修改为宽度比例，其实是通过修改logicalDisplay参数方法修改...

zangcf

1，修改成新的之后，copy图片无效了？是什么原因呢？

zangcf

    public void updateLocked(List<DisplayDevice> devices) {
        // Nothing to update if already invalid.
        if (mPrimaryDisplayDevice == null) {
            return;
        }

        // Check whether logical display has become invalid.
        if (!devices.contains(mPrimaryDisplayDevice)) {
            mPrimaryDisplayDevice = null;
            return;
        }

        // Bootstrap the logical display using its associated primary physical display.
        // We might use more elaborate configurations later.  It's possible that the
        // configuration of several physical displays might be used to determine the
        // logical display that they are sharing.  (eg. Adjust size for pixel-perfect
        // mirroring over HDMI.)
        DisplayDeviceInfo deviceInfo = mPrimaryDisplayDevice.getDisplayDeviceInfoLocked();
        if (!Objects.equal(mPrimaryDisplayDeviceInfo, deviceInfo)) {
            mBaseDisplayInfo.layerStack = mLayerStack;
            mBaseDisplayInfo.flags = 0;
            if ((deviceInfo.flags & DisplayDeviceInfo.FLAG_SUPPORTS_PROTECTED_BUFFERS) != 0) {
                mBaseDisplayInfo.flags |= Display.FLAG_SUPPORTS_PROTECTED_BUFFERS;
            }
            if ((deviceInfo.flags & DisplayDeviceInfo.FLAG_SECURE) != 0) {
                mBaseDisplayInfo.flags |= Display.FLAG_SECURE;
            }
            if ((deviceInfo.flags & DisplayDeviceInfo.FLAG_PRIVATE) != 0) {
                mBaseDisplayInfo.flags |= Display.FLAG_PRIVATE;
            }
            if ((deviceInfo.flags & DisplayDeviceInfo.FLAG_PRESENTATION) != 0) {
                mBaseDisplayInfo.flags |= Display.FLAG_PRESENTATION;
            }
            mBaseDisplayInfo.type = deviceInfo.type;
            mBaseDisplayInfo.address = deviceInfo.address;
            mBaseDisplayInfo.name = deviceInfo.name;
            mBaseDisplayInfo.appWidth = deviceInfo.width;
            mBaseDisplayInfo.appHeight = deviceInfo.height;
            mBaseDisplayInfo.logicalWidth = deviceInfo.width;        //zcfdebug
            mBaseDisplayInfo.logicalHeight = deviceInfo.height/2;        //zcfdebug
            mBaseDisplayInfo.rotation = Surface.ROTATION_0;
            mBaseDisplayInfo.refreshRate = deviceInfo.refreshRate;
            mBaseDisplayInfo.supportedRefreshRates = Arrays.copyOf(
                    deviceInfo.supportedRefreshRates, deviceInfo.supportedRefreshRates.length);
            mBaseDisplayInfo.logicalDensityDpi = deviceInfo.densityDpi;
            mBaseDisplayInfo.physicalXDpi = deviceInfo.xDpi;
            mBaseDisplayInfo.physicalYDpi = deviceInfo.yDpi;
            mBaseDisplayInfo.appVsyncOffsetNanos = deviceInfo.appVsyncOffsetNanos;
            mBaseDisplayInfo.presentationDeadlineNanos = deviceInfo.presentationDeadlineNanos;
            mBaseDisplayInfo.state = deviceInfo.state;
            mBaseDisplayInfo.smallestNominalAppWidth = deviceInfo.width;
            mBaseDisplayInfo.smallestNominalAppHeight = deviceInfo.height;
            mBaseDisplayInfo.largestNominalAppWidth = deviceInfo.width;
            mBaseDisplayInfo.largestNominalAppHeight = deviceInfo.height;
            mBaseDisplayInfo.ownerUid = deviceInfo.ownerUid;
            mBaseDisplayInfo.ownerPackageName = deviceInfo.ownerPackageName;

            mPrimaryDisplayDeviceInfo = deviceInfo;
            mInfo = null;
        }
    }

    /**
     * Applies the layer stack and transformation to the given display device
     * so that it shows the contents of this logical display.
     *
     * We know that the given display device is only ever showing the contents of
     * a single logical display, so this method is expected to blow away all of its
     * transformation properties to make it happen regardless of what the
     * display device was previously showing.
     *
     * The caller must have an open Surface transaction.
     *
     * The display device may not be the primary display device, in the case
     * where the display is being mirrored.
     *
     * @param device The display device to modify.
     * @param isBlanked True if the device is being blanked.
     */
    public void configureDisplayInTransactionLocked(DisplayDevice device,
            boolean isBlanked) {
        final DisplayInfo displayInfo = getDisplayInfoLocked();
        final DisplayDeviceInfo displayDeviceInfo = device.getDisplayDeviceInfoLocked();

        // Set the layer stack.
        device.setLayerStackInTransactionLocked(isBlanked ? BLANK_LAYER_STACK : mLayerStack);

        // Set the refresh rate
        device.requestRefreshRateLocked(mRequestedRefreshRate);

        // Set the viewport.
        // This is the area of the logical display that we intend to show on the
        // display device.  For now, it is always the full size of the logical display.
        mTempLayerStackRect.set(0, 0, displayInfo.logicalWidth, displayInfo.logicalHeight);

        // Set the orientation.
        // The orientation specifies how the physical coordinate system of the display
        // is rotated when the contents of the logical display are rendered.
        int orientation = Surface.ROTATION_0;
        if ((displayDeviceInfo.flags & DisplayDeviceInfo.FLAG_ROTATES_WITH_CONTENT) != 0) {
            orientation = displayInfo.rotation;
        }

        // Apply the physical rotation of the display device itself.
        orientation = (orientation + displayDeviceInfo.rotation) % 4;

        // Set the frame.
        // The frame specifies the rotated physical coordinates into which the viewport
        // is mapped.  We need to take care to preserve the aspect ratio of the viewport.
        // Currently we maximize the area to fill the display, but we could try to be
        // more clever and match resolutions.
        boolean rotated = (orientation == Surface.ROTATION_90
                || orientation == Surface.ROTATION_270);
        int physWidth = rotated ? displayDeviceInfo.height : displayDeviceInfo.width;
        int physHeight = rotated ? displayDeviceInfo.width : displayDeviceInfo.height;

        // Determine whether the width or height is more constrained to be scaled.
        //    physWidth / displayInfo.logicalWidth    => letter box
        // or physHeight / displayInfo.logicalHeight  => pillar box
        //
        // We avoid a division (and possible floating point imprecision) here by
        // multiplying the fractions by the product of their denominators before
        // comparing them.
        int displayRectWidth, displayRectHeight;
        if (physWidth * displayInfo.logicalHeight
                < physHeight * displayInfo.logicalWidth) {
            // Letter box.
            displayRectWidth = physWidth;
            displayRectHeight = displayInfo.logicalHeight * physWidth / displayInfo.logicalWidth;
        } else {
            // Pillar box.
            displayRectWidth = displayInfo.logicalWidth * physHeight / displayInfo.logicalHeight;
            displayRectHeight = physHeight;
        }
        /// M: Enable anti-overscan capability on wifi display @{
        if (displayDeviceInfo.type == Display.TYPE_WIFI) {
            displayRectWidth = (int) (displayRectWidth * ANTI_OVERSCAN_RATIO);
            displayRectHeight = (int) (displayRectHeight * ANTI_OVERSCAN_RATIO);
        }
        /// @}

        int displayRectTop = (physHeight - displayRectHeight) / 2;
        int displayRectLeft = (physWidth - displayRectWidth) / 2;
        mTempDisplayRect.set(displayRectLeft, displayRectTop,
                displayRectLeft + displayRectWidth, displayRectTop + displayRectHeight);

        device.setProjectionInTransactionLocked(orientation, mTempLayerStackRect, mTempDisplayRect);
    }