opengl 画扇形

        glColor4f(0.0f, 0.0f, 0.0f, 0.35f);        // 设置为Array        glDisable(GL_TEXTURE_2D);        glDisableClientState(GL_TEXTURE_COORD_ARRAY);        glDisableClientState(GL_COLOR_ARRAY);        GLfloat *vertices = malloc(2 * sizeof(GLfloat) * (angle + 1));        vertices[0] = 0;        vertices[1] = 0;         for(int i = 0;i < angle; i++)        {            GLfloat x = r * cosf(CC_DEGREES_TO_RADIANS(i));            GLfloat y = r * sinf(CC_DEGREES_TO_RADIANS(i));                        vertices[i * 2 + 2] = x;            vertices[i * 2 + 2 + 1] = y;        }                   glDisable(GL_TEXTURE_2D);        glDisableClientState(GL_TEXTURE_COORD_ARRAY);        glDisableClientState(GL_COLOR_ARRAY);                glVertexPointer(2, GL_FLOAT, 0, vertices);        glDrawArrays(GL_TRIANGLE_FAN, 0, (GLsizei)(angle + 2));            // restore default state        glEnableClientState(GL_COLOR_ARRAY);        glEnableClientState(GL_TEXTURE_COORD_ARRAY);        glEnable(GL_TEXTURE_2D);        free( vertices );