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