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
  20 EffectChain::EffectChain(unsigned width, unsigned height)
  21         : width(width), height(height), use_srgb_texture_format(false), finalized(false) {}
  22
  23 void EffectChain::add_input(const ImageFormat &format)
  24 {
  25         input_format = format;
  26         current_color_space = format.color_space;
  27         current_gamma_curve = format.gamma_curve;
  28 }
  29
  30 void EffectChain::add_output(const ImageFormat &format)
  31 {
  32         output_format = format;
  33 }
  34
  35 Effect *instantiate_effect(EffectId effect)
  36 {
  37         switch (effect) {
  38         case EFFECT_GAMMA_EXPANSION:
  39                 return new GammaExpansionEffect();
  40         case EFFECT_GAMMA_COMPRESSION:
  41                 return new GammaCompressionEffect();
  42         case EFFECT_COLOR_SPACE_CONVERSION:
  43                 return new ColorSpaceConversionEffect();
  44         case EFFECT_LIFT_GAMMA_GAIN:
  45                 return new LiftGammaGainEffect();
  46         case EFFECT_SATURATION:
  47                 return new SaturationEffect();
  48         case EFFECT_MIRROR:
  49                 return new MirrorEffect();
  50         case EFFECT_VIGNETTE:
  51                 return new VignetteEffect();
  52         }
  53         assert(false);
  54 }
  55
  56 void EffectChain::normalize_to_linear_gamma()
  57 {
  58         if (current_gamma_curve == GAMMA_sRGB) {
  59                 // TODO: check if the extension exists
  60                 use_srgb_texture_format = true;
  61         } else {
  62                 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
  63                 gamma_conversion->set_int("source_curve", current_gamma_curve);
  64                 effects.push_back(gamma_conversion);
  65         }
  66         current_gamma_curve = GAMMA_LINEAR;
  67 }
  68
  69 void EffectChain::normalize_to_srgb()
  70 {
  71         assert(current_gamma_curve == GAMMA_LINEAR);
  72         ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
  73         colorspace_conversion->set_int("source_space", current_color_space);
  74         colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
  75         effects.push_back(colorspace_conversion);
  76         current_color_space = COLORSPACE_sRGB;
  77 }
  78
  79 Effect *EffectChain::add_effect(EffectId effect_id)
  80 {
  81         Effect *effect = instantiate_effect(effect_id);
  82
  83         if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
  84                 normalize_to_linear_gamma();
  85         }
  86
  87         if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
  88                 normalize_to_srgb();
  89         }
  90
  91         // not handled yet
  92         assert(!effect->needs_many_samples());
  93         assert(!effect->needs_mipmaps());
  94
  95         effects.push_back(effect);
  96         return effect;
  97 }
  98
  99 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 100 std::string replace_prefix(const std::string &text, const std::string &prefix)
 101 {
 102         std::string output;
 103         size_t start = 0;
 104
 105         while (start < text.size()) {
 106                 size_t pos = text.find("PREFIX(", start);
 107                 if (pos == std::string::npos) {
 108                         output.append(text.substr(start, std::string::npos));
 109                         break;
 110                 }
 111
 112                 output.append(text.substr(start, pos - start));
 113                 output.append(prefix);
 114                 output.append("_");
 115
 116                 pos += strlen("PREFIX(");
 117
 118                 // Output stuff until we find the matching ), which we then eat.
 119                 int depth = 1;
 120                 size_t end_arg_pos = pos;
 121                 while (end_arg_pos < text.size()) {
 122                         if (text[end_arg_pos] == '(') {
 123                                 ++depth;
 124                         } else if (text[end_arg_pos] == ')') {
 125                                 --depth;
 126                                 if (depth == 0) {
 127                                         break;
 128                                 }
 129                         }
 130                         ++end_arg_pos;
 131                 }
 132                 output.append(text.substr(pos, end_arg_pos - pos));
 133                 ++end_arg_pos;
 134                 assert(depth == 0);
 135                 start = end_arg_pos;
 136         }
 137         return output;
 138 }
 139
 140 void EffectChain::finalize()
 141 {
 142         if (current_color_space != output_format.color_space) {
 143                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
 144                 colorspace_conversion->set_int("source_space", current_color_space);
 145                 colorspace_conversion->set_int("destination_space", output_format.color_space);
 146                 effects.push_back(colorspace_conversion);
 147                 current_color_space = output_format.color_space;
 148         }
 149
 150         if (current_gamma_curve != output_format.gamma_curve) {
 151                 if (current_gamma_curve != GAMMA_LINEAR) {
 152                         normalize_to_linear_gamma();
 153                 }
 154                 assert(current_gamma_curve == GAMMA_LINEAR);
 155                 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
 156                 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
 157                 effects.push_back(gamma_conversion);
 158                 current_gamma_curve = output_format.gamma_curve;
 159         }
 160
 161         std::string frag_shader = read_file("header.frag");
 162         for (unsigned i = 0; i < effects.size(); ++i) {
 163                 char effect_id[256];
 164                 sprintf(effect_id, "eff%d", i);
 165
 166                 frag_shader += "\n";
 167                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 168                 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
 169                 frag_shader += replace_prefix(effects[i]->output_fragment_shader(), effect_id);
 170                 frag_shader += "#undef PREFIX\n";
 171                 frag_shader += "#undef FUNCNAME\n";
 172                 frag_shader += "#undef LAST_INPUT\n";
 173                 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
 174                 frag_shader += "\n";
 175         }
 176         frag_shader.append(read_file("footer.frag"));
 177         printf("%s\n", frag_shader.c_str());
 178
 179         glsl_program_num = glCreateProgram();
 180         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 181         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 182         glAttachShader(glsl_program_num, vs_obj);
 183         check_error();
 184         glAttachShader(glsl_program_num, fs_obj);
 185         check_error();
 186         glLinkProgram(glsl_program_num);
 187         check_error();
 188
 189         // Translate the format to OpenGL's enums.
 190         GLenum internal_format;
 191         if (use_srgb_texture_format) {
 192                 internal_format = GL_SRGB8;
 193         } else {
 194                 internal_format = GL_RGBA8;
 195         }
 196         if (input_format.pixel_format == FORMAT_RGB) {
 197                 format = GL_RGB;
 198                 bytes_per_pixel = 3;
 199         } else if (input_format.pixel_format == FORMAT_RGBA) {
 200                 format = GL_RGBA;
 201                 bytes_per_pixel = 4;
 202         } else if (input_format.pixel_format == FORMAT_BGR) {
 203                 format = GL_BGR;
 204                 bytes_per_pixel = 3;
 205         } else if (input_format.pixel_format == FORMAT_BGRA) {
 206                 format = GL_BGRA;
 207                 bytes_per_pixel = 4;
 208         } else {
 209                 assert(false);
 210         }
 211
 212         // Create PBO to hold the texture, and then the texture itself.
 213         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
 214         check_error();
 215         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
 216         check_error();
 217
 218         void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 219         memset(mapped_pbo, 0, width * height * bytes_per_pixel);
 220         glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 221
 222         glGenTextures(1, &source_image_num);
 223         check_error();
 224         glBindTexture(GL_TEXTURE_2D, source_image_num);
 225         check_error();
 226         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 227         check_error();
 228         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
 229         check_error();
 230         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 231         check_error();
 232
 233         finalized = true;
 234 }
 235
 236 void EffectChain::render_to_screen(unsigned char *src)
 237 {
 238         assert(finalized);
 239
 240         // Copy the pixel data into the PBO.
 241         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
 242         check_error();
 243         void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 244         memcpy(mapped_pbo, src, width * height * bytes_per_pixel);
 245         glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 246         check_error();
 247
 248         // Re-upload the texture from the PBO.
 249         glActiveTexture(GL_TEXTURE0);
 250         check_error();
 251         glBindTexture(GL_TEXTURE_2D, source_image_num);
 252         check_error();
 253         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
 254         check_error();
 255         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 256         check_error();
 257
 258         glUseProgram(glsl_program_num);
 259         check_error();
 260
 261         check_error();
 262         glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
 263
 264         for (unsigned i = 0; i < effects.size(); ++i) {
 265                 char effect_id[256];
 266                 sprintf(effect_id, "eff%d", i);
 267                 effects[i]->set_uniforms(glsl_program_num, effect_id);
 268         }
 269
 270         glDisable(GL_BLEND);
 271         check_error();
 272         glDisable(GL_DEPTH_TEST);
 273         check_error();
 274         glDepthMask(GL_FALSE);
 275         check_error();
 276
 277         glMatrixMode(GL_PROJECTION);
 278         glLoadIdentity();
 279         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 280
 281         glMatrixMode(GL_MODELVIEW);
 282         glLoadIdentity();
 283
 284         glBegin(GL_QUADS);
 285
 286         glTexCoord2f(0.0f, 1.0f);
 287         glVertex2f(0.0f, 0.0f);
 288
 289         glTexCoord2f(1.0f, 1.0f);
 290         glVertex2f(1.0f, 0.0f);
 291
 292         glTexCoord2f(1.0f, 0.0f);
 293         glVertex2f(1.0f, 1.0f);
 294
 295         glTexCoord2f(0.0f, 0.0f);
 296         glVertex2f(0.0f, 1.0f);
 297
 298         glEnd();
 299         check_error();
 300 }