Method flip

systemvm/agent/noVNC/core/display.js:253–297

(fromQueue)

    // Update the visible canvas with the contents of the
    // rendering canvas
    flip(fromQueue) {
        if (this._renderQ.length !== 0 && !fromQueue) {
            this._renderQPush({
                'type': 'flip'
            });
        } else {
            let x = this._damageBounds.left;
            let y = this._damageBounds.top;
            let w = this._damageBounds.right - x;
            let h = this._damageBounds.bottom - y;

            let vx = x - this._viewportLoc.x;
            let vy = y - this._viewportLoc.y;

            if (vx < 0) {
                w += vx;
                x -= vx;
                vx = 0;
            }
            if (vy < 0) {
                h += vy;
                y -= vy;
                vy = 0;
            }

            if ((vx + w) > this._viewportLoc.w) {
                w = this._viewportLoc.w - vx;
            }
            if ((vy + h) > this._viewportLoc.h) {
                h = this._viewportLoc.h - vy;
            }

            if ((w > 0) && (h > 0)) {
                // FIXME: We may need to disable image smoothing here
                //        as well (see copyImage()), but we haven't
                //        noticed any problem yet.
                this._targetCtx.drawImage(this._backbuffer,
                                          x, y, w, h,
                                          vx, vy, w, h);
            }

            this._damageBounds.left = this._damageBounds.top = 65535;
            this._damageBounds.right = this._damageBounds.bottom = 0;
        }
    }

    pending() {
        return this._renderQ.length > 0;