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