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