Make Phase take other Phases as inputs, not Nodes.
[movit] / effect_chain.cpp
index c886155..c5e10e8 100644 (file)
@@ -227,24 +227,13 @@ string replace_prefix(const string &text, const string &prefix)
        return output;
 }
 
-Phase *EffectChain::compile_glsl_program(
-       const vector<Node *> &inputs,
-       const vector<Node *> &effects)
+void EffectChain::compile_glsl_program(Phase *phase)
 {
-       Phase *phase = new Phase;
-       assert(!effects.empty());
-
-       // Deduplicate the inputs.
-       vector<Node *> true_inputs = inputs;
-       sort(true_inputs.begin(), true_inputs.end());
-       true_inputs.erase(unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
-
-       bool input_needs_mipmaps = false;
        string frag_shader = read_file("header.frag");
 
        // Create functions for all the texture inputs that we need.
-       for (unsigned i = 0; i < true_inputs.size(); ++i) {
-               Node *input = true_inputs[i];
+       for (unsigned i = 0; i < phase->inputs.size(); ++i) {
+               Node *input = phase->inputs[i]->output_node;
                char effect_id[256];
                sprintf(effect_id, "in%u", i);
                phase->effect_ids.insert(make_pair(input, effect_id));
@@ -256,10 +245,8 @@ Phase *EffectChain::compile_glsl_program(
                frag_shader += "\n";
        }
 
-       vector<Node *> sorted_effects = topological_sort(effects);
-
-       for (unsigned i = 0; i < sorted_effects.size(); ++i) {
-               Node *node = sorted_effects[i];
+       for (unsigned i = 0; i < phase->effects.size(); ++i) {
+               Node *node = phase->effects[i];
                char effect_id[256];
                sprintf(effect_id, "eff%u", i);
                phase->effect_ids.insert(make_pair(node, effect_id));
@@ -290,24 +277,11 @@ Phase *EffectChain::compile_glsl_program(
                        }
                }
                frag_shader += "\n";
-
-               input_needs_mipmaps |= node->effect->needs_mipmaps();
-       }
-       for (unsigned i = 0; i < sorted_effects.size(); ++i) {
-               Node *node = sorted_effects[i];
-               if (node->effect->num_inputs() == 0) {
-                       CHECK(node->effect->set_int("needs_mipmaps", input_needs_mipmaps));
-               }
        }
-       frag_shader += string("#define INPUT ") + phase->effect_ids[sorted_effects.back()] + "\n";
+       frag_shader += string("#define INPUT ") + phase->effect_ids[phase->effects.back()] + "\n";
        frag_shader.append(read_file("footer.frag"));
 
        phase->glsl_program_num = resource_pool->compile_glsl_program(read_file("vs.vert"), frag_shader);
-       phase->input_needs_mipmaps = input_needs_mipmaps;
-       phase->inputs = true_inputs;
-       phase->effects = sorted_effects;
-
-       return phase;
 }
 
 // Construct GLSL programs, starting at the given effect and following
@@ -317,130 +291,118 @@ Phase *EffectChain::compile_glsl_program(
 // and of course at the end.
 //
 // We follow a quite simple depth-first search from the output, although
-// without any explicit recursion.
-void EffectChain::construct_glsl_programs(Node *output)
+// without recursing explicitly within each phase.
+Phase *EffectChain::construct_phase(Node *output, map<Node *, Phase *> *completed_effects)
 {
-       // Which effects have already been completed?
-       // We need to keep track of it, as an effect with multiple outputs
-       // could otherwise be calculated multiple times.
-       set<Node *> completed_effects;
+       if (completed_effects->count(output)) {
+               return (*completed_effects)[output];
+       }
 
-       // Effects in the current phase, as well as inputs (outputs from other phases
-       // that we depend on). Note that since we start iterating from the end,
-       // the effect list will be in the reverse order.
-       vector<Node *> this_phase_inputs;
-       vector<Node *> this_phase_effects;
+       Phase *phase = new Phase;
+       phase->output_node = output;
 
        // Effects that we have yet to calculate, but that we know should
        // be in the current phase.
        stack<Node *> effects_todo_this_phase;
-
-       // Effects that we have yet to calculate, but that come from other phases.
-       // We delay these until we have this phase done in its entirety,
-       // at which point we pick any of them and start a new phase from that.
-       stack<Node *> effects_todo_other_phases;
-
        effects_todo_this_phase.push(output);
 
-       for ( ;; ) {  // Termination condition within loop.
-               if (!effects_todo_this_phase.empty()) {
-                       // OK, we have more to do this phase.
-                       Node *node = effects_todo_this_phase.top();
-                       effects_todo_this_phase.pop();
-
-                       // This should currently only happen for effects that are inputs
-                       // (either true inputs or phase outputs). We special-case inputs,
-                       // and then deduplicate phase outputs in compile_glsl_program().
-                       if (node->effect->num_inputs() == 0) {
-                               if (find(this_phase_effects.begin(), this_phase_effects.end(), node) != this_phase_effects.end()) {
-                                       continue;
-                               }
-                       } else {
-                               assert(completed_effects.count(node) == 0);
+       while (!effects_todo_this_phase.empty()) {
+               Node *node = effects_todo_this_phase.top();
+               effects_todo_this_phase.pop();
+
+               // This should currently only happen for effects that are inputs
+               // (either true inputs or phase outputs). We special-case inputs,
+               // and then deduplicate phase outputs below.
+               if (node->effect->num_inputs() == 0) {
+                       if (find(phase->effects.begin(), phase->effects.end(), node) != phase->effects.end()) {
+                               continue;
                        }
+               } else {
+                       assert(completed_effects->count(node) == 0);
+               }
 
-                       this_phase_effects.push_back(node);
-                       completed_effects.insert(node);
+               phase->effects.push_back(node);
 
-                       // Find all the dependencies of this effect, and add them to the stack.
-                       vector<Node *> deps = node->incoming_links;
-                       assert(node->effect->num_inputs() == deps.size());
-                       for (unsigned i = 0; i < deps.size(); ++i) {
-                               bool start_new_phase = false;
+               // Find all the dependencies of this effect, and add them to the stack.
+               vector<Node *> deps = node->incoming_links;
+               assert(node->effect->num_inputs() == deps.size());
+               for (unsigned i = 0; i < deps.size(); ++i) {
+                       bool start_new_phase = false;
 
-                               if (node->effect->needs_texture_bounce() &&
-                                   !deps[i]->effect->is_single_texture()) {
-                                       start_new_phase = true;
-                               }
+                       if (node->effect->needs_texture_bounce() &&
+                           !deps[i]->effect->is_single_texture()) {
+                               start_new_phase = true;
+                       }
 
-                               if (deps[i]->outgoing_links.size() > 1) {
-                                       if (!deps[i]->effect->is_single_texture()) {
-                                               // More than one effect uses this as the input,
-                                               // and it is not a texture itself.
-                                               // The easiest thing to do (and probably also the safest
-                                               // performance-wise in most cases) is to bounce it to a texture
-                                               // and then let the next passes read from that.
-                                               start_new_phase = true;
-                                       } else {
-                                               assert(deps[i]->effect->num_inputs() == 0);
-
-                                               // For textures, we try to be slightly more clever;
-                                               // if none of our outputs need a bounce, we don't bounce
-                                               // but instead simply use the effect many times.
-                                               //
-                                               // Strictly speaking, we could bounce it for some outputs
-                                               // and use it directly for others, but the processing becomes
-                                               // somewhat simpler if the effect is only used in one such way.
-                                               for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
-                                                       Node *rdep = deps[i]->outgoing_links[j];
-                                                       start_new_phase |= rdep->effect->needs_texture_bounce();
-                                               }
+                       if (deps[i]->outgoing_links.size() > 1) {
+                               if (!deps[i]->effect->is_single_texture()) {
+                                       // More than one effect uses this as the input,
+                                       // and it is not a texture itself.
+                                       // The easiest thing to do (and probably also the safest
+                                       // performance-wise in most cases) is to bounce it to a texture
+                                       // and then let the next passes read from that.
+                                       start_new_phase = true;
+                               } else {
+                                       assert(deps[i]->effect->num_inputs() == 0);
+
+                                       // For textures, we try to be slightly more clever;
+                                       // if none of our outputs need a bounce, we don't bounce
+                                       // but instead simply use the effect many times.
+                                       //
+                                       // Strictly speaking, we could bounce it for some outputs
+                                       // and use it directly for others, but the processing becomes
+                                       // somewhat simpler if the effect is only used in one such way.
+                                       for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
+                                               Node *rdep = deps[i]->outgoing_links[j];
+                                               start_new_phase |= rdep->effect->needs_texture_bounce();
                                        }
                                }
+                       }
 
-                               if (deps[i]->effect->changes_output_size()) {
-                                       start_new_phase = true;
-                               }
+                       if (deps[i]->effect->changes_output_size()) {
+                               start_new_phase = true;
+                       }
 
-                               if (start_new_phase) {
-                                       effects_todo_other_phases.push(deps[i]);
-                                       this_phase_inputs.push_back(deps[i]);
-                               } else {
-                                       effects_todo_this_phase.push(deps[i]);
-                               }
+                       if (start_new_phase) {
+                               phase->inputs.push_back(construct_phase(deps[i], completed_effects));
+                       } else {
+                               effects_todo_this_phase.push(deps[i]);
                        }
-                       continue;
                }
+       }
 
-               // No more effects to do this phase. Take all the ones we have,
-               // and create a GLSL program for it.
-               if (!this_phase_effects.empty()) {
-                       reverse(this_phase_effects.begin(), this_phase_effects.end());
-                       phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
-                       this_phase_effects.back()->phase = phases.back();
-                       this_phase_inputs.clear();
-                       this_phase_effects.clear();
-               }
-               assert(this_phase_inputs.empty());
-               assert(this_phase_effects.empty());
+       // No more effects to do this phase. Take all the ones we have,
+       // and create a GLSL program for it.
+       assert(!phase->effects.empty());
 
-               // If we have no effects left, exit.
-               if (effects_todo_other_phases.empty()) {
-                       break;
-               }
+       // Deduplicate the inputs.
+       sort(phase->inputs.begin(), phase->inputs.end());
+       phase->inputs.erase(unique(phase->inputs.begin(), phase->inputs.end()), phase->inputs.end());
 
-               Node *node = effects_todo_other_phases.top();
-               effects_todo_other_phases.pop();
+       // We added the effects from the output and back, but we need to output
+       // them in topological sort order in the shader.
+       phase->effects = topological_sort(phase->effects);
 
-               if (completed_effects.count(node) == 0) {
-                       // Start a new phase, calculating from this effect.
-                       effects_todo_this_phase.push(node);
+       // Figure out if we need mipmaps or not, and if so, tell the inputs that.
+       phase->input_needs_mipmaps = false;
+       for (unsigned i = 0; i < phase->effects.size(); ++i) {
+               Node *node = phase->effects[i];
+               phase->input_needs_mipmaps |= node->effect->needs_mipmaps();
+       }
+       for (unsigned i = 0; i < phase->effects.size(); ++i) {
+               Node *node = phase->effects[i];
+               if (node->effect->num_inputs() == 0) {
+                       CHECK(node->effect->set_int("needs_mipmaps", phase->input_needs_mipmaps));
                }
        }
 
-       // Finally, since the phases are found from the output but must be executed
-       // from the input(s), reverse them, too.
-       reverse(phases.begin(), phases.end());
+       // Actually make the shader for this phase.
+       compile_glsl_program(phase);
+
+       assert(completed_effects->count(output) == 0);
+       completed_effects->insert(make_pair(output, phase));
+       phases.push_back(phase);
+       return phase;
 }
 
 void EffectChain::output_dot(const char *filename)
@@ -621,11 +583,11 @@ void EffectChain::inform_input_sizes(Phase *phase)
                }
        }
        for (unsigned i = 0; i < phase->inputs.size(); ++i) {
-               Node *input = phase->inputs[i];
-               input->output_width = input->phase->virtual_output_width;
-               input->output_height = input->phase->virtual_output_height;
-               assert(input->output_width != 0);
-               assert(input->output_height != 0);
+               Phase *input = phase->inputs[i];
+               input->output_node->output_width = input->virtual_output_width;
+               input->output_node->output_height = input->virtual_output_height;
+               assert(input->output_node->output_width != 0);
+               assert(input->output_node->output_height != 0);
        }
 
        // Now propagate from the inputs towards the end, and inform as we go.
@@ -676,14 +638,14 @@ void EffectChain::find_output_size(Phase *phase)
        bool all_inputs_same_size = true;
 
        for (unsigned i = 0; i < phase->inputs.size(); ++i) {
-               Node *input = phase->inputs[i];
-               assert(input->phase->output_width != 0);
-               assert(input->phase->output_height != 0);
+               Phase *input = phase->inputs[i];
+               assert(input->output_width != 0);
+               assert(input->output_height != 0);
                if (output_width == 0 && output_height == 0) {
-                       output_width = input->phase->virtual_output_width;
-                       output_height = input->phase->virtual_output_height;
-               } else if (output_width != input->phase->virtual_output_width ||
-                          output_height != input->phase->virtual_output_height) {
+                       output_width = input->virtual_output_width;
+                       output_height = input->virtual_output_height;
+               } else if (output_width != input->virtual_output_width ||
+                          output_height != input->virtual_output_height) {
                        all_inputs_same_size = false;
                }
        }
@@ -715,10 +677,10 @@ void EffectChain::find_output_size(Phase *phase)
        output_width = 0;
        output_height = 0;
        for (unsigned i = 0; i < phase->inputs.size(); ++i) {
-               Node *input = phase->inputs[i];
-               assert(input->phase->output_width != 0);
-               assert(input->phase->output_height != 0);
-               size_rectangle_to_fit(input->phase->output_width, input->phase->output_height, &output_width, &output_height);
+               Phase *input = phase->inputs[i];
+               assert(input->output_width != 0);
+               assert(input->output_height != 0);
+               size_rectangle_to_fit(input->output_width, input->output_height, &output_width, &output_height);
        }
        for (unsigned i = 0; i < phase->effects.size(); ++i) {
                Effect *effect = phase->effects[i]->effect;
@@ -1422,7 +1384,11 @@ void EffectChain::finalize()
        output_dot("step18-final.dot");
        
        // Construct all needed GLSL programs, starting at the output.
-       construct_glsl_programs(find_output_node());
+       // We need to keep track of which effects have already been computed,
+       // as an effect with multiple users could otherwise be calculated
+       // multiple times.
+       map<Node *, Phase *> completed_effects;
+       construct_phase(find_output_node(), &completed_effects);
 
        output_dot("step19-split-to-phases.dot");
 
@@ -1464,7 +1430,7 @@ void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height
                check_error();
        }
 
-       set<Node *> generated_mipmaps;
+       set<Phase *> generated_mipmaps;
 
        // We choose the simplest option of having one texture per output,
        // since otherwise this turns into an (albeit simple) register allocation problem.
@@ -1488,9 +1454,9 @@ void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height
                // Set up RTT inputs for this phase.
                for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
                        glActiveTexture(GL_TEXTURE0 + sampler);
-                       Node *input = phases[phase]->inputs[sampler];
-                       input->bound_sampler_num = sampler;
-                       glBindTexture(GL_TEXTURE_2D, output_textures[input->phase]);
+                       Phase *input = phases[phase]->inputs[sampler];
+                       input->output_node->bound_sampler_num = sampler;
+                       glBindTexture(GL_TEXTURE_2D, output_textures[input]);
                        check_error();
                        if (phases[phase]->input_needs_mipmaps) {
                                if (generated_mipmaps.count(input) == 0) {
@@ -1509,7 +1475,7 @@ void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
                        check_error();
 
-                       string texture_name = string("tex_") + phases[phase]->effect_ids[input];
+                       string texture_name = string("tex_") + phases[phase]->effect_ids[input->output_node];
                        glUniform1i(glGetUniformLocation(glsl_program_num, texture_name.c_str()), sampler);
                        check_error();
                }