Question

我的程序的目标是使用VBO显示旋转的简单三角形。程序在glDrawArrays调用时失败（分段错误）。这是我的c ++代码的一部分：

#include <iostream>
#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include <gl/glew.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

#define OFFSET_BUFFER(offset)   ((char*)NULL + (offset))

GLfloat angle = 0.0f;

const static int WIDTH = 500;
const static int HEIGHT = 500;

struct Vertex
{
    float x, y, z;
    float nx, ny, nz;
    float s0, t0;
};

Vertex vertices[3] =
{
    1.000000f, -1.000000f, -1.000000f,
    0.000000f, -1.000000f, 0.000000f,
    0.626059f, 0.734295f,

    1.000000f, -1.000000f, 1.000000f,
    0.000000f, -1.000000f, 0.000000f,
    0.626059f, 0.512602f,

    -1.000000f, -1.000000f, 1.000000f,
    0.000000f, -1.000000f, 0.000000f,
    0.404365f, 0.512602f,
};

[...]

static GLuint       applyVBO(void)
{
    GLuint          vboID;

    glGenBuffers(1, &vboID);
    glBindBuffer(GL_VERTEX_ARRAY, vboID);
    glBufferData(GL_VERTEX_ARRAY, 3 * sizeof(Vertex), &vertices[0], GL_STATIC_DRAW);
    glBindBuffer(GL_VERTEX_ARRAY, NULL);
    return (vboID);
}

int                 main(int ac, char **av)
{
    bool            continuer = true;
    SDL_Event       event;

    SDL_Init(SDL_INIT_VIDEO);
    SDL_WM_SetCaption("VBO tests",NULL);
    SDL_SetVideoMode(WIDTH, HEIGHT, 32, SDL_OPENGL);

    if (glewInit() != GLEW_OK)
        return (-1);

    glEnable(GL_DEPTH_TEST);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    //glEnable(GL_NORMALIZE);

    //Initialize projection

    glViewport(0, 0, WIDTH, HEIGHT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0, (float)WIDTH/(float)HEIGHT, 1.0f, 100.0f);
    gluLookAt(0.0f, 0.0f, 8.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f);

    //Initialize VBO

    GLuint vboID = applyVBO();

    //Initialize uv-mapping

    GLuint texID = applyTexture("Box.bmp");

    //Initialize camera

    //Main loop

    while (continuer)
    {
        eventListener(&event, &continuer);

        glClearDepth(1.0f);
        glClearColor(0.13f, 0.12f, 0.13f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

        glPushMatrix();
        glRotatef(angle, 1.0f, 1.0f, 1.0f);

        glBindBuffer(GL_VERTEX_ARRAY, vboID);

        glEnableClientState(GL_VERTEX_ARRAY);
        glVertexPointer(3, GL_FLOAT, sizeof(Vertex), OFFSET_BUFFER(0));
        glEnableClientState(GL_NORMAL_ARRAY);
        glNormalPointer(GL_FLOAT, sizeof(Vertex), OFFSET_BUFFER(12));
        glEnableClientState(GL_TEXTURE_COORD_ARRAY);
        glBindTexture(GL_TEXTURE_2D, texID);
        glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), OFFSET_BUFFER(24));

        glDrawArrays(GL_TRIANGLES, 0, 3);

        glBindTexture(GL_TEXTURE_2D, NULL);
        glBindBuffer(GL_VERTEX_ARRAY, NULL);

        glDisableClientState(GL_TEXTURE_COORD_ARRAY);
        glDisableClientState(GL_NORMAL_ARRAY);
        glDisableClientState(GL_VERTEX_ARRAY);

        angle += 0.50f;
        glPopMatrix();

        glFlush();
        SDL_GL_SwapBuffers();
    }

    SDL_Quit();
    return (0);
}

有人可以帮助我吗？

Answer 1

问题来自于GL_VERTEX_ARRAY标志不是好的标志。它们必须由GL_ARRAY_BUFFER替换。

glDrawArrays使用VBO失败

1 个答案: