Question

尝试在OpenGL桌面中渲染多维数据集，但glVertexAttribPointer(...)的参数对我不起作用。请求建议以使代码正常工作.Below是相关的代码段

<小时/>

struct vertex{
        GLfloat x,y,z;
        GLfloat tU,tV;
    };
    float dim = 1.0f;
    vertex vertexData[] = { 
        -dim, -dim,  dim, 0.0f, 0.0f,
         dim, -dim,  dim, 1.0f, 0.0f,
         dim,  dim,  dim, 1.0f, 1.0f,
        -dim,  dim,  dim, 0.0f, 1.0f,
        -dim, -dim, -dim, 0.0f, 0.0f,
         dim, -dim, -dim, 1.0f, 0.0f,
         dim,  dim, -dim, 1.0f, 1.0f,
        -dim,  dim, -dim, 0.0f, 1.0f,
    };
    #define BUFFER_OFFSET(offset) ((void *)(offset))
    g_vertexLocation = glGetAttribLocation(program, "vertexPosition");
    glEnableVertexAttribArray(g_vertexLocation);
    glBindBuffer(GL_ARRAY_BUFFER, vertexBufferID);
    glVertexAttribPointer(g_vertexLocation,3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
    g_texCoordLocation = glGetAttribLocation(program, "in_texCoord");
    glEnableVertexAttribArray(g_texCoordLocation);
    glBindBuffer(GL_ARRAY_BUFFER, vertexBufferID);
    glVertexAttribPointer(g_texCoordLocation,2, GL_FLOAT, GL_FALSE, 5, BUFFER_OFFSET(3));
GLushort indexData[] = 
    {
       0,1,2,
       0,2,3,
       1,5,6,
       1,6,2,
       2,6,7,
       2,7,3,
       0,3,4,
       3,7,4,
       4,7,5,
       5,7,6,
       1,0,4,
       1,4,5,
    };
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,indexBufferID);
    int size;
    glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_SIZE, &size);
    glDrawElements(GL_TRIANGLES, size/sizeof(GLushort), GL_UNSIGNED_SHORT, 0);

注意：顶点着色器工作正常

Answer 1

缓冲区偏移量以字节为单位计算，因此步幅和位置需要乘以sizeof(float)才能正确。

第一个stride调用的glVertexAttribPointer参数需要是5 * sizeof(float)以及第二个调用：顶点组件位于属性缓冲区的每个5 * sizeof(float)。

OpenGL（使用GLSL）使用自定义顶点数据进行多维数据集渲染

1 个答案: