Change so that all modifications to the graph (meta-effects, colorspace information...
authorSteinar H. Gunderson <sgunderson@bigfoot.com>
Mon, 8 Oct 2012 16:08:40 +0000 (18:08 +0200)
committerSteinar H. Gunderson <sgunderson@bigfoot.com>
Mon, 8 Oct 2012 16:08:40 +0000 (18:08 +0200)
12 files changed:
.gitignore
blur_effect.cpp
blur_effect.h
diffusion_effect.cpp
diffusion_effect.h
effect.cpp
effect.h
effect_chain.cpp
effect_chain.h
glow_effect.cpp
glow_effect.h
image_format.h

index 64d8c11..e3c7f01 100644 (file)
@@ -4,3 +4,4 @@ test
 *.jpg
 *.png
 perf.data
+*.dot
index c8cf539..f5d9927 100644 (file)
@@ -2,6 +2,7 @@
 #include <assert.h>
 
 #include "blur_effect.h"
+#include "effect_chain.h"
 #include "util.h"
 #include "opengl.h"
 
@@ -19,14 +20,14 @@ BlurEffect::BlurEffect()
        update_radius();
 }
 
-void BlurEffect::add_self_to_effect_chain(EffectChain *chain, const std::vector<Effect *> &inputs)
+void BlurEffect::rewrite_graph(EffectChain *graph, Node *self)
 {
-       assert(inputs.size() == 1);
-       hpass->add_self_to_effect_chain(chain, inputs);
-
-       std::vector<Effect *> vpass_inputs;
-       vpass_inputs.push_back(hpass);
-       vpass->add_self_to_effect_chain(chain, vpass_inputs); 
+       Node *hpass_node = graph->add_node(hpass);
+       Node *vpass_node = graph->add_node(vpass);
+       graph->connect_nodes(hpass_node, vpass_node);
+       graph->replace_receiver(self, hpass_node);
+       graph->replace_sender(self, vpass_node);
+       self->disabled = true;
 }
                
 void BlurEffect::update_radius()
index 788d337..2aada42 100644 (file)
@@ -32,7 +32,7 @@ public:
                assert(false);
        }
 
-       virtual void add_self_to_effect_chain(EffectChain *chain, const std::vector<Effect *> &input);
+       virtual void rewrite_graph(EffectChain *graph, Node *self);
        virtual bool set_float(const std::string &key, float value);
        
 private:
index 8d2903b..f07f9d1 100644 (file)
@@ -12,14 +12,19 @@ DiffusionEffect::DiffusionEffect()
 {
 }
 
-void DiffusionEffect::add_self_to_effect_chain(EffectChain *chain, const std::vector<Effect *> &inputs) {
-       assert(inputs.size() == 1);
-       blur->add_self_to_effect_chain(chain, inputs);
-
-       std::vector<Effect *> overlay_matte_inputs;
-       overlay_matte_inputs.push_back(inputs[0]);
-       overlay_matte_inputs.push_back(chain->last_added_effect());  // FIXME
-       overlay_matte->add_self_to_effect_chain(chain, overlay_matte_inputs);
+void DiffusionEffect::rewrite_graph(EffectChain *graph, Node *self)
+{
+       assert(self->incoming_links.size() == 1);
+       Node *input = self->incoming_links[0];
+
+       Node *blur_node = graph->add_node(blur);
+       Node *overlay_matte_node = graph->add_node(overlay_matte);
+       graph->replace_receiver(self, overlay_matte_node);
+       graph->connect_nodes(input, blur_node);
+       graph->connect_nodes(blur_node, overlay_matte_node);
+       graph->replace_sender(self, overlay_matte_node);
+
+       self->disabled = true;
 }
 
 bool DiffusionEffect::set_float(const std::string &key, float value) {
index f8ed77c..624990c 100644 (file)
@@ -22,7 +22,7 @@ public:
        DiffusionEffect();
        virtual std::string effect_type_id() const { return "DiffusionEffect"; }
 
-       virtual void add_self_to_effect_chain(EffectChain *chain, const std::vector<Effect *> &input);
+       virtual void rewrite_graph(EffectChain *graph, Node *self);
        virtual bool set_float(const std::string &key, float value);
        
        virtual std::string output_fragment_shader() {
index 6f3121d..d0222de 100644 (file)
@@ -167,11 +167,6 @@ void Effect::invalidate_1d_texture(const std::string &key)
        params_tex_1d[key].needs_update = true;
 }
 
-void Effect::add_self_to_effect_chain(EffectChain *chain, const std::vector<Effect *> &inputs)
-{
-       chain->add_effect_raw(this, inputs);
-}
-
 // Output convenience uniforms for each parameter.
 // These will be filled in per-frame.
 std::string Effect::output_convenience_uniforms() const
index f1520b7..ef58392 100644 (file)
--- a/effect.h
+++ b/effect.h
@@ -19,6 +19,7 @@
 #include "opengl.h"
 
 class EffectChain;
+class Node;
 
 // Can alias on a float[2].
 struct Point2D {
@@ -123,11 +124,19 @@ public:
        // if you have several, they will be INPUT1(), INPUT2(), and so on.
        virtual unsigned num_inputs() const { return 1; }
 
-       // Requests that this effect adds itself to the given effect chain.
-       // For most effects, the default will be fine, but for effects that
-       // consist of multiple passes, it is often useful to replace this
-       // with something that adds completely different things to the chain.
-       virtual void add_self_to_effect_chain(EffectChain *graph, const std::vector<Effect *> &inputs);
+       // Let the effect rewrite the effect chain as it sees fit.
+       // Most effects won't need to do this, but this is very useful
+       // if you have an effect that consists of multiple sub-effects
+       // (for instance, two passes). The effect is given to its own
+       // pointer, and it can add new ones (by using add_node()
+       // and connect_node()) as it sees fit. This is called at
+       // EffectChain::finalize() time, when the entire graph is known,
+       // in the order that the effects were originally added.
+       //
+       // Note that if the effect wants to take itself entirely out
+       // of the chain, it must set “disabled” to true and then disconnect
+       // itself from all other effects.
+       virtual void rewrite_graph(EffectChain *graph, Node *self) {}
 
        // Outputs one GLSL uniform declaration for each registered parameter
        // (see below), with the right prefix prepended to each uniform name.
index aae2941..b04727b 100644 (file)
@@ -24,20 +24,11 @@ EffectChain::EffectChain(unsigned width, unsigned height)
 
 Input *EffectChain::add_input(Input *input)
 {
-       char eff_id[256];
-       sprintf(eff_id, "src_image%u", (unsigned)inputs.size());
-
        inputs.push_back(input);
 
-       Node *node = new Node;
-       node->effect = input;
-       node->effect_id = eff_id;
+       Node *node = add_node(input);
        node->output_color_space = input->get_color_space();
        node->output_gamma_curve = input->get_gamma_curve();
-
-       nodes.push_back(node);
-       node_map[input] = node;
-
        return input;
 }
 
@@ -46,37 +37,78 @@ void EffectChain::add_output(const ImageFormat &format)
        output_format = format;
 }
 
-void EffectChain::add_effect_raw(Effect *effect, const std::vector<Effect *> &inputs)
+Node *EffectChain::add_node(Effect *effect)
 {
        char effect_id[256];
        sprintf(effect_id, "eff%u", (unsigned)nodes.size());
 
        Node *node = new Node;
        node->effect = effect;
+       node->disabled = false;
        node->effect_id = effect_id;
+       node->output_color_space = COLORSPACE_INVALID;
+       node->output_gamma_curve = GAMMA_INVALID;
 
-       assert(inputs.size() == effect->num_inputs());
-       assert(inputs.size() >= 1);
-       for (unsigned i = 0; i < inputs.size(); ++i) {
-               assert(node_map.count(inputs[i]) != 0);
-               node_map[inputs[i]]->outgoing_links.push_back(node);
-               node->incoming_links.push_back(node_map[inputs[i]]);
-               if (i == 0) {
-                       node->output_gamma_curve = node_map[inputs[i]]->output_gamma_curve;
-                       node->output_color_space = node_map[inputs[i]]->output_color_space;
-               } else {
-                       assert(node->output_gamma_curve == node_map[inputs[i]]->output_gamma_curve);
-                       assert(node->output_color_space == node_map[inputs[i]]->output_color_space);
+       nodes.push_back(node);
+       node_map[effect] = node;
+       return node;
+}
+
+void EffectChain::connect_nodes(Node *sender, Node *receiver)
+{
+       sender->outgoing_links.push_back(receiver);
+       receiver->incoming_links.push_back(sender);
+}
+
+void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
+{
+       new_receiver->incoming_links = old_receiver->incoming_links;
+       old_receiver->incoming_links.clear();
+       
+       for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
+               Node *sender = new_receiver->incoming_links[i];
+               for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
+                       if (sender->outgoing_links[j] == old_receiver) {
+                               sender->outgoing_links[j] = new_receiver;
+                       }
+               }
+       }       
+}
+
+void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
+{
+       new_sender->outgoing_links = old_sender->outgoing_links;
+       old_sender->outgoing_links.clear();
+       
+       for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
+               Node *receiver = new_sender->outgoing_links[i];
+               for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
+                       if (receiver->incoming_links[j] == old_sender) {
+                               receiver->incoming_links[j] = new_sender;
+                       }
+               }
+       }       
+}
+
+void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
+{
+       for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
+               if (sender->outgoing_links[i] == receiver) {
+                       sender->outgoing_links[i] = middle;
+                       middle->incoming_links.push_back(sender);
+               }
+       }
+       for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
+               if (receiver->incoming_links[i] == sender) {
+                       receiver->incoming_links[i] = middle;
+                       middle->outgoing_links.push_back(receiver);
                }
        }
 
-       nodes.push_back(node);
-       node_map[effect] = node;
+       assert(middle->incoming_links.size() == middle->effect->num_inputs());
 }
 
-void EffectChain::find_all_nonlinear_inputs(Node *node,
-                                            std::vector<Node *> *nonlinear_inputs,
-                                            std::vector<Node *> *intermediates)
+void EffectChain::find_all_nonlinear_inputs(Node *node, std::vector<Node *> *nonlinear_inputs)
 {
        if (node->output_gamma_curve == GAMMA_LINEAR) {
                return;
@@ -84,96 +116,21 @@ void EffectChain::find_all_nonlinear_inputs(Node *node,
        if (node->effect->num_inputs() == 0) {
                nonlinear_inputs->push_back(node);
        } else {
-               intermediates->push_back(node);
                assert(node->effect->num_inputs() == node->incoming_links.size());
                for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
-                       find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs, intermediates);
+                       find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
                }
        }
 }
 
-Node *EffectChain::normalize_to_linear_gamma(Node *input)
-{
-       // Find out if all the inputs can be set to deliver sRGB inputs.
-       // If so, we can just ask them to do that instead of inserting a
-       // (possibly expensive) conversion operation.
-       //
-       // NOTE: We assume that effects generally don't mess with the gamma
-       // curve (except GammaCompressionEffect, which should never be
-       // inserted into a chain when this is called), so that we can just
-       // update the output gamma as we go.
-       //
-       // TODO: Setting this flag for one source might confuse a different
-       // part of the pipeline using the same source.
-       std::vector<Node *> nonlinear_inputs;
-       std::vector<Node *> intermediates;
-       find_all_nonlinear_inputs(input, &nonlinear_inputs, &intermediates);
-
-       bool all_ok = true;
-       for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
-               Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
-               all_ok &= input->can_output_linear_gamma();
-       }
-
-       if (all_ok) {
-               for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
-                       bool ok = nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1);
-                       assert(ok);
-                       nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
-               }
-               for (unsigned i = 0; i < intermediates.size(); ++i) {
-                       intermediates[i]->output_gamma_curve = GAMMA_LINEAR;
-               }
-               return input;
-       }
-
-       // OK, that didn't work. Insert a conversion effect.
-       GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
-       gamma_conversion->set_int("source_curve", input->output_gamma_curve);
-       std::vector<Effect *> inputs;
-       inputs.push_back(input->effect);
-       gamma_conversion->add_self_to_effect_chain(this, inputs);
-
-       assert(node_map.count(gamma_conversion) != 0);
-       Node *node = node_map[gamma_conversion];
-       node->output_gamma_curve = GAMMA_LINEAR;
-       return node;
-}
-
-Node *EffectChain::normalize_to_srgb(Node *input)
-{
-       assert(input->output_gamma_curve == GAMMA_LINEAR);
-       ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
-       colorspace_conversion->set_int("source_space", input->output_color_space);
-       colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
-       std::vector<Effect *> inputs;
-       inputs.push_back(input->effect);
-       colorspace_conversion->add_self_to_effect_chain(this, inputs);
-
-       assert(node_map.count(colorspace_conversion) != 0);
-       Node *node = node_map[colorspace_conversion];
-       node->output_color_space = COLORSPACE_sRGB;
-       return node;
-}
-
 Effect *EffectChain::add_effect(Effect *effect, const std::vector<Effect *> &inputs)
 {
        assert(inputs.size() == effect->num_inputs());
-
-       std::vector<Effect *> normalized_inputs = inputs;
-       for (unsigned i = 0; i < normalized_inputs.size(); ++i) {
-               assert(node_map.count(normalized_inputs[i]) != 0);
-               Node *input = node_map[normalized_inputs[i]];
-               if (effect->needs_linear_light() && input->output_gamma_curve != GAMMA_LINEAR) {
-                       input = normalize_to_linear_gamma(input);
-               }
-               if (effect->needs_srgb_primaries() && input->output_color_space != COLORSPACE_sRGB) {
-                       input = normalize_to_srgb(input);
-               }
-               normalized_inputs[i] = input->effect;
+       Node *node = add_node(effect);
+       for (unsigned i = 0; i < inputs.size(); ++i) {
+               assert(node_map.count(inputs[i]) != 0);
+               connect_nodes(node_map[inputs[i]], node);
        }
-
-       effect->add_self_to_effect_chain(this, normalized_inputs);
        return effect;
 }
 
@@ -436,6 +393,9 @@ void EffectChain::output_dot(const char *filename)
                        }
 
                        switch (nodes[i]->output_color_space) {
+                       case COLORSPACE_INVALID:
+                               labels.push_back("spc[invalid]");
+                               break;
                        case COLORSPACE_REC_601_525:
                                labels.push_back("spc[rec601-525]");
                                break;
@@ -447,6 +407,9 @@ void EffectChain::output_dot(const char *filename)
                        }
 
                        switch (nodes[i]->output_gamma_curve) {
+                       case GAMMA_INVALID:
+                               labels.push_back("gamma[invalid]");
+                               break;
                        case GAMMA_sRGB:
                                labels.push_back("gamma[sRGB]");
                                break;
@@ -510,53 +473,349 @@ void EffectChain::find_output_size(Phase *phase)
        phase->output_height = height;
 }
 
-void EffectChain::finalize()
+void EffectChain::sort_nodes_topologically()
 {
-       output_dot("final.dot");
+       std::set<Node *> visited_nodes;
+       std::vector<Node *> sorted_list;
+       for (unsigned i = 0; i < nodes.size(); ++i) {
+               if (nodes[i]->incoming_links.size() == 0) {
+                       topological_sort_visit_node(nodes[i], &visited_nodes, &sorted_list);
+               }
+       }
+       reverse(sorted_list.begin(), sorted_list.end());
+       nodes = sorted_list;
+}
+
+void EffectChain::topological_sort_visit_node(Node *node, std::set<Node *> *visited_nodes, std::vector<Node *> *sorted_list)
+{
+       if (visited_nodes->count(node) != 0) {
+               return;
+       }
+       visited_nodes->insert(node);
+       for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
+               topological_sort_visit_node(node->outgoing_links[i], visited_nodes, sorted_list);
+       }
+       sorted_list->push_back(node);
+}
+
+// Propagate gamma and color space information as far as we can in the graph.
+// The rules are simple: Anything where all the inputs agree, get that as
+// output as well. Anything else keeps having *_INVALID.
+void EffectChain::propagate_gamma_and_color_space()
+{
+       // We depend on going through the nodes in order.
+       sort_nodes_topologically();
 
-       // Find the output effect. This is, simply, one that has no outgoing links.
-       // If there are multiple ones, the graph is malformed (we do not support
-       // multiple outputs right now).
-       std::vector<Node *> output_nodes;
        for (unsigned i = 0; i < nodes.size(); ++i) {
                Node *node = nodes[i];
-               if (node->outgoing_links.empty()) {
-                       output_nodes.push_back(node);
+               if (node->disabled) {
+                       continue;
+               }
+               assert(node->incoming_links.size() == node->effect->num_inputs());
+               if (node->incoming_links.size() == 0) {
+                       assert(node->output_color_space != COLORSPACE_INVALID);
+                       assert(node->output_gamma_curve != GAMMA_INVALID);
+                       continue;
+               }
+
+               ColorSpace color_space = node->incoming_links[0]->output_color_space;
+               GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
+               for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
+                       if (node->incoming_links[j]->output_color_space != color_space) {
+                               color_space = COLORSPACE_INVALID;
+                       }
+                       if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
+                               gamma_curve = GAMMA_INVALID;
+                       }
                }
+
+               // The conversion effects already have their outputs set correctly,
+               // so leave them alone.
+               if (node->effect->effect_type_id() != "ColorSpaceConversionEffect") {
+                       node->output_color_space = color_space;
+               }               
+               if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
+                   node->effect->effect_type_id() != "GammaExpansionEffect") {
+                       node->output_gamma_curve = gamma_curve;
+               }               
        }
-       assert(output_nodes.size() == 1);
-       Node *output_node = output_nodes[0];
+}
 
-       // Add normalizers to get the output format right.
-       if (output_node->output_color_space != output_format.color_space) {
-               ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
-               colorspace_conversion->set_int("source_space", output_node->output_color_space);
-               colorspace_conversion->set_int("destination_space", output_format.color_space);
-               std::vector<Effect *> inputs;
-               inputs.push_back(output_node->effect);
-               colorspace_conversion->add_self_to_effect_chain(this, inputs);
+bool EffectChain::node_needs_colorspace_fix(Node *node)
+{
+       if (node->disabled) {
+               return false;
+       }
+       if (node->effect->num_inputs() == 0) {
+               return false;
+       }
 
-               assert(node_map.count(colorspace_conversion) != 0);
-               output_node = node_map[colorspace_conversion];
-               output_node->output_color_space = output_format.color_space;
+       // propagate_gamma_and_color_space() has already set our output
+       // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
+       if (node->output_color_space == COLORSPACE_INVALID) {
+               return true;
        }
-       if (output_node->output_gamma_curve != output_format.gamma_curve) {
-               if (output_node->output_gamma_curve != GAMMA_LINEAR) {
-                       output_node = normalize_to_linear_gamma(output_node);
+       return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
+}
+
+// Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
+// the graph. Our strategy is not always optimal, but quite simple:
+// Find an effect that's as early as possible where the inputs are of
+// unacceptable colorspaces (that is, either different, or, if the effect only
+// wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
+// propagate the information anew, and repeat until there are no more such
+// effects.
+void EffectChain::fix_internal_color_spaces()
+{
+       unsigned colorspace_propagation_pass = 0;
+       bool found_any;
+       do {
+               found_any = false;
+               for (unsigned i = 0; i < nodes.size(); ++i) {
+                       Node *node = nodes[i];
+                       if (!node_needs_colorspace_fix(node)) {
+                               continue;
+                       }
+
+                       // Go through each input that is not sRGB, and insert
+                       // a colorspace conversion before it.
+                       for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
+                               Node *input = node->incoming_links[j];
+                               assert(input->output_color_space != COLORSPACE_INVALID);
+                               if (input->output_color_space == COLORSPACE_sRGB) {
+                                       continue;
+                               }
+                               Node *conversion = add_node(new ColorSpaceConversionEffect());
+                               conversion->effect->set_int("source_space", input->output_color_space);
+                               conversion->effect->set_int("destination_space", COLORSPACE_sRGB);
+                               conversion->output_color_space = COLORSPACE_sRGB;
+                               insert_node_between(input, conversion, node);
+                       }
+
+                       // Re-sort topologically, and propagate the new information.
+                       propagate_gamma_and_color_space();
+                       
+                       found_any = true;
+                       break;
+               }
+       
+               char filename[256];
+               sprintf(filename, "step3-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
+               output_dot(filename);
+               assert(colorspace_propagation_pass < 100);
+       } while (found_any);
+
+       for (unsigned i = 0; i < nodes.size(); ++i) {
+               Node *node = nodes[i];
+               if (node->disabled) {
+                       continue;
+               }
+               assert(node->output_color_space != COLORSPACE_INVALID);
+       }
+}
+
+// Make so that the output is in the desired color space.
+void EffectChain::fix_output_color_space()
+{
+       Node *output = find_output_node();
+       if (output->output_color_space != output_format.color_space) {
+               Node *conversion = add_node(new ColorSpaceConversionEffect());
+               conversion->effect->set_int("source_space", output->output_color_space);
+               conversion->effect->set_int("destination_space", output_format.color_space);
+               conversion->output_color_space = output_format.color_space;
+               connect_nodes(output, conversion);
+       }
+}
+
+bool EffectChain::node_needs_gamma_fix(Node *node)
+{
+       if (node->disabled) {
+               return false;
+       }
+       if (node->effect->num_inputs() == 0) {
+               return false;
+       }
+
+       // propagate_gamma_and_color_space() has already set our output
+       // to GAMMA_INVALID if the inputs differ, so we can rely on that,
+       // except for GammaCompressionEffect.
+       if (node->output_gamma_curve == GAMMA_INVALID) {
+               return true;
+       }
+       if (node->effect->effect_type_id() == "GammaCompressionEffect") {
+               assert(node->incoming_links.size() == 1);
+               return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
+       }
+       return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
+}
+
+// Very similar to fix_internal_color_spaces(), but for gamma.
+// There is one difference, though; before we start adding conversion nodes,
+// we see if we can get anything out of asking the sources to deliver
+// linear gamma directly. fix_internal_gamma_by_asking_inputs()
+// does that part, while fix_internal_gamma_by_inserting_nodes()
+// inserts nodes as needed afterwards.
+void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
+{
+       unsigned gamma_propagation_pass = 0;
+       bool found_any;
+       do {
+               found_any = false;
+               for (unsigned i = 0; i < nodes.size(); ++i) {
+                       Node *node = nodes[i];
+                       if (!node_needs_gamma_fix(node)) {
+                               continue;
+                       }
+
+                       // See if all inputs can give us linear gamma. If not, leave it.
+                       std::vector<Node *> nonlinear_inputs;
+                       find_all_nonlinear_inputs(node, &nonlinear_inputs);
+
+                       bool all_ok = true;
+                       for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
+                               Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
+                               all_ok &= input->can_output_linear_gamma();
+                       }
+
+                       if (!all_ok) {
+                               continue;
+                       }
+
+                       for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
+                               nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1);
+                               nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
+                       }
+
+                       // Re-sort topologically, and propagate the new information.
+                       propagate_gamma_and_color_space();
+                       
+                       found_any = true;
+                       break;
                }
-               GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
-               gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
-               std::vector<Effect *> inputs;
-               inputs.push_back(output_node->effect);
-               gamma_conversion->add_self_to_effect_chain(this, inputs);
+       
+               char filename[256];
+               sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
+               output_dot(filename);
+               assert(gamma_propagation_pass < 100);
+       } while (found_any);
+}
+
+void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
+{
+       unsigned gamma_propagation_pass = 0;
+       bool found_any;
+       do {
+               found_any = false;
+               for (unsigned i = 0; i < nodes.size(); ++i) {
+                       Node *node = nodes[i];
+                       if (!node_needs_gamma_fix(node)) {
+                               continue;
+                       }
 
-               assert(node_map.count(gamma_conversion) != 0);
-               output_node = node_map[gamma_conversion];
-               output_node->output_gamma_curve = output_format.gamma_curve;
+                       // Go through each input that is not linear gamma, and insert
+                       // a gamma conversion before it.
+                       for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
+                               Node *input = node->incoming_links[j];
+                               assert(input->output_gamma_curve != GAMMA_INVALID);
+                               if (input->output_gamma_curve == GAMMA_LINEAR) {
+                                       continue;
+                               }
+                               Node *conversion = add_node(new GammaExpansionEffect());
+                               conversion->effect->set_int("destination_curve", GAMMA_LINEAR);
+                               conversion->output_gamma_curve = GAMMA_LINEAR;
+                               insert_node_between(input, conversion, node);
+                       }
+
+                       // Re-sort topologically, and propagate the new information.
+                       propagate_gamma_and_color_space();
+                       
+                       found_any = true;
+                       break;
+               }
+       
+               char filename[256];
+               sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
+               output_dot(filename);
+               assert(gamma_propagation_pass < 100);
+       } while (found_any);
+
+       for (unsigned i = 0; i < nodes.size(); ++i) {
+               Node *node = nodes[i];
+               if (node->disabled) {
+                       continue;
+               }
+               assert(node->output_gamma_curve != GAMMA_INVALID);
        }
+}
 
+// Make so that the output is in the desired gamma.
+// Note that this assumes linear input gamma, so it might create the need
+// for another pass of fix_internal_gamma().
+void EffectChain::fix_output_gamma()
+{
+       Node *output = find_output_node();
+       if (output->output_gamma_curve != output_format.gamma_curve) {
+               Node *conversion = add_node(new GammaCompressionEffect());
+               conversion->effect->set_int("destination_curve", output_format.gamma_curve);
+               conversion->output_gamma_curve = output_format.gamma_curve;
+               connect_nodes(output, conversion);
+       }
+}
+
+// Find the output node. This is, simply, one that has no outgoing links.
+// If there are multiple ones, the graph is malformed (we do not support
+// multiple outputs right now).
+Node *EffectChain::find_output_node()
+{
+       std::vector<Node *> output_nodes;
+       for (unsigned i = 0; i < nodes.size(); ++i) {
+               Node *node = nodes[i];
+               if (node->disabled) {
+                       continue;
+               }
+               if (node->outgoing_links.empty()) {
+                       output_nodes.push_back(node);
+               }
+       }
+       assert(output_nodes.size() == 1);
+       return output_nodes[0];
+}
+
+void EffectChain::finalize()
+{
+       // Output the graph as it is before we do any conversions on it.
+       output_dot("step0-start.dot");
+
+       // Give each effect in turn a chance to rewrite its own part of the graph.
+       // Note that if more effects are added as part of this, they will be
+       // picked up as part of the same for loop, since they are added at the end.
+       for (unsigned i = 0; i < nodes.size(); ++i) {
+               nodes[i]->effect->rewrite_graph(this, nodes[i]);
+       }
+       output_dot("step1-rewritten.dot");
+
+       propagate_gamma_and_color_space();
+       output_dot("step2-propagated.dot");
+
+       fix_internal_color_spaces();
+       fix_output_color_space();
+       output_dot("step4-output-colorspacefix.dot");
+
+       // Note that we need to fix gamma after colorspace conversion,
+       // because colorspace conversions might create needs for gamma conversions.
+       // Also, we need to run an extra pass of fix_internal_gamma() after 
+       // fixing the output gamma, as we only have conversions to/from linear.
+       fix_internal_gamma_by_asking_inputs(5);
+       fix_internal_gamma_by_inserting_nodes(6);
+       fix_output_gamma();
+       output_dot("step8-output-gammafix.dot");
+       fix_internal_gamma_by_asking_inputs(9);
+       fix_internal_gamma_by_inserting_nodes(10);
+
+       output_dot("step11-final.dot");
+       
        // Construct all needed GLSL programs, starting at the output.
-       construct_glsl_programs(output_node);
+       construct_glsl_programs(find_output_node());
 
        // If we have more than one phase, we need intermediate render-to-texture.
        // Construct an FBO, and then as many textures as we need.
index 0abd518..cf96293 100644 (file)
@@ -15,6 +15,7 @@ class Phase;
 class Node {
 public:
        Effect *effect;
+       bool disabled;
 
        // Edges in the graph (forward and backward).
        std::vector<Node *> outgoing_links;
@@ -80,16 +81,6 @@ public:
        }
        Effect *add_effect(Effect *effect, const std::vector<Effect *> &inputs);
 
-       // Similar to add_effect, but:
-       //
-       //  * Does not insert any normalizing effects.
-       //  * Does not ask the effect to insert itself, so it won't work
-       //    with meta-effects.
-       //
-       // We should really separate out these two “sides” of Effect in the
-       // type system soon.
-       void add_effect_raw(Effect *effect, const std::vector<Effect *> &inputs);
-
        void add_output(const ImageFormat &format);
        void finalize();
 
@@ -104,16 +95,25 @@ public:
                }       
        }
 
+       // API for manipulating the graph directly. Intended to be used from
+       // effects and by EffectChain itself.
+       //
+       // Note that for nodes with multiple inputs, the order of calls to
+       // connect_nodes() will matter.
+       Node *add_node(Effect *effect);
+       void connect_nodes(Node *sender, Node *receiver);
+       void replace_receiver(Node *old_receiver, Node *new_receiver);
+       void replace_sender(Node *new_sender, Node *receiver);
+       void insert_node_between(Node *sender, Node *middle, Node *receiver);
+
 private:
        // Determine the preferred output size of a given phase.
        // Requires that all input phases (if any) already have output sizes set.
        void find_output_size(Phase *phase);
 
-       void find_all_nonlinear_inputs(Node *effect,
-                                      std::vector<Node *> *nonlinear_inputs,
-                                      std::vector<Node *> *intermediates);
-       Node *normalize_to_linear_gamma(Node *input);
-       Node *normalize_to_srgb(Node *input);
+       // Find all inputs eventually feeding into this effect that have
+       // output gamma different from GAMMA_LINEAR.
+       void find_all_nonlinear_inputs(Node *effect, std::vector<Node *> *nonlinear_inputs);
 
        // Create a GLSL program computing the given effects in order.
        Phase *compile_glsl_program(const std::vector<Node *> &inputs,
@@ -127,6 +127,25 @@ private:
        // only useful for debugging.
        void output_dot(const char *filename);
 
+       // Some of the graph algorithms assume that the nodes array is sorted
+       // topologically (inputs are always before outputs), but some operations
+       // (like graph rewriting) can change that. This function restores that order.
+       void sort_nodes_topologically();
+       void topological_sort_visit_node(Node *node, std::set<Node *> *visited_nodes, std::vector<Node *> *sorted_list);
+
+       // Used during finalize().
+       void propagate_gamma_and_color_space();
+       Node *find_output_node();
+
+       bool node_needs_colorspace_fix(Node *node);
+       void fix_internal_color_spaces();
+       void fix_output_color_space();
+
+       bool node_needs_gamma_fix(Node *node);
+       void fix_internal_gamma_by_asking_inputs(unsigned step);
+       void fix_internal_gamma_by_inserting_nodes(unsigned step);
+       void fix_output_gamma();
+
        unsigned width, height;
        ImageFormat output_format;
 
index e4c9a42..0868eb0 100644 (file)
@@ -15,14 +15,19 @@ GlowEffect::GlowEffect()
        mix->set_float("strength_second", 0.3f);
 }
 
-void GlowEffect::add_self_to_effect_chain(EffectChain *chain, const std::vector<Effect *> &inputs) {
-       assert(inputs.size() == 1);
-       blur->add_self_to_effect_chain(chain, inputs);
+void GlowEffect::rewrite_graph(EffectChain *graph, Node *self)
+{
+       assert(self->incoming_links.size() == 1);
+       Node *input = self->incoming_links[0];
+
+       Node *blur_node = graph->add_node(blur);
+       Node *mix_node = graph->add_node(mix);
+       graph->replace_receiver(self, mix_node);
+       graph->connect_nodes(input, blur_node);
+       graph->connect_nodes(blur_node, mix_node);
+       graph->replace_sender(self, mix_node);
 
-       std::vector<Effect *> mix_inputs;
-       mix_inputs.push_back(inputs[0]);
-       mix_inputs.push_back(chain->last_added_effect());  // FIXME
-       mix->add_self_to_effect_chain(chain, mix_inputs);
+       self->disabled = true;
 }
 
 bool GlowEffect::set_float(const std::string &key, float value) {
index 1b5644b..04b48f9 100644 (file)
@@ -15,7 +15,7 @@ public:
 
        virtual bool needs_srgb_primaries() const { return false; }
 
-       virtual void add_self_to_effect_chain(EffectChain *chain, const std::vector<Effect *> &input);
+       virtual void rewrite_graph(EffectChain *graph, Node *self);
        virtual bool set_float(const std::string &key, float value);
 
        virtual std::string output_fragment_shader() {
index 2f72317..55aa8d4 100644 (file)
@@ -4,6 +4,7 @@
 enum MovitPixelFormat { FORMAT_RGB, FORMAT_RGBA, FORMAT_BGR, FORMAT_BGRA, FORMAT_GRAYSCALE };
 
 enum ColorSpace {
+       COLORSPACE_INVALID = -1,  // For internal use.
        COLORSPACE_sRGB = 0,
        COLORSPACE_REC_709 = 0,  // Same as sRGB.
        COLORSPACE_REC_601_525 = 1,
@@ -11,6 +12,7 @@ enum ColorSpace {
 };
 
 enum GammaCurve {
+       GAMMA_INVALID = -1,  // For internal use.
        GAMMA_LINEAR = 0,
        GAMMA_sRGB = 1,
        GAMMA_REC_601 = 2,