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 #include "texture_enum.h"
  16
  17 EffectChain::EffectChain(unsigned width, unsigned height)
  18         : width(width), height(height), finalized(false) {}
  19
  20 void EffectChain::add_input(const ImageFormat &format)
  21 {
  22         input_format = format;
  23         current_color_space = format.color_space;
  24         current_gamma_curve = format.gamma_curve;
  25 }
  26
  27 void EffectChain::add_output(const ImageFormat &format)
  28 {
  29         output_format = format;
  30 }
  31
  32 Effect *instantiate_effect(EffectId effect)
  33 {
  34         switch (effect) {
  35         case GAMMA_CONVERSION:
  36                 return new GammaExpansionEffect();
  37         case RGB_PRIMARIES_CONVERSION:
  38                 return new GammaExpansionEffect();
  39         case LIFT_GAMMA_GAIN:
  40                 return new LiftGammaGainEffect();
  41         }
  42         assert(false);
  43 }
  44
  45 Effect *EffectChain::add_effect(EffectId effect_id)
  46 {
  47         Effect *effect = instantiate_effect(effect_id);
  48
  49         if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
  50                 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
  51                 gamma_conversion->set_int("source_curve", current_gamma_curve);
  52                 effects.push_back(gamma_conversion);
  53                 current_gamma_curve = GAMMA_LINEAR;
  54         }
  55
  56         if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
  57                 assert(current_gamma_curve == GAMMA_LINEAR);
  58                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
  59                 colorspace_conversion->set_int("source_space", current_color_space);
  60                 colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
  61                 effects.push_back(colorspace_conversion);
  62                 current_color_space = COLORSPACE_sRGB;
  63         }
  64
  65         // not handled yet
  66         assert(!effect->needs_many_samples());
  67         assert(!effect->needs_mipmaps());
  68
  69         effects.push_back(effect);
  70         return effect;
  71 }
  72
  73 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
  74 std::string replace_prefix(const std::string &text, const std::string &prefix)
  75 {
  76         std::string output;
  77         size_t start = 0;
  78
  79         while (start < text.size()) {
  80                 size_t pos = text.find("PREFIX(", start);
  81                 if (pos == std::string::npos) {
  82                         output.append(text.substr(start, std::string::npos));
  83                         break;
  84                 }
  85
  86                 output.append(text.substr(start, pos - start));
  87                 output.append(prefix);
  88                 output.append("_");
  89
  90                 pos += strlen("PREFIX(");
  91
  92                 // Output stuff until we find the matching ), which we then eat.
  93                 int depth = 1;
  94                 size_t end_arg_pos = pos;
  95                 while (end_arg_pos < text.size()) {
  96                         if (text[end_arg_pos] == '(') {
  97                                 ++depth;
  98                         } else if (text[end_arg_pos] == ')') {
  99                                 --depth;
 100                                 if (depth == 0) {
 101                                         break;
 102                                 }
 103                         }
 104                         ++end_arg_pos;
 105                 }
 106                 output.append(text.substr(pos, end_arg_pos - pos));
 107                 ++end_arg_pos;
 108                 assert(depth == 0);
 109                 start = end_arg_pos;
 110         }
 111         return output;
 112 }
 113
 114 void EffectChain::finalize()
 115 {
 116         std::string frag_shader = read_file("header.glsl");
 117
 118         for (unsigned i = 0; i < effects.size(); ++i) {
 119                 char effect_id[256];
 120                 sprintf(effect_id, "eff%d", i);
 121
 122                 frag_shader += "\n";
 123                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 124                 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
 125                 frag_shader += replace_prefix(effects[i]->output_glsl(), effect_id);
 126                 frag_shader += "#undef PREFIX\n";
 127                 frag_shader += "#undef FUNCNAME\n";
 128                 frag_shader += "#undef LAST_INPUT\n";
 129                 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
 130                 frag_shader += "\n";
 131         }
 132         frag_shader.append(read_file("footer.glsl"));
 133         printf("%s\n", frag_shader.c_str());
 134
 135         glsl_program_num = glCreateProgram();
 136         GLhandleARB vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
 137         GLhandleARB fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 138         glAttachShader(glsl_program_num, vs_obj);
 139         check_error();
 140         glAttachShader(glsl_program_num, fs_obj);
 141         check_error();
 142         glLinkProgram(glsl_program_num);
 143         check_error();
 144
 145         finalized = true;
 146 }
 147
 148 void EffectChain::render_to_screen(unsigned char *src)
 149 {
 150         assert(finalized);
 151
 152         check_error();
 153         glUseProgram(glsl_program_num);
 154         check_error();
 155
 156         glActiveTexture(GL_TEXTURE0);
 157         glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
 158
 159         // TODO: use sRGB textures if applicable
 160         if (input_format.pixel_format == FORMAT_RGB) {
 161                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, src);
 162         } else if (input_format.pixel_format == FORMAT_RGBA) {
 163                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, src);
 164         } else {
 165                 assert(false);
 166         }
 167         check_error();
 168         glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
 169
 170         //for (unsigned i = 0; i < effects.size(); ++i) {
 171         //      effects[i]->set_uniforms();
 172         //}
 173
 174         glDisable(GL_BLEND);
 175         check_error();
 176         glDisable(GL_DEPTH_TEST);
 177         check_error();
 178         glDepthMask(GL_FALSE);
 179         check_error();
 180
 181         glMatrixMode(GL_PROJECTION);
 182         glLoadIdentity();
 183         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 184
 185         glMatrixMode(GL_MODELVIEW);
 186         glLoadIdentity();
 187
 188         glBegin(GL_QUADS);
 189
 190         glTexCoord2f(0.0f, 1.0f);
 191         glVertex2f(0.0f, 0.0f);
 192
 193         glTexCoord2f(1.0f, 1.0f);
 194         glVertex2f(1.0f, 0.0f);
 195
 196         glTexCoord2f(1.0f, 0.0f);
 197         glVertex2f(1.0f, 1.0f);
 198
 199         glTexCoord2f(0.0f, 0.0f);
 200         glVertex2f(0.0f, 1.0f);
 201
 202         glEnd();
 203         check_error();
 204 }