git.sesse.net Git - movit/blob - effect_chain.cpp

   1 #define GL_GLEXT_PROTOTYPES 1
   2
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <assert.h>
   6
   7 #include <GL/gl.h>
   8 #include <GL/glext.h>
   9
  10 #include "util.h"
  11 #include "effect_chain.h"
  12 #include "gamma_expansion_effect.h"
  13 #include "gamma_compression_effect.h"
  14 #include "lift_gamma_gain_effect.h"
  15 #include "colorspace_conversion_effect.h"
  16 #include "saturation_effect.h"
  17 #include "mirror_effect.h"
  18 #include "vignette_effect.h"
  19 #include "blur_effect.h"
  20
  21 EffectChain::EffectChain(unsigned width, unsigned height)
  22         : width(width), height(height), use_srgb_texture_format(false), finalized(false) {}
  23
  24 void EffectChain::add_input(const ImageFormat &format)
  25 {
  26         input_format = format;
  27         current_color_space = format.color_space;
  28         current_gamma_curve = format.gamma_curve;
  29 }
  30
  31 void EffectChain::add_output(const ImageFormat &format)
  32 {
  33         output_format = format;
  34 }
  35
  36 Effect *instantiate_effect(EffectId effect)
  37 {
  38         switch (effect) {
  39         case EFFECT_GAMMA_EXPANSION:
  40                 return new GammaExpansionEffect();
  41         case EFFECT_GAMMA_COMPRESSION:
  42                 return new GammaCompressionEffect();
  43         case EFFECT_COLOR_SPACE_CONVERSION:
  44                 return new ColorSpaceConversionEffect();
  45         case EFFECT_LIFT_GAMMA_GAIN:
  46                 return new LiftGammaGainEffect();
  47         case EFFECT_SATURATION:
  48                 return new SaturationEffect();
  49         case EFFECT_MIRROR:
  50                 return new MirrorEffect();
  51         case EFFECT_VIGNETTE:
  52                 return new VignetteEffect();
  53         case EFFECT_BLUR:
  54                 return new BlurEffect();
  55         }
  56         assert(false);
  57 }
  58
  59 void EffectChain::normalize_to_linear_gamma()
  60 {
  61         if (current_gamma_curve == GAMMA_sRGB) {
  62                 // TODO: check if the extension exists
  63                 use_srgb_texture_format = true;
  64         } else {
  65                 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
  66                 gamma_conversion->set_int("source_curve", current_gamma_curve);
  67                 effects.push_back(gamma_conversion);
  68         }
  69         current_gamma_curve = GAMMA_LINEAR;
  70 }
  71
  72 void EffectChain::normalize_to_srgb()
  73 {
  74         assert(current_gamma_curve == GAMMA_LINEAR);
  75         ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
  76         colorspace_conversion->set_int("source_space", current_color_space);
  77         colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
  78         effects.push_back(colorspace_conversion);
  79         current_color_space = COLORSPACE_sRGB;
  80 }
  81
  82 Effect *EffectChain::add_effect(EffectId effect_id)
  83 {
  84         Effect *effect = instantiate_effect(effect_id);
  85
  86         if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
  87                 normalize_to_linear_gamma();
  88         }
  89
  90         if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
  91                 normalize_to_srgb();
  92         }
  93
  94         effects.push_back(effect);
  95         return effect;
  96 }
  97
  98 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
  99 std::string replace_prefix(const std::string &text, const std::string &prefix)
 100 {
 101         std::string output;
 102         size_t start = 0;
 103
 104         while (start < text.size()) {
 105                 size_t pos = text.find("PREFIX(", start);
 106                 if (pos == std::string::npos) {
 107                         output.append(text.substr(start, std::string::npos));
 108                         break;
 109                 }
 110
 111                 output.append(text.substr(start, pos - start));
 112                 output.append(prefix);
 113                 output.append("_");
 114
 115                 pos += strlen("PREFIX(");
 116
 117                 // Output stuff until we find the matching ), which we then eat.
 118                 int depth = 1;
 119                 size_t end_arg_pos = pos;
 120                 while (end_arg_pos < text.size()) {
 121                         if (text[end_arg_pos] == '(') {
 122                                 ++depth;
 123                         } else if (text[end_arg_pos] == ')') {
 124                                 --depth;
 125                                 if (depth == 0) {
 126                                         break;
 127                                 }
 128                         }
 129                         ++end_arg_pos;
 130                 }
 131                 output.append(text.substr(pos, end_arg_pos - pos));
 132                 ++end_arg_pos;
 133                 assert(depth == 0);
 134                 start = end_arg_pos;
 135         }
 136         return output;
 137 }
 138
 139 EffectChain::Phase EffectChain::compile_glsl_program(unsigned start_index, unsigned end_index)
 140 {
 141         bool input_needs_mipmaps = false;
 142         std::string frag_shader = read_file("header.frag");
 143         for (unsigned i = start_index; i < end_index; ++i) {
 144                 char effect_id[256];
 145                 sprintf(effect_id, "eff%d", i);
 146
 147                 frag_shader += "\n";
 148                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 149                 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
 150                 frag_shader += replace_prefix(effects[i]->output_fragment_shader(), effect_id);
 151                 frag_shader += "#undef PREFIX\n";
 152                 frag_shader += "#undef FUNCNAME\n";
 153                 frag_shader += "#undef LAST_INPUT\n";
 154                 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
 155                 frag_shader += "\n";
 156
 157                 input_needs_mipmaps |= effects[i]->needs_mipmaps();
 158         }
 159         frag_shader.append(read_file("footer.frag"));
 160         printf("%s\n", frag_shader.c_str());
 161
 162         GLuint glsl_program_num = glCreateProgram();
 163         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 164         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 165         glAttachShader(glsl_program_num, vs_obj);
 166         check_error();
 167         glAttachShader(glsl_program_num, fs_obj);
 168         check_error();
 169         glLinkProgram(glsl_program_num);
 170         check_error();
 171
 172         Phase phase;
 173         phase.glsl_program_num = glsl_program_num;
 174         phase.input_needs_mipmaps = input_needs_mipmaps;
 175         phase.start = start_index;
 176         phase.end = end_index;
 177
 178         return phase;
 179 }
 180
 181 void EffectChain::finalize()
 182 {
 183         // Add normalizers to get the output format right.
 184         if (current_color_space != output_format.color_space) {
 185                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
 186                 colorspace_conversion->set_int("source_space", current_color_space);
 187                 colorspace_conversion->set_int("destination_space", output_format.color_space);
 188                 effects.push_back(colorspace_conversion);
 189                 current_color_space = output_format.color_space;
 190         }
 191         if (current_gamma_curve != output_format.gamma_curve) {
 192                 if (current_gamma_curve != GAMMA_LINEAR) {
 193                         normalize_to_linear_gamma();
 194                 }
 195                 assert(current_gamma_curve == GAMMA_LINEAR);
 196                 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
 197                 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
 198                 effects.push_back(gamma_conversion);
 199                 current_gamma_curve = output_format.gamma_curve;
 200         }
 201
 202         // Construct the GLSL programs. We end a program every time we come
 203         // to an effect marked as "needs many samples" (ie. "please let me
 204         // sample directly from a texture, with no arithmetic in-between"),
 205         // and of course at the end.
 206         unsigned start = 0;
 207         for (unsigned i = 0; i < effects.size(); ++i) {
 208                 if (effects[i]->needs_many_samples() && i != start) {
 209                         phases.push_back(compile_glsl_program(start, i));
 210                         start = i;
 211                 }
 212         }
 213         phases.push_back(compile_glsl_program(start, effects.size()));
 214
 215         // If we have more than one phase, we need intermediate render-to-texture.
 216         // Construct an FBO, and then as many textures as we need.
 217         if (phases.size() > 1) {
 218                 glGenFramebuffers(1, &fbo);
 219
 220                 unsigned num_textures = std::max<int>(phases.size() - 1, 2);
 221                 glGenTextures(num_textures, temp_textures);
 222
 223                 unsigned char *empty = new unsigned char[width * height * 4];
 224                 for (unsigned i = 0; i < num_textures; ++i) {
 225                         glBindTexture(GL_TEXTURE_2D, temp_textures[i]);
 226                         check_error();
 227                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, empty);
 228                         check_error();
 229                 }
 230                 delete[] empty;
 231         }
 232
 233         // Translate the input format to OpenGL's enums.
 234         GLenum internal_format;
 235         if (use_srgb_texture_format) {
 236                 internal_format = GL_SRGB8;
 237         } else {
 238                 internal_format = GL_RGBA8;
 239         }
 240         if (input_format.pixel_format == FORMAT_RGB) {
 241                 format = GL_RGB;
 242                 bytes_per_pixel = 3;
 243         } else if (input_format.pixel_format == FORMAT_RGBA) {
 244                 format = GL_RGBA;
 245                 bytes_per_pixel = 4;
 246         } else if (input_format.pixel_format == FORMAT_BGR) {
 247                 format = GL_BGR;
 248                 bytes_per_pixel = 3;
 249         } else if (input_format.pixel_format == FORMAT_BGRA) {
 250                 format = GL_BGRA;
 251                 bytes_per_pixel = 4;
 252         } else {
 253                 assert(false);
 254         }
 255
 256         // Create PBO to hold the texture holding the input image, and then the texture itself.
 257         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
 258         check_error();
 259         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
 260         check_error();
 261
 262         void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 263         memset(mapped_pbo, 0, width * height * bytes_per_pixel);
 264         glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 265
 266         glGenTextures(1, &source_image_num);
 267         check_error();
 268         glBindTexture(GL_TEXTURE_2D, source_image_num);
 269         check_error();
 270         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 271         check_error();
 272         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
 273         check_error();
 274         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 275         check_error();
 276
 277         finalized = true;
 278 }
 279
 280 void EffectChain::render_to_screen(unsigned char *src)
 281 {
 282         assert(finalized);
 283
 284         // Copy the pixel data into the PBO.
 285         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
 286         check_error();
 287         void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 288         memcpy(mapped_pbo, src, width * height * bytes_per_pixel);
 289         glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 290         check_error();
 291
 292         // Re-upload the texture from the PBO.
 293         glActiveTexture(GL_TEXTURE0);
 294         check_error();
 295         glBindTexture(GL_TEXTURE_2D, source_image_num);
 296         check_error();
 297         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
 298         check_error();
 299         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 300         check_error();
 301         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 302         check_error();
 303         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 304         check_error();
 305
 306         // Basic state.
 307         glDisable(GL_BLEND);
 308         check_error();
 309         glDisable(GL_DEPTH_TEST);
 310         check_error();
 311         glDepthMask(GL_FALSE);
 312         check_error();
 313
 314         glMatrixMode(GL_PROJECTION);
 315         glLoadIdentity();
 316         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 317
 318         glMatrixMode(GL_MODELVIEW);
 319         glLoadIdentity();
 320
 321         if (phases.size() > 1) {
 322                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 323                 check_error();
 324         }
 325
 326         for (unsigned phase = 0; phase < phases.size(); ++phase) {
 327                 // Set up inputs and outputs for this phase.
 328                 if (phase == 0) {
 329                         // First phase reads from the input texture (which is already bound).
 330                 } else {
 331                         glBindTexture(GL_TEXTURE_2D, temp_textures[(phase + 1) % 2]);
 332                         check_error();
 333                 }
 334                 if (phases[phase].input_needs_mipmaps) {
 335                         glGenerateMipmap(GL_TEXTURE_2D);
 336                         check_error();
 337                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
 338                         check_error();
 339                 } else {
 340                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 341                         check_error();
 342                 }
 343
 344                 if (phase == phases.size() - 1) {
 345                         // Last phase goes directly to the screen.
 346                         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 347                         check_error();
 348                 } else {
 349                         glFramebufferTexture2D(
 350                                 GL_FRAMEBUFFER,
 351                                 GL_COLOR_ATTACHMENT0,
 352                                 GL_TEXTURE_2D,
 353                                 temp_textures[phase % 2],
 354                                 0);
 355                 }
 356
 357                 // We have baked an upside-down transform into the quad coordinates,
 358                 // since the typical graphics program will have the origin at the upper-left,
 359                 // while OpenGL uses lower-left. In the next ones, however, the origin
 360                 // is all right, and we need to reverse that.
 361                 if (phase == 1) {
 362                         glTranslatef(0.0f, 1.0f, 0.0f);
 363                         glScalef(1.0f, -1.0f, 1.0f);
 364                 }
 365
 366                 // Give the required parameters to all the effects.
 367                 glUseProgram(phases[phase].glsl_program_num);
 368                 check_error();
 369
 370                 glUniform1i(glGetUniformLocation(phases[phase].glsl_program_num, "input_tex"), 0);
 371                 check_error();
 372
 373                 unsigned sampler_num = 1;
 374                 for (unsigned i = phases[phase].start; i < phases[phase].end; ++i) {
 375                         char effect_id[256];
 376                         sprintf(effect_id, "eff%d", i);
 377                         effects[i]->set_uniforms(phases[phase].glsl_program_num, effect_id, &sampler_num);
 378                 }
 379
 380                 // Now draw!
 381                 glBegin(GL_QUADS);
 382
 383                 glTexCoord2f(0.0f, 1.0f);
 384                 glVertex2f(0.0f, 0.0f);
 385
 386                 glTexCoord2f(1.0f, 1.0f);
 387                 glVertex2f(1.0f, 0.0f);
 388
 389                 glTexCoord2f(1.0f, 0.0f);
 390                 glVertex2f(1.0f, 1.0f);
 391
 392                 glTexCoord2f(0.0f, 0.0f);
 393                 glVertex2f(0.0f, 1.0f);
 394
 395                 glEnd();
 396                 check_error();
 397
 398                 // HACK
 399                 glActiveTexture(GL_TEXTURE0);
 400                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
 401                 check_error();
 402         }
 403 }