Diff: player.cpp

Revision:

0:6679ec22f0e5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/player.cpp	Sun Nov 10 23:19:38 2019 +0000
@@ -0,0 +1,106 @@
+#include "player.h"
+
+#include <string.h>
+#include <math.h>
+#include <stdlib.h>
+
+Note* song = NULL;
+uint32_t songLength = 0;
+
+
+struct osc {
+    uint32_t duration_remaining;
+    uint16_t period;
+    uint16_t on_time;
+};
+
+static osc oscs[MAX_NOTES];
+static osc* oscPool[MAX_NOTES];
+static osc** oscPoolEnd;
+static osc** oscPoolPtr;
+static uint32_t now = 0;
+static uint32_t songPosition = 0;
+bool songDone = false;
+static uint32_t nextNoteTick = 0;
+static uint16_t frequencyTable[256];
+static uint16_t periodTable[256];
+static uint8_t nPlaying = 0;
+
+void initialize_play() {
+    memset((void*)oscs,0,MAX_NOTES*sizeof(osc));
+    now = 0;
+    songPosition = 0;
+    songDone = false;
+    nextNoteTick = song[0]._start_tick;
+    nPlaying = 0;
+    for(int i = 0; i < 256; i++)
+    {
+        float offset = 69;
+        float f = 440.f * pow(2.f, (i - offset)/12.0f);
+        float f2 = ((float)SAMPLE_FREQEUENCY) / f;
+        frequencyTable[i] = 440*pow(2,(i - offset)/12.0f);
+        periodTable[i] = ((uint32_t)f2) > 1 ? f2 : 1;
+        //printf("period %d %d (%d Hz)\n", i, periodTable[i],frequencyTable[i]);
+    }
+    printf("Done initialize\n");
+
+    for(int i = 0; i < MAX_NOTES; i++) {
+        oscPool[i] = oscs + i;
+    }
+    oscPoolEnd = oscPool + MAX_NOTES;
+    oscPoolPtr = oscPool;
+}
+
+
+uint16_t play() {
+    if(songDone) return 0;
+    uint16_t isOn = 0;
+
+    // play/end notes
+    for(uint8_t i = 0; i < MAX_NOTES; i++) {
+        osc* o = oscs + i;
+        if(!o->duration_remaining) continue;
+
+        // note is playing
+        uint16_t progress = now % o->period;
+        uint16_t effectiveOnTime = o->on_time / nPlaying;
+
+        if(progress < effectiveOnTime) {
+            isOn += 1;
+        }
+
+        if(o->duration_remaining == 1) {
+            nPlaying--;
+            *(--oscPoolPtr) = o;
+        }
+        o->duration_remaining--;
+    }
+
+    // avoids mod.
+    if(!(now & (1 << CHEATER_FREQUENCY_MULT_POWER))) {
+        // is there a new note?
+        if(nextNoteTick <= (now >> CHEATER_FREQUENCY_MULT_POWER) && oscPoolPtr < oscPoolEnd) {
+            // there is note to load right now, find an oscillator
+            osc* o = *(oscPoolPtr++);
+
+            if(!o) {
+                printf("Too many notes! skipping...\n");
+            } else {
+                Note* note = song + songPosition;
+                o->duration_remaining = ((uint32_t)note->_duration) << CHEATER_FREQUENCY_MULT_POWER;
+                o->period = periodTable[note->_note];
+                o->on_time = 5 + o->period / 20;
+                nPlaying++;
+            }
+
+            // prepare for next note
+            songPosition++;
+            if(songPosition >= songLength) songDone = true;
+            nextNoteTick = song[songPosition]._start_tick;
+        }
+    }
+
+
+    now++;
+    return isOn;
+}