OpenGL texture not rendering if it's currently active
I was using QOpenGLWidget to render textured triangle, the code was looking good but the triangle was always rendering black i had problem with it for two days until i accidentally found out what the title says.
This is the code, the texture gets loaded to default location of GL_TEXTURE0 and the it will not work unless i call glActiveTexture(GL_TEXTURE1) at the end, GL_TEXTURE1 is just an example it can be any other texture slot except the one where texture actually is. Without the call the object will be black.
glGenTextures(1, &texture); glBindTexture(GL_TEXTURE_2D, texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, ready.width(), ready.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, ready.constBits()); glGenerateMipmap(GL_TEXTURE_2D); glActiveTexture(GL_TEXTURE1);
I've tried some tests, creating multiple textures and displaying them all at once, the last active texture was always black unless i activate some other unoccupied slot.
I don't know what to make of this, i'm begginer in OpenGL and Qt but this doesn't sound right.