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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <android/bitmap.h>
     18 #include <jni.h>
     19 
     20 #include "utils.h"
     21 #include "_jni.h"
     22 
     23 using android::apps::photoeditor::utils::LockBitmaps;
     24 using android::apps::photoeditor::utils::pixel32_t;
     25 using android::apps::photoeditor::utils::UnlockBitmaps;
     26 
     27 namespace {
     28 
     29 extern "C" JNIEXPORT void JNICALL Java_com_android_photoeditor_filters_ImageUtils_nativeGrayscale(
     30     JNIEnv *env, jobject obj, jobject src_bitmap, jobject dst_bitmap, jfloat scale) {
     31    pGrayscaleType f = (pGrayscaleType)JNIFunc[JNI_Grayscale].func_ptr;
     32    return f(env, obj, src_bitmap, dst_bitmap, scale);
     33 }
     34 
     35 extern "C" void Grayscale(
     36     JNIEnv *env, jobject obj, jobject src_bitmap, jobject dst_bitmap, jfloat scale) {
     37   AndroidBitmapInfo src_info;
     38   AndroidBitmapInfo dst_info;
     39   void* src_pixels;
     40   void* dst_pixels;
     41 
     42   int ret = LockBitmaps(
     43       env, src_bitmap, dst_bitmap, &src_info, &dst_info, &src_pixels, &dst_pixels);
     44   if (ret < 0) {
     45     LOGE("LockBitmaps in GrayScale failed, error=%d", ret);
     46     return;
     47   }
     48 
     49   const int kShiftBits = 20;
     50   const int32_t kRedRatio = static_cast<int32_t>((1 << kShiftBits) * 0.21f);
     51   const int32_t kGreenRatio = static_cast<int32_t>((1 << kShiftBits) * 0.71f);
     52   const int32_t kBlueRatio = static_cast<int32_t>((1 << kShiftBits) * 0.07f);
     53 
     54   for (uint32_t scan_line = 0; scan_line < dst_info.height; scan_line++) {
     55     uint32_t* dst = reinterpret_cast<uint32_t*>(dst_pixels);
     56     pixel32_t* src = reinterpret_cast<pixel32_t*>(src_pixels);
     57     pixel32_t* src_line_end = src + src_info.width;
     58     while (src < src_line_end) {
     59       int32_t src_red = src->rgba8[0];
     60       int32_t src_green = src->rgba8[1];
     61       int32_t src_blue = src->rgba8[2];
     62       int32_t src_alpha = src->rgba8[3];
     63 
     64       int32_t dst_color = (kRedRatio * src_red + kGreenRatio * src_green +
     65           kBlueRatio * src_blue) >> kShiftBits;
     66       if (dst_color > 255) {
     67         dst_color = 255;
     68       }
     69       *dst = (src_alpha << 24) | (dst_color << 16) | (dst_color << 8) | dst_color;
     70       dst++;
     71       src++;
     72     }
     73     dst_pixels = reinterpret_cast<char*>(dst_pixels) + dst_info.stride;
     74     src_pixels = reinterpret_cast<char*>(src_pixels) + src_info.stride;
     75   }
     76 
     77   UnlockBitmaps(env, src_bitmap, dst_bitmap);
     78 }
     79 
     80 }  // namespace
     81