When its translated in an integral value (1,2,3, etc....), there are no black lines in-between the tiles, it looks fine. But when it's translated to a non-integral (1.1, 1.5, 1.67), there are small blackish lines between each tile (I'm imagining that it's due to subpixel rendering, right?) ... and it doesn't look pretty =P

So... what should I do?

This is my image-loading code, by the way:

bool Image::load_opengl() {
    this->id = 0;

    glGenTextures(1, &this->id);

    this->bind();

    // Parameters... TODO: Should we change this?
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, this->size.x, this->size.y,
   0, GL_BGRA, GL_UNSIGNED_BYTE, (void*) FreeImage_GetBits(this->data));

    this->unbind();

    return true;
}

I've also tried using:

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

and:

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

Here is my image drawing code:

void Image::draw(Pos pos, CROP crop, SCALE scale) {
    if (!this->loaded || this->id == 0) {
        return;
    }

    // Start position & size
    Pos s_p;
    Pos s_s;

    // End size
    Pos e_s;

    if (crop.active) {
        s_p = crop.pos / this->size;
        s_s = crop.size / this->size;
        //debug("%f %f", s_s.x, s_s.y);
        s_s = s_s + s_p;
        s_s.clamp(1);
        //debug("%f %f", s_s.x, s_s.y);
    } else {
        s_s = 1;
    }

    if (scale.active) {
        e_s = scale.size;
    } else if (crop.active) {
        e_s = crop.size;
    } else {
        e_s = this->size;
    }

    // FIXME: Is this okay?
    s_p.y = 1 - s_p.y;
    s_s.y = 1 - s_s.y;

    // TODO: Make this use VAO/VBO's!!
    glPushMatrix();

        glTranslate(pos.x, pos.y, 0);

        this->bind();

        glBegin(GL_QUADS);

            glTexCoord2(s_p.x, s_p.y);
            glVertex2(0, 0);

            glTexCoord2(s_s.x, s_p.y);
            glVertex2(e_s.x, 0);

            glTexCoord2(s_s.x, s_s.y);
            glVertex2(e_s.x, e_s.y);

            glTexCoord2(s_p.x, s_s.y);
            glVertex2(0, e_s.y);

        glEnd();

        this->unbind();

    glPopMatrix();
}

OpenGL Initialization code:

void game__gl_init() {
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, config.window.size.x, config.window.size.y, 0.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glDisable(GL_DEPTH_TEST);
    glEnable(GL_BLEND);
    glEnable(GL_TEXTURE_2D);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

Screenshots of the issue: