+ gamma_conversion->set_int("source_curve", output_gamma_curve[input]);
+ std::vector<Effect *> inputs;
+ inputs.push_back(input);
+ gamma_conversion->add_self_to_effect_chain(this, inputs);
+ output_gamma_curve[gamma_conversion] = GAMMA_LINEAR;
+ return gamma_conversion;
+ }
+}
+
+Effect *EffectChain::normalize_to_srgb(Effect *input)
+{
+ assert(output_gamma_curve.count(input) != 0);
+ assert(output_color_space.count(input) != 0);
+ assert(output_gamma_curve[input] == GAMMA_LINEAR);
+ ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
+ colorspace_conversion->set_int("source_space", output_color_space[input]);
+ colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
+ std::vector<Effect *> inputs;
+ inputs.push_back(input);
+ colorspace_conversion->add_self_to_effect_chain(this, inputs);
+ output_color_space[colorspace_conversion] = COLORSPACE_sRGB;
+ return colorspace_conversion;
+}
+
+Effect *EffectChain::add_effect(EffectId effect_id, const std::vector<Effect *> &inputs)
+{
+ Effect *effect = instantiate_effect(effect_id);
+
+ assert(inputs.size() == effect->num_inputs());
+
+ std::vector<Effect *> normalized_inputs = inputs;
+ for (unsigned i = 0; i < normalized_inputs.size(); ++i) {
+ assert(output_gamma_curve.count(normalized_inputs[i]) != 0);
+ if (effect->needs_linear_light() && output_gamma_curve[normalized_inputs[i]] != GAMMA_LINEAR) {
+ normalized_inputs[i] = normalize_to_linear_gamma(normalized_inputs[i]);
+ }
+ assert(output_color_space.count(normalized_inputs[i]) != 0);
+ if (effect->needs_srgb_primaries() && output_color_space[normalized_inputs[i]] != COLORSPACE_sRGB) {
+ normalized_inputs[i] = normalize_to_srgb(normalized_inputs[i]);
+ }
+ }
+
+ effect->add_self_to_effect_chain(this, normalized_inputs);
+ return effect;
+}
+
+// GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
+std::string replace_prefix(const std::string &text, const std::string &prefix)
+{
+ std::string output;
+ size_t start = 0;
+
+ while (start < text.size()) {
+ size_t pos = text.find("PREFIX(", start);
+ if (pos == std::string::npos) {
+ output.append(text.substr(start, std::string::npos));
+ break;
+ }
+
+ output.append(text.substr(start, pos - start));
+ output.append(prefix);
+ output.append("_");
+
+ pos += strlen("PREFIX(");
+
+ // Output stuff until we find the matching ), which we then eat.
+ int depth = 1;
+ size_t end_arg_pos = pos;
+ while (end_arg_pos < text.size()) {
+ if (text[end_arg_pos] == '(') {
+ ++depth;
+ } else if (text[end_arg_pos] == ')') {
+ --depth;
+ if (depth == 0) {
+ break;
+ }
+ }
+ ++end_arg_pos;
+ }
+ output.append(text.substr(pos, end_arg_pos - pos));
+ ++end_arg_pos;
+ assert(depth == 0);
+ start = end_arg_pos;
+ }
+ return output;
+}
+
+EffectChain::Phase EffectChain::compile_glsl_program(const std::vector<Effect *> &inputs, const std::vector<Effect *> &effects)
+{
+ assert(!effects.empty());
+
+ // Deduplicate the inputs.
+ std::vector<Effect *> true_inputs = inputs;
+ std::sort(true_inputs.begin(), true_inputs.end());
+ true_inputs.erase(std::unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
+
+ bool input_needs_mipmaps = false;
+ std::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) {
+ Effect *effect = true_inputs[i];
+ assert(effect_ids.count(effect) != 0);
+ std::string effect_id = effect_ids[effect];
+
+ frag_shader += std::string("uniform sampler2D tex_") + effect_id + ";\n";
+ frag_shader += std::string("vec4 ") + effect_id + "(vec2 tc) {\n";
+ if (effect->num_inputs() == 0) {
+ // OpenGL's origin is bottom-left, but most graphics software assumes
+ // a top-left origin. Thus, for inputs that come from the user,
+ // we flip the y coordinate. However, for FBOs, the origin
+ // is all correct, so don't do anything.
+ frag_shader += "\ttc.y = 1.0f - tc.y;\n";
+ }
+ frag_shader += "\treturn texture2D(tex_" + effect_id + ", tc);\n";
+ frag_shader += "}\n";
+ frag_shader += "\n";
+ }
+
+ std::string last_effect_id;
+ for (unsigned i = 0; i < effects.size(); ++i) {
+ Effect *effect = effects[i];
+ assert(effect != NULL);
+ assert(effect_ids.count(effect) != 0);
+ std::string effect_id = effect_ids[effect];
+ last_effect_id = effect_id;
+
+ if (incoming_links[effect].size() == 1) {
+ frag_shader += std::string("#define INPUT ") + effect_ids[incoming_links[effect][0]] + "\n";
+ } else {
+ for (unsigned j = 0; j < incoming_links[effect].size(); ++j) {
+ char buf[256];
+ sprintf(buf, "#define INPUT%d %s\n", j + 1, effect_ids[incoming_links[effect][j]].c_str());
+ frag_shader += buf;
+ }
+ }
+
+ frag_shader += "\n";
+ frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
+ frag_shader += replace_prefix(effect->output_convenience_uniforms(), effect_id);
+ frag_shader += replace_prefix(effect->output_fragment_shader(), effect_id);
+ frag_shader += "#undef PREFIX\n";
+ frag_shader += "#undef FUNCNAME\n";
+ if (incoming_links[effect].size() == 1) {
+ frag_shader += "#undef INPUT\n";
+ } else {
+ for (unsigned j = 0; j < incoming_links[effect].size(); ++j) {
+ char buf[256];
+ sprintf(buf, "#undef INPUT%d\n", j + 1);
+ frag_shader += buf;
+ }
+ }
+ frag_shader += "\n";
+
+ input_needs_mipmaps |= effect->needs_mipmaps();
+ }
+ for (unsigned i = 0; i < effects.size(); ++i) {
+ Effect *effect = effects[i];
+ if (effect->num_inputs() == 0) {
+ effect->set_int("needs_mipmaps", input_needs_mipmaps);
+ }
+ }
+ assert(!last_effect_id.empty());
+ frag_shader += std::string("#define INPUT ") + last_effect_id + "\n";
+ frag_shader.append(read_file("footer.frag"));
+ printf("%s\n", frag_shader.c_str());
+
+ GLuint glsl_program_num = glCreateProgram();
+ GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
+ glAttachShader(glsl_program_num, vs_obj);
+ check_error();
+ glAttachShader(glsl_program_num, fs_obj);
+ check_error();
+ glLinkProgram(glsl_program_num);
+ check_error();
+
+ Phase phase;
+ phase.glsl_program_num = glsl_program_num;
+ phase.input_needs_mipmaps = input_needs_mipmaps;
+ phase.inputs = true_inputs;
+ phase.effects = effects;
+
+ return phase;
+}
+
+// Construct GLSL programs, starting at the given effect and following
+// the chain from there. We end a program every time we come to an effect
+// marked as "needs texture bounce", one that is used by multiple other
+// effects, 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(Effect *output)
+{
+ // Which effects have already been completed in this phase?
+ // We need to keep track of it, as an effect with multiple outputs
+ // could otherwise be calculate multiple times.
+ std::set<Effect *> completed_effects;
+
+ // 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.
+ std::vector<Effect *> this_phase_inputs;
+ std::vector<Effect *> this_phase_effects;
+
+ // Effects that we have yet to calculate, but that we know should
+ // be in the current phase.
+ std::stack<Effect *> 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.
+ std::stack<Effect *> 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.
+ Effect *effect = effects_todo_this_phase.top();
+ effects_todo_this_phase.pop();
+
+ // This should currently only happen for effects that are phase outputs,
+ // and we throw those out separately below.
+ assert(completed_effects.count(effect) == 0);
+
+ this_phase_effects.push_back(effect);
+ completed_effects.insert(effect);
+
+ // Find all the dependencies of this effect, and add them to the stack.
+ assert(incoming_links.count(effect) == 1);
+ std::vector<Effect *> deps = incoming_links[effect];
+ assert(effect->num_inputs() == deps.size());
+ for (unsigned i = 0; i < deps.size(); ++i) {
+ bool start_new_phase = false;
+
+ if (effect->needs_texture_bounce()) {
+ start_new_phase = true;
+ }
+
+ assert(outgoing_links.count(deps[i]) == 1);
+ if (outgoing_links[deps[i]].size() > 1 && deps[i]->num_inputs() > 0) {
+ // 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;
+ }
+
+ 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]);
+ }
+ }
+ 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_inputs.clear();
+ this_phase_effects.clear();
+ }
+ assert(this_phase_inputs.empty());
+ assert(this_phase_effects.empty());
+
+ // If we have no effects left, exit.
+ if (effects_todo_other_phases.empty()) {
+ break;
+ }
+
+ Effect *effect = effects_todo_other_phases.top();
+ effects_todo_other_phases.pop();
+
+ if (completed_effects.count(effect) == 0) {
+ // Start a new phase, calculating from this effect.
+ effects_todo_this_phase.push(effect);
+ }