git.sesse.net Git - pitch/blob - glpitch.cpp

   1 #include <SDL.h>
   2 #include <GL/gl.h>
   3
   4 #include "config.h"
   5 #include "linux_audio.h"
   6 #include "notes.h"
   7 #include "pitchdetector.h"
   8
   9 #define MIN_X -40
  10 #define MAX_X 5
  11
  12 double find_pos(double freq)
  13 {
  14         return 12.0 * log2(freq / BASE_PITCH) - 3.0;
  15 }
  16
  17 int main(void)
  18 {
  19         PitchDetector pd(SAMPLE_RATE, FFT_LENGTH, PAD_FACTOR, OVERLAP);
  20         int fd = get_dsp_fd(SAMPLE_RATE, FFT_LENGTH, OVERLAP);
  21
  22         SDL_Init(SDL_INIT_VIDEO);
  23         SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
  24         SDL_SetVideoMode(1024, 200, 32, SDL_OPENGL);
  25
  26         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  27         glClear(GL_COLOR_BUFFER_BIT);
  28
  29         for ( ;; ) {
  30                 SDL_Event event;
  31                 while (SDL_PollEvent(&event)) {
  32                         switch (event.type) {
  33                         case SDL_KEYUP:
  34                                 if (event.key.keysym.sym == SDLK_ESCAPE) {
  35                                         exit(0);
  36                                 }
  37                                 break;
  38                         case SDL_QUIT:
  39                                 exit(0);
  40                         }
  41                 }
  42
  43                 short buf[FFT_LENGTH / PAD_FACTOR / OVERLAP];
  44                 read_chunk(fd, buf, FFT_LENGTH / PAD_FACTOR / OVERLAP);
  45                 std::pair<double, double> peak = pd.detect_pitch(buf);
  46
  47                 glMatrixMode(GL_PROJECTION);
  48                 glLoadIdentity();
  49                 glOrtho(MIN_X, MAX_X, 1.0f, 0.0f, 0.0f, 1.0f);
  50
  51                 glMatrixMode(GL_MODELVIEW);
  52                 glLoadIdentity();
  53
  54                 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  55                 glEnable(GL_BLEND);
  56
  57                 glBegin(GL_QUADS);
  58                 glColor4f(0.0, 0.0f, 0.0f, 0.05f);
  59                 glVertex2f(MIN_X, 0.0f);
  60                 glVertex2f(MIN_X, 1.0f);
  61                 glVertex2f(MAX_X, 1.0f);
  62                 glVertex2f(MAX_X, 0.0f);
  63                 glEnd();
  64
  65                 if (peak.second - log10(FFT_LENGTH) >= 0.0) {
  66                         double peak_pos = find_pos(peak.first);
  67
  68                         glBlendFunc(GL_SRC_ALPHA, GL_ONE);
  69                         glBegin(GL_QUADS);
  70                         glColor4f(0.0, 1.0f, 0.0f, 0.2f);
  71                         glVertex2f(peak_pos - 0.1, 0.0f);
  72                         glVertex2f(peak_pos - 0.1, 1.0f);
  73                         glVertex2f(peak_pos + 0.1, 1.0f);
  74                         glVertex2f(peak_pos + 0.1, 0.0f);
  75                         glEnd();
  76                 }
  77
  78                 glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
  79                 glBegin(GL_LINES);
  80
  81                 for (int i = 0; i < 6; ++i) {
  82                         double pos = find_pos(notes[i].freq);
  83                         glVertex2f(pos, 0.0f);
  84                         glVertex2f(pos, 1.0f);
  85                 }
  86                 glEnd();
  87
  88                 SDL_GL_SwapBuffers();
  89         }
  90 }