1 /*
2  * Copyright 2013 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 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
18 
19 #include "ProgramCache.h"
20 
21 #include <GLES2/gl2.h>
22 #include <GLES2/gl2ext.h>
23 #include <log/log.h>
24 #include <renderengine/private/Description.h>
25 #include <utils/String8.h>
26 #include <utils/Trace.h>
27 #include "Program.h"
28 
29 ANDROID_SINGLETON_STATIC_INSTANCE(android::renderengine::gl::ProgramCache)
30 
31 namespace android {
32 namespace renderengine {
33 namespace gl {
34 
35 /*
36  * A simple formatter class to automatically add the endl and
37  * manage the indentation.
38  */
39 
40 class Formatter;
41 static Formatter& indent(Formatter& f);
42 static Formatter& dedent(Formatter& f);
43 
44 class Formatter {
45     String8 mString;
46     int mIndent;
47     typedef Formatter& (*FormaterManipFunc)(Formatter&);
48     friend Formatter& indent(Formatter& f);
49     friend Formatter& dedent(Formatter& f);
50 
51 public:
Formatter()52     Formatter() : mIndent(0) {}
53 
getString() const54     String8 getString() const { return mString; }
55 
operator <<(Formatter & out,const char * in)56     friend Formatter& operator<<(Formatter& out, const char* in) {
57         for (int i = 0; i < out.mIndent; i++) {
58             out.mString.append("    ");
59         }
60         out.mString.append(in);
61         out.mString.append("\n");
62         return out;
63     }
operator <<(Formatter & out,const String8 & in)64     friend inline Formatter& operator<<(Formatter& out, const String8& in) {
65         return operator<<(out, in.string());
66     }
operator <<(Formatter & to,FormaterManipFunc func)67     friend inline Formatter& operator<<(Formatter& to, FormaterManipFunc func) {
68         return (*func)(to);
69     }
70 };
indent(Formatter & f)71 Formatter& indent(Formatter& f) {
72     f.mIndent++;
73     return f;
74 }
dedent(Formatter & f)75 Formatter& dedent(Formatter& f) {
76     f.mIndent--;
77     return f;
78 }
79 
primeCache(EGLContext context,bool useColorManagement)80 void ProgramCache::primeCache(EGLContext context, bool useColorManagement) {
81     auto& cache = mCaches[context];
82     uint32_t shaderCount = 0;
83     uint32_t keyMask = Key::BLEND_MASK | Key::OPACITY_MASK | Key::ALPHA_MASK | Key::TEXTURE_MASK
84         | Key::ROUNDED_CORNERS_MASK;
85     // Prime the cache for all combinations of the above masks,
86     // leaving off the experimental color matrix mask options.
87 
88     nsecs_t timeBefore = systemTime();
89     for (uint32_t keyVal = 0; keyVal <= keyMask; keyVal++) {
90         Key shaderKey;
91         shaderKey.set(keyMask, keyVal);
92         uint32_t tex = shaderKey.getTextureTarget();
93         if (tex != Key::TEXTURE_OFF && tex != Key::TEXTURE_EXT && tex != Key::TEXTURE_2D) {
94             continue;
95         }
96         if (cache.count(shaderKey) == 0) {
97             cache.emplace(shaderKey, generateProgram(shaderKey));
98             shaderCount++;
99         }
100     }
101 
102     // Prime for sRGB->P3 conversion
103     if (useColorManagement) {
104         Key shaderKey;
105         shaderKey.set(Key::BLEND_MASK | Key::OUTPUT_TRANSFORM_MATRIX_MASK | Key::INPUT_TF_MASK |
106                               Key::OUTPUT_TF_MASK,
107                       Key::BLEND_PREMULT | Key::OUTPUT_TRANSFORM_MATRIX_ON | Key::INPUT_TF_SRGB |
108                               Key::OUTPUT_TF_SRGB);
109         for (int i = 0; i < 16; i++) {
110             shaderKey.set(Key::OPACITY_MASK,
111                           (i & 1) ? Key::OPACITY_OPAQUE : Key::OPACITY_TRANSLUCENT);
112             shaderKey.set(Key::ALPHA_MASK, (i & 2) ? Key::ALPHA_LT_ONE : Key::ALPHA_EQ_ONE);
113 
114             // Cache rounded corners
115             shaderKey.set(Key::ROUNDED_CORNERS_MASK,
116                           (i & 4) ? Key::ROUNDED_CORNERS_ON : Key::ROUNDED_CORNERS_OFF);
117 
118             // Cache texture off option for window transition
119             shaderKey.set(Key::TEXTURE_MASK, (i & 8) ? Key::TEXTURE_EXT : Key::TEXTURE_OFF);
120             if (cache.count(shaderKey) == 0) {
121                 cache.emplace(shaderKey, generateProgram(shaderKey));
122                 shaderCount++;
123             }
124         }
125     }
126 
127     nsecs_t timeAfter = systemTime();
128     float compileTimeMs = static_cast<float>(timeAfter - timeBefore) / 1.0E6;
129     ALOGD("shader cache generated - %u shaders in %f ms\n", shaderCount, compileTimeMs);
130 }
131 
computeKey(const Description & description)132 ProgramCache::Key ProgramCache::computeKey(const Description& description) {
133     Key needs;
134     needs.set(Key::TEXTURE_MASK,
135               !description.textureEnabled
136                       ? Key::TEXTURE_OFF
137                       : description.texture.getTextureTarget() == GL_TEXTURE_EXTERNAL_OES
138                               ? Key::TEXTURE_EXT
139                               : description.texture.getTextureTarget() == GL_TEXTURE_2D
140                                       ? Key::TEXTURE_2D
141                                       : Key::TEXTURE_OFF)
142             .set(Key::ALPHA_MASK, (description.color.a < 1) ? Key::ALPHA_LT_ONE : Key::ALPHA_EQ_ONE)
143             .set(Key::BLEND_MASK,
144                  description.isPremultipliedAlpha ? Key::BLEND_PREMULT : Key::BLEND_NORMAL)
145             .set(Key::OPACITY_MASK,
146                  description.isOpaque ? Key::OPACITY_OPAQUE : Key::OPACITY_TRANSLUCENT)
147             .set(Key::Key::INPUT_TRANSFORM_MATRIX_MASK,
148                  description.hasInputTransformMatrix()
149                          ? Key::INPUT_TRANSFORM_MATRIX_ON : Key::INPUT_TRANSFORM_MATRIX_OFF)
150             .set(Key::Key::OUTPUT_TRANSFORM_MATRIX_MASK,
151                  description.hasOutputTransformMatrix() || description.hasColorMatrix()
152                          ? Key::OUTPUT_TRANSFORM_MATRIX_ON
153                          : Key::OUTPUT_TRANSFORM_MATRIX_OFF)
154             .set(Key::ROUNDED_CORNERS_MASK,
155                  description.cornerRadius > 0
156                          ? Key::ROUNDED_CORNERS_ON : Key::ROUNDED_CORNERS_OFF);
157 
158     needs.set(Key::Y410_BT2020_MASK,
159               description.isY410BT2020 ? Key::Y410_BT2020_ON : Key::Y410_BT2020_OFF);
160 
161     if (needs.hasTransformMatrix() ||
162         (description.inputTransferFunction != description.outputTransferFunction)) {
163         switch (description.inputTransferFunction) {
164             case Description::TransferFunction::LINEAR:
165             default:
166                 needs.set(Key::INPUT_TF_MASK, Key::INPUT_TF_LINEAR);
167                 break;
168             case Description::TransferFunction::SRGB:
169                 needs.set(Key::INPUT_TF_MASK, Key::INPUT_TF_SRGB);
170                 break;
171             case Description::TransferFunction::ST2084:
172                 needs.set(Key::INPUT_TF_MASK, Key::INPUT_TF_ST2084);
173                 break;
174             case Description::TransferFunction::HLG:
175                 needs.set(Key::INPUT_TF_MASK, Key::INPUT_TF_HLG);
176                 break;
177         }
178 
179         switch (description.outputTransferFunction) {
180             case Description::TransferFunction::LINEAR:
181             default:
182                 needs.set(Key::OUTPUT_TF_MASK, Key::OUTPUT_TF_LINEAR);
183                 break;
184             case Description::TransferFunction::SRGB:
185                 needs.set(Key::OUTPUT_TF_MASK, Key::OUTPUT_TF_SRGB);
186                 break;
187             case Description::TransferFunction::ST2084:
188                 needs.set(Key::OUTPUT_TF_MASK, Key::OUTPUT_TF_ST2084);
189                 break;
190             case Description::TransferFunction::HLG:
191                 needs.set(Key::OUTPUT_TF_MASK, Key::OUTPUT_TF_HLG);
192                 break;
193         }
194     }
195 
196     return needs;
197 }
198 
199 // Generate EOTF that converts signal values to relative display light,
200 // both normalized to [0, 1].
generateEOTF(Formatter & fs,const Key & needs)201 void ProgramCache::generateEOTF(Formatter& fs, const Key& needs) {
202     switch (needs.getInputTF()) {
203         case Key::INPUT_TF_SRGB:
204             fs << R"__SHADER__(
205                 float EOTF_sRGB(float srgb) {
206                     return srgb <= 0.04045 ? srgb / 12.92 : pow((srgb + 0.055) / 1.055, 2.4);
207                 }
208 
209                 vec3 EOTF_sRGB(const vec3 srgb) {
210                     return vec3(EOTF_sRGB(srgb.r), EOTF_sRGB(srgb.g), EOTF_sRGB(srgb.b));
211                 }
212 
213                 vec3 EOTF(const vec3 srgb) {
214                     return sign(srgb.rgb) * EOTF_sRGB(abs(srgb.rgb));
215                 }
216             )__SHADER__";
217             break;
218         case Key::INPUT_TF_ST2084:
219             fs << R"__SHADER__(
220                 vec3 EOTF(const highp vec3 color) {
221                     const highp float m1 = (2610.0 / 4096.0) / 4.0;
222                     const highp float m2 = (2523.0 / 4096.0) * 128.0;
223                     const highp float c1 = (3424.0 / 4096.0);
224                     const highp float c2 = (2413.0 / 4096.0) * 32.0;
225                     const highp float c3 = (2392.0 / 4096.0) * 32.0;
226 
227                     highp vec3 tmp = pow(clamp(color, 0.0, 1.0), 1.0 / vec3(m2));
228                     tmp = max(tmp - c1, 0.0) / (c2 - c3 * tmp);
229                     return pow(tmp, 1.0 / vec3(m1));
230                 }
231             )__SHADER__";
232             break;
233         case Key::INPUT_TF_HLG:
234             fs << R"__SHADER__(
235                 highp float EOTF_channel(const highp float channel) {
236                     const highp float a = 0.17883277;
237                     const highp float b = 0.28466892;
238                     const highp float c = 0.55991073;
239                     return channel <= 0.5 ? channel * channel / 3.0 :
240                             (exp((channel - c) / a) + b) / 12.0;
241                 }
242 
243                 vec3 EOTF(const highp vec3 color) {
244                     return vec3(EOTF_channel(color.r), EOTF_channel(color.g),
245                             EOTF_channel(color.b));
246                 }
247             )__SHADER__";
248             break;
249         default:
250             fs << R"__SHADER__(
251                 vec3 EOTF(const vec3 linear) {
252                     return linear;
253                 }
254             )__SHADER__";
255             break;
256     }
257 }
258 
generateToneMappingProcess(Formatter & fs,const Key & needs)259 void ProgramCache::generateToneMappingProcess(Formatter& fs, const Key& needs) {
260     // Convert relative light to absolute light.
261     switch (needs.getInputTF()) {
262         case Key::INPUT_TF_ST2084:
263             fs << R"__SHADER__(
264                 highp vec3 ScaleLuminance(highp vec3 color) {
265                     return color * 10000.0;
266                 }
267             )__SHADER__";
268             break;
269         case Key::INPUT_TF_HLG:
270             fs << R"__SHADER__(
271                 highp vec3 ScaleLuminance(highp vec3 color) {
272                     // The formula is:
273                     // alpha * pow(Y, gamma - 1.0) * color + beta;
274                     // where alpha is 1000.0, gamma is 1.2, beta is 0.0.
275                     return color * 1000.0 * pow(color.y, 0.2);
276                 }
277             )__SHADER__";
278             break;
279         default:
280             fs << R"__SHADER__(
281                 highp vec3 ScaleLuminance(highp vec3 color) {
282                     return color * displayMaxLuminance;
283                 }
284             )__SHADER__";
285             break;
286     }
287 
288     // Tone map absolute light to display luminance range.
289     switch (needs.getInputTF()) {
290         case Key::INPUT_TF_ST2084:
291         case Key::INPUT_TF_HLG:
292             switch (needs.getOutputTF()) {
293                 case Key::OUTPUT_TF_HLG:
294                     // Right now when mixed PQ and HLG contents are presented,
295                     // HLG content will always be converted to PQ. However, for
296                     // completeness, we simply clamp the value to [0.0, 1000.0].
297                     fs << R"__SHADER__(
298                         highp vec3 ToneMap(highp vec3 color) {
299                             return clamp(color, 0.0, 1000.0);
300                         }
301                     )__SHADER__";
302                     break;
303                 case Key::OUTPUT_TF_ST2084:
304                     fs << R"__SHADER__(
305                         highp vec3 ToneMap(highp vec3 color) {
306                             return color;
307                         }
308                     )__SHADER__";
309                     break;
310                 default:
311                     fs << R"__SHADER__(
312                         highp vec3 ToneMap(highp vec3 color) {
313                             const float maxMasteringLumi = 1000.0;
314                             const float maxContentLumi = 1000.0;
315                             const float maxInLumi = min(maxMasteringLumi, maxContentLumi);
316                             float maxOutLumi = displayMaxLuminance;
317 
318                             float nits = color.y;
319 
320                             // clamp to max input luminance
321                             nits = clamp(nits, 0.0, maxInLumi);
322 
323                             // scale [0.0, maxInLumi] to [0.0, maxOutLumi]
324                             if (maxInLumi <= maxOutLumi) {
325                                 return color * (maxOutLumi / maxInLumi);
326                             } else {
327                                 // three control points
328                                 const float x0 = 10.0;
329                                 const float y0 = 17.0;
330                                 float x1 = maxOutLumi * 0.75;
331                                 float y1 = x1;
332                                 float x2 = x1 + (maxInLumi - x1) / 2.0;
333                                 float y2 = y1 + (maxOutLumi - y1) * 0.75;
334 
335                                 // horizontal distances between the last three control points
336                                 float h12 = x2 - x1;
337                                 float h23 = maxInLumi - x2;
338                                 // tangents at the last three control points
339                                 float m1 = (y2 - y1) / h12;
340                                 float m3 = (maxOutLumi - y2) / h23;
341                                 float m2 = (m1 + m3) / 2.0;
342 
343                                 if (nits < x0) {
344                                     // scale [0.0, x0] to [0.0, y0] linearly
345                                     float slope = y0 / x0;
346                                     return color * slope;
347                                 } else if (nits < x1) {
348                                     // scale [x0, x1] to [y0, y1] linearly
349                                     float slope = (y1 - y0) / (x1 - x0);
350                                     nits = y0 + (nits - x0) * slope;
351                                 } else if (nits < x2) {
352                                     // scale [x1, x2] to [y1, y2] using Hermite interp
353                                     float t = (nits - x1) / h12;
354                                     nits = (y1 * (1.0 + 2.0 * t) + h12 * m1 * t) * (1.0 - t) * (1.0 - t) +
355                                             (y2 * (3.0 - 2.0 * t) + h12 * m2 * (t - 1.0)) * t * t;
356                                 } else {
357                                     // scale [x2, maxInLumi] to [y2, maxOutLumi] using Hermite interp
358                                     float t = (nits - x2) / h23;
359                                     nits = (y2 * (1.0 + 2.0 * t) + h23 * m2 * t) * (1.0 - t) * (1.0 - t) +
360                                             (maxOutLumi * (3.0 - 2.0 * t) + h23 * m3 * (t - 1.0)) * t * t;
361                                 }
362                             }
363 
364                             // color.y is greater than x0 and is thus non-zero
365                             return color * (nits / color.y);
366                         }
367                     )__SHADER__";
368                     break;
369             }
370             break;
371         default:
372             // inverse tone map; the output luminance can be up to maxOutLumi.
373             fs << R"__SHADER__(
374                 highp vec3 ToneMap(highp vec3 color) {
375                     const float maxOutLumi = 3000.0;
376 
377                     const float x0 = 5.0;
378                     const float y0 = 2.5;
379                     float x1 = displayMaxLuminance * 0.7;
380                     float y1 = maxOutLumi * 0.15;
381                     float x2 = displayMaxLuminance * 0.9;
382                     float y2 = maxOutLumi * 0.45;
383                     float x3 = displayMaxLuminance;
384                     float y3 = maxOutLumi;
385 
386                     float c1 = y1 / 3.0;
387                     float c2 = y2 / 2.0;
388                     float c3 = y3 / 1.5;
389 
390                     float nits = color.y;
391 
392                     float scale;
393                     if (nits <= x0) {
394                         // scale [0.0, x0] to [0.0, y0] linearly
395                         const float slope = y0 / x0;
396                         return color * slope;
397                     } else if (nits <= x1) {
398                         // scale [x0, x1] to [y0, y1] using a curve
399                         float t = (nits - x0) / (x1 - x0);
400                         nits = (1.0 - t) * (1.0 - t) * y0 + 2.0 * (1.0 - t) * t * c1 + t * t * y1;
401                     } else if (nits <= x2) {
402                         // scale [x1, x2] to [y1, y2] using a curve
403                         float t = (nits - x1) / (x2 - x1);
404                         nits = (1.0 - t) * (1.0 - t) * y1 + 2.0 * (1.0 - t) * t * c2 + t * t * y2;
405                     } else {
406                         // scale [x2, x3] to [y2, y3] using a curve
407                         float t = (nits - x2) / (x3 - x2);
408                         nits = (1.0 - t) * (1.0 - t) * y2 + 2.0 * (1.0 - t) * t * c3 + t * t * y3;
409                     }
410 
411                     // color.y is greater than x0 and is thus non-zero
412                     return color * (nits / color.y);
413                 }
414             )__SHADER__";
415             break;
416     }
417 
418     // convert absolute light to relative light.
419     switch (needs.getOutputTF()) {
420         case Key::OUTPUT_TF_ST2084:
421             fs << R"__SHADER__(
422                 highp vec3 NormalizeLuminance(highp vec3 color) {
423                     return color / 10000.0;
424                 }
425             )__SHADER__";
426             break;
427         case Key::OUTPUT_TF_HLG:
428             fs << R"__SHADER__(
429                 highp vec3 NormalizeLuminance(highp vec3 color) {
430                     return color / 1000.0 * pow(color.y / 1000.0, -0.2 / 1.2);
431                 }
432             )__SHADER__";
433             break;
434         default:
435             fs << R"__SHADER__(
436                 highp vec3 NormalizeLuminance(highp vec3 color) {
437                     return color / displayMaxLuminance;
438                 }
439             )__SHADER__";
440             break;
441     }
442 }
443 
444 // Generate OOTF that modifies the relative scence light to relative display light.
generateOOTF(Formatter & fs,const ProgramCache::Key & needs)445 void ProgramCache::generateOOTF(Formatter& fs, const ProgramCache::Key& needs) {
446     if (!needs.needsToneMapping()) {
447         fs << R"__SHADER__(
448             highp vec3 OOTF(const highp vec3 color) {
449                 return color;
450             }
451         )__SHADER__";
452     } else {
453         generateToneMappingProcess(fs, needs);
454         fs << R"__SHADER__(
455             highp vec3 OOTF(const highp vec3 color) {
456                 return NormalizeLuminance(ToneMap(ScaleLuminance(color)));
457             }
458         )__SHADER__";
459     }
460 }
461 
462 // Generate OETF that converts relative display light to signal values,
463 // both normalized to [0, 1]
generateOETF(Formatter & fs,const Key & needs)464 void ProgramCache::generateOETF(Formatter& fs, const Key& needs) {
465     switch (needs.getOutputTF()) {
466         case Key::OUTPUT_TF_SRGB:
467             fs << R"__SHADER__(
468                 float OETF_sRGB(const float linear) {
469                     return linear <= 0.0031308 ?
470                             linear * 12.92 : (pow(linear, 1.0 / 2.4) * 1.055) - 0.055;
471                 }
472 
473                 vec3 OETF_sRGB(const vec3 linear) {
474                     return vec3(OETF_sRGB(linear.r), OETF_sRGB(linear.g), OETF_sRGB(linear.b));
475                 }
476 
477                 vec3 OETF(const vec3 linear) {
478                     return sign(linear.rgb) * OETF_sRGB(abs(linear.rgb));
479                 }
480             )__SHADER__";
481             break;
482         case Key::OUTPUT_TF_ST2084:
483             fs << R"__SHADER__(
484                 vec3 OETF(const vec3 linear) {
485                     const highp float m1 = (2610.0 / 4096.0) / 4.0;
486                     const highp float m2 = (2523.0 / 4096.0) * 128.0;
487                     const highp float c1 = (3424.0 / 4096.0);
488                     const highp float c2 = (2413.0 / 4096.0) * 32.0;
489                     const highp float c3 = (2392.0 / 4096.0) * 32.0;
490 
491                     highp vec3 tmp = pow(linear, vec3(m1));
492                     tmp = (c1 + c2 * tmp) / (1.0 + c3 * tmp);
493                     return pow(tmp, vec3(m2));
494                 }
495             )__SHADER__";
496             break;
497         case Key::OUTPUT_TF_HLG:
498             fs << R"__SHADER__(
499                 highp float OETF_channel(const highp float channel) {
500                     const highp float a = 0.17883277;
501                     const highp float b = 0.28466892;
502                     const highp float c = 0.55991073;
503                     return channel <= 1.0 / 12.0 ? sqrt(3.0 * channel) :
504                             a * log(12.0 * channel - b) + c;
505                 }
506 
507                 vec3 OETF(const highp vec3 color) {
508                     return vec3(OETF_channel(color.r), OETF_channel(color.g),
509                             OETF_channel(color.b));
510                 }
511             )__SHADER__";
512             break;
513         default:
514             fs << R"__SHADER__(
515                 vec3 OETF(const vec3 linear) {
516                     return linear;
517                 }
518             )__SHADER__";
519             break;
520     }
521 }
522 
generateVertexShader(const Key & needs)523 String8 ProgramCache::generateVertexShader(const Key& needs) {
524     Formatter vs;
525     if (needs.isTexturing()) {
526         vs << "attribute vec4 texCoords;"
527            << "varying vec2 outTexCoords;";
528     }
529     if (needs.hasRoundedCorners()) {
530         vs << "attribute lowp vec4 cropCoords;";
531         vs << "varying lowp vec2 outCropCoords;";
532     }
533     vs << "attribute vec4 position;"
534        << "uniform mat4 projection;"
535        << "uniform mat4 texture;"
536        << "void main(void) {" << indent << "gl_Position = projection * position;";
537     if (needs.isTexturing()) {
538         vs << "outTexCoords = (texture * texCoords).st;";
539     }
540     if (needs.hasRoundedCorners()) {
541         vs << "outCropCoords = cropCoords.st;";
542     }
543     vs << dedent << "}";
544     return vs.getString();
545 }
546 
generateFragmentShader(const Key & needs)547 String8 ProgramCache::generateFragmentShader(const Key& needs) {
548     Formatter fs;
549     if (needs.getTextureTarget() == Key::TEXTURE_EXT) {
550         fs << "#extension GL_OES_EGL_image_external : require";
551     }
552 
553     // default precision is required-ish in fragment shaders
554     fs << "precision mediump float;";
555 
556     if (needs.getTextureTarget() == Key::TEXTURE_EXT) {
557         fs << "uniform samplerExternalOES sampler;"
558            << "varying vec2 outTexCoords;";
559     } else if (needs.getTextureTarget() == Key::TEXTURE_2D) {
560         fs << "uniform sampler2D sampler;"
561            << "varying vec2 outTexCoords;";
562     }
563 
564     if (needs.hasRoundedCorners()) {
565         // Rounded corners implementation using a signed distance function.
566         fs << R"__SHADER__(
567             uniform float cornerRadius;
568             uniform vec2 cropCenter;
569             varying vec2 outCropCoords;
570 
571             /**
572              * This function takes the current crop coordinates and calculates an alpha value based
573              * on the corner radius and distance from the crop center.
574              */
575             float applyCornerRadius(vec2 cropCoords)
576             {
577                 vec2 position = cropCoords - cropCenter;
578                 // Scale down the dist vector here, as otherwise large corner
579                 // radii can cause floating point issues when computing the norm
580                 vec2 dist = (abs(position) - cropCenter + vec2(cornerRadius)) / 16.0;
581                 // Once we've found the norm, then scale back up.
582                 float plane = length(max(dist, vec2(0.0))) * 16.0;
583                 return 1.0 - clamp(plane - cornerRadius, 0.0, 1.0);
584             }
585             )__SHADER__";
586     }
587 
588     if (needs.getTextureTarget() == Key::TEXTURE_OFF || needs.hasAlpha()) {
589         fs << "uniform vec4 color;";
590     }
591 
592     if (needs.isY410BT2020()) {
593         fs << R"__SHADER__(
594             vec3 convertY410BT2020(const vec3 color) {
595                 const vec3 offset = vec3(0.0625, 0.5, 0.5);
596                 const mat3 transform = mat3(
597                     vec3(1.1678,  1.1678, 1.1678),
598                     vec3(   0.0, -0.1878, 2.1481),
599                     vec3(1.6836, -0.6523,   0.0));
600                 // Y is in G, U is in R, and V is in B
601                 return clamp(transform * (color.grb - offset), 0.0, 1.0);
602             }
603             )__SHADER__";
604     }
605 
606     if (needs.hasTransformMatrix() || (needs.getInputTF() != needs.getOutputTF())) {
607         // Currently, display maximum luminance is needed when doing tone mapping.
608         if (needs.needsToneMapping()) {
609             fs << "uniform float displayMaxLuminance;";
610         }
611 
612         if (needs.hasInputTransformMatrix()) {
613             fs << "uniform mat4 inputTransformMatrix;";
614             fs << R"__SHADER__(
615                 highp vec3 InputTransform(const highp vec3 color) {
616                     return clamp(vec3(inputTransformMatrix * vec4(color, 1.0)), 0.0, 1.0);
617                 }
618             )__SHADER__";
619         } else {
620             fs << R"__SHADER__(
621                 highp vec3 InputTransform(const highp vec3 color) {
622                     return color;
623                 }
624             )__SHADER__";
625         }
626 
627         // the transformation from a wider colorspace to a narrower one can
628         // result in >1.0 or <0.0 pixel values
629         if (needs.hasOutputTransformMatrix()) {
630             fs << "uniform mat4 outputTransformMatrix;";
631             fs << R"__SHADER__(
632                 highp vec3 OutputTransform(const highp vec3 color) {
633                     return clamp(vec3(outputTransformMatrix * vec4(color, 1.0)), 0.0, 1.0);
634                 }
635             )__SHADER__";
636         } else {
637             fs << R"__SHADER__(
638                 highp vec3 OutputTransform(const highp vec3 color) {
639                     return clamp(color, 0.0, 1.0);
640                 }
641             )__SHADER__";
642         }
643 
644         generateEOTF(fs, needs);
645         generateOOTF(fs, needs);
646         generateOETF(fs, needs);
647     }
648 
649     fs << "void main(void) {" << indent;
650     if (needs.isTexturing()) {
651         fs << "gl_FragColor = texture2D(sampler, outTexCoords);";
652         if (needs.isY410BT2020()) {
653             fs << "gl_FragColor.rgb = convertY410BT2020(gl_FragColor.rgb);";
654         }
655     } else {
656         fs << "gl_FragColor.rgb = color.rgb;";
657         fs << "gl_FragColor.a = 1.0;";
658     }
659     if (needs.isOpaque()) {
660         fs << "gl_FragColor.a = 1.0;";
661     }
662     if (needs.hasAlpha()) {
663         // modulate the current alpha value with alpha set
664         if (needs.isPremultiplied()) {
665             // ... and the color too if we're premultiplied
666             fs << "gl_FragColor *= color.a;";
667         } else {
668             fs << "gl_FragColor.a *= color.a;";
669         }
670     }
671 
672     if (needs.hasTransformMatrix() || (needs.getInputTF() != needs.getOutputTF())) {
673         if (!needs.isOpaque() && needs.isPremultiplied()) {
674             // un-premultiply if needed before linearization
675             // avoid divide by 0 by adding 0.5/256 to the alpha channel
676             fs << "gl_FragColor.rgb = gl_FragColor.rgb / (gl_FragColor.a + 0.0019);";
677         }
678         fs << "gl_FragColor.rgb = "
679               "OETF(OutputTransform(OOTF(InputTransform(EOTF(gl_FragColor.rgb)))));";
680         if (!needs.isOpaque() && needs.isPremultiplied()) {
681             // and re-premultiply if needed after gamma correction
682             fs << "gl_FragColor.rgb = gl_FragColor.rgb * (gl_FragColor.a + 0.0019);";
683         }
684     }
685 
686     if (needs.hasRoundedCorners()) {
687         if (needs.isPremultiplied()) {
688             fs << "gl_FragColor *= vec4(applyCornerRadius(outCropCoords));";
689         } else {
690             fs << "gl_FragColor.a *= applyCornerRadius(outCropCoords);";
691         }
692     }
693 
694     fs << dedent << "}";
695     return fs.getString();
696 }
697 
generateProgram(const Key & needs)698 std::unique_ptr<Program> ProgramCache::generateProgram(const Key& needs) {
699     ATRACE_CALL();
700 
701     // vertex shader
702     String8 vs = generateVertexShader(needs);
703 
704     // fragment shader
705     String8 fs = generateFragmentShader(needs);
706 
707     return std::make_unique<Program>(needs, vs.string(), fs.string());
708 }
709 
useProgram(EGLContext context,const Description & description)710 void ProgramCache::useProgram(EGLContext context, const Description& description) {
711     // generate the key for the shader based on the description
712     Key needs(computeKey(description));
713 
714     // look-up the program in the cache
715     auto& cache = mCaches[context];
716     auto it = cache.find(needs);
717     if (it == cache.end()) {
718         // we didn't find our program, so generate one...
719         nsecs_t time = systemTime();
720         it = cache.emplace(needs, generateProgram(needs)).first;
721         time = systemTime() - time;
722 
723         ALOGV(">>> generated new program for context %p: needs=%08X, time=%u ms (%zu programs)",
724               context, needs.mKey, uint32_t(ns2ms(time)), cache.size());
725     }
726 
727     // here we have a suitable program for this description
728     std::unique_ptr<Program>& program = it->second;
729     if (program->isValid()) {
730         program->use();
731         program->setUniforms(description);
732     }
733 }
734 
735 } // namespace gl
736 } // namespace renderengine
737 } // namespace android
738