+void EffectChain::output_dot(const char *filename)
+{
+ if (movit_debug_level != MOVIT_DEBUG_ON) {
+ return;
+ }
+
+ FILE *fp = fopen(filename, "w");
+ if (fp == NULL) {
+ perror(filename);
+ exit(1);
+ }
+
+ fprintf(fp, "digraph G {\n");
+ fprintf(fp, " output [shape=box label=\"(output)\"];\n");
+ for (unsigned i = 0; i < nodes.size(); ++i) {
+ // Find out which phase this event belongs to.
+ std::vector<int> in_phases;
+ for (unsigned j = 0; j < phases.size(); ++j) {
+ const Phase* p = phases[j];
+ if (std::find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
+ in_phases.push_back(j);
+ }
+ }
+
+ if (in_phases.empty()) {
+ fprintf(fp, " n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
+ } else if (in_phases.size() == 1) {
+ fprintf(fp, " n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
+ (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
+ (in_phases[0] % 8) + 1);
+ } else {
+ // If we had new enough Graphviz, style="wedged" would probably be ideal here.
+ // But alas.
+ fprintf(fp, " n%ld [label=\"%s [in multiple phases]\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
+ (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
+ (in_phases[0] % 8) + 1);
+ }
+
+ char from_node_id[256];
+ snprintf(from_node_id, 256, "n%ld", (long)nodes[i]);
+
+ for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
+ char to_node_id[256];
+ snprintf(to_node_id, 256, "n%ld", (long)nodes[i]->outgoing_links[j]);
+
+ std::vector<std::string> labels = get_labels_for_edge(nodes[i], nodes[i]->outgoing_links[j]);
+ output_dot_edge(fp, from_node_id, to_node_id, labels);
+ }
+
+ if (nodes[i]->outgoing_links.empty() && !nodes[i]->disabled) {
+ // Output node.
+ std::vector<std::string> labels = get_labels_for_edge(nodes[i], NULL);
+ output_dot_edge(fp, from_node_id, "output", labels);
+ }
+ }
+ fprintf(fp, "}\n");
+
+ fclose(fp);
+}
+
+std::vector<std::string> EffectChain::get_labels_for_edge(const Node *from, const Node *to)
+{
+ std::vector<std::string> labels;
+
+ if (to != NULL && to->effect->needs_texture_bounce()) {
+ labels.push_back("needs_bounce");
+ }
+ if (from->effect->changes_output_size()) {
+ labels.push_back("resize");
+ }
+
+ switch (from->output_color_space) {
+ case COLORSPACE_INVALID:
+ labels.push_back("spc[invalid]");
+ break;
+ case COLORSPACE_REC_601_525:
+ labels.push_back("spc[rec601-525]");
+ break;
+ case COLORSPACE_REC_601_625:
+ labels.push_back("spc[rec601-625]");
+ break;
+ default:
+ break;
+ }
+
+ switch (from->output_gamma_curve) {
+ case GAMMA_INVALID:
+ labels.push_back("gamma[invalid]");
+ break;
+ case GAMMA_sRGB:
+ labels.push_back("gamma[sRGB]");
+ break;
+ case GAMMA_REC_601: // and GAMMA_REC_709
+ labels.push_back("gamma[rec601/709]");
+ break;
+ default:
+ break;
+ }
+
+ switch (from->output_alpha_type) {
+ case ALPHA_INVALID:
+ labels.push_back("alpha[invalid]");
+ break;
+ case ALPHA_BLANK:
+ labels.push_back("alpha[blank]");
+ break;
+ case ALPHA_POSTMULTIPLIED:
+ labels.push_back("alpha[postmult]");
+ break;
+ default:
+ break;
+ }
+
+ return labels;
+}
+
+void EffectChain::output_dot_edge(FILE *fp,
+ const std::string &from_node_id,
+ const std::string &to_node_id,
+ const std::vector<std::string> &labels)
+{
+ if (labels.empty()) {
+ fprintf(fp, " %s -> %s;\n", from_node_id.c_str(), to_node_id.c_str());
+ } else {
+ std::string label = labels[0];
+ for (unsigned k = 1; k < labels.size(); ++k) {
+ label += ", " + labels[k];
+ }
+ fprintf(fp, " %s -> %s [label=\"%s\"];\n", from_node_id.c_str(), to_node_id.c_str(), label.c_str());
+ }
+}
+
+void EffectChain::size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height)
+{
+ unsigned scaled_width, scaled_height;
+
+ if (float(width) * aspect_denom >= float(height) * aspect_nom) {
+ // Same aspect, or W/H > aspect (image is wider than the frame).
+ // In either case, keep width, and adjust height.
+ scaled_width = width;
+ scaled_height = lrintf(width * aspect_denom / aspect_nom);
+ } else {
+ // W/H < aspect (image is taller than the frame), so keep height,
+ // and adjust width.
+ scaled_width = lrintf(height * aspect_nom / aspect_denom);
+ scaled_height = height;
+ }
+
+ // We should be consistently larger or smaller then the existing choice,
+ // since we have the same aspect.
+ assert(!(scaled_width < *output_width && scaled_height > *output_height));
+ assert(!(scaled_height < *output_height && scaled_width > *output_width));
+
+ if (scaled_width >= *output_width && scaled_height >= *output_height) {
+ *output_width = scaled_width;
+ *output_height = scaled_height;
+ }
+}
+
+// Propagate input texture sizes throughout, and inform effects downstream.
+// (Like a lot of other code, we depend on effects being in topological order.)
+void EffectChain::inform_input_sizes(Phase *phase)
+{
+ // All effects that have a defined size (inputs and RTT inputs)
+ // get that. Reset all others.
+ for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ Node *node = phase->effects[i];
+ if (node->effect->num_inputs() == 0) {
+ Input *input = static_cast<Input *>(node->effect);
+ node->output_width = input->get_width();
+ node->output_height = input->get_height();
+ assert(node->output_width != 0);
+ assert(node->output_height != 0);
+ } else {
+ node->output_width = node->output_height = 0;
+ }
+ }
+ 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);
+ }
+
+ // Now propagate from the inputs towards the end, and inform as we go.
+ // The rules are simple:
+ //
+ // 1. Don't touch effects that already have given sizes (ie., inputs).
+ // 2. If all of your inputs have the same size, that will be your output size.
+ // 3. Otherwise, your output size is 0x0.
+ for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ Node *node = phase->effects[i];
+ if (node->effect->num_inputs() == 0) {
+ continue;
+ }
+ unsigned this_output_width = 0;
+ unsigned this_output_height = 0;
+ for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
+ Node *input = node->incoming_links[j];
+ node->effect->inform_input_size(j, input->output_width, input->output_height);
+ if (j == 0) {
+ this_output_width = input->output_width;
+ this_output_height = input->output_height;
+ } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
+ // Inputs disagree.
+ this_output_width = 0;
+ this_output_height = 0;
+ }
+ }
+ node->output_width = this_output_width;
+ node->output_height = this_output_height;
+ }
+}
+
+// Note: You should call inform_input_sizes() before this, as the last effect's
+// desired output size might change based on the inputs.
+void EffectChain::find_output_size(Phase *phase)
+{
+ Node *output_node = phase->effects.back();
+
+ // If the last effect explicitly sets an output size, use that.
+ if (output_node->effect->changes_output_size()) {
+ output_node->effect->get_output_size(&phase->output_width, &phase->output_height,
+ &phase->virtual_output_width, &phase->virtual_output_height);
+ return;
+ }
+
+ // If all effects have the same size, use that.
+ unsigned output_width = 0, output_height = 0;
+ 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);
+ 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) {
+ all_inputs_same_size = false;
+ }
+ }
+ for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ Effect *effect = phase->effects[i]->effect;
+ if (effect->num_inputs() != 0) {
+ continue;
+ }
+
+ Input *input = static_cast<Input *>(effect);
+ if (output_width == 0 && output_height == 0) {
+ output_width = input->get_width();
+ output_height = input->get_height();
+ } else if (output_width != input->get_width() ||
+ output_height != input->get_height()) {
+ all_inputs_same_size = false;
+ }
+ }
+
+ if (all_inputs_same_size) {
+ assert(output_width != 0);
+ assert(output_height != 0);
+ phase->virtual_output_width = phase->output_width = output_width;
+ phase->virtual_output_height = phase->output_height = output_height;
+ return;
+ }
+
+ // If not, fit all the inputs into the current aspect, and select the largest one.
+ 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);
+ }
+ for (unsigned i = 0; i < phase->effects.size(); ++i) {
+ Effect *effect = phase->effects[i]->effect;
+ if (effect->num_inputs() != 0) {
+ continue;
+ }
+
+ Input *input = static_cast<Input *>(effect);
+ size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
+ }
+ assert(output_width != 0);
+ assert(output_height != 0);
+ phase->virtual_output_width = phase->output_width = output_width;
+ phase->virtual_output_height = phase->output_height = output_height;
+}
+
+void EffectChain::sort_all_nodes_topologically()
+{
+ nodes = topological_sort(nodes);
+}
+
+std::vector<Node *> EffectChain::topological_sort(const std::vector<Node *> &nodes)
+{
+ std::set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
+ std::vector<Node *> sorted_list;
+ for (unsigned i = 0; i < nodes.size(); ++i) {
+ topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
+ }
+ reverse(sorted_list.begin(), sorted_list.end());
+ return sorted_list;
+}
+
+void EffectChain::topological_sort_visit_node(Node *node, std::set<Node *> *nodes_left_to_visit, std::vector<Node *> *sorted_list)
+{
+ if (nodes_left_to_visit->count(node) == 0) {
+ return;
+ }
+ nodes_left_to_visit->erase(node);
+ for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
+ topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
+ }
+ sorted_list->push_back(node);
+}
+
+void EffectChain::find_color_spaces_for_inputs()
+{
+ for (unsigned i = 0; i < nodes.size(); ++i) {
+ Node *node = nodes[i];
+ if (node->disabled) {
+ continue;
+ }
+ if (node->incoming_links.size() == 0) {
+ Input *input = static_cast<Input *>(node->effect);
+ node->output_color_space = input->get_color_space();
+ node->output_gamma_curve = input->get_gamma_curve();
+
+ Effect::AlphaHandling alpha_handling = input->alpha_handling();
+ switch (alpha_handling) {
+ case Effect::OUTPUT_BLANK_ALPHA:
+ node->output_alpha_type = ALPHA_BLANK;
+ break;
+ case Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA:
+ node->output_alpha_type = ALPHA_PREMULTIPLIED;
+ break;
+ case Effect::OUTPUT_POSTMULTIPLIED_ALPHA:
+ node->output_alpha_type = ALPHA_POSTMULTIPLIED;
+ break;
+ case Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK:
+ case Effect::DONT_CARE_ALPHA_TYPE:
+ default:
+ assert(false);
+ }
+
+ if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
+ assert(node->output_gamma_curve == GAMMA_LINEAR);
+ }
+ }
+ }
+}
+
+// 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_all_nodes_topologically();
+
+ for (unsigned i = 0; i < nodes.size(); ++i) {
+ Node *node = nodes[i];
+ 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;
+ }
+ }
+}
+
+// Propagate alpha information as far as we can in the graph.
+// Similar to propagate_gamma_and_color_space().
+void EffectChain::propagate_alpha()
+{
+ // We depend on going through the nodes in order.
+ sort_all_nodes_topologically();
+
+ for (unsigned i = 0; i < nodes.size(); ++i) {
+ Node *node = nodes[i];
+ if (node->disabled) {
+ continue;
+ }
+ assert(node->incoming_links.size() == node->effect->num_inputs());
+ if (node->incoming_links.size() == 0) {
+ assert(node->output_alpha_type != ALPHA_INVALID);
+ continue;
+ }
+
+ // The alpha multiplication/division effects are special cases.
+ if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
+ assert(node->incoming_links.size() == 1);
+ assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
+ node->output_alpha_type = ALPHA_PREMULTIPLIED;
+ continue;
+ }
+ if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
+ assert(node->incoming_links.size() == 1);
+ assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
+ node->output_alpha_type = ALPHA_POSTMULTIPLIED;
+ continue;
+ }
+
+ // GammaCompressionEffect and GammaExpansionEffect are also a special case,
+ // because they are the only one that _need_ postmultiplied alpha.
+ if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
+ node->effect->effect_type_id() == "GammaExpansionEffect") {
+ assert(node->incoming_links.size() == 1);
+ if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
+ node->output_alpha_type = ALPHA_BLANK;
+ } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
+ node->output_alpha_type = ALPHA_POSTMULTIPLIED;
+ } else {
+ node->output_alpha_type = ALPHA_INVALID;
+ }
+ continue;
+ }
+
+ // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
+ // or OUTPUT_POSTMULTIPLIED_ALPHA), and they have already been
+ // taken care of above. Rationale: Even if you could imagine
+ // e.g. an effect that took in an image and set alpha=1.0
+ // unconditionally, it wouldn't make any sense to have it as
+ // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
+ // got its input pre- or postmultiplied, so it wouldn't know
+ // whether to divide away the old alpha or not.
+ Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
+ assert(alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
+ alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK ||
+ alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
+
+ // If the node has multiple inputs, check that they are all valid and
+ // the same.
+ bool any_invalid = false;
+ bool any_premultiplied = false;
+ bool any_postmultiplied = false;
+
+ for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
+ switch (node->incoming_links[j]->output_alpha_type) {
+ case ALPHA_INVALID:
+ any_invalid = true;
+ break;
+ case ALPHA_BLANK:
+ // Blank is good as both pre- and postmultiplied alpha,
+ // so just ignore it.
+ break;
+ case ALPHA_PREMULTIPLIED:
+ any_premultiplied = true;
+ break;
+ case ALPHA_POSTMULTIPLIED:
+ any_postmultiplied = true;
+ break;
+ default:
+ assert(false);
+ }
+ }
+
+ if (any_invalid) {
+ node->output_alpha_type = ALPHA_INVALID;
+ continue;
+ }
+
+ // Inputs must be of the same type.
+ if (any_premultiplied && any_postmultiplied) {
+ node->output_alpha_type = ALPHA_INVALID;
+ continue;
+ }
+
+ if (alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
+ alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
+ // If the effect has asked for premultiplied alpha, check that it has got it.
+ if (any_postmultiplied) {
+ node->output_alpha_type = ALPHA_INVALID;
+ } else if (!any_premultiplied &&
+ alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
+ // Blank input alpha, and the effect preserves blank alpha.
+ node->output_alpha_type = ALPHA_BLANK;
+ } else {
+ node->output_alpha_type = ALPHA_PREMULTIPLIED;
+ }
+ } else {
+ // OK, all inputs are the same, and this effect is not going
+ // to change it.
+ assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
+ if (any_premultiplied) {
+ node->output_alpha_type = ALPHA_PREMULTIPLIED;
+ } else if (any_postmultiplied) {
+ node->output_alpha_type = ALPHA_POSTMULTIPLIED;
+ } else {
+ node->output_alpha_type = ALPHA_BLANK;
+ }
+ }
+ }
+}
+
+bool EffectChain::node_needs_colorspace_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 COLORSPACE_INVALID if the inputs differ, so we can rely on that.
+ if (node->output_color_space == COLORSPACE_INVALID) {
+ return true;
+ }
+ 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 after 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());
+ CHECK(conversion->effect->set_int("source_space", input->output_color_space));
+ CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
+ conversion->output_color_space = COLORSPACE_sRGB;
+ replace_sender(input, conversion);
+ connect_nodes(input, conversion);
+ }
+
+ // Re-sort topologically, and propagate the new information.
+ propagate_gamma_and_color_space();
+
+ found_any = true;
+ break;
+ }
+
+ char filename[256];
+ sprintf(filename, "step5-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);
+ }
+}
+
+bool EffectChain::node_needs_alpha_fix(Node *node)
+{
+ if (node->disabled) {
+ return false;
+ }
+
+ // propagate_alpha() has already set our output to ALPHA_INVALID if the
+ // inputs differ or we are otherwise in mismatch, so we can rely on that.
+ return (node->output_alpha_type == ALPHA_INVALID);
+}
+
+// Fix up alpha so that there are no ALPHA_INVALID nodes left in
+// the graph. Similar to fix_internal_color_spaces().
+void EffectChain::fix_internal_alpha(unsigned step)
+{
+ unsigned alpha_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_alpha_fix(node)) {
+ continue;
+ }
+
+ // If we need to fix up GammaExpansionEffect, then clearly something
+ // is wrong, since the combination of premultiplied alpha and nonlinear inputs
+ // is meaningless.
+ assert(node->effect->effect_type_id() != "GammaExpansionEffect");
+
+ AlphaType desired_type = ALPHA_PREMULTIPLIED;
+
+ // GammaCompressionEffect is special; it needs postmultiplied alpha.
+ if (node->effect->effect_type_id() == "GammaCompressionEffect") {
+ assert(node->incoming_links.size() == 1);
+ assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
+ desired_type = ALPHA_POSTMULTIPLIED;
+ }
+
+ // Go through each input that is not premultiplied alpha, and insert
+ // a conversion before it.
+ for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
+ Node *input = node->incoming_links[j];
+ assert(input->output_alpha_type != ALPHA_INVALID);
+ if (input->output_alpha_type == desired_type ||
+ input->output_alpha_type == ALPHA_BLANK) {
+ continue;
+ }
+ Node *conversion;
+ if (desired_type == ALPHA_PREMULTIPLIED) {
+ conversion = add_node(new AlphaMultiplicationEffect());
+ } else {
+ conversion = add_node(new AlphaDivisionEffect());
+ }
+ conversion->output_alpha_type = desired_type;
+ replace_sender(input, conversion);
+ connect_nodes(input, conversion);
+ }
+
+ // Re-sort topologically, and propagate the new information.
+ propagate_gamma_and_color_space();
+ propagate_alpha();
+
+ found_any = true;
+ break;
+ }
+
+ char filename[256];
+ sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
+ output_dot(filename);
+ assert(alpha_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_alpha_type != ALPHA_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());
+ CHECK(conversion->effect->set_int("source_space", output->output_color_space));
+ CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
+ conversion->output_color_space = output_format.color_space;
+ connect_nodes(output, conversion);
+ propagate_alpha();
+ propagate_gamma_and_color_space();
+ }
+}
+
+// Make so that the output is in the desired pre-/postmultiplication alpha state.
+void EffectChain::fix_output_alpha()