUFFER, vbo);
        glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(GLVertex), vertices.data(), GL_STATIC_DRAW);
        glBindBuffer(GL_ARRAY_BUFFER, 0);
    }

    ~Sphere()
    {
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glDeleteBuffers(1, &vbo);
    }

    void draw(float x, float y, float z)
    {
        glPushMatrix();
        glTranslatef(x, y, z);


        glEnableClientState(GL_VERTEX_ARRAY);
        glBindBuffer(GL_ARRAY_BUFFER, vbo);
        glVertexPointer(3, GL_FLOAT, sizeof(GLVertex), 0);
        glColor4f(1, 1, 1, 1);
        glDrawArrays(GL_POINTS, 0, count);
        glDisableClientState(GL_VERTEX_ARRAY);

        glPopMatrix();
    }
};

然后我像这样设置和绘制：

glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
glClearColor(0, 104.0/255.0, 55.0/255.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glClearStencil(0);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);


GLKMatrix4 projection = GLKMatrix4MakePerspective(60.0, self.bounds.size.width / self.bounds.size.height, 1.0, 100);
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(&projection.m[0]);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();


static Sphere sphere(20, 30);
sphere.draw(0, 0, -5);

[_context presentRenderbuffer:GL_RENDERBUFFER];