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 <cmath>
21 #include <cstdlib>
22
23 #include "utils.h"
24 #include "_jni.h"
25
26 using android::apps::photoeditor::utils::LockBitmaps;
27 using android::apps::photoeditor::utils::UnlockBitmaps;
28
29 namespace {
30
BilinearPixelInterpolation(float x,float y,uint8_t * p00,uint8_t * p01,uint8_t * p10,uint8_t * p11)31 uint32_t BilinearPixelInterpolation(
32 float x, float y, uint8_t *p00, uint8_t *p01, uint8_t *p10, uint8_t *p11) {
33
34 float coef4 = x * y;
35 float coef2 = x - coef4; // x * (1 - y)
36 float coef3 = y - coef4; // (1 - x) * y
37 float coef1 = 1 - x - coef3; // (1 - x) * (1 - y)
38
39 int dst_red = p00[0] * coef1 + p10[0] * coef2 + p01[0] * coef3 + p11[0] * coef4;
40 int dst_green = p00[1] * coef1 + p10[1] * coef2 + p01[1] * coef3 + p11[1] * coef4;
41 int dst_blue = p00[2] * coef1 + p10[2] * coef2 + p01[2] * coef3 + p11[2] * coef4;
42 if (dst_red > 255) {
43 dst_red = 255;
44 }
45 if (dst_green > 255) {
46 dst_green = 255;
47 }
48 if (dst_blue > 255) {
49 dst_blue = 255;
50 }
51
52 // alpha is not calculated, directly from any point should do.
53 return p00[3] << 24 | (dst_blue << 16) | (dst_green << 8) | dst_red;
54 }
55
FisheyeMapPixels(float px,float py,uint32_t x,uint32_t y,AndroidBitmapInfo * src_info,AndroidBitmapInfo * dst_info,void * src_pixels,void * dst_pixels)56 void FisheyeMapPixels(
57 float px, float py, uint32_t x, uint32_t y, AndroidBitmapInfo *src_info,
58 AndroidBitmapInfo *dst_info, void *src_pixels, void *dst_pixels) {
59 if (x >= src_info->width || y >= src_info->height) {
60 return;
61 }
62
63 uint32_t px_floor = floor(px);
64 uint32_t py_floor = floor(py);
65
66 uint32_t *p00 = (uint32_t*)((char*)src_pixels + src_info->stride * py_floor) + px_floor;
67 uint32_t *p01, *p10, *p11;
68 if (py_floor + 1 < src_info->height) {
69 p01 = (uint32_t*)((char*)p00 + src_info->stride);
70 } else {
71 p01 = p00;
72 }
73 if (py_floor + 1 < src_info->width) {
74 p10 = p00 + 1;
75 p11 = p01 + 1;
76 } else {
77 p10 = p00;
78 p11 = p01;
79 }
80
81 uint32_t *dst = (uint32_t*)((char*)dst_pixels + dst_info->stride * y) + x;
82 *dst = BilinearPixelInterpolation(px - px_floor, py - py_floor,
83 (uint8_t*)p00, (uint8_t*)p01, (uint8_t*)p10, (uint8_t*)p11);
84 }
85
86 /*
87 * @param scale ranges from 0.0 to 1.0.
88 * @param focus_x is the X-coord of the center of the projection ranging from 0 to 1.
89 * @param focus_y is the Y-coord of the center of the projection ranging from 0 to 1.
90 */
Java_com_android_photoeditor_filters_ImageUtils_nativeFisheye(JNIEnv * env,jobject obj,jobject src_bitmap,jobject dst_bitmap,jfloat focus_x,jfloat focus_y,jfloat scale)91 extern "C" JNIEXPORT void JNICALL Java_com_android_photoeditor_filters_ImageUtils_nativeFisheye(
92 JNIEnv *env, jobject obj, jobject src_bitmap, jobject dst_bitmap,
93 jfloat focus_x, jfloat focus_y, jfloat scale) {
94 pFisheyeType f = (pFisheyeType)JNIFunc[JNI_Fisheye].func_ptr;
95 return f(env, obj, src_bitmap, dst_bitmap, focus_x, focus_y, scale);
96 }
97
Fisheye(JNIEnv * env,jobject obj,jobject src_bitmap,jobject dst_bitmap,jfloat focus_x,jfloat focus_y,jfloat scale)98 extern "C" void Fisheye(
99 JNIEnv *env, jobject obj, jobject src_bitmap, jobject dst_bitmap,
100 jfloat focus_x, jfloat focus_y, jfloat scale) {
101 AndroidBitmapInfo src_info;
102 AndroidBitmapInfo dst_info;
103 void* src_pixels;
104 void* dst_pixels;
105
106 int ret = LockBitmaps(
107 env, src_bitmap, dst_bitmap, &src_info, &dst_info, &src_pixels, &dst_pixels);
108 if (ret < 0) {
109 LOGE("LockBitmaps in FishEye failed, error=%d", ret);
110 return;
111 }
112
113 if (scale == 0) {
114 memcpy(dst_pixels, src_pixels, src_info.stride * src_info.height);
115 return;
116 }
117
118 float far_point = hypotf(src_info.height * focus_y, src_info.width * focus_x);
119 const float r = far_point * 1.15; // radius
120 const float r2 = r * r;
121 const uint32_t center_x = round(src_info.width * focus_x);
122 const uint32_t center_y = round(src_info.height * focus_y);
123 float alpha = 0.75 + scale * 2.0;
124 float linear_scale = far_point /
125 (M_PI_2 - atan(alpha * sqrtf(r2 - far_point * far_point) / far_point));
126
127 for (uint32_t scan_line = 0; scan_line <= center_y; scan_line++) {
128
129 int y = scan_line - center_y;
130 int y2 = y * y;
131
132 for (uint32_t dst_x = 0; dst_x <= center_x; dst_x++) {
133 int x = dst_x - center_x;
134 float xy2 = (x * x + y2);
135 float s_xy2 = sqrtf(xy2);
136 float r_scale = linear_scale * (M_PI_2 - atan(alpha * sqrtf(r2 - xy2) / s_xy2)) / s_xy2;
137 float scaled_x = x * r_scale;
138 float scaled_y = y * r_scale;
139 int nx = center_x - x;
140 int ny = center_y - y;
141 float fpx = center_x + scaled_x;
142 float fnx = center_x - scaled_x;
143 float fpy = center_y + scaled_y;
144 float fny = center_y - scaled_y;
145
146 FisheyeMapPixels(fpx, fpy, dst_x, scan_line, &src_info, &dst_info, src_pixels, dst_pixels);
147 FisheyeMapPixels(fpx, fny, dst_x, ny, &src_info, &dst_info, src_pixels, dst_pixels);
148 FisheyeMapPixels(fnx, fpy, nx, scan_line, &src_info, &dst_info, src_pixels, dst_pixels);
149 FisheyeMapPixels(fnx, fny, nx, ny, &src_info, &dst_info, src_pixels, dst_pixels);
150 }
151 }
152 // Deal with the condition when x = 0 and y = 0 (dst_x = center_x and
153 // scan_line = center_y.
154 uint32_t *dst = (uint32_t*)((char*)dst_pixels + dst_info.stride * center_y) + center_x;
155 *dst = *((uint32_t*)((char*)src_pixels + src_info.stride * center_y) + center_x);
156
157 UnlockBitmaps(env, src_bitmap, dst_bitmap);
158 }
159
160 } // namespace
161