现代OpenGL 3.3核心黑色纹理

我正在尝试使用OpenGL绘制PNG文件，并且似乎对如何设置纹理有问题。

main.cpp：

float positions[] = {
    -1.0f, -1.0f,
    0.0f, 1.0f,
    1.0f, 1.0f,
};
float texCoords[] = {
    -1.0f, -1.0f,
    -1.0f, 1.0f,
    1.0f, 1.0f,
};

unsigned int buffer;
glGenBuffers(1, &buffer);
glBindBuffer(GL_ARRAY_BUFFER, buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(positions), positions, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
unsigned int texBuffer;
glGenBuffers(1, &texBuffer);
glBindBuffer(GL_ARRAY_BUFFER, texBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(texCoords), texCoords, GL_STATIC_DRAW);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
int w;
int h;
int comp;
unsigned char* image = stbi_load("res/images/background_level.png", &w, &h, &comp, STBI_rgb_alpha);
if (image == nullptr)
    throw(std::string("Failed to load texture"));
//std::cout << image << std::endl;
unsigned int m_texture;
glGenTextures(1, &m_texture);
glBindTexture(GL_TEXTURE_2D, m_texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
if (comp == 3)
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
else if (comp == 4)
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, image);
glBindTexture(GL_TEXTURE_2D, 0);
stbi_image_free(image);

/* Loop until the user closes the window */
while (!glfwWindowShouldClose(window))
{
    /* Render here */
    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT);
    // draw our first triangle
    glUseProgram(programID);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, 0);
    int uniformLoc = glGetUniformLocation(programID, "tex");
    glUniform1i(uniformLoc, 0);
    glDrawArrays(GL_TRIANGLES, 0, 3);

    /* Swap front and back buffers */
    glfwSwapBuffers(window);
    /* Poll for and process events */
    glfwPollEvents();
}

vertex.shader：

#shader VERTEX
#version 330 core
layout (location=0) in vec2 vert;
layout (location=1) in vec2 vertTexCoord;
out vec2 fragTexCoord;
void main() {
    // Pass the tex coord straight through to the fragment shader
    fragTexCoord = vertTexCoord;
    gl_Position = vec4(vert, 0, 1);
}

fragment.shader：

#shader FRAGMENT
#version 330 core
uniform sampler2D tex; //this is the texture
in vec2 fragTexCoord; //this is the texture coord
out vec4 finalColor; //this is the output color of the pixel
void main() {
    //finalColor = vec4(1.0, 1.0, 1.0, 1.0);
    finalColor = texture(tex, fragTexCoord);
}

如果我在片段着色器中交换了线条，我会呈现一个全白三角。但是，随着线条试图使用纹理，三角形出现了全黑。我只是从OpenGL开始，所以我不一定会将所有开始概念放在PAT上。纹理可能领先于我的技能水平，但我认为尝试在这里询问这不会有什么伤害