From 2d9cbe79972ac5218972d4e922610871e974de34 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= <tastyfish@seznam.cz>
Date: Thu, 27 Feb 2020 20:18:35 +0100
Subject: [PATCH] Add pokitto sound

---
 main.c             |  7 +-----
 platform_pokitto.h | 61 +++++++++++++++++++++++++++++++++++++++++++++-
 sounds.h           |  3 +++
 3 files changed, 64 insertions(+), 7 deletions(-)

diff --git a/main.c b/main.c
index f05eb17..f0094bc 100755
--- a/main.c
+++ b/main.c
@@ -2436,7 +2436,7 @@ void SFG_gameStepPlaying()
       {
         case SFG_WEAPON_KNIFE:           sound = 255; break;
         case SFG_WEAPON_ROCKET_LAUNCHER: 
-        case SFG_WEAPON_SHOTGUN:         sound = 2; break;
+        case SFG_WEAPON_SHOTGUN:         sound = 2; break; 
         case SFG_WEAPON_PLASMAGUN:
         case SFG_WEAPON_SOLUTION:        sound = 4; break;
         default:                         sound = 0; break;
@@ -2445,11 +2445,6 @@ void SFG_gameStepPlaying()
       if (sound != 255)
         SFG_playSoundSafe(sound,255);
 
-      if (SFG_player.weapon != SFG_WEAPON_KNIFE)
-        SFG_playSoundSafe(
-          (SFG_player.weapon == SFG_WEAPON_SHOTGUN ||
-           SFG_player.weapon == SFG_WEAPON_MACHINE_GUN) ? 0 : 4,255);
-
       if (ammo != SFG_AMMO_NONE)
         SFG_player.ammo[ammo] -= projectileCount;
 
diff --git a/platform_pokitto.h b/platform_pokitto.h
index d21e982..728faf3 100644
--- a/platform_pokitto.h
+++ b/platform_pokitto.h
@@ -1,7 +1,8 @@
 /**
   @file platform_pokitto.h
 
-  This is Pokitto implementation of the game front end.
+  This is Pokitto implementation of the game front end, using the official
+  PokittoLib.
 
   by Miloslav Ciz (drummyfish), 2019
 
@@ -44,8 +45,12 @@
 #define SFG_RAYCASTING_SUBSAMPLE 2
 
 #include "Pokitto.h"
+#include "clock_11u6x.h"
+#include "timer_11u6x.h"
 #include "palette.h"
 
+#include "sounds.h"
+
 Pokitto::Core pokitto;
 
 uint8_t *pokittoScreen;
@@ -85,13 +90,66 @@ void SFG_getMouseOffset(int16_t *x, int16_t *y)
   *y = 0;
 }
 
+uint8_t audioBuff[SFG_SFX_SAMPLE_COUNT];
+uint16_t audioPos = 0;
+
+void onTimer() // for sound
+{
+  if (Chip_TIMER_MatchPending(LPC_TIMER32_0, 1))
+  {
+    Chip_TIMER_ClearMatch(LPC_TIMER32_0, 1);
+
+    Pokitto::dac_write(audioBuff[audioPos]);
+
+    audioBuff[audioPos] = 127;
+
+    audioPos = (audioPos + 1) % SFG_SFX_SAMPLE_COUNT;
+  }
+}
+
+void timerInit(uint32_t samplingRate)
+{
+  Chip_TIMER_Init(LPC_TIMER32_0);
+  Chip_TIMER_Reset(LPC_TIMER32_0);
+  Chip_TIMER_MatchEnableInt(LPC_TIMER32_0, 1);
+  Chip_TIMER_SetMatch(LPC_TIMER32_0, 1, 
+    (Chip_Clock_GetSystemClockRate() / samplingRate));
+  Chip_TIMER_ResetOnMatchEnable(LPC_TIMER32_0, 1);
+  Chip_TIMER_Enable(LPC_TIMER32_0);
+
+  #define weirdNumber ((IRQn_Type) 18)
+  NVIC_ClearPendingIRQ(weirdNumber);
+  NVIC_SetVector(weirdNumber, (uint32_t) &onTimer);
+  NVIC_EnableIRQ(weirdNumber);
+  #undef weirdNumber
+}
+
 void SFG_playSound(uint8_t soundIndex, uint8_t volume)
 {
+  uint8_t volumeStep = volume / 16;
+
+  uint16_t pos = audioPos;
+
+  for (int i = 0; i < SFG_SFX_SAMPLE_COUNT; ++i)
+  {
+    int16_t mixedValue =
+      audioBuff[pos] - 127 + SFG_GET_SFX_SAMPLE(soundIndex,i) * volumeStep;
+
+    mixedValue = (mixedValue > 0) ? ((mixedValue < 255) ? mixedValue : 255) : 0;
+
+    audioBuff[pos] = mixedValue;// SFG_GET_SFX_SAMPLE(soundIndex,i) * volumeStep;
+
+    pos = (pos < SFG_SFX_SAMPLE_COUNT - 1) ? (pos + 1) : 0;
+  }
 }
 
 int main()
 {
   pokitto.begin(); 
+  timerInit(8000);
+
+  for (uint16_t i = 0; i < SFG_SFX_SAMPLE_COUNT; ++i)
+    audioBuff[i] = 127;
 
   pokitto.setFrameRate(255);
   pokitto.display.setFont(fontTiny);
@@ -115,3 +173,4 @@ int main()
 }
 
 #endif // guard
+
diff --git a/sounds.h b/sounds.h
index d311f03..fcc5f69 100644
--- a/sounds.h
+++ b/sounds.h
@@ -22,6 +22,9 @@
 #define SFG_SFX_SAMPLE_COUNT 2048
 #define SFG_SFX_SIZE (SFG_SFX_SAMPLE_COUNT / 2)
 
+/**
+  Gets a 4-bit sound sample.
+*/
 #define SFG_GET_SFX_SAMPLE(soundIndex,sampleIndex) \
   ((sampleIndex % 2 == 0) ? \
    (SFG_sounds[soundIndex][sampleIndex / 2] >> 4) : \