summaryrefslogtreecommitdiffstats
path: root/jni/mosaic_renderer_jni.cpp
blob: bb01e7fc62eecd2fc81e22978dd2156f16e6e4d4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
/*
 * Copyright (C) 2011 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 <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <jni.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "db_utilities_camera.h"
#include "mosaic/ImageUtils.h"
#include "mosaic_renderer/FrameBuffer.h"
#include "mosaic_renderer/WarpRenderer.h"
#include "mosaic_renderer/SurfaceTextureRenderer.h"
#include "mosaic_renderer/YVURenderer.h"

#include "mosaic/Log.h"
#define LOG_TAG "MosaicRenderer"

#include "mosaic_renderer_jni.h"

// Texture handle
GLuint gSurfaceTextureID[1];

bool gWarpImage = true;

// Low-Res input image frame in YUVA format for preview rendering and processing
// and high-res YUVA input image for processing.
unsigned char* gPreviewImage[NR];
// Low-Res & high-res preview image width
int gPreviewImageWidth[NR];
// Low-Res & high-res preview image height
int gPreviewImageHeight[NR];

// Semaphore to protect simultaneous read/writes from gPreviewImage
sem_t gPreviewImage_semaphore;

// Off-screen preview FBO width (large enough to store the entire
// preview mosaic).
int gPreviewFBOWidth;
// Off-screen preview FBO height (large enough to store the entire
// preview mosaic).
int gPreviewFBOHeight;

// gK is the transformation to map the canonical {-1,1} vertex coordinate system
// to the {0,gPreviewImageWidth[LR]} input image frame coordinate system before
// applying the given affine transformation trs. gKm is the corresponding
// transformation for going to the {0,gPreviewFBOWidth}.
double gK[9];
double gKinv[9];
double gKm[9];
double gKminv[9];

// Shader to copy input SurfaceTexture into and RGBA FBO. The two shaders
// render to the textures with dimensions corresponding to the low-res and
// high-res image frames.
SurfaceTextureRenderer gSurfTexRenderer[NR];
// Off-screen FBOs to store the low-res and high-res RGBA copied out from
// the SurfaceTexture by the gSurfTexRenderers.
FrameBuffer gBufferInput[NR];

// Shader to convert RGBA textures into YVU textures for processing
YVURenderer gYVURenderer[NR];
// Off-screen FBOs to store the low-res and high-res YVU textures for processing
FrameBuffer gBufferInputYVU[NR];

// Shader to translate the flip-flop FBO - gBuffer[1-current] -> gBuffer[current]
WarpRenderer gWarper1;
// Shader to add warped current frame to the flip-flop FBO - gBuffer[current]
WarpRenderer gWarper2;
// Off-screen FBOs (flip-flop) to store the result of gWarper1 & gWarper2
FrameBuffer gBuffer[2];

// Shader to warp and render the preview FBO to the screen
WarpRenderer gPreview;

// Index of the gBuffer FBO gWarper1 is going to write into
int gCurrentFBOIndex = 0;

// 3x3 Matrices holding the transformation of this frame (gThisH1t) and of
// the last frame (gLastH1t) w.r.t the first frame.
double gThisH1t[9];
double gLastH1t[9];

// Variables to represent the fixed position of the top-left corner of the
// current frame in the previewFBO
double gCenterOffsetX = 0.0f;
double gCenterOffsetY = 0.0f;

// X-Offset of the viewfinder (current frame) w.r.t
// (gCenterOffsetX, gCenterOffsetY). This offset varies with time and is
// used to pan the viewfinder across the UI layout.
double gPanOffset = 0.0f;

// Variables tracking the translation value for the current frame and the
// last frame (both w.r.t the first frame). The difference between these
// values is used to control the panning speed of the viewfinder display
// on the UI screen.
double gThisTx = 0.0f;
double gLastTx = 0.0f;

// These are the scale factors used by the gPreview shader to ensure that
// the image frame is correctly scaled to the full UI layout height while
// maintaining its aspect ratio
double gUILayoutScalingX = 1.0f;
double gUILayoutScalingY = 1.0f;

// Whether the view that we will render preview FBO onto is in landscape or portrait
// orientation.
bool gIsLandscapeOrientation = true;

// State of the viewfinder. Set to false when the viewfinder hits the UI edge.
bool gPanViewfinder = true;

// Affine transformation in GL 4x4 format (column-major) to warp the
// last frame mosaic into the current frame coordinate system.
GLfloat g_dAffinetransGL[16];
double g_dAffinetrans[16];

// Affine transformation in GL 4x4 format (column-major) to translate the
// preview FBO across the screen (viewfinder panning).
GLfloat g_dAffinetransPanGL[16];
double g_dAffinetransPan[16];

// XY translation in GL 4x4 format (column-major) to center the current
// preview mosaic in the preview FBO
GLfloat g_dTranslationToFBOCenterGL[16];
double g_dTranslationToFBOCenter[16];

// GL 4x4 Identity transformation
GLfloat g_dAffinetransIdentGL[] = {
    1., 0., 0., 0.,
    0., 1., 0., 0.,
    0., 0., 1., 0.,
    0., 0., 0., 1.};

// GL 4x4 Rotation transformation (column-majored): 90 degree
GLfloat g_dAffinetransRotation90GL[] = {
    0., 1., 0., 0.,
    -1., 0., 0., 0.,
    0., 0., 1., 0.,
    0., 0., 0., 1.};

// 3x3 Rotation transformation (row-majored): 90 degree
double gRotation90[] = {
    0., -1., 0.,
    1., 0., 0.,
    0., 0., 1.,};


float g_dIdent3x3[] = {
    1.0, 0.0, 0.0,
    0.0, 1.0, 0.0,
    0.0, 0.0, 1.0};

const int GL_TEXTURE_EXTERNAL_OES_ENUM = 0x8D65;

static void printGLString(const char *name, GLenum s) {
    const char *v = (const char *) glGetString(s);
    LOGI("GL %s = %s", name, v);
}

// @return false if there was an error
bool checkGlError(const char* op) {
    GLint error = glGetError();
    if (error != 0) {
        LOGE("after %s() glError (0x%x)", op, error);
        return false;
    }
    return true;
}

void bindSurfaceTexture(GLuint texId)
{
    glBindTexture(GL_TEXTURE_EXTERNAL_OES_ENUM, texId);

    // Can't do mipmapping with camera source
    glTexParameterf(GL_TEXTURE_EXTERNAL_OES_ENUM, GL_TEXTURE_MIN_FILTER,
            GL_LINEAR);
    glTexParameterf(GL_TEXTURE_EXTERNAL_OES_ENUM, GL_TEXTURE_MAG_FILTER,
            GL_LINEAR);
    // Clamp to edge is the only option
    glTexParameteri(GL_TEXTURE_EXTERNAL_OES_ENUM, GL_TEXTURE_WRAP_S,
            GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_EXTERNAL_OES_ENUM, GL_TEXTURE_WRAP_T,
            GL_CLAMP_TO_EDGE);
}

void ClearPreviewImage(int mID)
{
    unsigned char* ptr = gPreviewImage[mID];
    for(int j = 0, i = 0;
            j < gPreviewImageWidth[mID] * gPreviewImageHeight[mID] * 4;
            j += 4)
    {
            ptr[i++] = 0;
            ptr[i++] = 0;
            ptr[i++] = 0;
            ptr[i++] = 255;
    }

}

void ConvertAffine3x3toGL4x4(double *matGL44, double *mat33)
{
    matGL44[0] = mat33[0];
    matGL44[1] = mat33[3];
    matGL44[2] = 0.0;
    matGL44[3] = mat33[6];

    matGL44[4] = mat33[1];
    matGL44[5] = mat33[4];
    matGL44[6] = 0.0;
    matGL44[7] = mat33[7];

    matGL44[8] = 0;
    matGL44[9] = 0;
    matGL44[10] = 1.0;
    matGL44[11] = 0.0;

    matGL44[12] = mat33[2];
    matGL44[13] = mat33[5];
    matGL44[14] = 0.0;
    matGL44[15] = mat33[8];
}

bool continuePanningFBO(double panOffset) {
    double normalizedScreenLimitLeft = -1.0 + VIEWPORT_BORDER_FACTOR_HORZ * 2.0;
    double normalizedScreenLimitRight = 1.0 - VIEWPORT_BORDER_FACTOR_HORZ * 2.0;
    double normalizedXPositionOnScreenLeft;
    double normalizedXPositionOnScreenRight;

    // Compute the position of the current frame in the screen coordinate system
    if (gIsLandscapeOrientation) {
        normalizedXPositionOnScreenLeft = (2.0 *
            (gCenterOffsetX + panOffset) / gPreviewFBOWidth - 1.0) *
            gUILayoutScalingX;
        normalizedXPositionOnScreenRight = (2.0 *
            ((gCenterOffsetX + panOffset) + gPreviewImageWidth[HR]) /
            gPreviewFBOWidth - 1.0) * gUILayoutScalingX;
    } else {
        normalizedXPositionOnScreenLeft = (2.0 *
            (gCenterOffsetX + panOffset) / gPreviewFBOWidth - 1.0) *
            gUILayoutScalingY;
        normalizedXPositionOnScreenRight = (2.0 *
            ((gCenterOffsetX + panOffset) + gPreviewImageWidth[HR]) /
            gPreviewFBOWidth - 1.0) * gUILayoutScalingY;
    }

    // Stop the viewfinder panning if we hit the maximum border allowed for
    // this UI layout
    if (normalizedXPositionOnScreenRight > normalizedScreenLimitRight ||
            normalizedXPositionOnScreenLeft < normalizedScreenLimitLeft) {
        return false;
    } else {
        return true;
    }
}

// This function computes fills the 4x4 matrices g_dAffinetrans,
// and g_dAffinetransPan using the specified 3x3 affine
// transformation between the first captured frame and the current frame.
// The computed g_dAffinetrans is such that it warps the preview mosaic in
// the last frame's coordinate system into the coordinate system of the
// current frame. Thus, applying this transformation will create the current
// frame mosaic but with the current frame missing. This frame will then be
// pasted in by gWarper2 after translating it by g_dTranslationToFBOCenter.
// The computed g_dAffinetransPan is such that it offsets the computed preview
// mosaic horizontally to make the viewfinder pan within the UI layout.
void UpdateWarpTransformation(float *trs)
{
    double H[9], Hp[9], Htemp1[9], Htemp2[9], T[9];

    for(int i = 0; i < 9; i++)
    {
        gThisH1t[i] = trs[i];
    }

    // Alignment is done based on low-res data.
    // To render the preview mosaic, the translation of the high-res mosaic is estimated to
    // H2L_FACTOR x low-res-based tranlation.
    gThisH1t[2] *= H2L_FACTOR;
    gThisH1t[5] *= H2L_FACTOR;

    db_Identity3x3(T);
    T[2] = -gCenterOffsetX;
    T[5] = -gCenterOffsetY;

    // H = ( inv(gThisH1t) * gLastH1t ) * T
    db_Identity3x3(Htemp1);
    db_Identity3x3(Htemp2);
    db_Identity3x3(H);
    db_InvertAffineTransform(Htemp1, gThisH1t);
    db_Multiply3x3_3x3(Htemp2, Htemp1, gLastH1t);
    db_Multiply3x3_3x3(H, Htemp2, T);

    for(int i = 0; i < 9; i++)
    {
        gLastH1t[i] = gThisH1t[i];
    }

    // Move the origin such that the frame is centered in the previewFBO
    // i.e. H = inv(T) * H
    H[2] += gCenterOffsetX;
    H[5] += gCenterOffsetY;

    // Hp = inv(Km) * H * Km
    // Km moves the coordinate system from openGL to image pixels so
    // that the alignment transform H can be applied to them.
    // inv(Km) moves the coordinate system back to openGL normalized
    // coordinates so that the shader can correctly render it.
    db_Identity3x3(Htemp1);
    db_Multiply3x3_3x3(Htemp1, H, gKm);
    db_Multiply3x3_3x3(Hp, gKminv, Htemp1);

    ConvertAffine3x3toGL4x4(g_dAffinetrans, Hp);

    ////////////////////////////////////////////////
    ////// Compute g_dAffinetransPan now...   //////
    ////////////////////////////////////////////////

    gThisTx = trs[2];

    if(gPanViewfinder)
    {
        gPanOffset += (gThisTx - gLastTx) * VIEWFINDER_PAN_FACTOR_HORZ;
    }

    gLastTx = gThisTx;
    gPanViewfinder = continuePanningFBO(gPanOffset);

    db_Identity3x3(H);
    H[2] = gPanOffset;

    // Hp = inv(Km) * H * Km
    db_Identity3x3(Htemp1);
    db_Multiply3x3_3x3(Htemp1, H, gKm);
    db_Multiply3x3_3x3(Hp, gKminv, Htemp1);

    if (gIsLandscapeOrientation) {
        ConvertAffine3x3toGL4x4(g_dAffinetransPan, Hp);
    } else {
        // rotate Hp by 90 degress.
        db_Multiply3x3_3x3(Htemp1, gRotation90, Hp);
        ConvertAffine3x3toGL4x4(g_dAffinetransPan, Htemp1);
    }
}

void AllocateTextureMemory(int widthHR, int heightHR, int widthLR, int heightLR)
{
    gPreviewImageWidth[HR] = widthHR;
    gPreviewImageHeight[HR] = heightHR;

    gPreviewImageWidth[LR] = widthLR;
    gPreviewImageHeight[LR] = heightLR;

    sem_init(&gPreviewImage_semaphore, 0, 1);

    sem_wait(&gPreviewImage_semaphore);
    gPreviewImage[LR] = ImageUtils::allocateImage(gPreviewImageWidth[LR],
            gPreviewImageHeight[LR], 4);
    ClearPreviewImage(LR);
    gPreviewImage[HR] = ImageUtils::allocateImage(gPreviewImageWidth[HR],
            gPreviewImageHeight[HR], 4);
    ClearPreviewImage(HR);
    sem_post(&gPreviewImage_semaphore);

    gPreviewFBOWidth = PREVIEW_FBO_WIDTH_SCALE * gPreviewImageWidth[HR];
    gPreviewFBOHeight = PREVIEW_FBO_HEIGHT_SCALE * gPreviewImageHeight[HR];

    // The origin is such that the current frame will sit with its center
    // at the center of the previewFBO
    gCenterOffsetX = (gPreviewFBOWidth / 2 - gPreviewImageWidth[HR] / 2);
    gCenterOffsetY = (gPreviewFBOHeight / 2 - gPreviewImageHeight[HR] / 2);

    gPanOffset = 0.0f;

    db_Identity3x3(gThisH1t);
    db_Identity3x3(gLastH1t);

    gPanViewfinder = true;

    int w = gPreviewImageWidth[HR];
    int h = gPreviewImageHeight[HR];

    int wm = gPreviewFBOWidth;
    int hm = gPreviewFBOHeight;

    // K is the transformation to map the canonical [-1,1] vertex coordinate
    // system to the [0,w] image coordinate system before applying the given
    // affine transformation trs.
    gKm[0] = wm / 2.0 - 0.5;
    gKm[1] = 0.0;
    gKm[2] = wm / 2.0 - 0.5;
    gKm[3] = 0.0;
    gKm[4] = hm / 2.0 - 0.5;
    gKm[5] = hm / 2.0 - 0.5;
    gKm[6] = 0.0;
    gKm[7] = 0.0;
    gKm[8] = 1.0;

    gK[0] = w / 2.0 - 0.5;
    gK[1] = 0.0;
    gK[2] = w / 2.0 - 0.5;
    gK[3] = 0.0;
    gK[4] = h / 2.0 - 0.5;
    gK[5] = h / 2.0 - 0.5;
    gK[6] = 0.0;
    gK[7] = 0.0;
    gK[8] = 1.0;

    db_Identity3x3(gKinv);
    db_InvertCalibrationMatrix(gKinv, gK);

    db_Identity3x3(gKminv);
    db_InvertCalibrationMatrix(gKminv, gKm);

    //////////////////////////////////////////
    ////// Compute g_Translation now... //////
    //////////////////////////////////////////
    double T[9], Tp[9], Ttemp[9];

    db_Identity3x3(T);
    T[2] = gCenterOffsetX;
    T[5] = gCenterOffsetY;

    // Tp = inv(K) * T * K
    db_Identity3x3(Ttemp);
    db_Multiply3x3_3x3(Ttemp, T, gK);
    db_Multiply3x3_3x3(Tp, gKinv, Ttemp);

    ConvertAffine3x3toGL4x4(g_dTranslationToFBOCenter, Tp);

    UpdateWarpTransformation(g_dIdent3x3);
}

void FreeTextureMemory()
{
    sem_wait(&gPreviewImage_semaphore);
    ImageUtils::freeImage(gPreviewImage[LR]);
    ImageUtils::freeImage(gPreviewImage[HR]);
    sem_post(&gPreviewImage_semaphore);

    sem_destroy(&gPreviewImage_semaphore);
}

extern "C"
{
    JNIEXPORT jint JNICALL Java_com_android_camera_panorama_MosaicRenderer_init(
            JNIEnv * env, jobject obj);
    JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_reset(
            JNIEnv * env, jobject obj,  jint width, jint height,
            jboolean isLandscapeOrientation);
    JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_preprocess(
            JNIEnv * env, jobject obj, jfloatArray stMatrix);
    JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_transferGPUtoCPU(
            JNIEnv * env, jobject obj);
    JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_step(
            JNIEnv * env, jobject obj);
    JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_ready(
            JNIEnv * env, jobject obj);
    JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_setWarping(
            JNIEnv * env, jobject obj, jboolean flag);
};

JNIEXPORT jint JNICALL Java_com_android_camera_panorama_MosaicRenderer_init(
        JNIEnv * env, jobject obj)
{
    gSurfTexRenderer[LR].InitializeGLProgram();
    gSurfTexRenderer[HR].InitializeGLProgram();
    gYVURenderer[LR].InitializeGLProgram();
    gYVURenderer[HR].InitializeGLProgram();
    gWarper1.InitializeGLProgram();
    gWarper2.InitializeGLProgram();
    gPreview.InitializeGLProgram();
    gBuffer[0].InitializeGLContext();
    gBuffer[1].InitializeGLContext();
    gBufferInput[LR].InitializeGLContext();
    gBufferInput[HR].InitializeGLContext();
    gBufferInputYVU[LR].InitializeGLContext();
    gBufferInputYVU[HR].InitializeGLContext();

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glGenTextures(1, gSurfaceTextureID);
    // bind the surface texture
    bindSurfaceTexture(gSurfaceTextureID[0]);

    return (jint) gSurfaceTextureID[0];
}


void calculateUILayoutScaling(int width, int height, bool isLandscape) {
    if (isLandscape) {
        //  __________        ______
        // |__________|  =>  |______|
        // (Preview FBO)      (View)
        //
        // Scale the preview FBO's height to the height of view and
        // maintain the aspect ratio of the current frame on the screen.
        gUILayoutScalingY = PREVIEW_FBO_HEIGHT_SCALE;

        // Note that OpenGL scales a texture to view's width and height automatically.
        // The "width / height" inverts the scaling, so as to maintain the aspect ratio
        // of the current frame.
        gUILayoutScalingX = ((float) (PREVIEW_FBO_WIDTH_SCALE * gPreviewImageWidth[LR])
                / (PREVIEW_FBO_HEIGHT_SCALE * gPreviewImageHeight[LR]) *  PREVIEW_FBO_HEIGHT_SCALE)
                / ((float) width / height);
    } else {
        //                     __
        //  __________        |  |
        // |__________|  =>   |  |
        // (Preview FBO)      |  |
        //                    |__|
        //                   (View)
        // Scale the preview FBO's height to the width of view and
        // maintain the aspect ratio of the current frame on the screen.
        gUILayoutScalingX = PREVIEW_FBO_HEIGHT_SCALE;

        // Note that OpenGL scales a texture to view's width and height automatically.
        // The "height / width" inverts the scaling, so as to maintain the aspect ratio
        // of the current frame.
        gUILayoutScalingY = ((float) (PREVIEW_FBO_WIDTH_SCALE * gPreviewImageWidth[LR])
                / (PREVIEW_FBO_HEIGHT_SCALE * gPreviewImageHeight[LR]) *  PREVIEW_FBO_HEIGHT_SCALE)
                / ((float) height / width);

    }
}

JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_reset(
        JNIEnv * env, jobject obj,  jint width, jint height, jboolean isLandscapeOrientation)
{
    gIsLandscapeOrientation = isLandscapeOrientation;
    calculateUILayoutScaling(width, height, gIsLandscapeOrientation);

    gBuffer[0].Init(gPreviewFBOWidth, gPreviewFBOHeight, GL_RGBA);
    gBuffer[1].Init(gPreviewFBOWidth, gPreviewFBOHeight, GL_RGBA);

    gBufferInput[LR].Init(gPreviewImageWidth[LR],
            gPreviewImageHeight[LR], GL_RGBA);

    gBufferInput[HR].Init(gPreviewImageWidth[HR],
            gPreviewImageHeight[HR], GL_RGBA);

    gBufferInputYVU[LR].Init(gPreviewImageWidth[LR],
            gPreviewImageHeight[LR], GL_RGBA);

    gBufferInputYVU[HR].Init(gPreviewImageWidth[HR],
            gPreviewImageHeight[HR], GL_RGBA);

    sem_wait(&gPreviewImage_semaphore);
    ClearPreviewImage(LR);
    ClearPreviewImage(HR);
    sem_post(&gPreviewImage_semaphore);

    // bind the surface texture
    bindSurfaceTexture(gSurfaceTextureID[0]);

    gSurfTexRenderer[LR].SetupGraphics(&gBufferInput[LR]);
    gSurfTexRenderer[LR].Clear(0.0, 0.0, 0.0, 1.0);
    gSurfTexRenderer[LR].SetViewportMatrix(1, 1, 1, 1);
    gSurfTexRenderer[LR].SetScalingMatrix(1.0f, -1.0f);
    gSurfTexRenderer[LR].SetInputTextureName(gSurfaceTextureID[0]);
    gSurfTexRenderer[LR].SetInputTextureType(GL_TEXTURE_EXTERNAL_OES_ENUM);

    gSurfTexRenderer[HR].SetupGraphics(&gBufferInput[HR]);
    gSurfTexRenderer[HR].Clear(0.0, 0.0, 0.0, 1.0);
    gSurfTexRenderer[HR].SetViewportMatrix(1, 1, 1, 1);
    gSurfTexRenderer[HR].SetScalingMatrix(1.0f, -1.0f);
    gSurfTexRenderer[HR].SetInputTextureName(gSurfaceTextureID[0]);
    gSurfTexRenderer[HR].SetInputTextureType(GL_TEXTURE_EXTERNAL_OES_ENUM);

    gYVURenderer[LR].SetupGraphics(&gBufferInputYVU[LR]);
    gYVURenderer[LR].Clear(0.0, 0.0, 0.0, 1.0);
    gYVURenderer[LR].SetInputTextureName(gBufferInput[LR].GetTextureName());
    gYVURenderer[LR].SetInputTextureType(GL_TEXTURE_2D);

    gYVURenderer[HR].SetupGraphics(&gBufferInputYVU[HR]);
    gYVURenderer[HR].Clear(0.0, 0.0, 0.0, 1.0);
    gYVURenderer[HR].SetInputTextureName(gBufferInput[HR].GetTextureName());
    gYVURenderer[HR].SetInputTextureType(GL_TEXTURE_2D);

    // gBuffer[1-gCurrentFBOIndex] --> gWarper1 --> gBuffer[gCurrentFBOIndex]
    gWarper1.SetupGraphics(&gBuffer[gCurrentFBOIndex]);
    gWarper1.Clear(0.0, 0.0, 0.0, 1.0);
    gWarper1.SetViewportMatrix(1, 1, 1, 1);
    gWarper1.SetScalingMatrix(1.0f, 1.0f);
    gWarper1.SetInputTextureName(gBuffer[1 - gCurrentFBOIndex].GetTextureName());
    gWarper1.SetInputTextureType(GL_TEXTURE_2D);

    // gBufferInput[HR] --> gWarper2 --> gBuffer[gCurrentFBOIndex]
    gWarper2.SetupGraphics(&gBuffer[gCurrentFBOIndex]);
    gWarper2.Clear(0.0, 0.0, 0.0, 1.0);
    gWarper2.SetViewportMatrix(gPreviewImageWidth[HR],
            gPreviewImageHeight[HR], gBuffer[gCurrentFBOIndex].GetWidth(),
            gBuffer[gCurrentFBOIndex].GetHeight());
    gWarper2.SetScalingMatrix(1.0f, 1.0f);
    gWarper2.SetInputTextureName(gBufferInput[HR].GetTextureName());
    gWarper2.SetInputTextureType(GL_TEXTURE_2D);

    gPreview.SetupGraphics(width, height);
    gPreview.Clear(0.0, 0.0, 0.0, 1.0);
    gPreview.SetViewportMatrix(1, 1, 1, 1);

    // Scale the previewFBO so that the viewfinder window fills the layout height
    // while maintaining the image aspect ratio
    gPreview.SetScalingMatrix(gUILayoutScalingX, -1.0f * gUILayoutScalingY);
    gPreview.SetInputTextureName(gBuffer[gCurrentFBOIndex].GetTextureName());
    gPreview.SetInputTextureType(GL_TEXTURE_2D);
}

JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_preprocess(
        JNIEnv * env, jobject obj, jfloatArray stMatrix)
{
    jfloat *stmat = env->GetFloatArrayElements(stMatrix, 0);

    gSurfTexRenderer[LR].SetSTMatrix((float*) stmat);
    gSurfTexRenderer[HR].SetSTMatrix((float*) stmat);

    env->ReleaseFloatArrayElements(stMatrix, stmat, 0);

    gSurfTexRenderer[LR].DrawTexture(g_dAffinetransIdentGL);
    gSurfTexRenderer[HR].DrawTexture(g_dAffinetransIdentGL);
}

#ifndef now_ms
#include <time.h>
static double
now_ms(void)
{
    //struct timespec res;
    struct timeval res;
    //clock_gettime(CLOCK_REALTIME, &res);
    gettimeofday(&res, NULL);
    return 1000.0*res.tv_sec + (double)res.tv_usec/1e3;
}
#endif



JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_transferGPUtoCPU(
        JNIEnv * env, jobject obj)
{
    double t0, t1, time_c;

    gYVURenderer[LR].DrawTexture();
    gYVURenderer[HR].DrawTexture();

    sem_wait(&gPreviewImage_semaphore);
    // Bind to the input LR FBO and read the Low-Res data from there...
    glBindFramebuffer(GL_FRAMEBUFFER, gBufferInputYVU[LR].GetFrameBufferName());
    t0 = now_ms();
    glReadPixels(0,
                 0,
                 gBufferInput[LR].GetWidth(),
                 gBufferInput[LR].GetHeight(),
                 GL_RGBA,
                 GL_UNSIGNED_BYTE,
                 gPreviewImage[LR]);

    checkGlError("glReadPixels LR");

    // Bind to the input HR FBO and read the high-res data from there...
    glBindFramebuffer(GL_FRAMEBUFFER, gBufferInputYVU[HR].GetFrameBufferName());
    t0 = now_ms();
    glReadPixels(0,
                 0,
                 gBufferInput[HR].GetWidth(),
                 gBufferInput[HR].GetHeight(),
                 GL_RGBA,
                 GL_UNSIGNED_BYTE,
                 gPreviewImage[HR]);

    checkGlError("glReadPixels HR");

    sem_post(&gPreviewImage_semaphore);
}

JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_step(
        JNIEnv * env, jobject obj)
{
    if(!gWarpImage) // ViewFinder
    {
        gWarper2.SetupGraphics(&gBuffer[gCurrentFBOIndex]);
        gPreview.SetInputTextureName(gBuffer[gCurrentFBOIndex].GetTextureName());

        gWarper2.DrawTexture(g_dTranslationToFBOCenterGL);

        if (gIsLandscapeOrientation) {
            gPreview.DrawTexture(g_dAffinetransIdentGL);
        } else {
            gPreview.DrawTexture(g_dAffinetransRotation90GL);
        }
    }
    else
    {
        gWarper1.SetupGraphics(&gBuffer[gCurrentFBOIndex]);
        // Clear the destination so that we can paint on it afresh
        gWarper1.Clear(0.0, 0.0, 0.0, 1.0);
        gWarper1.SetInputTextureName(
                gBuffer[1 - gCurrentFBOIndex].GetTextureName());
        gWarper2.SetupGraphics(&gBuffer[gCurrentFBOIndex]);
        gPreview.SetInputTextureName(gBuffer[gCurrentFBOIndex].GetTextureName());

        gWarper1.DrawTexture(g_dAffinetransGL);
        gWarper2.DrawTexture(g_dTranslationToFBOCenterGL);
        gPreview.DrawTexture(g_dAffinetransPanGL);

        gCurrentFBOIndex = 1 - gCurrentFBOIndex;
    }
}

JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_setWarping(
        JNIEnv * env, jobject obj, jboolean flag)
{
    // TODO: Review this logic
    if(gWarpImage != (bool) flag) //switching from viewfinder to capture or vice-versa
    {
        // Clear gBuffer[0]
        gWarper1.SetupGraphics(&gBuffer[0]);
        gWarper1.Clear(0.0, 0.0, 0.0, 1.0);
        // Clear gBuffer[1]
        gWarper1.SetupGraphics(&gBuffer[1]);
        gWarper1.Clear(0.0, 0.0, 0.0, 1.0);
        // Clear the screen to black.
        gPreview.Clear(0.0, 0.0, 0.0, 1.0);

        gLastTx = 0.0f;
        gPanOffset = 0.0f;
        gPanViewfinder = true;

        db_Identity3x3(gThisH1t);
        db_Identity3x3(gLastH1t);
    }

    gWarpImage = (bool)flag;
}


JNIEXPORT void JNICALL Java_com_android_camera_panorama_MosaicRenderer_ready(
        JNIEnv * env, jobject obj)
{
    for(int i=0; i<16; i++)
    {
        g_dAffinetransGL[i] = g_dAffinetrans[i];
        g_dAffinetransPanGL[i] = g_dAffinetransPan[i];
        g_dTranslationToFBOCenterGL[i] = g_dTranslationToFBOCenter[i];
    }
}