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 "texture_enum.h"
  18
  19 EffectChain::EffectChain(unsigned width, unsigned height)
  20         : width(width), height(height), use_srgb_texture_format(false), finalized(false) {}
  21
  22 void EffectChain::add_input(const ImageFormat &format)
  23 {
  24         input_format = format;
  25         current_color_space = format.color_space;
  26         current_gamma_curve = format.gamma_curve;
  27 }
  28
  29 void EffectChain::add_output(const ImageFormat &format)
  30 {
  31         output_format = format;
  32 }
  33
  34 Effect *instantiate_effect(EffectId effect)
  35 {
  36         switch (effect) {
  37         case EFFECT_GAMMA_EXPANSION:
  38                 return new GammaExpansionEffect();
  39         case EFFECT_GAMMA_COMPRESSION:
  40                 return new GammaCompressionEffect();
  41         case EFFECT_COLOR_SPACE_CONVERSION:
  42                 return new ColorSpaceConversionEffect();
  43         case EFFECT_LIFT_GAMMA_GAIN:
  44                 return new LiftGammaGainEffect();
  45         case EFFECT_SATURATION:
  46                 return new SaturationEffect();
  47         }
  48         assert(false);
  49 }
  50
  51 void EffectChain::normalize_to_linear_gamma()
  52 {
  53         if (current_gamma_curve == GAMMA_sRGB) {
  54                 // TODO: check if the extension exists
  55                 use_srgb_texture_format = true;
  56         } else {
  57                 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
  58                 gamma_conversion->set_int("source_curve", current_gamma_curve);
  59                 effects.push_back(gamma_conversion);
  60         }
  61         current_gamma_curve = GAMMA_LINEAR;
  62 }
  63
  64 void EffectChain::normalize_to_srgb()
  65 {
  66         assert(current_gamma_curve == GAMMA_LINEAR);
  67         ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
  68         colorspace_conversion->set_int("source_space", current_color_space);
  69         colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
  70         effects.push_back(colorspace_conversion);
  71         current_color_space = COLORSPACE_sRGB;
  72 }
  73
  74 Effect *EffectChain::add_effect(EffectId effect_id)
  75 {
  76         Effect *effect = instantiate_effect(effect_id);
  77
  78         if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
  79                 normalize_to_linear_gamma();
  80         }
  81
  82         if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
  83                 normalize_to_srgb();
  84         }
  85
  86         // not handled yet
  87         assert(!effect->needs_many_samples());
  88         assert(!effect->needs_mipmaps());
  89
  90         effects.push_back(effect);
  91         return effect;
  92 }
  93
  94 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
  95 std::string replace_prefix(const std::string &text, const std::string &prefix)
  96 {
  97         std::string output;
  98         size_t start = 0;
  99
 100         while (start < text.size()) {
 101                 size_t pos = text.find("PREFIX(", start);
 102                 if (pos == std::string::npos) {
 103                         output.append(text.substr(start, std::string::npos));
 104                         break;
 105                 }
 106
 107                 output.append(text.substr(start, pos - start));
 108                 output.append(prefix);
 109                 output.append("_");
 110
 111                 pos += strlen("PREFIX(");
 112
 113                 // Output stuff until we find the matching ), which we then eat.
 114                 int depth = 1;
 115                 size_t end_arg_pos = pos;
 116                 while (end_arg_pos < text.size()) {
 117                         if (text[end_arg_pos] == '(') {
 118                                 ++depth;
 119                         } else if (text[end_arg_pos] == ')') {
 120                                 --depth;
 121                                 if (depth == 0) {
 122                                         break;
 123                                 }
 124                         }
 125                         ++end_arg_pos;
 126                 }
 127                 output.append(text.substr(pos, end_arg_pos - pos));
 128                 ++end_arg_pos;
 129                 assert(depth == 0);
 130                 start = end_arg_pos;
 131         }
 132         return output;
 133 }
 134
 135 void EffectChain::finalize()
 136 {
 137         if (current_color_space != output_format.color_space) {
 138                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
 139                 colorspace_conversion->set_int("source_space", current_color_space);
 140                 colorspace_conversion->set_int("destination_space", output_format.color_space);
 141                 effects.push_back(colorspace_conversion);
 142                 current_color_space = output_format.color_space;
 143         }
 144
 145         if (current_gamma_curve != output_format.gamma_curve) {
 146                 if (current_gamma_curve != GAMMA_LINEAR) {
 147                         normalize_to_linear_gamma();
 148                 }
 149                 assert(current_gamma_curve == GAMMA_LINEAR);
 150                 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
 151                 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
 152                 effects.push_back(gamma_conversion);
 153                 current_gamma_curve = output_format.gamma_curve;
 154         }
 155
 156         std::string frag_shader = read_file("header.glsl");
 157
 158         for (unsigned i = 0; i < effects.size(); ++i) {
 159                 char effect_id[256];
 160                 sprintf(effect_id, "eff%d", i);
 161
 162                 frag_shader += "\n";
 163                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 164                 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
 165                 frag_shader += replace_prefix(effects[i]->output_glsl(), effect_id);
 166                 frag_shader += "#undef PREFIX\n";
 167                 frag_shader += "#undef FUNCNAME\n";
 168                 frag_shader += "#undef LAST_INPUT\n";
 169                 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
 170                 frag_shader += "\n";
 171         }
 172         frag_shader.append(read_file("footer.glsl"));
 173         printf("%s\n", frag_shader.c_str());
 174
 175         glsl_program_num = glCreateProgram();
 176         GLhandleARB vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
 177         GLhandleARB fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 178         glAttachShader(glsl_program_num, vs_obj);
 179         check_error();
 180         glAttachShader(glsl_program_num, fs_obj);
 181         check_error();
 182         glLinkProgram(glsl_program_num);
 183         check_error();
 184
 185         finalized = true;
 186 }
 187
 188 void EffectChain::render_to_screen(unsigned char *src)
 189 {
 190         assert(finalized);
 191
 192         check_error();
 193         glUseProgram(glsl_program_num);
 194         check_error();
 195
 196         glActiveTexture(GL_TEXTURE0);
 197         glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
 198
 199         GLenum internal_format = GL_RGBA8;
 200         if (use_srgb_texture_format) {
 201                 internal_format = GL_SRGB8;
 202         }
 203
 204         if (input_format.pixel_format == FORMAT_RGB) {
 205                 glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, src);
 206         } else if (input_format.pixel_format == FORMAT_RGBA) {
 207                 glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, src);
 208         } else {
 209                 assert(false);
 210         }
 211         check_error();
 212         glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
 213
 214         for (unsigned i = 0; i < effects.size(); ++i) {
 215                 char effect_id[256];
 216                 sprintf(effect_id, "eff%d", i);
 217                 effects[i]->set_uniforms(glsl_program_num, effect_id);
 218         }
 219
 220         glDisable(GL_BLEND);
 221         check_error();
 222         glDisable(GL_DEPTH_TEST);
 223         check_error();
 224         glDepthMask(GL_FALSE);
 225         check_error();
 226
 227         glMatrixMode(GL_PROJECTION);
 228         glLoadIdentity();
 229         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 230
 231         glMatrixMode(GL_MODELVIEW);
 232         glLoadIdentity();
 233
 234         glBegin(GL_QUADS);
 235
 236         glTexCoord2f(0.0f, 1.0f);
 237         glVertex2f(0.0f, 0.0f);
 238
 239         glTexCoord2f(1.0f, 1.0f);
 240         glVertex2f(1.0f, 0.0f);
 241
 242         glTexCoord2f(1.0f, 0.0f);
 243         glVertex2f(1.0f, 1.0f);
 244
 245         glTexCoord2f(0.0f, 0.0f);
 246         glVertex2f(0.0f, 1.0f);
 247
 248         glEnd();
 249         check_error();
 250 }