Mip-Mapping for zoom-out

[eafurst]

Useful snippets:

auto glGenerateMipmap = (void(*)(GLenum))glfwGetProcAddress("glGenerateMipmap");
assert(glGenerateMipmap);

glBindTexture(GL_TEXTURE_2D, idTex);
    glTexImage2D(GL_TEXTURE_2D, ...)
    glGenerateMipMap(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);