glGenVertexArrays(1,& vao)的分段错误;

时间:2011-11-28 21:32:24

标签: c++ debugging opengl segmentation-fault

我的gdb backtrace给出了:

(gdb) backtrace
#0  0x00000000 in ?? ()
#1  0x0804a211 in init () at example1.cpp:147
#2  0x0804a6bc in main (argc=1, argv=0xbffff3d4) at example1.cpp:283

信息量不大。 Eclipse调试器至少让我看到它停在下面的第3行:

// Create a vertex array object
GLuint vao;
glGenVertexArrays( 1, &vao );
glBindVertexArray( vao );

这是在gl编程中看到的一个非常常见的块,我甚至可以使用相同的块运行其他代码而没有任何问题。所以我很困惑。

从运行make:

构建输出
g++ -g -DFREEGLUT_STATIC -DGLEW_STATIC -I../../include example1.cpp ../../Commo/InitShader.o  -L/usr/lib/mesa -lGLEW -lglut -lGL -lX11  -lm  -o example1

包含问题的程序:

// rotating cube with two texture objects
// change textures with 1 and 2 keys

#include "Angel.h"

const int  NumTriangles = 12; // (6 faces)(2 triangles/face)
const int  NumVertices  = 3 * NumTriangles;
const int  TextureSize  = 64;

typedef Angel::vec4 point4;
typedef Angel::vec4 color4;

// Texture objects and storage for texture image
GLuint textures[2];

GLubyte image[TextureSize][TextureSize][3];
GLubyte image2[TextureSize][TextureSize][3];

// Vertex data arrays
point4  points[NumVertices];
color4  quad_colors[NumVertices];
vec2    tex_coords[NumVertices];

// Array of rotation angles (in degrees) for each coordinate axis
enum { Xaxis = 0, Yaxis = 1, Zaxis = 2, NumAxes = 3 };
int      Axis = Xaxis;
GLfloat  Theta[NumAxes] = { 0.0, 0.0, 0.0 };
GLuint   theta;

//----------------------------------------------------------------------------
int Index = 0;
void quad( int a, int b, int c, int d )
{
    point4 vertices[8] = {
        point4( -0.5, -0.5,  0.5, 1.0 ),
        point4( -0.5,  0.5,  0.5, 1.0 ),
        point4(  0.5,  0.5,  0.5, 1.0 ),
        point4(  0.5, -0.5,  0.5, 1.0 ),
        point4( -0.5, -0.5, -0.5, 1.0 ),
        point4( -0.5,  0.5, -0.5, 1.0 ),
        point4(  0.5,  0.5, -0.5, 1.0 ),
        point4(  0.5, -0.5, -0.5, 1.0 )
    };

    color4 colors[8] = {
        color4( 0.0, 0.0, 0.0, 1.0 ),  // black
        color4( 1.0, 0.0, 0.0, 1.0 ),  // red
        color4( 1.0, 1.0, 0.0, 1.0 ),  // yellow
        color4( 0.0, 1.0, 0.0, 1.0 ),  // green
        color4( 0.0, 0.0, 1.0, 1.0 ),  // blue
        color4( 1.0, 0.0, 1.0, 1.0 ),  // magenta
        color4( 0.0, 1.0, 1.0, 1.0 ),  // white
        color4( 1.0, 1.0, 1.0, 1.0 )   // cyan
    };

    quad_colors[Index] = colors[a];
    points[Index] = vertices[a];
    tex_coords[Index] = vec2( 0.0, 0.0 );
    Index++;

    quad_colors[Index] = colors[a];
    points[Index] = vertices[b];
    tex_coords[Index] = vec2( 0.0, 1.0 );
    Index++;

    quad_colors[Index] = colors[a];
    points[Index] = vertices[c];
    tex_coords[Index] = vec2( 1.0, 1.0 );
    Index++;

    quad_colors[Index] = colors[a];
    points[Index] = vertices[a];
    tex_coords[Index] = vec2( 0.0, 0.0 );
    Index++;

    quad_colors[Index] = colors[a];
    points[Index] = vertices[c];
    tex_coords[Index] = vec2( 1.0, 1.0 );
    Index++;

    quad_colors[Index] = colors[a];
    points[Index] = vertices[d];
    tex_coords[Index] = vec2( 1.0, 0.0 );
    Index++;
}

//----------------------------------------------------------------------------
void colorcube()
{
    quad( 1, 0, 3, 2 );
    quad( 2, 3, 7, 6 );
    quad( 3, 0, 4, 7 );
    quad( 6, 5, 1, 2 );
    quad( 4, 5, 6, 7 );
    quad( 5, 4, 0, 1 );
}

//----------------------------------------------------------------------------
void init()
{
    colorcube();

    // Create a checkerboard pattern
    for ( int i = 0; i < 64; i++ ) {
        for ( int j = 0; j < 64; j++ ) {
            GLubyte c = (((i & 0x8) == 0) ^ ((j & 0x8)  == 0)) * 255;
            image[i][j][0]  = c;
            image[i][j][1]  = c;
            image[i][j][2]  = c;
            image2[i][j][0] = c;
            image2[i][j][1] = 0;
            image2[i][j][2] = c;
        }
    }

    // Initialize texture objects
    glGenTextures( 2, textures );

    glBindTexture( GL_TEXTURE_2D, textures[0] );
    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, TextureSize, TextureSize, 0,
        GL_RGB, GL_UNSIGNED_BYTE, image );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );

    glBindTexture( GL_TEXTURE_2D, textures[1] );
    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, TextureSize, TextureSize, 0,
        GL_RGB, GL_UNSIGNED_BYTE, image2 );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );

    glActiveTexture( GL_TEXTURE0 );
    glBindTexture( GL_TEXTURE_2D, textures[0] );

    // Create a vertex array object
    GLuint vao;
    glGenVertexArrays( 1, &vao );
    glBindVertexArray( vao );

    // Create and initialize a buffer object
    GLuint buffer;
    glGenBuffers( 1, &buffer );
    glBindBuffer( GL_ARRAY_BUFFER, buffer );
    glBufferData( GL_ARRAY_BUFFER,
        sizeof(points) + sizeof(quad_colors) + sizeof(tex_coords),
        NULL, GL_STATIC_DRAW );

    // Specify an offset to keep track of where we're placing data in our
    //   vertex array buffer.  We'll use the same technique when we
    //   associate the offsets with vertex attribute pointers.
    GLintptr offset = 0;
    glBufferSubData( GL_ARRAY_BUFFER, offset, sizeof(points), points );
    offset += sizeof(points);

    glBufferSubData( GL_ARRAY_BUFFER, offset,
        sizeof(quad_colors), quad_colors );
    offset += sizeof(quad_colors);

    glBufferSubData( GL_ARRAY_BUFFER, offset, sizeof(tex_coords), tex_coords );

    // Load shaders and use the resulting shader program
    GLuint program = InitShader( "vshader71.glsl", "fshader71.glsl" );
    glUseProgram( program );

    // set up vertex arrays
    offset = 0;
    GLuint vPosition = glGetAttribLocation( program, "vPosition" );
    glEnableVertexAttribArray( vPosition );
    glVertexAttribPointer( vPosition, 4, GL_FLOAT, GL_FALSE, 0,
        BUFFER_OFFSET(offset) );
    offset += sizeof(points);

    GLuint vColor = glGetAttribLocation( program, "vColor" ); 
    glEnableVertexAttribArray( vColor );
    glVertexAttribPointer( vColor, 4, GL_FLOAT, GL_FALSE, 0,
        BUFFER_OFFSET(offset) );
    offset += sizeof(quad_colors);

    GLuint vTexCoord = glGetAttribLocation( program, "vTexCoord" );
    glEnableVertexAttribArray( vTexCoord );
    glVertexAttribPointer( vTexCoord, 2, GL_FLOAT, GL_FALSE, 0,
        BUFFER_OFFSET(offset) );

    // Set the value of the fragment shader texture sampler variable
    //   ("texture") to the the appropriate texture unit. In this case,
    //   zero, for GL_TEXTURE0 which was previously set by calling
    //   glActiveTexture().
    glUniform1i( glGetUniformLocation(program, "texture"), 0 );

    theta = glGetUniformLocation( program, "theta" );

    glEnable( GL_DEPTH_TEST );

    glClearColor( 1.0, 1.0, 1.0, 1.0 );
}

void display( void )
{
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    glUniform3fv( theta, 1, Theta );

    glDrawArrays( GL_TRIANGLES, 0, NumVertices );

    glutSwapBuffers();
}

//----------------------------------------------------------------------------
void mouse( int button, int state, int x, int y )
{
    if ( state == GLUT_DOWN ) {
        switch( button ) {
        case GLUT_LEFT_BUTTON:    Axis = Xaxis;  break;
        case GLUT_MIDDLE_BUTTON:  Axis = Yaxis;  break;
        case GLUT_RIGHT_BUTTON:   Axis = Zaxis;  break;
        }
    }
}

//----------------------------------------------------------------------------
void idle( void )
{
    Theta[Axis] += 0.01;

    if ( Theta[Axis] > 360.0 ) {
        Theta[Axis] -= 360.0;
    }

    glutPostRedisplay();
}

//----------------------------------------------------------------------------
void keyboard( unsigned char key, int mousex, int mousey )
{
    switch( key ) {
    case 033: // Escape Key
    case 'q': case 'Q':
        exit( EXIT_SUCCESS );
        break;
    case '1':
        glBindTexture( GL_TEXTURE_2D, textures[0] );
        break;

    case '2':
        glBindTexture( GL_TEXTURE_2D, textures[1] );
        break;
    }

    glutPostRedisplay();
}

//----------------------------------------------------------------------------
int main( int argc, char **argv )
{
    glutInit( &argc, argv );
    glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH );
    glutInitWindowSize( 512, 512 );
    glutInitContextVersion( 3, 2 );
    glutInitContextProfile( GLUT_CORE_PROFILE );
    glutCreateWindow( "Color Cube" );

    glewInit();

    init();

    glutDisplayFunc( display );
    glutKeyboardFunc( keyboard );
    glutMouseFunc( mouse );
    glutIdleFunc( idle );

    glutMainLoop();
    return 0;
}

4 个答案:

答案 0 :(得分:125)

glewExperimental = GL_TRUE; 
glewInit();

应该做的魔术


<强> Experimental Drivers

  

GLEW从图形中获取有关受支持的扩展的信息   驱动程序。但是,实验或预发布驱动程序可能不会报告   通过标准机制的每个可用扩展,其中   案例GLEW将报告它不受支持。为了规避这种情况,   可以通过将glewExperimental全局开关设置为打开来打开它   在调用GL_TRUE之前glewInit(),确保所有扩展   有效的入境点将被曝光。

答案 1 :(得分:1)

对我来说很好:

screenshot

GL_VERSION  : 4.1.10750 Compatibility Profile Context
GL_VENDOR   : ATI Technologies Inc.
GL_RENDERER : AMD Radeon HD 6500 Series

编辑:我使用的是最新版本的FreeGLUT(2.8.0 RC2)和GLEW(1.7.0),如果您依赖于发行版提供的版本,这可能会有所不同

答案 2 :(得分:0)

您是否尝试过使用不同显卡的其他系统进行测试?如果您的代码符合OpenGL规范,并且在使用有效参数正确调用的函数内部神秘地崩溃,则很可能是驱动程序错误。如果它是一个驱动程序错误,你就会减少猜测,做出霰弹枪的改变,并逐渐建立一个健康的愤怒,一个拥有数十亿美元的大公司为显卡驱动程序提供绝对的废话借口。祝你好运!

答案 3 :(得分:0)

例如,Ubuntu 10.04带有glew 1.50,glGenVertexArrays在没有glewExperimental标志的情况下无效。 所以它依赖于glew版本