491626500ec78cc9a88e692e885ebcddd288a9c6
[movit] / effect_chain.cpp
1 #define GL_GLEXT_PROTOTYPES 1
2
3 #include <stdio.h>
4 #include <math.h>
5 #include <string.h>
6 #include <assert.h>
7
8 #include <algorithm>
9 #include <set>
10 #include <stack>
11 #include <vector>
12
13 #include "util.h"
14 #include "effect_chain.h"
15 #include "gamma_expansion_effect.h"
16 #include "gamma_compression_effect.h"
17 #include "colorspace_conversion_effect.h"
18 #include "dither_effect.h"
19 #include "input.h"
20 #include "opengl.h"
21
22 EffectChain::EffectChain(float aspect_nom, float aspect_denom)
23         : aspect_nom(aspect_nom),
24           aspect_denom(aspect_denom),
25           dither_effect(NULL),
26           fbo(0),
27           num_dither_bits(0),
28           finalized(false) {}
29
30 EffectChain::~EffectChain()
31 {
32         for (unsigned i = 0; i < nodes.size(); ++i) {
33                 if (nodes[i]->output_texture != 0) {
34                         glDeleteTextures(1, &nodes[i]->output_texture);
35                 }
36                 delete nodes[i]->effect;
37                 delete nodes[i];
38         }
39         for (unsigned i = 0; i < phases.size(); ++i) {
40                 glDeleteProgram(phases[i]->glsl_program_num);
41                 glDeleteShader(phases[i]->vertex_shader);
42                 glDeleteShader(phases[i]->fragment_shader);
43                 delete phases[i];
44         }
45         if (fbo != 0) {
46                 glDeleteFramebuffers(1, &fbo);
47         }
48 }
49
50 Input *EffectChain::add_input(Input *input)
51 {
52         inputs.push_back(input);
53
54         Node *node = add_node(input);
55         node->output_color_space = input->get_color_space();
56         node->output_gamma_curve = input->get_gamma_curve();
57         return input;
58 }
59
60 void EffectChain::add_output(const ImageFormat &format)
61 {
62         output_format = format;
63 }
64
65 Node *EffectChain::add_node(Effect *effect)
66 {
67         char effect_id[256];
68         sprintf(effect_id, "eff%u", (unsigned)nodes.size());
69
70         Node *node = new Node;
71         node->effect = effect;
72         node->disabled = false;
73         node->effect_id = effect_id;
74         node->output_color_space = COLORSPACE_INVALID;
75         node->output_gamma_curve = GAMMA_INVALID;
76         node->output_texture = 0;
77
78         nodes.push_back(node);
79         node_map[effect] = node;
80         return node;
81 }
82
83 void EffectChain::connect_nodes(Node *sender, Node *receiver)
84 {
85         sender->outgoing_links.push_back(receiver);
86         receiver->incoming_links.push_back(sender);
87 }
88
89 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
90 {
91         new_receiver->incoming_links = old_receiver->incoming_links;
92         old_receiver->incoming_links.clear();
93         
94         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
95                 Node *sender = new_receiver->incoming_links[i];
96                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
97                         if (sender->outgoing_links[j] == old_receiver) {
98                                 sender->outgoing_links[j] = new_receiver;
99                         }
100                 }
101         }       
102 }
103
104 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
105 {
106         new_sender->outgoing_links = old_sender->outgoing_links;
107         old_sender->outgoing_links.clear();
108         
109         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
110                 Node *receiver = new_sender->outgoing_links[i];
111                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
112                         if (receiver->incoming_links[j] == old_sender) {
113                                 receiver->incoming_links[j] = new_sender;
114                         }
115                 }
116         }       
117 }
118
119 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
120 {
121         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
122                 if (sender->outgoing_links[i] == receiver) {
123                         sender->outgoing_links[i] = middle;
124                         middle->incoming_links.push_back(sender);
125                 }
126         }
127         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
128                 if (receiver->incoming_links[i] == sender) {
129                         receiver->incoming_links[i] = middle;
130                         middle->outgoing_links.push_back(receiver);
131                 }
132         }
133
134         assert(middle->incoming_links.size() == middle->effect->num_inputs());
135 }
136
137 void EffectChain::find_all_nonlinear_inputs(Node *node, std::vector<Node *> *nonlinear_inputs)
138 {
139         if (node->output_gamma_curve == GAMMA_LINEAR &&
140             node->effect->effect_type_id() != "GammaCompressionEffect") {
141                 return;
142         }
143         if (node->effect->num_inputs() == 0) {
144                 nonlinear_inputs->push_back(node);
145         } else {
146                 assert(node->effect->num_inputs() == node->incoming_links.size());
147                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
148                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
149                 }
150         }
151 }
152
153 Effect *EffectChain::add_effect(Effect *effect, const std::vector<Effect *> &inputs)
154 {
155         assert(inputs.size() == effect->num_inputs());
156         Node *node = add_node(effect);
157         for (unsigned i = 0; i < inputs.size(); ++i) {
158                 assert(node_map.count(inputs[i]) != 0);
159                 connect_nodes(node_map[inputs[i]], node);
160         }
161         return effect;
162 }
163
164 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
165 std::string replace_prefix(const std::string &text, const std::string &prefix)
166 {
167         std::string output;
168         size_t start = 0;
169
170         while (start < text.size()) {
171                 size_t pos = text.find("PREFIX(", start);
172                 if (pos == std::string::npos) {
173                         output.append(text.substr(start, std::string::npos));
174                         break;
175                 }
176
177                 output.append(text.substr(start, pos - start));
178                 output.append(prefix);
179                 output.append("_");
180
181                 pos += strlen("PREFIX(");
182         
183                 // Output stuff until we find the matching ), which we then eat.
184                 int depth = 1;
185                 size_t end_arg_pos = pos;
186                 while (end_arg_pos < text.size()) {
187                         if (text[end_arg_pos] == '(') {
188                                 ++depth;
189                         } else if (text[end_arg_pos] == ')') {
190                                 --depth;
191                                 if (depth == 0) {
192                                         break;
193                                 }
194                         }
195                         ++end_arg_pos;
196                 }
197                 output.append(text.substr(pos, end_arg_pos - pos));
198                 ++end_arg_pos;
199                 assert(depth == 0);
200                 start = end_arg_pos;
201         }
202         return output;
203 }
204
205 Phase *EffectChain::compile_glsl_program(
206         const std::vector<Node *> &inputs,
207         const std::vector<Node *> &effects)
208 {
209         assert(!effects.empty());
210
211         // Deduplicate the inputs.
212         std::vector<Node *> true_inputs = inputs;
213         std::sort(true_inputs.begin(), true_inputs.end());
214         true_inputs.erase(std::unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
215
216         bool input_needs_mipmaps = false;
217         std::string frag_shader = read_file("header.frag");
218
219         // Create functions for all the texture inputs that we need.
220         for (unsigned i = 0; i < true_inputs.size(); ++i) {
221                 Node *input = true_inputs[i];
222         
223                 frag_shader += std::string("uniform sampler2D tex_") + input->effect_id + ";\n";
224                 frag_shader += std::string("vec4 ") + input->effect_id + "(vec2 tc) {\n";
225                 frag_shader += "\treturn texture2D(tex_" + input->effect_id + ", tc);\n";
226                 frag_shader += "}\n";
227                 frag_shader += "\n";
228         }
229
230         for (unsigned i = 0; i < effects.size(); ++i) {
231                 Node *node = effects[i];
232
233                 if (node->incoming_links.size() == 1) {
234                         frag_shader += std::string("#define INPUT ") + node->incoming_links[0]->effect_id + "\n";
235                 } else {
236                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
237                                 char buf[256];
238                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, node->incoming_links[j]->effect_id.c_str());
239                                 frag_shader += buf;
240                         }
241                 }
242         
243                 frag_shader += "\n";
244                 frag_shader += std::string("#define FUNCNAME ") + node->effect_id + "\n";
245                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), node->effect_id);
246                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), node->effect_id);
247                 frag_shader += "#undef PREFIX\n";
248                 frag_shader += "#undef FUNCNAME\n";
249                 if (node->incoming_links.size() == 1) {
250                         frag_shader += "#undef INPUT\n";
251                 } else {
252                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
253                                 char buf[256];
254                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
255                                 frag_shader += buf;
256                         }
257                 }
258                 frag_shader += "\n";
259
260                 input_needs_mipmaps |= node->effect->needs_mipmaps();
261         }
262         for (unsigned i = 0; i < effects.size(); ++i) {
263                 Node *node = effects[i];
264                 if (node->effect->num_inputs() == 0) {
265                         CHECK(node->effect->set_int("needs_mipmaps", input_needs_mipmaps));
266                 }
267         }
268         frag_shader += std::string("#define INPUT ") + effects.back()->effect_id + "\n";
269         frag_shader.append(read_file("footer.frag"));
270
271         // Output shader to a temporary file, for easier debugging.
272         static int compiled_shader_num = 0;
273         char filename[256];
274         sprintf(filename, "chain-%03d.frag", compiled_shader_num++);
275         FILE *fp = fopen(filename, "w");
276         if (fp == NULL) {
277                 perror(filename);
278                 exit(1);
279         }
280         fprintf(fp, "%s\n", frag_shader.c_str());
281         fclose(fp);
282         
283         GLuint glsl_program_num = glCreateProgram();
284         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
285         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
286         glAttachShader(glsl_program_num, vs_obj);
287         check_error();
288         glAttachShader(glsl_program_num, fs_obj);
289         check_error();
290         glLinkProgram(glsl_program_num);
291         check_error();
292
293         Phase *phase = new Phase;
294         phase->glsl_program_num = glsl_program_num;
295         phase->vertex_shader = vs_obj;
296         phase->fragment_shader = fs_obj;
297         phase->input_needs_mipmaps = input_needs_mipmaps;
298         phase->inputs = true_inputs;
299         phase->effects = effects;
300
301         return phase;
302 }
303
304 // Construct GLSL programs, starting at the given effect and following
305 // the chain from there. We end a program every time we come to an effect
306 // marked as "needs texture bounce", one that is used by multiple other
307 // effects, every time an effect wants to change the output size,
308 // and of course at the end.
309 //
310 // We follow a quite simple depth-first search from the output, although
311 // without any explicit recursion.
312 void EffectChain::construct_glsl_programs(Node *output)
313 {
314         // Which effects have already been completed in this phase?
315         // We need to keep track of it, as an effect with multiple outputs
316         // could otherwise be calculate multiple times.
317         std::set<Node *> completed_effects;
318
319         // Effects in the current phase, as well as inputs (outputs from other phases
320         // that we depend on). Note that since we start iterating from the end,
321         // the effect list will be in the reverse order.
322         std::vector<Node *> this_phase_inputs;
323         std::vector<Node *> this_phase_effects;
324
325         // Effects that we have yet to calculate, but that we know should
326         // be in the current phase.
327         std::stack<Node *> effects_todo_this_phase;
328
329         // Effects that we have yet to calculate, but that come from other phases.
330         // We delay these until we have this phase done in its entirety,
331         // at which point we pick any of them and start a new phase from that.
332         std::stack<Node *> effects_todo_other_phases;
333
334         effects_todo_this_phase.push(output);
335
336         for ( ;; ) {  // Termination condition within loop.
337                 if (!effects_todo_this_phase.empty()) {
338                         // OK, we have more to do this phase.
339                         Node *node = effects_todo_this_phase.top();
340                         effects_todo_this_phase.pop();
341
342                         // This should currently only happen for effects that are phase outputs,
343                         // and we throw those out separately below.
344                         assert(completed_effects.count(node) == 0);
345
346                         this_phase_effects.push_back(node);
347                         completed_effects.insert(node);
348
349                         // Find all the dependencies of this effect, and add them to the stack.
350                         std::vector<Node *> deps = node->incoming_links;
351                         assert(node->effect->num_inputs() == deps.size());
352                         for (unsigned i = 0; i < deps.size(); ++i) {
353                                 bool start_new_phase = false;
354
355                                 // FIXME: If we sample directly from a texture, we won't need this.
356                                 if (node->effect->needs_texture_bounce()) {
357                                         start_new_phase = true;
358                                 }
359
360                                 if (deps[i]->outgoing_links.size() > 1) {
361                                         if (deps[i]->effect->num_inputs() > 0) {
362                                                 // More than one effect uses this as the input,
363                                                 // and it is not a texture itself.
364                                                 // The easiest thing to do (and probably also the safest
365                                                 // performance-wise in most cases) is to bounce it to a texture
366                                                 // and then let the next passes read from that.
367                                                 start_new_phase = true;
368                                         } else {
369                                                 // For textures, we try to be slightly more clever;
370                                                 // if none of our outputs need a bounce, we don't bounce
371                                                 // but instead simply use the effect many times.
372                                                 //
373                                                 // Strictly speaking, we could bounce it for some outputs
374                                                 // and use it directly for others, but the processing becomes
375                                                 // somewhat simpler if the effect is only used in one such way.
376                                                 for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
377                                                         Node *rdep = deps[i]->outgoing_links[j];
378                                                         start_new_phase |= rdep->effect->needs_texture_bounce();
379                                                 }
380                                         }
381                                 }
382
383                                 if (deps[i]->effect->changes_output_size()) {
384                                         start_new_phase = true;
385                                 }
386
387                                 if (start_new_phase) {
388                                         effects_todo_other_phases.push(deps[i]);
389                                         this_phase_inputs.push_back(deps[i]);
390                                 } else {
391                                         effects_todo_this_phase.push(deps[i]);
392                                 }
393                         }
394                         continue;
395                 }
396
397                 // No more effects to do this phase. Take all the ones we have,
398                 // and create a GLSL program for it.
399                 if (!this_phase_effects.empty()) {
400                         reverse(this_phase_effects.begin(), this_phase_effects.end());
401                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
402                         this_phase_effects.back()->phase = phases.back();
403                         this_phase_inputs.clear();
404                         this_phase_effects.clear();
405                 }
406                 assert(this_phase_inputs.empty());
407                 assert(this_phase_effects.empty());
408
409                 // If we have no effects left, exit.
410                 if (effects_todo_other_phases.empty()) {
411                         break;
412                 }
413
414                 Node *node = effects_todo_other_phases.top();
415                 effects_todo_other_phases.pop();
416
417                 if (completed_effects.count(node) == 0) {
418                         // Start a new phase, calculating from this effect.
419                         effects_todo_this_phase.push(node);
420                 }
421         }
422
423         // Finally, since the phases are found from the output but must be executed
424         // from the input(s), reverse them, too.
425         std::reverse(phases.begin(), phases.end());
426 }
427
428 void EffectChain::output_dot(const char *filename)
429 {
430         FILE *fp = fopen(filename, "w");
431         if (fp == NULL) {
432                 perror(filename);
433                 exit(1);
434         }
435
436         fprintf(fp, "digraph G {\n");
437         for (unsigned i = 0; i < nodes.size(); ++i) {
438                 // Find out which phase this event belongs to.
439                 int in_phase = -1;
440                 for (unsigned j = 0; j < phases.size(); ++j) {
441                         const Phase* p = phases[j];
442                         if (std::find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
443                                 assert(in_phase == -1);
444                                 in_phase = j;
445                         }
446                 }
447
448                 if (in_phase == -1) {
449                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
450                 } else {
451                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
452                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
453                                 (in_phase % 8) + 1);
454                 }
455                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
456                         std::vector<std::string> labels;
457
458                         if (nodes[i]->outgoing_links[j]->effect->needs_texture_bounce()) {
459                                 labels.push_back("needs_bounce");
460                         }
461                         if (nodes[i]->effect->changes_output_size()) {
462                                 labels.push_back("resize");
463                         }
464
465                         switch (nodes[i]->output_color_space) {
466                         case COLORSPACE_INVALID:
467                                 labels.push_back("spc[invalid]");
468                                 break;
469                         case COLORSPACE_REC_601_525:
470                                 labels.push_back("spc[rec601-525]");
471                                 break;
472                         case COLORSPACE_REC_601_625:
473                                 labels.push_back("spc[rec601-625]");
474                                 break;
475                         default:
476                                 break;
477                         }
478
479                         switch (nodes[i]->output_gamma_curve) {
480                         case GAMMA_INVALID:
481                                 labels.push_back("gamma[invalid]");
482                                 break;
483                         case GAMMA_sRGB:
484                                 labels.push_back("gamma[sRGB]");
485                                 break;
486                         case GAMMA_REC_601:  // and GAMMA_REC_709
487                                 labels.push_back("gamma[rec601/709]");
488                                 break;
489                         default:
490                                 break;
491                         }
492
493                         if (labels.empty()) {
494                                 fprintf(fp, "  n%ld -> n%ld;\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j]);
495                         } else {
496                                 std::string label = labels[0];
497                                 for (unsigned k = 1; k < labels.size(); ++k) {
498                                         label += ", " + labels[k];
499                                 }
500                                 fprintf(fp, "  n%ld -> n%ld [label=\"%s\"];\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j], label.c_str());
501                         }
502                 }
503         }
504         fprintf(fp, "}\n");
505
506         fclose(fp);
507 }
508
509 unsigned EffectChain::fit_rectangle_to_aspect(unsigned width, unsigned height)
510 {
511         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
512                 // Same aspect, or W/H > aspect (image is wider than the frame).
513                 // In either case, keep width.
514                 return width;
515         } else {
516                 // W/H < aspect (image is taller than the frame), so keep height,
517                 // and adjust width correspondingly.
518                 return lrintf(height * aspect_nom / aspect_denom);
519         }
520 }
521
522 // Propagate input texture sizes throughout, and inform effects downstream.
523 // (Like a lot of other code, we depend on effects being in topological order.)
524 void EffectChain::inform_input_sizes(Phase *phase)
525 {
526         // All effects that have a defined size (inputs and RTT inputs)
527         // get that. Reset all others.
528         for (unsigned i = 0; i < phase->effects.size(); ++i) {
529                 Node *node = phase->effects[i];
530                 if (node->effect->num_inputs() == 0) {
531                         Input *input = static_cast<Input *>(node->effect);
532                         node->output_width = input->get_width();
533                         node->output_height = input->get_height();
534                         assert(node->output_width != 0);
535                         assert(node->output_height != 0);
536                 } else {
537                         node->output_width = node->output_height = 0;
538                 }
539         }
540         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
541                 Node *input = phase->inputs[i];
542                 input->output_width = input->phase->output_width;
543                 input->output_height = input->phase->output_height;
544                 assert(input->output_width != 0);
545                 assert(input->output_height != 0);
546         }
547
548         // Now propagate from the inputs towards the end, and inform as we go.
549         // The rules are simple:
550         //
551         //   1. Don't touch effects that already have given sizes (ie., inputs).
552         //   2. If all of your inputs have the same size, that will be your output size.
553         //   3. Otherwise, your output size is 0x0.
554         for (unsigned i = 0; i < phase->effects.size(); ++i) {
555                 Node *node = phase->effects[i];
556                 if (node->effect->num_inputs() == 0) {
557                         continue;
558                 }
559                 unsigned this_output_width = 0;
560                 unsigned this_output_height = 0;
561                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
562                         Node *input = node->incoming_links[j];
563                         node->effect->inform_input_size(j, input->output_width, input->output_height);
564                         if (j == 0) {
565                                 this_output_width = input->output_width;
566                                 this_output_height = input->output_height;
567                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
568                                 // Inputs disagree.
569                                 this_output_width = 0;
570                                 this_output_height = 0;
571                         }
572                 }
573                 node->output_width = this_output_width;
574                 node->output_height = this_output_height;
575         }
576 }
577
578 // Note: You should call inform_input_sizes() before this, as the last effect's
579 // desired output size might change based on the inputs.
580 void EffectChain::find_output_size(Phase *phase)
581 {
582         Node *output_node = phase->effects.back();
583
584         // If the last effect explicitly sets an output size, use that.
585         if (output_node->effect->changes_output_size()) {
586                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height);
587                 return;
588         }
589
590         // If not, look at the input phases and textures.
591         // We select the largest one (by fit into the current aspect).
592         unsigned best_width = 0;
593         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
594                 Node *input = phase->inputs[i];
595                 assert(input->phase->output_width != 0);
596                 assert(input->phase->output_height != 0);
597                 unsigned width = fit_rectangle_to_aspect(input->phase->output_width, input->phase->output_height);
598                 if (width > best_width) {
599                         best_width = width;
600                 }
601         }
602         for (unsigned i = 0; i < phase->effects.size(); ++i) {
603                 Effect *effect = phase->effects[i]->effect;
604                 if (effect->num_inputs() != 0) {
605                         continue;
606                 }
607
608                 Input *input = static_cast<Input *>(effect);
609                 unsigned width = fit_rectangle_to_aspect(input->get_width(), input->get_height());
610                 if (width > best_width) {
611                         best_width = width;
612                 }
613         }
614         assert(best_width != 0);
615         phase->output_width = best_width;
616         phase->output_height = best_width * aspect_denom / aspect_nom;
617 }
618
619 void EffectChain::sort_nodes_topologically()
620 {
621         std::set<Node *> visited_nodes;
622         std::vector<Node *> sorted_list;
623         for (unsigned i = 0; i < nodes.size(); ++i) {
624                 if (nodes[i]->incoming_links.size() == 0) {
625                         topological_sort_visit_node(nodes[i], &visited_nodes, &sorted_list);
626                 }
627         }
628         reverse(sorted_list.begin(), sorted_list.end());
629         nodes = sorted_list;
630 }
631
632 void EffectChain::topological_sort_visit_node(Node *node, std::set<Node *> *visited_nodes, std::vector<Node *> *sorted_list)
633 {
634         if (visited_nodes->count(node) != 0) {
635                 return;
636         }
637         visited_nodes->insert(node);
638         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
639                 topological_sort_visit_node(node->outgoing_links[i], visited_nodes, sorted_list);
640         }
641         sorted_list->push_back(node);
642 }
643
644 // Propagate gamma and color space information as far as we can in the graph.
645 // The rules are simple: Anything where all the inputs agree, get that as
646 // output as well. Anything else keeps having *_INVALID.
647 void EffectChain::propagate_gamma_and_color_space()
648 {
649         // We depend on going through the nodes in order.
650         sort_nodes_topologically();
651
652         for (unsigned i = 0; i < nodes.size(); ++i) {
653                 Node *node = nodes[i];
654                 if (node->disabled) {
655                         continue;
656                 }
657                 assert(node->incoming_links.size() == node->effect->num_inputs());
658                 if (node->incoming_links.size() == 0) {
659                         assert(node->output_color_space != COLORSPACE_INVALID);
660                         assert(node->output_gamma_curve != GAMMA_INVALID);
661                         continue;
662                 }
663
664                 Colorspace color_space = node->incoming_links[0]->output_color_space;
665                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
666                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
667                         if (node->incoming_links[j]->output_color_space != color_space) {
668                                 color_space = COLORSPACE_INVALID;
669                         }
670                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
671                                 gamma_curve = GAMMA_INVALID;
672                         }
673                 }
674
675                 // The conversion effects already have their outputs set correctly,
676                 // so leave them alone.
677                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
678                         node->output_color_space = color_space;
679                 }               
680                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
681                     node->effect->effect_type_id() != "GammaExpansionEffect") {
682                         node->output_gamma_curve = gamma_curve;
683                 }               
684         }
685 }
686
687 bool EffectChain::node_needs_colorspace_fix(Node *node)
688 {
689         if (node->disabled) {
690                 return false;
691         }
692         if (node->effect->num_inputs() == 0) {
693                 return false;
694         }
695
696         // propagate_gamma_and_color_space() has already set our output
697         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
698         if (node->output_color_space == COLORSPACE_INVALID) {
699                 return true;
700         }
701         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
702 }
703
704 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
705 // the graph. Our strategy is not always optimal, but quite simple:
706 // Find an effect that's as early as possible where the inputs are of
707 // unacceptable colorspaces (that is, either different, or, if the effect only
708 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
709 // propagate the information anew, and repeat until there are no more such
710 // effects.
711 void EffectChain::fix_internal_color_spaces()
712 {
713         unsigned colorspace_propagation_pass = 0;
714         bool found_any;
715         do {
716                 found_any = false;
717                 for (unsigned i = 0; i < nodes.size(); ++i) {
718                         Node *node = nodes[i];
719                         if (!node_needs_colorspace_fix(node)) {
720                                 continue;
721                         }
722
723                         // Go through each input that is not sRGB, and insert
724                         // a colorspace conversion before it.
725                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
726                                 Node *input = node->incoming_links[j];
727                                 assert(input->output_color_space != COLORSPACE_INVALID);
728                                 if (input->output_color_space == COLORSPACE_sRGB) {
729                                         continue;
730                                 }
731                                 Node *conversion = add_node(new ColorspaceConversionEffect());
732                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
733                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
734                                 conversion->output_color_space = COLORSPACE_sRGB;
735                                 insert_node_between(input, conversion, node);
736                         }
737
738                         // Re-sort topologically, and propagate the new information.
739                         propagate_gamma_and_color_space();
740                         
741                         found_any = true;
742                         break;
743                 }
744         
745                 char filename[256];
746                 sprintf(filename, "step3-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
747                 output_dot(filename);
748                 assert(colorspace_propagation_pass < 100);
749         } while (found_any);
750
751         for (unsigned i = 0; i < nodes.size(); ++i) {
752                 Node *node = nodes[i];
753                 if (node->disabled) {
754                         continue;
755                 }
756                 assert(node->output_color_space != COLORSPACE_INVALID);
757         }
758 }
759
760 // Make so that the output is in the desired color space.
761 void EffectChain::fix_output_color_space()
762 {
763         Node *output = find_output_node();
764         if (output->output_color_space != output_format.color_space) {
765                 Node *conversion = add_node(new ColorspaceConversionEffect());
766                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
767                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
768                 conversion->output_color_space = output_format.color_space;
769                 connect_nodes(output, conversion);
770                 propagate_gamma_and_color_space();
771         }
772 }
773
774 bool EffectChain::node_needs_gamma_fix(Node *node)
775 {
776         if (node->disabled) {
777                 return false;
778         }
779
780         // Small hack since the output is not an explicit node:
781         // If we are the last node and our output is in the wrong
782         // space compared to EffectChain's output, we need to fix it.
783         // This will only take us to linear, but fix_output_gamma()
784         // will come and take us to the desired output gamma
785         // if it is needed.
786         //
787         // This needs to be before everything else, since it could
788         // even apply to inputs (if they are the only effect).
789         if (node->outgoing_links.empty() &&
790             node->output_gamma_curve != output_format.gamma_curve &&
791             node->output_gamma_curve != GAMMA_LINEAR) {
792                 return true;
793         }
794
795         if (node->effect->num_inputs() == 0) {
796                 return false;
797         }
798
799         // propagate_gamma_and_color_space() has already set our output
800         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
801         // except for GammaCompressionEffect.
802         if (node->output_gamma_curve == GAMMA_INVALID) {
803                 return true;
804         }
805         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
806                 assert(node->incoming_links.size() == 1);
807                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
808         }
809
810         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
811 }
812
813 // Very similar to fix_internal_color_spaces(), but for gamma.
814 // There is one difference, though; before we start adding conversion nodes,
815 // we see if we can get anything out of asking the sources to deliver
816 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
817 // does that part, while fix_internal_gamma_by_inserting_nodes()
818 // inserts nodes as needed afterwards.
819 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
820 {
821         unsigned gamma_propagation_pass = 0;
822         bool found_any;
823         do {
824                 found_any = false;
825                 for (unsigned i = 0; i < nodes.size(); ++i) {
826                         Node *node = nodes[i];
827                         if (!node_needs_gamma_fix(node)) {
828                                 continue;
829                         }
830
831                         // See if all inputs can give us linear gamma. If not, leave it.
832                         std::vector<Node *> nonlinear_inputs;
833                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
834                         assert(!nonlinear_inputs.empty());
835
836                         bool all_ok = true;
837                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
838                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
839                                 all_ok &= input->can_output_linear_gamma();
840                         }
841
842                         if (!all_ok) {
843                                 continue;
844                         }
845
846                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
847                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
848                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
849                         }
850
851                         // Re-sort topologically, and propagate the new information.
852                         propagate_gamma_and_color_space();
853                         
854                         found_any = true;
855                         break;
856                 }
857         
858                 char filename[256];
859                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
860                 output_dot(filename);
861                 assert(gamma_propagation_pass < 100);
862         } while (found_any);
863 }
864
865 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
866 {
867         unsigned gamma_propagation_pass = 0;
868         bool found_any;
869         do {
870                 found_any = false;
871                 for (unsigned i = 0; i < nodes.size(); ++i) {
872                         Node *node = nodes[i];
873                         if (!node_needs_gamma_fix(node)) {
874                                 continue;
875                         }
876
877                         // Special case: We could be an input and still be asked to
878                         // fix our gamma; if so, we should be the only node
879                         // (as node_needs_gamma_fix() would only return true in
880                         // for an input in that case). That means we should insert
881                         // a conversion node _after_ ourselves.
882                         if (node->incoming_links.empty()) {
883                                 assert(node->outgoing_links.empty());
884                                 Node *conversion = add_node(new GammaExpansionEffect());
885                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
886                                 conversion->output_gamma_curve = GAMMA_LINEAR;
887                                 connect_nodes(node, conversion);
888                         }
889
890                         // If not, go through each input that is not linear gamma,
891                         // and insert a gamma conversion before it.
892                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
893                                 Node *input = node->incoming_links[j];
894                                 assert(input->output_gamma_curve != GAMMA_INVALID);
895                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
896                                         continue;
897                                 }
898                                 Node *conversion = add_node(new GammaExpansionEffect());
899                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
900                                 conversion->output_gamma_curve = GAMMA_LINEAR;
901                                 insert_node_between(input, conversion, node);
902                         }
903
904                         // Re-sort topologically, and propagate the new information.
905                         propagate_gamma_and_color_space();
906                         
907                         found_any = true;
908                         break;
909                 }
910         
911                 char filename[256];
912                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
913                 output_dot(filename);
914                 assert(gamma_propagation_pass < 100);
915         } while (found_any);
916
917         for (unsigned i = 0; i < nodes.size(); ++i) {
918                 Node *node = nodes[i];
919                 if (node->disabled) {
920                         continue;
921                 }
922                 assert(node->output_gamma_curve != GAMMA_INVALID);
923         }
924 }
925
926 // Make so that the output is in the desired gamma.
927 // Note that this assumes linear input gamma, so it might create the need
928 // for another pass of fix_internal_gamma().
929 void EffectChain::fix_output_gamma()
930 {
931         Node *output = find_output_node();
932         if (output->output_gamma_curve != output_format.gamma_curve) {
933                 Node *conversion = add_node(new GammaCompressionEffect());
934                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
935                 conversion->output_gamma_curve = output_format.gamma_curve;
936                 connect_nodes(output, conversion);
937         }
938 }
939         
940 // If the user has requested dither, add a DitherEffect right at the end
941 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
942 // since dither is about the only effect that can _not_ be done in linear space.
943 void EffectChain::add_dither_if_needed()
944 {
945         if (num_dither_bits == 0) {
946                 return;
947         }
948         Node *output = find_output_node();
949         Node *dither = add_node(new DitherEffect());
950         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
951         connect_nodes(output, dither);
952
953         dither_effect = dither->effect;
954 }
955
956 // Find the output node. This is, simply, one that has no outgoing links.
957 // If there are multiple ones, the graph is malformed (we do not support
958 // multiple outputs right now).
959 Node *EffectChain::find_output_node()
960 {
961         std::vector<Node *> output_nodes;
962         for (unsigned i = 0; i < nodes.size(); ++i) {
963                 Node *node = nodes[i];
964                 if (node->disabled) {
965                         continue;
966                 }
967                 if (node->outgoing_links.empty()) {
968                         output_nodes.push_back(node);
969                 }
970         }
971         assert(output_nodes.size() == 1);
972         return output_nodes[0];
973 }
974
975 void EffectChain::finalize()
976 {
977         // Output the graph as it is before we do any conversions on it.
978         output_dot("step0-start.dot");
979
980         // Give each effect in turn a chance to rewrite its own part of the graph.
981         // Note that if more effects are added as part of this, they will be
982         // picked up as part of the same for loop, since they are added at the end.
983         for (unsigned i = 0; i < nodes.size(); ++i) {
984                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
985         }
986         output_dot("step1-rewritten.dot");
987
988         propagate_gamma_and_color_space();
989         output_dot("step2-propagated.dot");
990
991         fix_internal_color_spaces();
992         fix_output_color_space();
993         output_dot("step4-output-colorspacefix.dot");
994
995         // Note that we need to fix gamma after colorspace conversion,
996         // because colorspace conversions might create needs for gamma conversions.
997         // Also, we need to run an extra pass of fix_internal_gamma() after 
998         // fixing the output gamma, as we only have conversions to/from linear.
999         fix_internal_gamma_by_asking_inputs(5);
1000         fix_internal_gamma_by_inserting_nodes(6);
1001         fix_output_gamma();
1002         output_dot("step7-output-gammafix.dot");
1003         fix_internal_gamma_by_asking_inputs(8);
1004         fix_internal_gamma_by_inserting_nodes(9);
1005
1006         output_dot("step10-before-dither.dot");
1007
1008         add_dither_if_needed();
1009
1010         output_dot("step11-final.dot");
1011         
1012         // Construct all needed GLSL programs, starting at the output.
1013         construct_glsl_programs(find_output_node());
1014
1015         output_dot("step12-split-to-phases.dot");
1016
1017         // If we have more than one phase, we need intermediate render-to-texture.
1018         // Construct an FBO, and then as many textures as we need.
1019         // We choose the simplest option of having one texture per output,
1020         // since otherwise this turns into an (albeit simple)
1021         // register allocation problem.
1022         if (phases.size() > 1) {
1023                 glGenFramebuffers(1, &fbo);
1024
1025                 for (unsigned i = 0; i < phases.size() - 1; ++i) {
1026                         inform_input_sizes(phases[i]);
1027                         find_output_size(phases[i]);
1028
1029                         Node *output_node = phases[i]->effects.back();
1030                         glGenTextures(1, &output_node->output_texture);
1031                         check_error();
1032                         glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1033                         check_error();
1034                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1035                         check_error();
1036                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1037                         check_error();
1038                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[i]->output_width, phases[i]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1039                         check_error();
1040
1041                         output_node->output_texture_width = phases[i]->output_width;
1042                         output_node->output_texture_height = phases[i]->output_height;
1043                 }
1044                 inform_input_sizes(phases.back());
1045         }
1046                 
1047         for (unsigned i = 0; i < inputs.size(); ++i) {
1048                 inputs[i]->finalize();
1049         }
1050
1051         assert(phases[0]->inputs.empty());
1052         
1053         finalized = true;
1054 }
1055
1056 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1057 {
1058         assert(finalized);
1059
1060         // Save original viewport.
1061         GLuint x = 0, y = 0;
1062
1063         if (width == 0 && height == 0) {
1064                 GLint viewport[4];
1065                 glGetIntegerv(GL_VIEWPORT, viewport);
1066                 x = viewport[0];
1067                 y = viewport[1];
1068                 width = viewport[2];
1069                 height = viewport[3];
1070         }
1071
1072         // Basic state.
1073         glDisable(GL_BLEND);
1074         check_error();
1075         glDisable(GL_DEPTH_TEST);
1076         check_error();
1077         glDepthMask(GL_FALSE);
1078         check_error();
1079
1080         glMatrixMode(GL_PROJECTION);
1081         glLoadIdentity();
1082         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
1083
1084         glMatrixMode(GL_MODELVIEW);
1085         glLoadIdentity();
1086
1087         if (phases.size() > 1) {
1088                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1089                 check_error();
1090         }
1091
1092         std::set<Node *> generated_mipmaps;
1093
1094         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1095                 // See if the requested output size has changed. If so, we need to recreate
1096                 // the texture (and before we start setting up inputs).
1097                 inform_input_sizes(phases[phase]);
1098                 if (phase != phases.size() - 1) {
1099                         find_output_size(phases[phase]);
1100
1101                         Node *output_node = phases[phase]->effects.back();
1102
1103                         if (output_node->output_texture_width != phases[phase]->output_width ||
1104                             output_node->output_texture_height != phases[phase]->output_height) {
1105                                 glActiveTexture(GL_TEXTURE0);
1106                                 check_error();
1107                                 glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1108                                 check_error();
1109                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1110                                 check_error();
1111                                 glBindTexture(GL_TEXTURE_2D, 0);
1112                                 check_error();
1113
1114                                 output_node->output_texture_width = phases[phase]->output_width;
1115                                 output_node->output_texture_height = phases[phase]->output_height;
1116                         }
1117                 }
1118
1119                 glUseProgram(phases[phase]->glsl_program_num);
1120                 check_error();
1121
1122                 // Set up RTT inputs for this phase.
1123                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1124                         glActiveTexture(GL_TEXTURE0 + sampler);
1125                         Node *input = phases[phase]->inputs[sampler];
1126                         glBindTexture(GL_TEXTURE_2D, input->output_texture);
1127                         check_error();
1128                         if (phases[phase]->input_needs_mipmaps) {
1129                                 if (generated_mipmaps.count(input) == 0) {
1130                                         glGenerateMipmap(GL_TEXTURE_2D);
1131                                         check_error();
1132                                         generated_mipmaps.insert(input);
1133                                 }
1134                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1135                                 check_error();
1136                         } else {
1137                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1138                                 check_error();
1139                         }
1140
1141                         std::string texture_name = std::string("tex_") + input->effect_id;
1142                         glUniform1i(glGetUniformLocation(phases[phase]->glsl_program_num, texture_name.c_str()), sampler);
1143                         check_error();
1144                 }
1145
1146                 // And now the output.
1147                 if (phase == phases.size() - 1) {
1148                         // Last phase goes to the output the user specified.
1149                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1150                         check_error();
1151                         glViewport(x, y, width, height);
1152                         if (dither_effect != NULL) {
1153                                 CHECK(dither_effect->set_int("output_width", width));
1154                                 CHECK(dither_effect->set_int("output_height", height));
1155                         }
1156                 } else {
1157                         Node *output_node = phases[phase]->effects.back();
1158                         glFramebufferTexture2D(
1159                                 GL_FRAMEBUFFER,
1160                                 GL_COLOR_ATTACHMENT0,
1161                                 GL_TEXTURE_2D,
1162                                 output_node->output_texture,
1163                                 0);
1164                         check_error();
1165                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1166                 }
1167
1168                 // Give the required parameters to all the effects.
1169                 unsigned sampler_num = phases[phase]->inputs.size();
1170                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1171                         Node *node = phases[phase]->effects[i];
1172                         node->effect->set_gl_state(phases[phase]->glsl_program_num, node->effect_id, &sampler_num);
1173                         check_error();
1174                 }
1175
1176                 // Now draw!
1177                 glBegin(GL_QUADS);
1178
1179                 glTexCoord2f(0.0f, 0.0f);
1180                 glVertex2f(0.0f, 0.0f);
1181
1182                 glTexCoord2f(1.0f, 0.0f);
1183                 glVertex2f(1.0f, 0.0f);
1184
1185                 glTexCoord2f(1.0f, 1.0f);
1186                 glVertex2f(1.0f, 1.0f);
1187
1188                 glTexCoord2f(0.0f, 1.0f);
1189                 glVertex2f(0.0f, 1.0f);
1190
1191                 glEnd();
1192                 check_error();
1193
1194                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1195                         Node *node = phases[phase]->effects[i];
1196                         node->effect->clear_gl_state();
1197                 }
1198         }
1199 }