]> git.sesse.net Git - movit/blobdiff - effect_chain.cpp
Add a diffusion effect, and hook it up in the GUI.
[movit] / effect_chain.cpp
index a8381505109affe8ade2becd09009c58b15b1233..fdc08cfa2ffcbfa30714f4030de96b2d2ce4ae77 100644 (file)
 #include <GL/gl.h>
 #include <GL/glext.h>
 
+#include <algorithm>
+#include <set>
+
 #include "util.h"
 #include "effect_chain.h"
 #include "gamma_expansion_effect.h"
+#include "gamma_compression_effect.h"
 #include "lift_gamma_gain_effect.h"
 #include "colorspace_conversion_effect.h"
-#include "texture_enum.h"
+#include "sandbox_effect.h"
+#include "saturation_effect.h"
+#include "mirror_effect.h"
+#include "vignette_effect.h"
+#include "blur_effect.h"
+#include "diffusion_effect.h"
 
 EffectChain::EffectChain(unsigned width, unsigned height)
-       : width(width), height(height), finalized(false) {}
+       : width(width),
+         height(height),
+         last_added_effect(NULL),
+         use_srgb_texture_format(false),
+         finalized(false) {}
 
 void EffectChain::add_input(const ImageFormat &format)
 {
        input_format = format;
-       current_color_space = format.color_space;
-       current_gamma_curve = format.gamma_curve;
+       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)
 {
        output_format = 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) {
+               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;
+}
+
 Effect *instantiate_effect(EffectId effect)
 {
        switch (effect) {
-       case GAMMA_CONVERSION:
+       case EFFECT_GAMMA_EXPANSION:
                return new GammaExpansionEffect();
-       case RGB_PRIMARIES_CONVERSION:
-               return new GammaExpansionEffect();
-       case LIFT_GAMMA_GAIN:
+       case EFFECT_GAMMA_COMPRESSION:
+               return new GammaCompressionEffect();
+       case EFFECT_COLOR_SPACE_CONVERSION:
+               return new ColorSpaceConversionEffect();
+       case EFFECT_SANDBOX:
+               return new SandboxEffect();
+       case EFFECT_LIFT_GAMMA_GAIN:
                return new LiftGammaGainEffect();
+       case EFFECT_SATURATION:
+               return new SaturationEffect();
+       case EFFECT_MIRROR:
+               return new MirrorEffect();
+       case EFFECT_VIGNETTE:
+               return new VignetteEffect();
+       case EFFECT_BLUR:
+               return new BlurEffect();
+       case EFFECT_DIFFUSION:
+               return new DiffusionEffect();
        }
        assert(false);
 }
 
-Effect *EffectChain::add_effect(EffectId effect_id)
+Effect *EffectChain::normalize_to_linear_gamma(Effect *input)
 {
-       Effect *effect = instantiate_effect(effect_id);
-
-       if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
+       GammaCurve current_gamma_curve = output_gamma_curve[input];
+       if (current_gamma_curve == GAMMA_sRGB) {
+               // TODO: check if the extension exists
+               use_srgb_texture_format = true;
+               current_gamma_curve = GAMMA_LINEAR;
+               return input;
+       } else {
                GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
                gamma_conversion->set_int("source_curve", current_gamma_curve);
-               effects.push_back(gamma_conversion);
+               std::vector<Effect *> inputs;
+               inputs.push_back(input);
+               gamma_conversion->add_self_to_effect_chain(this, inputs);
                current_gamma_curve = GAMMA_LINEAR;
+               return gamma_conversion;
        }
+}
 
-       if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
-               assert(current_gamma_curve == GAMMA_LINEAR);
-               ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
-               colorspace_conversion->set_int("source_space", current_color_space);
-               colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
-               effects.push_back(colorspace_conversion);
-               current_color_space = COLORSPACE_sRGB;
-       }
+Effect *EffectChain::normalize_to_srgb(Effect *input)
+{
+       GammaCurve current_gamma_curve = output_gamma_curve[input];
+       ColorSpace current_color_space = output_color_space[input];
+       assert(current_gamma_curve == GAMMA_LINEAR);
+       ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
+       colorspace_conversion->set_int("source_space", current_color_space);
+       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);
+       current_color_space = COLORSPACE_sRGB;
+       return colorspace_conversion;
+}
 
-       // not handled yet
-       assert(!effect->needs_many_samples());
-       assert(!effect->needs_mipmaps());
+Effect *EffectChain::add_effect(EffectId effect_id, const std::vector<Effect *> &inputs)
+{
+       Effect *effect = instantiate_effect(effect_id);
 
-       effects.push_back(effect);
+       assert(inputs.size() == effect->num_inputs());
+
+       std::vector<Effect *> normalized_inputs = inputs;
+       for (unsigned i = 0; i < normalized_inputs.size(); ++i) {
+               if (effect->needs_linear_light() && output_gamma_curve[normalized_inputs[i]] != GAMMA_LINEAR) {
+                       normalized_inputs[i] = normalize_to_linear_gamma(normalized_inputs[i]);
+               }
+               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;
 }
 
@@ -111,30 +183,88 @@ std::string replace_prefix(const std::string &text, const std::string &prefix)
        return output;
 }
 
-void EffectChain::finalize()
+EffectChain::Phase EffectChain::compile_glsl_program(const std::vector<Effect *> &inputs, const std::vector<Effect *> &effects)
 {
-       std::string frag_shader = read_file("header.glsl");
+       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");
+
+       // 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) {
-               char effect_id[256];
-               sprintf(effect_id, "eff%d", 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_glsl(), 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 LAST_INPUT\n";
-               frag_shader += std::string("#define LAST_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 |= effect->needs_mipmaps();
        }
-       frag_shader.append(read_file("footer.glsl"));
+       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());
        
-       glsl_program_num = glCreateProgram();
-       GLhandleARB vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
-       GLhandleARB fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
+       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);
@@ -142,35 +272,220 @@ void EffectChain::finalize()
        glLinkProgram(glsl_program_num);
        check_error();
 
-       finalized = true;
+       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;
 }
 
-void EffectChain::render_to_screen(unsigned char *src)
+// 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)
 {
-       assert(finalized);
+       if (completed_effects->count(start) != 0) {
+               // This has already been done for us.
+               return;
+       }
 
-       check_error();
-       glUseProgram(glsl_program_num);
-       check_error();
+       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);        
 
-       glActiveTexture(GL_TEXTURE0);
-       glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
+               // 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));
+                       }
 
-       // TODO: use sRGB textures if applicable
+                       // 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.
+       GammaCurve current_gamma_curve = output_gamma_curve[last_added_effect];  // FIXME
+       ColorSpace current_color_space = output_color_space[last_added_effect];  // FIXME
+       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);
+               effects.push_back(colorspace_conversion);
+               current_color_space = output_format.color_space;
+       }
+       if (current_gamma_curve != output_format.gamma_curve) {
+               if (current_gamma_curve != GAMMA_LINEAR) {
+                       normalize_to_linear_gamma(last_added_effect);  // FIXME
+               }
+               assert(current_gamma_curve == GAMMA_LINEAR);
+               GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
+               gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
+               effects.push_back(gamma_conversion);
+               current_gamma_curve = output_format.gamma_curve;
+       }
+
+       // 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);
+
+               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));
+               }
+       }
+       
+       // Translate the input format to OpenGL's enums.
+       GLenum internal_format;
+       if (use_srgb_texture_format) {
+               internal_format = GL_SRGB8;
+       } else {
+               internal_format = GL_RGBA8;
+       }
        if (input_format.pixel_format == FORMAT_RGB) {
-               glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, src);
+               format = GL_RGB;
+               bytes_per_pixel = 3;
        } else if (input_format.pixel_format == FORMAT_RGBA) {
-               glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, src);
+               format = GL_RGBA;
+               bytes_per_pixel = 4;
+       } else if (input_format.pixel_format == FORMAT_BGR) {
+               format = GL_BGR;
+               bytes_per_pixel = 3;
+       } else if (input_format.pixel_format == FORMAT_BGRA) {
+               format = GL_BGRA;
+               bytes_per_pixel = 4;
        } else {
                assert(false);
        }
+
+       // Create PBO to hold the texture holding the input image, and then the texture itself.
+       glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
+       check_error();
+       glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
+       check_error();
+       glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
+       check_error();
+       
+       glGenTextures(1, &source_image_num);
+       check_error();
+       glBindTexture(GL_TEXTURE_2D, source_image_num);
+       check_error();
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+       check_error();
+       // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here.
+       glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, phases[0].input_needs_mipmaps ? GL_TRUE : GL_FALSE);
+       check_error();
+       glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, NULL);
        check_error();
-       glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
 
-       //for (unsigned i = 0; i < effects.size(); ++i) {
-       //      effects[i]->set_uniforms();
-       //}
+       finalized = true;
+}
 
+void EffectChain::render_to_screen(unsigned char *src)
+{
+       assert(finalized);
+
+       // Copy the pixel data into the PBO.
+       glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
+       check_error();
+       void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
+       memcpy(mapped_pbo, src, width * height * bytes_per_pixel);
+       glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
+       check_error();
+
+       // Re-upload the texture from the PBO.
+       glActiveTexture(GL_TEXTURE0);
+       check_error();
+       glBindTexture(GL_TEXTURE_2D, source_image_num);
+       check_error();
+       glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
+       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();
+       glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
+       check_error();
+
+       // Basic state.
        glDisable(GL_BLEND);
        check_error();
        glDisable(GL_DEPTH_TEST);
@@ -185,20 +500,97 @@ void EffectChain::render_to_screen(unsigned char *src)
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
 
-       glBegin(GL_QUADS);
+       if (phases.size() > 1) {
+               glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+               check_error();
+       }
 
-       glTexCoord2f(0.0f, 1.0f);
-       glVertex2f(0.0f, 0.0f);
+       std::set<Effect *> generated_mipmaps;
+       generated_mipmaps.insert(NULL);  // Already done further up.
+
+       for (unsigned phase = 0; phase < phases.size(); ++phase) {
+               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();
+                       }
+                       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();
+                       }
 
-       glTexCoord2f(1.0f, 1.0f);
-       glVertex2f(1.0f, 0.0f);
+                       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();
+               }
 
-       glTexCoord2f(1.0f, 0.0f);
-       glVertex2f(1.0f, 1.0f);
+               // 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();
+               }
 
-       glTexCoord2f(0.0f, 0.0f);
-       glVertex2f(0.0f, 1.0f);
+               // 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_uniforms(phases[phase].glsl_program_num, effect_ids[effect], &sampler_num);
+               }
 
-       glEnd();
-       check_error();
+               // 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();
+
+               // HACK
+               glActiveTexture(GL_TEXTURE0);
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
+               check_error();
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 1000);
+               check_error();
+       }
 }