+
+ 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);
+ }
+ }
+
+ // Finally, since the phases are found from the output but must be executed
+ // from the input(s), reverse them, too.
+ std::reverse(phases.begin(), phases.end());
+}
+
+void EffectChain::finalize()
+{
+ // 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<Effect *> output_effects;
+ for (unsigned i = 0; i < effects.size(); ++i) {
+ Effect *effect = effects[i];
+ if (outgoing_links.count(effect) == 0 || outgoing_links[effect].size() == 0) {
+ output_effects.push_back(effect);
+ }
+ }
+ assert(output_effects.size() == 1);
+ Effect *output_effect = output_effects[0];
+
+ // Add normalizers to get the output format right.
+ assert(output_gamma_curve.count(output_effect) != 0);
+ assert(output_color_space.count(output_effect) != 0);
+ ColorSpace current_color_space = output_color_space[output_effect];
+ if (current_color_space != output_format.color_space) {
+ ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
+ colorspace_conversion->set_int("source_space", current_color_space);
+ colorspace_conversion->set_int("destination_space", output_format.color_space);
+ std::vector<Effect *> inputs;
+ inputs.push_back(output_effect);
+ colorspace_conversion->add_self_to_effect_chain(this, inputs);
+ output_color_space[colorspace_conversion] = output_format.color_space;
+ output_effect = colorspace_conversion;
+ }
+ GammaCurve current_gamma_curve = output_gamma_curve[output_effect];
+ if (current_gamma_curve != output_format.gamma_curve) {
+ if (current_gamma_curve != GAMMA_LINEAR) {
+ output_effect = normalize_to_linear_gamma(output_effect);
+ current_gamma_curve = GAMMA_LINEAR;
+ }
+ GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
+ gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
+ std::vector<Effect *> inputs;
+ inputs.push_back(output_effect);
+ gamma_conversion->add_self_to_effect_chain(this, inputs);
+ output_gamma_curve[gamma_conversion] = output_format.gamma_curve;
+ output_effect = gamma_conversion;
+ }
+
+ // Construct all needed GLSL programs, starting at the output.
+ construct_glsl_programs(output_effect);
+
+ // If we have more than one phase, we need intermediate render-to-texture.
+ // Construct an FBO, and then as many textures as we need.
+ // We choose the simplest option of having one texture per output,
+ // since otherwise this turns into an (albeit simple)
+ // register allocation problem.
+ if (phases.size() > 1) {
+ glGenFramebuffers(1, &fbo);
+
+ for (unsigned i = 0; i < phases.size() - 1; ++i) {
+ Effect *output_effect = phases[i].effects.back();
+ GLuint temp_texture;
+ glGenTextures(1, &temp_texture);
+ check_error();
+ glBindTexture(GL_TEXTURE_2D, temp_texture);
+ check_error();
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+ check_error();
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+ check_error();
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+ check_error();
+ effect_output_textures.insert(std::make_pair(output_effect, temp_texture));
+ }
+ }
+
+ for (unsigned i = 0; i < inputs.size(); ++i) {
+ inputs[i]->finalize();
+ }
+
+ finalized = true;
+}
+
+void EffectChain::render_to_screen()
+{
+ assert(finalized);
+
+ // Basic state.
+ glDisable(GL_BLEND);
+ check_error();
+ glDisable(GL_DEPTH_TEST);
+ check_error();
+ glDepthMask(GL_FALSE);
+ check_error();
+
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
+
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+
+ if (phases.size() > 1) {
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+ check_error();
+ }
+
+ std::set<Effect *> generated_mipmaps;
+ for (unsigned i = 0; i < inputs.size(); ++i) {
+ // Inputs generate their own mipmaps if they need to
+ // (see input.cpp).
+ generated_mipmaps.insert(inputs[i]);
+ }
+
+ for (unsigned phase = 0; phase < phases.size(); ++phase) {
+ glUseProgram(phases[phase].glsl_program_num);
+ check_error();
+
+ // Set up RTT inputs for this phase.
+ for (unsigned sampler = 0; sampler < phases[phase].inputs.size(); ++sampler) {
+ glActiveTexture(GL_TEXTURE0 + sampler);
+ Effect *input = phases[phase].inputs[sampler];
+ assert(effect_output_textures.count(input) != 0);
+ glBindTexture(GL_TEXTURE_2D, effect_output_textures[input]);
+ check_error();
+ if (phases[phase].input_needs_mipmaps) {
+ if (generated_mipmaps.count(input) == 0) {
+ glGenerateMipmap(GL_TEXTURE_2D);
+ check_error();
+ generated_mipmaps.insert(input);
+ }
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
+ check_error();
+ } else {
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ check_error();
+ }
+
+ assert(effect_ids.count(input));
+ std::string texture_name = std::string("tex_") + effect_ids[input];
+ glUniform1i(glGetUniformLocation(phases[phase].glsl_program_num, texture_name.c_str()), sampler);
+ check_error();
+ }
+
+ // And now the output.
+ if (phase == phases.size() - 1) {
+ // Last phase goes directly to the screen.
+ glBindFramebuffer(GL_FRAMEBUFFER, 0);
+ check_error();
+ } else {
+ Effect *last_effect = phases[phase].effects.back();
+ assert(effect_output_textures.count(last_effect) != 0);
+ glFramebufferTexture2D(
+ GL_FRAMEBUFFER,
+ GL_COLOR_ATTACHMENT0,
+ GL_TEXTURE_2D,
+ effect_output_textures[last_effect],
+ 0);
+ check_error();
+ }
+
+ // Give the required parameters to all the effects.
+ unsigned sampler_num = phases[phase].inputs.size();
+ for (unsigned i = 0; i < phases[phase].effects.size(); ++i) {
+ Effect *effect = phases[phase].effects[i];
+ effect->set_gl_state(phases[phase].glsl_program_num, effect_ids[effect], &sampler_num);
+ }
+
+ // Now draw!
+ glBegin(GL_QUADS);
+
+ glTexCoord2f(0.0f, 0.0f);
+ glVertex2f(0.0f, 0.0f);
+
+ glTexCoord2f(1.0f, 0.0f);
+ glVertex2f(1.0f, 0.0f);
+
+ glTexCoord2f(1.0f, 1.0f);
+ glVertex2f(1.0f, 1.0f);
+
+ glTexCoord2f(0.0f, 1.0f);
+ glVertex2f(0.0f, 1.0f);
+
+ glEnd();
+ check_error();
+
+ for (unsigned i = 0; i < phases[phase].effects.size(); ++i) {
+ Effect *effect = phases[phase].effects[i];
+ effect->clear_gl_state();
+ }
+ }