glTexSubImage leads to black texture, while glTexImage works fine - c++

Question

When I bind my image using glTexImage2D, it renders fine.
First, the code in the fragment shader:
uniform sampler2D tex;
in vec2 tex_coord;
// main:
fragment_out = mix(
texture(tex, tex_coord),
vec4(tex_coord.x, tex_coord.y, 0.0, 1.0),
0.5
);
Using this code, it draws the image:
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height,
0, GL_RGBA, GL_UNSIGNED_BYTE, image);
But if I bind it via glTexSubImage2D, the texture is drawn just black.
glTexStorage2D(GL_TEXTURE_2D,
1,
GL_RGBA,
width, height);
glTexSubImage2D(GL_TEXTURE_2D,
0,
0, 0,
width, height,
GL_RGBA,
GL_UNSIGNED_BYTE,
image);
When I replace GL_RGBA with GL_RGBA8 or GL_RGBA16 in the second code, the rendering is distorted.
This is the whole texture loading and binding code:
GLuint texture;
glGenTextures(1, &texture);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture);
int width, height;
unsigned char *image = SOIL_load_image(Resource::getPath("Images/2hehwdv.jpg").c_str(), &width, &height, 0, SOIL_LOAD_RGBA);
std::cout << SOIL_last_result() << std::endl;
std::cout << width << "x" << height << std::endl;
glTexStorage2D(GL_TEXTURE_2D,
1,
GL_RGBA,
width, height);
glTexSubImage2D(GL_TEXTURE_2D,
0,
0, 0,
width, height,
GL_RGBA,
GL_UNSIGNED_BYTE,
image);
//glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glGenerateMipmap(GL_TEXTURE_2D);
Can someone explain this behavior to me?

Answer 1

glTexStorage2D( GL_TEXTURE_2D, 1, GL_RGBA, width, height );
^^^^^^^ not sized
GL_RGBA is an unsized format.
glTexStorage2D()'s internalFormat parameter must be passed a sized internal format.
A glGetError() call after glTexStorage2D() would have returned GL_INVALID_ENUM:
GL_INVALID_ENUM is generated if internalformat is not a valid sized internal format.
Try a sized format from Table 1 like GL_RGBA8.