Actually implement multiple inputs to phases. Surprising amounts of stuff needed...
authorSteinar H. Gunderson <sgunderson@bigfoot.com>
Fri, 5 Oct 2012 10:03:49 +0000 (12:03 +0200)
committerSteinar H. Gunderson <sgunderson@bigfoot.com>
Fri, 5 Oct 2012 10:03:49 +0000 (12:03 +0200)
effect_chain.cpp
effect_chain.h
header.frag

index fc20ae1..1244ecb 100644 (file)
@@ -7,6 +7,9 @@
 #include <GL/gl.h>
 #include <GL/glext.h>
 
+#include <algorithm>
+#include <set>
+
 #include "util.h"
 #include "effect_chain.h"
 #include "gamma_expansion_effect.h"
@@ -31,6 +34,7 @@ void EffectChain::add_input(const ImageFormat &format)
        input_format = format;
        output_color_space.insert(std::make_pair(static_cast<Effect *>(NULL), format.color_space));
        output_gamma_curve.insert(std::make_pair(static_cast<Effect *>(NULL), format.gamma_curve));
+       effect_ids.insert(std::make_pair(static_cast<Effect *>(NULL), "src_image"));
 }
 
 void EffectChain::add_output(const ImageFormat &format)
@@ -40,12 +44,19 @@ void EffectChain::add_output(const ImageFormat &format)
 
 void EffectChain::add_effect_raw(Effect *effect, const std::vector<Effect *> &inputs)
 {
+       char effect_id[256];
+       sprintf(effect_id, "eff%u", (unsigned)effects.size());
+
        effects.push_back(effect);
+       effect_ids.insert(std::make_pair(effect, effect_id));
        assert(inputs.size() == effect->num_inputs());
        for (unsigned i = 0; i < inputs.size(); ++i) {
-               outgoing_links.insert(std::make_pair(inputs[i], effect));
-               incoming_links.insert(std::make_pair(effect, inputs[i]));
+               if (inputs[i] != NULL) {
+                       assert(std::find(effects.begin(), effects.end(), inputs[i]) != effects.end());
+               }
+               outgoing_links[inputs[i]].push_back(effect);
        }
+       incoming_links.insert(std::make_pair(effect, inputs));
        last_added_effect = effect;
 }
 
@@ -169,26 +180,82 @@ std::string replace_prefix(const std::string &text, const std::string &prefix)
        return output;
 }
 
-EffectChain::Phase EffectChain::compile_glsl_program(unsigned start_index, unsigned end_index)
+EffectChain::Phase EffectChain::compile_glsl_program(const std::vector<Effect *> &inputs, const std::vector<Effect *> &effects)
 {
+       assert(!inputs.empty());
+       assert(!effects.empty());
+
+       // Figure out the true set of inputs to this phase. These are the ones
+       // that we need somehow but don't calculate ourselves.
+       std::set<Effect *> effect_set(effects.begin(), effects.end());
+       std::set<Effect *> input_set(inputs.begin(), inputs.end());
+       std::vector<Effect *> true_inputs;
+       std::set_difference(input_set.begin(), input_set.end(),
+               effect_set.begin(), effect_set.end(),
+               std::back_inserter(true_inputs));
+
        bool input_needs_mipmaps = false;
        std::string frag_shader = read_file("header.frag");
-       for (unsigned i = start_index; i < end_index; ++i) {
-               char effect_id[256];
-               sprintf(effect_id, "eff%d", i);
+
+       // 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 == NULL) {
+                       // 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(effects[i]->output_convenience_uniforms(), effect_id);
-               frag_shader += replace_prefix(effects[i]->output_fragment_shader(), effect_id);
+               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";
-               frag_shader += "#undef INPUT\n";
-               frag_shader += std::string("#define INPUT ") + effect_id + "\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 |= effects[i]->needs_mipmaps();
+               input_needs_mipmaps |= effect->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());
        
@@ -205,12 +272,92 @@ EffectChain::Phase EffectChain::compile_glsl_program(unsigned start_index, unsig
        Phase phase;
        phase.glsl_program_num = glsl_program_num;
        phase.input_needs_mipmaps = input_needs_mipmaps;
-       phase.start = start_index;
-       phase.end = end_index;
+       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.
+void EffectChain::construct_glsl_programs(Effect *start, std::set<Effect *> *completed_effects)
+{
+       if (completed_effects->count(start) != 0) {
+               // This has already been done for us.
+               return;
+       }
+
+       std::vector<Effect *> this_phase_inputs;  // Also includes all intermediates; these will be filtered away later.
+       std::vector<Effect *> this_phase_effects;
+       Effect *node = start;
+       for ( ;; ) {  // Termination condition within loop.
+               if (node == NULL) {
+                       this_phase_inputs.push_back(node);
+               } else {
+                       // Check that we have all the inputs we need for this effect.
+                       // If not, we end the phase here right away; the other side
+                       // of the input chain will eventually come and pick the effect up.
+                       assert(incoming_links.count(node) != 0);
+                       std::vector<Effect *> deps = incoming_links[node];
+                       assert(!deps.empty());
+                       bool have_all_deps = true;
+                       for (unsigned i = 0; i < deps.size(); ++i) {
+                               if (completed_effects->count(deps[i]) == 0) {
+                                       have_all_deps = false;
+                                       break;
+                               }
+                       }
+               
+                       if (!have_all_deps) {
+                               if (!this_phase_effects.empty()) {
+                                       phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
+                               }
+                               return;
+                       }
+                       this_phase_inputs.insert(this_phase_inputs.end(), deps.begin(), deps.end());    
+                       this_phase_effects.push_back(node);
+               }
+               completed_effects->insert(node);        
+
+               // Find all the effects that use this one as a direct input.
+               if (outgoing_links.count(node) == 0) {
+                       // End of the line; output.
+                       phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
+                       return;
+               }
+
+               std::vector<Effect *> next = outgoing_links[node];
+               assert(!next.empty());
+               if (next.size() > 1) {
+                       // More than one effect uses this as the input.
+                       // 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.
+                       if (node != NULL) {
+                               phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
+                       }
+
+                       // Start phases for all the effects that need us (in arbitrary order).
+                       for (unsigned i = 0; i < next.size(); ++i) {
+                               construct_glsl_programs(next[i], completed_effects);
+                       }
+                       return;
+               }
+       
+               // OK, only one effect uses this as the input. Keep iterating,
+               // but first see if it requires a texture bounce; if so, give it
+               // one by starting a new phase.
+               node = next[0];
+               if (node->needs_texture_bounce()) {
+                       phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
+                       this_phase_inputs.clear();
+                       this_phase_effects.clear();
+               }
+       }
+}
+
 void EffectChain::finalize()
 {
        // Add normalizers to get the output format right.
@@ -234,29 +381,24 @@ void EffectChain::finalize()
                current_gamma_curve = output_format.gamma_curve;
        }
 
-       // Construct the GLSL programs. We end a program every time we come
-       // to an effect marked as "needs many samples" (ie. "please let me
-       // sample directly from a texture, with no arithmetic in-between"),
-       // and of course at the end.
-       unsigned start = 0;
-       for (unsigned i = 0; i < effects.size(); ++i) {
-               if (effects[i]->needs_texture_bounce() && i != start) {
-                       phases.push_back(compile_glsl_program(start, i));
-                       start = i;
-               }
-       }
-       phases.push_back(compile_glsl_program(start, effects.size()));
+       // Construct all needed GLSL programs, starting at the input.
+       std::set<Effect *> completed_effects;
+       construct_glsl_programs(NULL, &completed_effects);
 
        // 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);
 
-               unsigned num_textures = std::max<int>(phases.size() - 1, 2);
-               glGenTextures(num_textures, temp_textures);
-
-               for (unsigned i = 0; i < num_textures; ++i) {
-                       glBindTexture(GL_TEXTURE_2D, temp_textures[i]);
+               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();
@@ -264,6 +406,7 @@ void EffectChain::finalize()
                        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));
                }
        }
        
@@ -359,78 +502,82 @@ void EffectChain::render_to_screen(unsigned char *src)
                check_error();
        }
 
+       std::set<Effect *> generated_mipmaps;
+       generated_mipmaps.insert(NULL);  // Already done further up.
+
        for (unsigned phase = 0; phase < phases.size(); ++phase) {
-               // Set up inputs and outputs for this phase.
-               glActiveTexture(GL_TEXTURE0);
-               if (phase == 0) {
-                       // First phase reads from the input texture (which is already bound).
-               } else {
-                       glBindTexture(GL_TEXTURE_2D, temp_textures[(phase + 1) % 2]);
-                       check_error();
-               }
-               if (phases[phase].input_needs_mipmaps) {
-                       if (phase != 0) {
-                               // For phase 0, it's done further up.
-                               glGenerateMipmap(GL_TEXTURE_2D);
+               glUseProgram(phases[phase].glsl_program_num);
+               check_error();
+
+               // Set up inputs for this phase.
+               assert(!phases[phase].inputs.empty());
+               for (unsigned sampler = 0; sampler < phases[phase].inputs.size(); ++sampler) {
+                       glActiveTexture(GL_TEXTURE0 + sampler);
+                       Effect *input = phases[phase].inputs[sampler];
+                       if (input == NULL) {
+                               glBindTexture(GL_TEXTURE_2D, source_image_num);
+                               check_error();
+                       } else {
+                               assert(effect_output_textures.count(input) != 0);
+                               glBindTexture(GL_TEXTURE_2D, effect_output_textures[input]);
                                check_error();
                        }
-                       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);
+                       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,
-                               temp_textures[phase % 2],
+                               effect_output_textures[last_effect],
                                0);
                        check_error();
                }
 
-               // We have baked an upside-down transform into the quad coordinates,
-               // since the typical graphics program will have the origin at the upper-left,
-               // while OpenGL uses lower-left. In the next ones, however, the origin
-               // is all right, and we need to reverse that.
-               if (phase == 1) {
-                       glTranslatef(0.0f, 1.0f, 0.0f);
-                       glScalef(1.0f, -1.0f, 1.0f);
-               }
-
                // Give the required parameters to all the effects.
-               glUseProgram(phases[phase].glsl_program_num);
-               check_error();
-
-               glUniform1i(glGetUniformLocation(phases[phase].glsl_program_num, "input_tex"), 0);
-               check_error();
-
-               unsigned sampler_num = 1;
-               for (unsigned i = phases[phase].start; i < phases[phase].end; ++i) {
-                       char effect_id[256];
-                       sprintf(effect_id, "eff%d", i);
-                       effects[i]->set_uniforms(phases[phase].glsl_program_num, effect_id, &sampler_num);
+               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_uniforms(phases[phase].glsl_program_num, effect_ids[effect], &sampler_num);
                }
 
                // Now draw!
                glBegin(GL_QUADS);
 
-               glTexCoord2f(0.0f, 1.0f);
+               glTexCoord2f(0.0f, 0.0f);
                glVertex2f(0.0f, 0.0f);
 
-               glTexCoord2f(1.0f, 1.0f);
+               glTexCoord2f(1.0f, 0.0f);
                glVertex2f(1.0f, 0.0f);
 
-               glTexCoord2f(1.0f, 0.0f);
+               glTexCoord2f(1.0f, 1.0f);
                glVertex2f(1.0f, 1.0f);
 
-               glTexCoord2f(0.0f, 0.0f);
+               glTexCoord2f(0.0f, 1.0f);
                glVertex2f(0.0f, 1.0f);
 
                glEnd();
index f521e9c..dc52d3e 100644 (file)
@@ -1,6 +1,7 @@
 #ifndef _EFFECT_CHAIN_H
 #define _EFFECT_CHAIN_H 1
 
+#include <set>
 #include <vector>
 
 #include "effect.h"
@@ -78,28 +79,35 @@ private:
        struct Phase {
                GLint glsl_program_num;
                bool input_needs_mipmaps;
-               unsigned start, end;
+               std::vector<Effect *> inputs;
+               std::vector<Effect *> effects;  // In order.
        };
 
        Effect *normalize_to_linear_gamma(Effect *input);
        Effect *normalize_to_srgb(Effect *input);
 
-       // Create a GLSL program computing effects [start, end>.
-       Phase compile_glsl_program(unsigned start_index, unsigned end_index);
+       void draw_vertex(float x, float y, const std::vector<Effect *> &inputs);
+
+       // Create a GLSL program computing the given effects in order.
+       Phase compile_glsl_program(const std::vector<Effect *> &inputs, const std::vector<Effect *> &effects);
+
+       // Create all GLSL programs needed to compute the given effect, and all outputs
+       // that depends on it (whenever possible).
+       void construct_glsl_programs(Effect *start, std::set<Effect *> *completed_effects);
 
        unsigned width, height;
        ImageFormat input_format, output_format;
-       std::vector<Effect *> effects;
-       std::multimap<Effect *, Effect *> outgoing_links;
-       std::multimap<Effect *, Effect *> incoming_links;
+       std::vector<Effect *> effects, unexpanded_effects;
+       std::map<Effect *, std::string> effect_ids;
+       std::map<Effect *, GLuint> effect_output_textures;
+       std::map<Effect *, std::vector<Effect *> > outgoing_links;
+       std::map<Effect *, std::vector<Effect *> > incoming_links;
        Effect *last_added_effect;
 
        GLuint source_image_num;
        bool use_srgb_texture_format;
 
        GLuint fbo;
-       GLuint temp_textures[2];
-
        std::vector<Phase> phases;
 
        GLenum format, bytes_per_pixel;
index 539eb8d..86c5730 100644 (file)
@@ -1,9 +1 @@
-uniform sampler2D input_tex;
 varying vec2 tc;
-
-vec4 read_input(vec2 tc)
-{
-       return texture2D(input_tex, tc.st);
-}
-
-#define INPUT read_input