From ccdfc23de0e5a8f750836580e7b5dc621ffcf36d Mon Sep 17 00:00:00 2001
From: Chih-Wei Huang <cwhuang@linux.org.tw>
Date: Sun, 2 Nov 2014 01:21:12 +0800
Subject: [PATCH] InputReader: add 5-point calibration

Updated for Android 5.0.
---
 services/inputflinger/InputReader.cpp | 42 ++++++++++++++++++++++++++++-------
 services/inputflinger/InputReader.h   |  3 +++
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index e00c347144..f5d1d6ff86 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -3305,6 +3305,19 @@ void TouchInputMapper::configure(nsecs_t when,
         configureSurface(when, &resetNeeded);
     }
 
+    if (!changes || (changes & InputReaderConfiguration::CHANGE_DEVICE_ALIAS)) {
+        // Get 5-point calibration parameters
+        int *p = mCalibration.fiveCal;
+        p[6] = 0;
+        if (FILE *file = fopen("/data/misc/tscal/pointercal", "r")) {
+            if (fscanf(file, "%d %d %d %d %d %d %d", &p[0], &p[1], &p[2], &p[3], &p[4], &p[5], &p[6]) == 7) {
+                p[0] *= mXScale, p[1] *= mYScale, p[3] *= mXScale, p[4] *= mYScale;
+                ALOGD("pointercal loaded ok");
+            }
+            fclose(file);
+        }
+    }
+
     if (changes && resetNeeded) {
         // Send reset, unless this is the first time the device has been configured,
         // in which case the reader will call reset itself after all mappers are ready.
@@ -5089,11 +5102,24 @@ void TouchInputMapper::cookPointerData() {
         // Adjust X, Y, and coverage coords for surface orientation.
         float x, y;
         float left, top, right, bottom;
+        float x_temp = float(xTransformed - mRawPointerAxes.x.minValue);
+        float y_temp = float(yTransformed - mRawPointerAxes.y.minValue);
+        float x_cal, y_cal;
+        int *p = mCalibration.fiveCal;
+        if (p[6]) {
+            // Apply 5-point calibration algorithm
+            x_cal = (x_temp * p[0] + y_temp * p[1] + p[2] ) / p[6];
+            y_cal = (x_temp * p[3] + y_temp * p[4] + p[5] ) / p[6];
+            ALOGV("5cal: x_temp=%f y_temp=%f x_cal=%f y_cal=%f", x_temp, y_temp, x_cal, y_cal);
+        } else {
+            x_cal = x_temp * mXScale;
+            y_cal = y_temp * mYScale;
+        }
 
         switch (mSurfaceOrientation) {
         case DISPLAY_ORIENTATION_90:
-            x = float(yTransformed - mRawPointerAxes.y.minValue) * mYScale + mYTranslate;
-            y = float(mRawPointerAxes.x.maxValue - xTransformed) * mXScale + mXTranslate;
+            x = y_cal + mYTranslate;
+            y = mSurfaceWidth - x_cal + mXTranslate;
             left = float(rawTop - mRawPointerAxes.y.minValue) * mYScale + mYTranslate;
             right = float(rawBottom- mRawPointerAxes.y.minValue) * mYScale + mYTranslate;
             bottom = float(mRawPointerAxes.x.maxValue - rawLeft) * mXScale + mXTranslate;
@@ -5104,8 +5130,8 @@ void TouchInputMapper::cookPointerData() {
             }
             break;
         case DISPLAY_ORIENTATION_180:
-            x = float(mRawPointerAxes.x.maxValue - xTransformed) * mXScale + mXTranslate;
-            y = float(mRawPointerAxes.y.maxValue - yTransformed) * mYScale + mYTranslate;
+            x = mSurfaceWidth - x_cal + mXTranslate;
+            y = mSurfaceHeight - y_cal + mYTranslate;
             left = float(mRawPointerAxes.x.maxValue - rawRight) * mXScale + mXTranslate;
             right = float(mRawPointerAxes.x.maxValue - rawLeft) * mXScale + mXTranslate;
             bottom = float(mRawPointerAxes.y.maxValue - rawTop) * mYScale + mYTranslate;
@@ -5116,8 +5142,8 @@ void TouchInputMapper::cookPointerData() {
             }
             break;
         case DISPLAY_ORIENTATION_270:
-            x = float(mRawPointerAxes.y.maxValue - yTransformed) * mYScale + mYTranslate;
-            y = float(xTransformed - mRawPointerAxes.x.minValue) * mXScale + mXTranslate;
+            x = mSurfaceHeight - y_cal + mYTranslate;
+            y = x_cal + mXTranslate;
             left = float(mRawPointerAxes.y.maxValue - rawBottom) * mYScale + mYTranslate;
             right = float(mRawPointerAxes.y.maxValue - rawTop) * mYScale + mYTranslate;
             bottom = float(rawRight - mRawPointerAxes.x.minValue) * mXScale + mXTranslate;
@@ -5128,8 +5154,8 @@ void TouchInputMapper::cookPointerData() {
             }
             break;
         default:
-            x = float(xTransformed - mRawPointerAxes.x.minValue) * mXScale + mXTranslate;
-            y = float(yTransformed - mRawPointerAxes.y.minValue) * mYScale + mYTranslate;
+            x = x_cal + mXTranslate;
+            y = y_cal + mYTranslate;
             left = float(rawLeft - mRawPointerAxes.x.minValue) * mXScale + mXTranslate;
             right = float(rawRight - mRawPointerAxes.x.minValue) * mXScale + mXTranslate;
             bottom = float(rawBottom - mRawPointerAxes.y.minValue) * mYScale + mYTranslate;
diff --git a/services/inputflinger/InputReader.h b/services/inputflinger/InputReader.h
index 54cf590b4a..e00b9b095f 100644
--- a/services/inputflinger/InputReader.h
+++ b/services/inputflinger/InputReader.h
@@ -1389,6 +1389,9 @@ protected:
                 *outSize = 0;
             }
         }
+
+        // 5-point calibration parameters
+        int fiveCal[7];
     } mCalibration;
 
     // Affine location transformation/calibration
-- 
2.11.0