OpenGL:未绘制地形(高度图）

编辑：我认为问题可能是在加载顶点和索引时。也许重点关注这一部分：）

我正在尝试从bmp文件加载一个高度图，并将其显示在OpenGL中。和我尝试的大多数东西一样，所有东西都编译和运行时没有错误，但屏幕上什么都没有画出来。我似乎不能太多地孤立这个问题，因为所有的代码都是单独工作的，但当结合起来绘制地形时，什么都不起作用。

地形类别

我上地形课。它有2个VBO、1个IBO和1个VAO。它还存储顶点、索引、顶点的颜色和高度。它是从bmp文件加载的。

装载地形：

Terrain* Terrain::loadTerrain(const std::string& filename, float height)
{
    BitMap* bmp = BitMap::load(filename);
    Terrain* t = new Terrain(bmp->width, bmp->length);
    for(unsigned y = 0; y < bmp->length; y++)
    {
        for(unsigned x = 0; x < bmp->width; x++)
        {
            unsigned char color =
                (unsigned char)bmp->pixels[3 * (y * bmp->width + x)];
            float h = height * ((color / 255.0f) - 0.5f);
            t->setHeight(x, y, h);
        }
    }
    delete bmp;
    t->initGL();
    return t;
}

初始化缓冲区：

void Terrain::initGL()
{
    // load vertices from heights data
    vertices = new Vector4f[w * l];
    int vertIndex = 0;
    for(unsigned y = 0; y < l; y++)
    {
        for(unsigned x = 0; x < w; x++)
        {
            vertices[vertIndex++] = Vector4f((float)x, (float)y, heights[y][x], 1.0f);
        }
    }
    // generate indices for indexed drawing
    indices = new GLshort[(w - 1) * (l - 1) * 6]; // patch count * 6 (2 triangles per terrain patch)
    int indicesIndex = 0;
    for(unsigned y = 0; y < (l - 1); ++y)
    {
        for(unsigned x = 0; x < (w - 1); ++x)
        {
            int start = y * w + x;
            indices[indicesIndex++] = (GLshort)start;
            indices[indicesIndex++] = (GLshort)(start + 1);
            indices[indicesIndex++] = (GLshort)(start + w);
            indices[indicesIndex++] = (GLshort)(start + 1);
            indices[indicesIndex++] = (GLshort)(start + 1 + w);
            indices[indicesIndex++] = (GLshort)(start + w);
        }
    }
    // generate colours for the vertices
    colours = new Vector4f[w * l];
    for(unsigned i = 0; i < w * l; i++)
    {
        colours[i] = Vector4f(0.0f, 1.0f, 0.0f, 1.0f); // let's make the entire terrain green
    }
    // THIS CODE WORKS FOR CUBES (BEGIN)
    // vertex buffer object
    glGenBuffers(1, &vbo);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    // index buffer object
    glGenBuffers(1, &ibo);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    // colours vertex buffer object
    glGenBuffers(1, &colour_vbo);
    glBindBuffer(GL_ARRAY_BUFFER, colour_vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(colours), colours, GL_STATIC_DRAW);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    // create vertex array object
    glGenVertexArrays(1, &vao);
    glBindVertexArray(vao);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);
    glBindBuffer(GL_ARRAY_BUFFER, colour_vbo);
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, 0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
    glBindVertexArray(0);
    // THIS CODE WORKS FOR CUBES (END)
}

我创建VBO、IBO和VAO的部分适用于立方体，它们绘制得很好。

渲染地形：

void Terrain::render()
{
    glUseProgram(shaderProgram);
    glBindVertexArray(vao);
    int indices_length = (w - 1) * (l - 1) * 6;
    glDrawElements(GL_TRIANGLES, indices_length, GL_UNSIGNED_SHORT, 0);
}

着色器

这些是顶点着色器和片段着色器。

顶点：

#version 330
layout (location = 0) in vec4 position;
layout (location = 1) in vec4 vertexColour;
out vec4 fragmentColour;
uniform vec3 offset;
uniform mat4 perspectiveMatrix;
void main()
{
    vec4 cameraPos = position + vec4(offset.x, offset.y, offset.z, 0.0);
    gl_Position = perspectiveMatrix * cameraPos;
    fragmentColour = vertexColour;
}

片段：

#version 330
in vec4 fragmentColour;
out vec4 outputColour;
void main()
{
    outputColour = fragmentColour;
}

透视矩阵

以下是"相机"的设置：

struct CameraSettings
{
    static const float FRUSTUM_SCALE = 1.0f;
    static const float Z_NEAR = 0.5f;
    static const float Z_FAR = 3.0f;
    static float perspective_matrix[16];
};
float CameraSettings::perspective_matrix[16] = {
    FRUSTUM_SCALE,
        0, 0, 0, 0,
        FRUSTUM_SCALE,
        0, 0, 0, 0,
        (Z_FAR + Z_NEAR) / (Z_NEAR - Z_FAR),
        -1.0f,
        0, 0,
        (2 * Z_FAR * Z_NEAR) / (Z_NEAR - Z_FAR),
        0
};

制服在initGL()被称为后填写

// get offset uniform
    offsetUniform = ShaderManager::getUniformLocation(shaderProgram, "offset");
    perspectiveMatrixUniform = ShaderManager::getUniformLocation(shaderProgram, "perspectiveMatrix");
    // set standard uniform data
    glUseProgram(shaderProgram);
    glUniform3f(offsetUniform, xOffset, yOffset, zOffset);
    glUniformMatrix4fv(perspectiveMatrixUniform, 1, GL_FALSE, CameraSettings::perspective_matrix);
    glUseProgram(0);

有人能检查一下我的代码并提出建议吗？