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 "lift_gamma_gain_effect.h"
  14 #include "colorspace_conversion_effect.h"
  15
  16 EffectChain::EffectChain(unsigned width, unsigned height)
  17         : width(width), height(height), finalized(false) {}
  18
  19 void EffectChain::add_input(const ImageFormat &format)
  20 {
  21         input_format = format;
  22         current_color_space = format.color_space;
  23         current_gamma_curve = format.gamma_curve;
  24 }
  25
  26 void EffectChain::add_output(const ImageFormat &format)
  27 {
  28         output_format = format;
  29 }
  30
  31 Effect *instantiate_effect(EffectId effect)
  32 {
  33         switch (effect) {
  34         case GAMMA_CONVERSION:
  35                 return new GammaExpansionEffect();
  36         case RGB_PRIMARIES_CONVERSION:
  37                 return new GammaExpansionEffect();
  38         case LIFT_GAMMA_GAIN:
  39                 return new LiftGammaGainEffect();
  40         }
  41         assert(false);
  42 }
  43
  44 Effect *EffectChain::add_effect(EffectId effect_id)
  45 {
  46         Effect *effect = instantiate_effect(effect_id);
  47
  48         if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
  49                 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
  50                 gamma_conversion->set_int("source_curve", current_gamma_curve);
  51                 effects.push_back(gamma_conversion);
  52                 current_gamma_curve = GAMMA_LINEAR;
  53         }
  54
  55         if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
  56                 assert(current_gamma_curve == GAMMA_LINEAR);
  57                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
  58                 colorspace_conversion->set_int("source_space", current_color_space);
  59                 colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
  60                 effects.push_back(colorspace_conversion);
  61                 current_color_space = COLORSPACE_sRGB;
  62         }
  63
  64         // not handled yet
  65         assert(!effect->needs_many_samples());
  66         assert(!effect->needs_mipmaps());
  67
  68         effects.push_back(effect);
  69         return effect;
  70 }
  71
  72 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
  73 std::string replace_prefix(const std::string &text, const std::string &prefix)
  74 {
  75         std::string output;
  76         size_t start = 0;
  77
  78         while (start < text.size()) {
  79                 size_t pos = text.find("PREFIX(", start);
  80                 if (pos == std::string::npos) {
  81                         output.append(text.substr(start, std::string::npos));
  82                         break;
  83                 }
  84
  85                 output.append(text.substr(start, pos - start));
  86                 output.append(prefix);
  87                 output.append("_");
  88
  89                 pos += strlen("PREFIX(");
  90
  91                 // Output stuff until we find the matching ), which we then eat.
  92                 int depth = 1;
  93                 size_t end_arg_pos = pos;
  94                 while (end_arg_pos < text.size()) {
  95                         if (text[end_arg_pos] == '(') {
  96                                 ++depth;
  97                         } else if (text[end_arg_pos] == ')') {
  98                                 --depth;
  99                                 if (depth == 0) {
 100                                         break;
 101                                 }
 102                         }
 103                         ++end_arg_pos;
 104                 }
 105                 output.append(text.substr(pos, end_arg_pos - pos));
 106                 ++end_arg_pos;
 107                 assert(depth == 0);
 108                 start = end_arg_pos;
 109         }
 110         return output;
 111 }
 112
 113 void EffectChain::finalize()
 114 {
 115         std::string frag_shader = read_file("header.glsl");
 116
 117         for (unsigned i = 0; i < effects.size(); ++i) {
 118                 char effect_id[256];
 119                 sprintf(effect_id, "eff%d", i);
 120
 121                 frag_shader += "\n";
 122                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 123                 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
 124                 frag_shader += replace_prefix(effects[i]->output_glsl(), effect_id);
 125                 frag_shader += "#undef PREFIX\n";
 126                 frag_shader += "#undef FUNCNAME\n";
 127                 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
 128                 frag_shader += "\n";
 129         }
 130         printf("%s\n", frag_shader.c_str());
 131
 132         glsl_program_num = glCreateProgram();
 133         GLhandleARB vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
 134         GLhandleARB fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 135         glAttachObjectARB(glsl_program_num, vs_obj);
 136         check_error();
 137         glAttachObjectARB(glsl_program_num, fs_obj);
 138         check_error();
 139         glLinkProgram(glsl_program_num);
 140         check_error();
 141 }