services/camera/libcameraservice/device3/RotateAndCropMapper.cpp - platform/frameworks/av - Git at Google

 /*
  * Copyright (C) 2020 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #define LOG_TAG "Camera3-RotCropMapper"
 #define ATRACE_TAG ATRACE_TAG_CAMERA
 //#define LOG_NDEBUG 0

 #include <algorithm>
 #include <cmath>

 #include "device3/RotateAndCropMapper.h"

 namespace android {

 namespace camera3 {

 void RotateAndCropMapper::initRemappedKeys() {
     mRemappedKeys.insert(
             kMeteringRegionsToCorrect.begin(),
             kMeteringRegionsToCorrect.end());
     mRemappedKeys.insert(
             kResultPointsToCorrectNoClamp.begin(),
             kResultPointsToCorrectNoClamp.end());

     mRemappedKeys.insert(ANDROID_SCALER_ROTATE_AND_CROP);
     mRemappedKeys.insert(ANDROID_SCALER_CROP_REGION);
     if (flags::concert_mode()) {
         mRemappedKeys.insert(ANDROID_LOGICAL_MULTI_CAMERA_ACTIVE_PHYSICAL_SENSOR_CROP_REGION);
     }
 }

 bool RotateAndCropMapper::isNeeded(const CameraMetadata* deviceInfo) {
     auto entry = deviceInfo->find(ANDROID_SCALER_AVAILABLE_ROTATE_AND_CROP_MODES);
     for (size_t i = 0; i < entry.count; i++) {
         if (entry.data.u8[i] == ANDROID_SCALER_ROTATE_AND_CROP_AUTO) return true;
     }
     return false;
 }

 RotateAndCropMapper::RotateAndCropMapper(const CameraMetadata* deviceInfo) {
     initRemappedKeys();

     auto entry = deviceInfo->find(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE);
     if (entry.count != 4) return;

     mArrayWidth = entry.data.i32[2];
     mArrayHeight = entry.data.i32[3];
     mArrayAspect = static_cast<float>(mArrayWidth) / mArrayHeight;
     mRotateAspect = 1.f/mArrayAspect;
 }

 /**
  * Adjust capture request when rotate and crop AUTO is enabled
  */
 status_t RotateAndCropMapper::updateCaptureRequest(CameraMetadata *request) {
     auto entry = request->find(ANDROID_SCALER_ROTATE_AND_CROP);
     if (entry.count == 0) return OK;
     uint8_t rotateMode = entry.data.u8[0];
     if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_NONE) return OK;

     int32_t cx = 0;
     int32_t cy = 0;
     int32_t cw = mArrayWidth;
     int32_t ch = mArrayHeight;
     entry = request->find(ANDROID_SCALER_CROP_REGION);
     if (entry.count == 4) {
         cx = entry.data.i32[0];
         cy = entry.data.i32[1];
         cw = entry.data.i32[2];
         ch = entry.data.i32[3];
     }

     // User inputs are relative to the rotated-and-cropped view, so convert back
     // to active array coordinates. To be more specific, the application is
     // calculating coordinates based on the crop rectangle and the active array,
     // even though the view the user sees is the cropped-and-rotated one. So we
     // need to adjust the coordinates so that a point that would be on the
     // top-left corner of the crop region is mapped to the top-left corner of
     // the rotated-and-cropped fov within the crop region, and the same for the
     // bottom-right corner.
     //
     // Since the zoom ratio control scales everything uniformly (so an app does
     // not need to adjust anything if it wants to put a metering region on the
     // top-left quadrant of the preview FOV, when changing zoomRatio), it does
     // not need to be factored into this calculation at all.
     //
     //   ->+x                       active array  aw
     //  |+--------------------------------------------------------------------+
     //  v|                                                                    |
     // +y|         a         1       cw        2           b                  |
     //   |          +=========*HHHHHHHHHHHHHHH*===========+                   |
     //   |          I         H      rw       H           I                   |
     //   |          I         H               H           I                   |
     //   |          I         H               H           I                   |
     //ah |       ch I         H rh            H           I crop region       |
     //   |          I         H               H           I                   |
     //   |          I         H               H           I                   |
     //   |          I         H rotate region H           I                   |
     //   |          +=========*HHHHHHHHHHHHHHH*===========+                   |
     //   |         d         4                 3           c                  |
     //   |                                                                    |
     //   +--------------------------------------------------------------------+
     //
     // aw , ah = active array width,height
     // cw , ch = crop region width,height
     // rw , rh = rotated-and-cropped region width,height
     // aw / ah = array aspect = rh / rw = 1 / rotated aspect
     // Coordinate mappings:
     //    ROTATE_AND_CROP_90: point a -> point 2
     //                        point c -> point 4 = +x -> +y, +y -> -x
     //    ROTATE_AND_CROP_180: point a -> point c
     //                         point c -> point a = +x -> -x, +y -> -y
     //    ROTATE_AND_CROP_270: point a -> point 4
     //                         point c -> point 2 = +x -> -y, +y -> +x

     float cropAspect = static_cast<float>(cw) / ch;
     float transformMat[4] = {0, 0,
                              0, 0};
     float xShift = 0;
     float yShift = 0;

     if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_180) {
         transformMat[0] = -1;
         transformMat[3] = -1;
         xShift = cw;
         yShift = ch;
     } else {
         float rw = cropAspect > mRotateAspect ?
                    ch * mRotateAspect : // pillarbox, not full width
                    cw;                  // letterbox or 1:1, full width
         float rh = cropAspect >= mRotateAspect ?
                    ch :                 // pillarbox or 1:1, full height
                    cw / mRotateAspect;  // letterbox, not full height
         switch (rotateMode) {
             case ANDROID_SCALER_ROTATE_AND_CROP_270:
                 transformMat[1] = -rw / ch; // +y -> -x
                 transformMat[2] =  rh / cw; // +x -> +y
                 xShift = (cw + rw) / 2; // left edge of crop to right edge of rotated
                 yShift = (ch - rh) / 2; // top edge of crop to top edge of rotated
                 break;
             case ANDROID_SCALER_ROTATE_AND_CROP_90:
                 transformMat[1] =  rw / ch; // +y -> +x
                 transformMat[2] = -rh / cw; // +x -> -y
                 xShift = (cw - rw) / 2; // left edge of crop to left edge of rotated
                 yShift = (ch + rh) / 2; // top edge of crop to bottom edge of rotated
                 break;
             default:
                 ALOGE("%s: Unexpected rotate mode: %d", __FUNCTION__, rotateMode);
                 return BAD_VALUE;
         }
     }

     for (auto regionTag : kMeteringRegionsToCorrect) {
         entry = request->find(regionTag);
         for (size_t i = 0; i < entry.count; i += 5) {
             int32_t weight = entry.data.i32[i + 4];
             if (weight == 0) {
                 continue;
             }
             transformPoints(entry.data.i32 + i, 2, transformMat, xShift, yShift, cx, cy);
             swapRectToMinFirst(entry.data.i32 + i);
         }
     }

     return OK;
 }

 /**
  * Adjust capture result when rotate and crop AUTO is enabled
  */
 status_t RotateAndCropMapper::updateCaptureResult(CameraMetadata *result) {
     auto entry = result->find(ANDROID_SCALER_ROTATE_AND_CROP);
     if (entry.count == 0) return OK;
     uint8_t rotateMode = entry.data.u8[0];
     if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_NONE) return OK;

     int32_t cx = 0;
     int32_t cy = 0;
     int32_t cw = mArrayWidth;
     int32_t ch = mArrayHeight;
     entry = result->find(ANDROID_SCALER_CROP_REGION);
     if (entry.count == 4) {
         cx = entry.data.i32[0];
         cy = entry.data.i32[1];
         cw = entry.data.i32[2];
         ch = entry.data.i32[3];
     }

     // HAL inputs are relative to the full active array, so convert back to
     // rotated-and-cropped coordinates for apps. To be more specific, the
     // application is calculating coordinates based on the crop rectangle and
     // the active array, even though the view the user sees is the
     // cropped-and-rotated one. So we need to adjust the coordinates so that a
     // point that would be on the top-left corner of the rotate-and-cropped
     // region is mapped to the top-left corner of the crop region, and the same
     // for the bottom-right corner.
     //
     // Since the zoom ratio control scales everything uniformly (so an app does
     // not need to adjust anything if it wants to put a metering region on the
     // top-left quadrant of the preview FOV, when changing zoomRatio), it does
     // not need to be factored into this calculation at all.
     //
     // Also note that round-tripping between original request and final result
     // fields can't be perfect, since the intermediate values have to be
     // integers on a smaller range than the original crop region range. That
     // means that multiple input values map to a single output value in
     // adjusting a request, so when adjusting a result, the original answer may
     // not be obtainable.  Given that aspect ratios are rarely > 16/9, the
     // round-trip values should generally only be off by 1 at most.
     //
     //   ->+x                       active array  aw
     //  |+--------------------------------------------------------------------+
     //  v|                                                                    |
     // +y|         a         1       cw        2           b                  |
     //   |          +=========*HHHHHHHHHHHHHHH*===========+                   |
     //   |          I         H      rw       H           I                   |
     //   |          I         H               H           I                   |
     //   |          I         H               H           I                   |
     //ah |       ch I         H rh            H           I crop region       |
     //   |          I         H               H           I                   |
     //   |          I         H               H           I                   |
     //   |          I         H rotate region H           I                   |
     //   |          +=========*HHHHHHHHHHHHHHH*===========+                   |
     //   |         d         4                 3           c                  |
     //   |                                                                    |
     //   +--------------------------------------------------------------------+
     //
     // aw , ah = active array width,height
     // cw , ch = crop region width,height
     // rw , rh = rotated-and-cropped region width,height
     // aw / ah = array aspect = rh / rw = 1 / rotated aspect
     // Coordinate mappings:
     //    ROTATE_AND_CROP_90: point 2 -> point a
     //                        point 4 -> point c = +x -> -y, +y -> +x
     //    ROTATE_AND_CROP_180: point c -> point a
     //                         point a -> point c = +x -> -x, +y -> -y
     //    ROTATE_AND_CROP_270: point 4 -> point a
     //                         point 2 -> point c = +x -> +y, +y -> -x

     float cropAspect = static_cast<float>(cw) / ch;
     float transformMat[4] = {0, 0,
                              0, 0};
     float xShift = 0;
     float yShift = 0;
     float rx = 0; // top-left corner of rotated region
     float ry = 0;
     if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_180) {
         transformMat[0] = -1;
         transformMat[3] = -1;
         xShift = cw;
         yShift = ch;
         rx = cx;
         ry = cy;
     } else {
         float rw = cropAspect > mRotateAspect ?
                    ch * mRotateAspect : // pillarbox, not full width
                    cw;                  // letterbox or 1:1, full width
         float rh = cropAspect >= mRotateAspect ?
                    ch :                 // pillarbox or 1:1, full height
                    cw / mRotateAspect;  // letterbox, not full height
         rx = cx + (cw - rw) / 2;
         ry = cy + (ch - rh) / 2;
         switch (rotateMode) {
             case ANDROID_SCALER_ROTATE_AND_CROP_270:
                 transformMat[1] =  ch / rw; // +y -> +x
                 transformMat[2] = -cw / rh; // +x -> -y
                 xShift = -(cw - rw) / 2; // left edge of rotated to left edge of cropped
                 yShift = ry - cy + ch;   // top edge of rotated to bottom edge of cropped
                 break;
             case ANDROID_SCALER_ROTATE_AND_CROP_90:
                 transformMat[1] = -ch / rw; // +y -> -x
                 transformMat[2] =  cw / rh; // +x -> +y
                 xShift = (cw + rw) / 2; // left edge of rotated to left edge of cropped
                 yShift = (ch - rh) / 2; // top edge of rotated to bottom edge of cropped
                 break;
             default:
                 ALOGE("%s: Unexpected rotate mode: %d", __FUNCTION__, rotateMode);
                 return BAD_VALUE;
         }
     }

     for (auto regionTag : kMeteringRegionsToCorrect) {
         entry = result->find(regionTag);
         for (size_t i = 0; i < entry.count; i += 5) {
             int32_t weight = entry.data.i32[i + 4];
             if (weight == 0) {
                 continue;
             }
             transformPoints(entry.data.i32 + i, 2, transformMat, xShift, yShift, rx, ry);
             swapRectToMinFirst(entry.data.i32 + i);
         }
     }

     for (auto pointsTag: kResultPointsToCorrectNoClamp) {
         entry = result->find(pointsTag);
         transformPoints(entry.data.i32, entry.count / 2, transformMat, xShift, yShift, rx, ry);
         if (pointsTag == ANDROID_STATISTICS_FACE_RECTANGLES) {
             for (size_t i = 0; i < entry.count; i += 4) {
                 swapRectToMinFirst(entry.data.i32 + i);
             }
         }
     }

     return OK;
 }

 void RotateAndCropMapper::transformPoints(int32_t* pts, size_t count, float transformMat[4],
         float xShift, float yShift, float ox, float oy) {
     for (size_t i = 0; i < count * 2; i += 2) {
         float x0 = pts[i] - ox;
         float y0 = pts[i + 1] - oy;
         int32_t nx = std::round(transformMat[0] * x0 + transformMat[1] * y0 + xShift + ox);
         int32_t ny = std::round(transformMat[2] * x0 + transformMat[3] * y0 + yShift + oy);

         pts[i] = std::min(std::max(nx, 0), mArrayWidth);
         pts[i + 1] = std::min(std::max(ny, 0), mArrayHeight);
     }
 }

 void RotateAndCropMapper::swapRectToMinFirst(int32_t* rect) {
     if (rect[0] > rect[2]) {
         auto tmp = rect[0];
         rect[0] = rect[2];
         rect[2] = tmp;
     }
     if (rect[1] > rect[3]) {
         auto tmp = rect[1];
         rect[1] = rect[3];
         rect[3] = tmp;
     }
 }

 } // namespace camera3

 } // namespace android
	/*
	* Copyright (C) 2020 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#define LOG_TAG "Camera3-RotCropMapper"
	#define ATRACE_TAG ATRACE_TAG_CAMERA
	//#define LOG_NDEBUG 0

	#include <algorithm>
	#include <cmath>

	#include "device3/RotateAndCropMapper.h"

	namespace android {

	namespace camera3 {

	void RotateAndCropMapper::initRemappedKeys() {
	mRemappedKeys.insert(
	kMeteringRegionsToCorrect.begin(),
	kMeteringRegionsToCorrect.end());
	mRemappedKeys.insert(
	kResultPointsToCorrectNoClamp.begin(),
	kResultPointsToCorrectNoClamp.end());

	mRemappedKeys.insert(ANDROID_SCALER_ROTATE_AND_CROP);
	mRemappedKeys.insert(ANDROID_SCALER_CROP_REGION);
	if (flags::concert_mode()) {
	mRemappedKeys.insert(ANDROID_LOGICAL_MULTI_CAMERA_ACTIVE_PHYSICAL_SENSOR_CROP_REGION);
	}
	}

	bool RotateAndCropMapper::isNeeded(const CameraMetadata* deviceInfo) {
	auto entry = deviceInfo->find(ANDROID_SCALER_AVAILABLE_ROTATE_AND_CROP_MODES);
	for (size_t i = 0; i < entry.count; i++) {
	if (entry.data.u8[i] == ANDROID_SCALER_ROTATE_AND_CROP_AUTO) return true;
	}
	return false;
	}

	RotateAndCropMapper::RotateAndCropMapper(const CameraMetadata* deviceInfo) {
	initRemappedKeys();

	auto entry = deviceInfo->find(ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE);
	if (entry.count != 4) return;

	mArrayWidth = entry.data.i32[2];
	mArrayHeight = entry.data.i32[3];
	mArrayAspect = static_cast<float>(mArrayWidth) / mArrayHeight;
	mRotateAspect = 1.f/mArrayAspect;
	}

	/**
	* Adjust capture request when rotate and crop AUTO is enabled
	*/
	status_t RotateAndCropMapper::updateCaptureRequest(CameraMetadata *request) {
	auto entry = request->find(ANDROID_SCALER_ROTATE_AND_CROP);
	if (entry.count == 0) return OK;
	uint8_t rotateMode = entry.data.u8[0];
	if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_NONE) return OK;

	int32_t cx = 0;
	int32_t cy = 0;
	int32_t cw = mArrayWidth;
	int32_t ch = mArrayHeight;
	entry = request->find(ANDROID_SCALER_CROP_REGION);
	if (entry.count == 4) {
	cx = entry.data.i32[0];
	cy = entry.data.i32[1];
	cw = entry.data.i32[2];
	ch = entry.data.i32[3];
	}

	// User inputs are relative to the rotated-and-cropped view, so convert back
	// to active array coordinates. To be more specific, the application is
	// calculating coordinates based on the crop rectangle and the active array,
	// even though the view the user sees is the cropped-and-rotated one. So we
	// need to adjust the coordinates so that a point that would be on the
	// top-left corner of the crop region is mapped to the top-left corner of
	// the rotated-and-cropped fov within the crop region, and the same for the
	// bottom-right corner.
	//
	// Since the zoom ratio control scales everything uniformly (so an app does
	// not need to adjust anything if it wants to put a metering region on the
	// top-left quadrant of the preview FOV, when changing zoomRatio), it does
	// not need to be factored into this calculation at all.
	//
	// ->+x active array aw
	// \|+--------------------------------------------------------------------+
	// v\| \|
	// +y\| a 1 cw 2 b \|
	// \| +=========HHHHHHHHHHHHHHH===========+ \|
	// \| I H rw H I \|
	// \| I H H I \|
	// \| I H H I \|
	//ah \| ch I H rh H I crop region \|
	// \| I H H I \|
	// \| I H H I \|
	// \| I H rotate region H I \|
	// \| +=========HHHHHHHHHHHHHHH===========+ \|
	// \| d 4 3 c \|
	// \| \|
	// +--------------------------------------------------------------------+
	//
	// aw , ah = active array width,height
	// cw , ch = crop region width,height
	// rw , rh = rotated-and-cropped region width,height
	// aw / ah = array aspect = rh / rw = 1 / rotated aspect
	// Coordinate mappings:
	// ROTATE_AND_CROP_90: point a -> point 2
	// point c -> point 4 = +x -> +y, +y -> -x
	// ROTATE_AND_CROP_180: point a -> point c
	// point c -> point a = +x -> -x, +y -> -y
	// ROTATE_AND_CROP_270: point a -> point 4
	// point c -> point 2 = +x -> -y, +y -> +x

	float cropAspect = static_cast<float>(cw) / ch;
	float transformMat[4] = {0, 0,
	0, 0};
	float xShift = 0;
	float yShift = 0;

	if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_180) {
	transformMat[0] = -1;
	transformMat[3] = -1;
	xShift = cw;
	yShift = ch;
	} else {
	float rw = cropAspect > mRotateAspect ?
	ch * mRotateAspect : // pillarbox, not full width
	cw; // letterbox or 1:1, full width
	float rh = cropAspect >= mRotateAspect ?
	ch : // pillarbox or 1:1, full height
	cw / mRotateAspect; // letterbox, not full height
	switch (rotateMode) {
	case ANDROID_SCALER_ROTATE_AND_CROP_270:
	transformMat[1] = -rw / ch; // +y -> -x
	transformMat[2] = rh / cw; // +x -> +y
	xShift = (cw + rw) / 2; // left edge of crop to right edge of rotated
	yShift = (ch - rh) / 2; // top edge of crop to top edge of rotated
	break;
	case ANDROID_SCALER_ROTATE_AND_CROP_90:
	transformMat[1] = rw / ch; // +y -> +x
	transformMat[2] = -rh / cw; // +x -> -y
	xShift = (cw - rw) / 2; // left edge of crop to left edge of rotated
	yShift = (ch + rh) / 2; // top edge of crop to bottom edge of rotated
	break;
	default:
	ALOGE("%s: Unexpected rotate mode: %d", __FUNCTION__, rotateMode);
	return BAD_VALUE;
	}
	}

	for (auto regionTag : kMeteringRegionsToCorrect) {
	entry = request->find(regionTag);
	for (size_t i = 0; i < entry.count; i += 5) {
	int32_t weight = entry.data.i32[i + 4];
	if (weight == 0) {
	continue;
	}
	transformPoints(entry.data.i32 + i, 2, transformMat, xShift, yShift, cx, cy);
	swapRectToMinFirst(entry.data.i32 + i);
	}
	}

	return OK;
	}

	/**
	* Adjust capture result when rotate and crop AUTO is enabled
	*/
	status_t RotateAndCropMapper::updateCaptureResult(CameraMetadata *result) {
	auto entry = result->find(ANDROID_SCALER_ROTATE_AND_CROP);
	if (entry.count == 0) return OK;
	uint8_t rotateMode = entry.data.u8[0];
	if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_NONE) return OK;

	int32_t cx = 0;
	int32_t cy = 0;
	int32_t cw = mArrayWidth;
	int32_t ch = mArrayHeight;
	entry = result->find(ANDROID_SCALER_CROP_REGION);
	if (entry.count == 4) {
	cx = entry.data.i32[0];
	cy = entry.data.i32[1];
	cw = entry.data.i32[2];
	ch = entry.data.i32[3];
	}

	// HAL inputs are relative to the full active array, so convert back to
	// rotated-and-cropped coordinates for apps. To be more specific, the
	// application is calculating coordinates based on the crop rectangle and
	// the active array, even though the view the user sees is the
	// cropped-and-rotated one. So we need to adjust the coordinates so that a
	// point that would be on the top-left corner of the rotate-and-cropped
	// region is mapped to the top-left corner of the crop region, and the same
	// for the bottom-right corner.
	//
	// Since the zoom ratio control scales everything uniformly (so an app does
	// not need to adjust anything if it wants to put a metering region on the
	// top-left quadrant of the preview FOV, when changing zoomRatio), it does
	// not need to be factored into this calculation at all.
	//
	// Also note that round-tripping between original request and final result
	// fields can't be perfect, since the intermediate values have to be
	// integers on a smaller range than the original crop region range. That
	// means that multiple input values map to a single output value in
	// adjusting a request, so when adjusting a result, the original answer may
	// not be obtainable. Given that aspect ratios are rarely > 16/9, the
	// round-trip values should generally only be off by 1 at most.
	//
	// ->+x active array aw
	// \|+--------------------------------------------------------------------+
	// v\| \|
	// +y\| a 1 cw 2 b \|
	// \| +=========HHHHHHHHHHHHHHH===========+ \|
	// \| I H rw H I \|
	// \| I H H I \|
	// \| I H H I \|
	//ah \| ch I H rh H I crop region \|
	// \| I H H I \|
	// \| I H H I \|
	// \| I H rotate region H I \|
	// \| +=========HHHHHHHHHHHHHHH===========+ \|
	// \| d 4 3 c \|
	// \| \|
	// +--------------------------------------------------------------------+
	//
	// aw , ah = active array width,height
	// cw , ch = crop region width,height
	// rw , rh = rotated-and-cropped region width,height
	// aw / ah = array aspect = rh / rw = 1 / rotated aspect
	// Coordinate mappings:
	// ROTATE_AND_CROP_90: point 2 -> point a
	// point 4 -> point c = +x -> -y, +y -> +x
	// ROTATE_AND_CROP_180: point c -> point a
	// point a -> point c = +x -> -x, +y -> -y
	// ROTATE_AND_CROP_270: point 4 -> point a
	// point 2 -> point c = +x -> +y, +y -> -x

	float cropAspect = static_cast<float>(cw) / ch;
	float transformMat[4] = {0, 0,
	0, 0};
	float xShift = 0;
	float yShift = 0;
	float rx = 0; // top-left corner of rotated region
	float ry = 0;
	if (rotateMode == ANDROID_SCALER_ROTATE_AND_CROP_180) {
	transformMat[0] = -1;
	transformMat[3] = -1;
	xShift = cw;
	yShift = ch;
	rx = cx;
	ry = cy;
	} else {
	float rw = cropAspect > mRotateAspect ?
	ch * mRotateAspect : // pillarbox, not full width
	cw; // letterbox or 1:1, full width
	float rh = cropAspect >= mRotateAspect ?
	ch : // pillarbox or 1:1, full height
	cw / mRotateAspect; // letterbox, not full height
	rx = cx + (cw - rw) / 2;
	ry = cy + (ch - rh) / 2;
	switch (rotateMode) {
	case ANDROID_SCALER_ROTATE_AND_CROP_270:
	transformMat[1] = ch / rw; // +y -> +x
	transformMat[2] = -cw / rh; // +x -> -y
	xShift = -(cw - rw) / 2; // left edge of rotated to left edge of cropped
	yShift = ry - cy + ch; // top edge of rotated to bottom edge of cropped
	break;
	case ANDROID_SCALER_ROTATE_AND_CROP_90:
	transformMat[1] = -ch / rw; // +y -> -x
	transformMat[2] = cw / rh; // +x -> +y
	xShift = (cw + rw) / 2; // left edge of rotated to left edge of cropped
	yShift = (ch - rh) / 2; // top edge of rotated to bottom edge of cropped
	break;
	default:
	ALOGE("%s: Unexpected rotate mode: %d", __FUNCTION__, rotateMode);
	return BAD_VALUE;
	}
	}

	for (auto regionTag : kMeteringRegionsToCorrect) {
	entry = result->find(regionTag);
	for (size_t i = 0; i < entry.count; i += 5) {
	int32_t weight = entry.data.i32[i + 4];
	if (weight == 0) {
	continue;
	}
	transformPoints(entry.data.i32 + i, 2, transformMat, xShift, yShift, rx, ry);
	swapRectToMinFirst(entry.data.i32 + i);
	}
	}

	for (auto pointsTag: kResultPointsToCorrectNoClamp) {
	entry = result->find(pointsTag);
	transformPoints(entry.data.i32, entry.count / 2, transformMat, xShift, yShift, rx, ry);
	if (pointsTag == ANDROID_STATISTICS_FACE_RECTANGLES) {
	for (size_t i = 0; i < entry.count; i += 4) {
	swapRectToMinFirst(entry.data.i32 + i);
	}
	}
	}

	return OK;
	}

	void RotateAndCropMapper::transformPoints(int32_t* pts, size_t count, float transformMat[4],
	float xShift, float yShift, float ox, float oy) {
	for (size_t i = 0; i < count * 2; i += 2) {
	float x0 = pts[i] - ox;
	float y0 = pts[i + 1] - oy;
	int32_t nx = std::round(transformMat[0] * x0 + transformMat[1] * y0 + xShift + ox);
	int32_t ny = std::round(transformMat[2] * x0 + transformMat[3] * y0 + yShift + oy);

	pts[i] = std::min(std::max(nx, 0), mArrayWidth);
	pts[i + 1] = std::min(std::max(ny, 0), mArrayHeight);
	}
	}

	void RotateAndCropMapper::swapRectToMinFirst(int32_t* rect) {
	if (rect[0] > rect[2]) {
	auto tmp = rect[0];
	rect[0] = rect[2];
	rect[2] = tmp;
	}
	if (rect[1] > rect[3]) {
	auto tmp = rect[1];
	rect[1] = rect[3];
	rect[3] = tmp;
	}
	}

	} // namespace camera3

	} // namespace android