| 89 | |
| 90 | template<typename T> |
| 91 | void Beeper::generateSamples(T *stream, int length) { |
| 92 | const int AMPLITUDE = (sizeof(T) == 2) ? 28000 : 120; |
| 93 | const int offset = (sdlAudioFormat == AUDIO_U8) ? 120 : 0; |
| 94 | |
| 95 | int i = 0; |
| 96 | length /= numChannels; |
| 97 | while (i < length) { |
| 98 | if (beeps.empty()) { |
| 99 | memset(stream + numChannels*i, 0, sizeof(T)*numChannels*(length-i)); |
| 100 | return; |
| 101 | } |
| 102 | BeepObject& bo = beeps.front(); |
| 103 | |
| 104 | // In Stereo tests, mute one of the channels to be able to distinguish that Stereo output works. |
| 105 | if (bo.samplesLeft > tone_duration * frequency / 2 / 1000) { |
| 106 | mutedChannel = 1; |
| 107 | } else { |
| 108 | mutedChannel = 0; |
| 109 | } |
| 110 | |
| 111 | int samplesToDo = std::min(i + bo.samplesLeft, length); |
| 112 | bo.samplesLeft -= samplesToDo - i; |
| 113 | |
| 114 | while (i < samplesToDo) { |
| 115 | for(int j = 0; j < numChannels; ++j) { |
| 116 | stream[numChannels*i+j] = (T)(offset + (int)(AMPLITUDE * std::sin(phase * 2 * M_PI / frequency))); |
| 117 | if (numChannels > 1 && j == mutedChannel) { |
| 118 | stream[numChannels*i+j] = 0; |
| 119 | } |
| 120 | } |
| 121 | phase += bo.toneFrequency; |
| 122 | i++; |
| 123 | } |
| 124 | |
| 125 | if (bo.samplesLeft == 0) { |
| 126 | beeps.pop(); |
| 127 | } |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | void Beeper::beep(double toneFrequency, int durationMSecs) { |
| 132 | BeepObject bo; |