| /* |
| * Copyright (C) 2012 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. |
| */ |
| |
| #include <math.h> |
| #include "filters.h" |
| |
| unsigned char clamp(int c) |
| { |
| int N = 255; |
| c &= ~(c >> 31); |
| c -= N; |
| c &= (c >> 31); |
| c += N; |
| return (unsigned char) c; |
| } |
| |
| int clampMax(int c,int max) |
| { |
| c &= ~(c >> 31); |
| c -= max; |
| c &= (c >> 31); |
| c += max; |
| return c; |
| } |
| |
| void JNIFUNCF(ImageFilterContrast, nativeApplyFilter, jobject bitmap, jint width, jint height, jfloat bright) |
| { |
| char* destination = 0; |
| AndroidBitmap_lockPixels(env, bitmap, (void**) &destination); |
| unsigned char * rgb = (unsigned char * )destination; |
| int i; |
| int len = width * height * 4; |
| float m = (float)pow(2, bright/100.); |
| float c = 127-m*127; |
| |
| for (i = 0; i < len; i+=4) { |
| rgb[RED] = clamp((int)(m*rgb[RED]+c)); |
| rgb[GREEN] = clamp((int)(m*rgb[GREEN]+c)); |
| rgb[BLUE] = clamp((int)(m*rgb[BLUE]+c)); |
| } |
| AndroidBitmap_unlockPixels(env, bitmap); |
| } |
| |