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 "texture_enum.h"
  17
  18 EffectChain::EffectChain(unsigned width, unsigned height)
  19         : width(width), height(height), finalized(false) {}
  20
  21 void EffectChain::add_input(const ImageFormat &format)
  22 {
  23         input_format = format;
  24         current_color_space = format.color_space;
  25         current_gamma_curve = format.gamma_curve;
  26 }
  27
  28 void EffectChain::add_output(const ImageFormat &format)
  29 {
  30         output_format = format;
  31 }
  32
  33 Effect *instantiate_effect(EffectId effect)
  34 {
  35         switch (effect) {
  36         case GAMMA_CONVERSION:
  37                 return new GammaExpansionEffect();
  38         case RGB_PRIMARIES_CONVERSION:
  39                 return new GammaExpansionEffect();
  40         case LIFT_GAMMA_GAIN:
  41                 return new LiftGammaGainEffect();
  42         }
  43         assert(false);
  44 }
  45
  46 void EffectChain::normalize_to_linear_gamma()
  47 {
  48         GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
  49         gamma_conversion->set_int("source_curve", current_gamma_curve);
  50         effects.push_back(gamma_conversion);
  51         current_gamma_curve = GAMMA_LINEAR;
  52 }
  53
  54 void EffectChain::normalize_to_srgb()
  55 {
  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 Effect *EffectChain::add_effect(EffectId effect_id)
  65 {
  66         Effect *effect = instantiate_effect(effect_id);
  67
  68         if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
  69                 normalize_to_linear_gamma();
  70         }
  71
  72         if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
  73                 normalize_to_srgb();
  74         }
  75
  76         // not handled yet
  77         assert(!effect->needs_many_samples());
  78         assert(!effect->needs_mipmaps());
  79
  80         effects.push_back(effect);
  81         return effect;
  82 }
  83
  84 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
  85 std::string replace_prefix(const std::string &text, const std::string &prefix)
  86 {
  87         std::string output;
  88         size_t start = 0;
  89
  90         while (start < text.size()) {
  91                 size_t pos = text.find("PREFIX(", start);
  92                 if (pos == std::string::npos) {
  93                         output.append(text.substr(start, std::string::npos));
  94                         break;
  95                 }
  96
  97                 output.append(text.substr(start, pos - start));
  98                 output.append(prefix);
  99                 output.append("_");
 100
 101                 pos += strlen("PREFIX(");
 102
 103                 // Output stuff until we find the matching ), which we then eat.
 104                 int depth = 1;
 105                 size_t end_arg_pos = pos;
 106                 while (end_arg_pos < text.size()) {
 107                         if (text[end_arg_pos] == '(') {
 108                                 ++depth;
 109                         } else if (text[end_arg_pos] == ')') {
 110                                 --depth;
 111                                 if (depth == 0) {
 112                                         break;
 113                                 }
 114                         }
 115                         ++end_arg_pos;
 116                 }
 117                 output.append(text.substr(pos, end_arg_pos - pos));
 118                 ++end_arg_pos;
 119                 assert(depth == 0);
 120                 start = end_arg_pos;
 121         }
 122         return output;
 123 }
 124
 125 void EffectChain::finalize()
 126 {
 127         // TODO: If we want a non-sRGB output color space, convert.
 128
 129         if (current_gamma_curve != output_format.gamma_curve) {
 130                 if (current_gamma_curve != GAMMA_LINEAR) {
 131                         normalize_to_linear_gamma();
 132                 }
 133                 assert(current_gamma_curve == GAMMA_LINEAR);
 134                 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
 135                 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
 136                 effects.push_back(gamma_conversion);
 137                 current_gamma_curve = output_format.gamma_curve;
 138         }
 139
 140         std::string frag_shader = read_file("header.glsl");
 141
 142         for (unsigned i = 0; i < effects.size(); ++i) {
 143                 char effect_id[256];
 144                 sprintf(effect_id, "eff%d", i);
 145
 146                 frag_shader += "\n";
 147                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 148                 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
 149                 frag_shader += replace_prefix(effects[i]->output_glsl(), effect_id);
 150                 frag_shader += "#undef PREFIX\n";
 151                 frag_shader += "#undef FUNCNAME\n";
 152                 frag_shader += "#undef LAST_INPUT\n";
 153                 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
 154                 frag_shader += "\n";
 155         }
 156         frag_shader.append(read_file("footer.glsl"));
 157         printf("%s\n", frag_shader.c_str());
 158
 159         glsl_program_num = glCreateProgram();
 160         GLhandleARB vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
 161         GLhandleARB fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 162         glAttachShader(glsl_program_num, vs_obj);
 163         check_error();
 164         glAttachShader(glsl_program_num, fs_obj);
 165         check_error();
 166         glLinkProgram(glsl_program_num);
 167         check_error();
 168
 169         finalized = true;
 170 }
 171
 172 void EffectChain::render_to_screen(unsigned char *src)
 173 {
 174         assert(finalized);
 175
 176         check_error();
 177         glUseProgram(glsl_program_num);
 178         check_error();
 179
 180         glActiveTexture(GL_TEXTURE0);
 181         glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
 182
 183         // TODO: use sRGB textures if applicable
 184         if (input_format.pixel_format == FORMAT_RGB) {
 185                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, src);
 186         } else if (input_format.pixel_format == FORMAT_RGBA) {
 187                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, src);
 188         } else {
 189                 assert(false);
 190         }
 191         check_error();
 192         glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
 193
 194         //for (unsigned i = 0; i < effects.size(); ++i) {
 195         //      effects[i]->set_uniforms();
 196         //}
 197
 198         glDisable(GL_BLEND);
 199         check_error();
 200         glDisable(GL_DEPTH_TEST);
 201         check_error();
 202         glDepthMask(GL_FALSE);
 203         check_error();
 204
 205         glMatrixMode(GL_PROJECTION);
 206         glLoadIdentity();
 207         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 208
 209         glMatrixMode(GL_MODELVIEW);
 210         glLoadIdentity();
 211
 212         glBegin(GL_QUADS);
 213
 214         glTexCoord2f(0.0f, 1.0f);
 215         glVertex2f(0.0f, 0.0f);
 216
 217         glTexCoord2f(1.0f, 1.0f);
 218         glVertex2f(1.0f, 0.0f);
 219
 220         glTexCoord2f(1.0f, 0.0f);
 221         glVertex2f(1.0f, 1.0f);
 222
 223         glTexCoord2f(0.0f, 0.0f);
 224         glVertex2f(0.0f, 1.0f);
 225
 226         glEnd();
 227         check_error();
 228 }