Added inter-time-of-day blending.

include/overworld.h

@@ -44,6 +44,12 @@ struct LinkPlayerObjectEvent
     u8 movementMode;
 };
 
+struct __attribute__((packed)) TimeBlendSettings {
+  u16 weight:9;
+  u16 time1:3;
+  u16 time0:3;
+};
+
 // Exported RAM declarations
 extern struct WarpData gLastUsedWarp;
 extern struct LinkPlayerObjectEvent gLinkPlayerObjectEvents[4];

include/palette.h

@@ -77,9 +77,9 @@ void BlendPalettes(u32 selectedPalettes, u8 coeff, u16 color);
 void BlendPalettesUnfaded(u32, u8, u16);
 void BlendPalettesGradually(u32 selectedPalettes, s8 delay, u8 coeff, u8 coeffTarget, u16 color, u8 priority, u8 id);
 void AveragePalettes(u16 *palette0, u16* palette1, u16* dest, u16 weight);
-void TimeBlendPalette(u16 palOffset, u16 numEntries, u8 coeff, u16 blendColor);
+void TimeBlendPalette(u16 palOffset, u32 coeff, u32 blendColor);
 void TintPalette_RGB_Copy(u16 palOffset, u16 numEntries, u8 coeff, u16 blendColor);
-void TimeBlendPalettes(u32 palettes, u8 coeff, u16 color);
+void TimeBlendPalettes(u32 palettes, u32 coeff, u32 blendColor);
 void TintPalette_GrayScale(u16 *palette, u16 count);
 void TintPalette_GrayScale2(u16 *palette, u16 count);
 void TintPalette_SepiaTone(u16 *palette, u16 count);

src/overworld.c

@@ -186,7 +186,9 @@ static u16 (*sPlayerKeyInterceptCallback)(u32);
 static bool8 sReceivingFromLink;
 static u8 sRfuKeepAliveTimer;
 
-u8 static gTimeOfDayState;
+static u8 gTimeOfDayState;
+static u8 timeCounter;
+static struct TimeBlendSettings currentTimeBlend;
 
 // IWRAM common
 u16 *gBGTilemapBuffers1;
@@ -1472,12 +1474,39 @@ static const struct TimeOfDayBlend sTimeOfDayBlendVars[] =
 };
 
 u8 UpdateTimeOfDay(void) {
+  s8 hours, minutes;
   RtcCalcLocalTime();
-  if (gLocalTime.hours >= 20 || gLocalTime.hours < 4)
+  hours = gLocalTime.hours;
-    return gTimeOfDay = TIME_OF_DAY_NIGHT;
+  minutes = gLocalTime.minutes;
-  else if (gLocalTime.hours >= 10 && gLocalTime.hours < 20)
+  if (hours >= 22 || hours < 4) {
+    currentTimeBlend.weight = 256;
+    return gTimeOfDay = currentTimeBlend.time0 = currentTimeBlend.time1 = TIME_OF_DAY_NIGHT;
+  } else if (hours >= 4 && hours < 7) { // night->twilight
+    currentTimeBlend.time0 = TIME_OF_DAY_NIGHT;
+    currentTimeBlend.time1 = TIME_OF_DAY_TWILIGHT;
+    currentTimeBlend.weight = 256 - 256 * ((hours - 4) * 60 + minutes) / ((7-4)*60);
     return gTimeOfDay = TIME_OF_DAY_DAY;
-  return gTimeOfDay = TIME_OF_DAY_TWILIGHT;
+  } else if (hours >= 7 && hours < 10) { // twilight->day
+    currentTimeBlend.time0 = TIME_OF_DAY_TWILIGHT;
+    currentTimeBlend.time1 = TIME_OF_DAY_DAY;
+    currentTimeBlend.weight = 256 - 256 * ((hours - 7) * 60 + minutes) / ((10-7)*60);
+    return gTimeOfDay = TIME_OF_DAY_DAY;
+  } else if (hours >= 10 && hours < 18) { // day
+    currentTimeBlend.weight = 256;
+    return gTimeOfDay = currentTimeBlend.time0 = currentTimeBlend.time1 = TIME_OF_DAY_DAY;
+  } else if (hours >= 18 && hours < 20) { // day->twilight
+    currentTimeBlend.time0 = TIME_OF_DAY_DAY;
+    currentTimeBlend.time1 = TIME_OF_DAY_TWILIGHT;
+    currentTimeBlend.weight = 256 - 256 * ((hours - 18) * 60 + minutes) / ((20-18)*60);
+    return gTimeOfDay = TIME_OF_DAY_TWILIGHT;
+  } else if (hours >= 20 && hours < 22) { // twilight->night
+    currentTimeBlend.time0 = TIME_OF_DAY_TWILIGHT;
+    currentTimeBlend.time1 = TIME_OF_DAY_NIGHT;
+    currentTimeBlend.weight = 256 - 256 * ((hours - 20) * 60 + minutes) / ((22-20)*60);
+    return gTimeOfDay = TIME_OF_DAY_NIGHT;
+  } else { // This should never occur
+    return TIME_OF_DAY_MAX;
+  }
 }
 
 static bool8 MapHasNaturalLight(u8 mapType) { // Weather a map type is naturally lit/outside
@@ -1485,7 +1514,7 @@ static bool8 MapHasNaturalLight(u8 mapType) { // Weather a map type is naturally
       || mapType == MAP_TYPE_OCEAN_ROUTE;
 }
 
-static bool8 FadePalettesWithTime(void) {
+static bool8 FadePalettesWithTime(void) { // Only used to fade back in
   gTimeOfDayState = 0;
   gTimeOfDay = UpdateTimeOfDay();
   if (MapHasNaturalLight(gMapHeader.mapType)) {
@@ -1495,8 +1524,7 @@ static bool8 FadePalettesWithTime(void) {
 }
 
 void UpdatePalettesWithTime(u32 palettes) {
-  // Only blend if not transitioning between times and the map type allows
+  if (MapHasNaturalLight(gMapHeader.mapType)) {
-  if (gTimeOfDayState == 0 && MapHasNaturalLight(gMapHeader.mapType)) {
     u8 i, j;
     u16 tempPaletteBuffer[16];
     for (i = 0; i < 16; i++) {
@@ -1509,10 +1537,14 @@ void UpdatePalettesWithTime(u32 palettes) {
       return;
     for (i = 0; palettes; i++) {
       if (palettes & 1) {
-        TimeBlendPalette(i*16, 16, sTimeOfDayBlendVars[gTimeOfDay].coeff, sTimeOfDayBlendVars[gTimeOfDay].blendColor);
+        TimeBlendPalette(i*16, sTimeOfDayBlendVars[currentTimeBlend.time0].coeff, sTimeOfDayBlendVars[currentTimeBlend.time0].blendColor);
+        if (currentTimeBlend.weight == 256) {
+          palettes >>= 1;
+          continue;
+        }
         CpuFastCopy(&gPlttBufferFaded[i*16], tempPaletteBuffer, 32);
-        TimeBlendPalette(i*16, 16, sTimeOfDayBlendVars[TIME_OF_DAY_TWILIGHT].coeff, sTimeOfDayBlendVars[TIME_OF_DAY_TWILIGHT].blendColor);
+        TimeBlendPalette(i*16, sTimeOfDayBlendVars[currentTimeBlend.time1].coeff, sTimeOfDayBlendVars[currentTimeBlend.time1].blendColor);
-        AveragePalettes(tempPaletteBuffer, &gPlttBufferFaded[i*16], &gPlttBufferFaded[i*16], 256);
+        AveragePalettes(tempPaletteBuffer, &gPlttBufferFaded[i*16], &gPlttBufferFaded[i*16], currentTimeBlend.weight);
       }
       palettes >>= 1;
     }
@@ -1535,6 +1567,19 @@ static void OverworldBasic(void)
     UpdatePaletteFade();
     UpdateTilesetAnimations();
     DoScheduledBgTilemapCopiesToVram();
+    if (!(gPaletteFade.active || (timeCounter++ % 60))) {
+      struct TimeBlendSettings cachedBlend = {
+        .time0 = currentTimeBlend.time0,
+        .time1 = currentTimeBlend.time1,
+        .weight = currentTimeBlend.weight,
+      };
+      timeCounter = 0;
+      UpdateTimeOfDay();
+      if (cachedBlend.time0 != currentTimeBlend.time0
+       || cachedBlend.time1 != currentTimeBlend.time1
+       || cachedBlend.weight != currentTimeBlend.weight)
+         UpdatePalettesWithTime(0xFFFFFFFF);
+    }
 }
 
 // This CB2 is used when starting
@@ -1545,9 +1590,7 @@ void CB2_OverworldBasic(void)
 
 void CB2_Overworld(void)
 {
-    u32 *debugPtr = (u32*) 0x0203de00;
     bool32 fading = (gPaletteFade.active != 0);
-    *debugPtr = (u32) &gTimeOfDay;
     if (fading)
         SetVBlankCallback(NULL);
     OverworldBasic();

src/palette.c

@@ -496,13 +496,13 @@ static u8 UpdateTimeOfDayPaletteFade(void)
         if (gPaletteFade.yDec) {
           if (gPaletteFade.objPaletteToggle) { // sprite palettes
             if (gPaletteFade.y >= gPaletteFade.targetY || GetSpritePaletteTagByPaletteNum(paletteNum) & 0x8000)
-              TimeBlendPalette(paletteOffset, 16, gPaletteFade.y, gPaletteFade.blendColor);
+              TimeBlendPalette(paletteOffset, gPaletteFade.y, gPaletteFade.blendColor);
           // tile palettes
           } else if (gPaletteFade.y >= gPaletteFade.targetY || (paletteNum >= 13 && paletteNum <= 15)) {
-              TimeBlendPalette(paletteOffset, 16, gPaletteFade.y, gPaletteFade.blendColor);
+              TimeBlendPalette(paletteOffset, gPaletteFade.y, gPaletteFade.blendColor);
           }
         } else {
-          TimeBlendPalette(paletteOffset, 16, gPaletteFade.y, gPaletteFade.blendColor);
+          TimeBlendPalette(paletteOffset, gPaletteFade.y, gPaletteFade.blendColor);
         }
       }
     }
@@ -1010,45 +1010,125 @@ void AveragePalettes(u16 *palette0, u16* palette1, u16* dest, u16 weight) {
 #define DEFAULT_LIGHT_COLOR 0x3f9f
 
 // Like BlendPalette, but ignores blendColor if the transparency high bit is set
-void TimeBlendPalette(u16 palOffset, u16 numEntries, u8 coeff, u16 blendColor) {
+// Optimization help by lucktyphlosion
-  u16 i;
+void TimeBlendPalette(u16 palOffset, u32 coeff, u32 blendColor) {
-  u16 defaultBlendColor = DEFAULT_LIGHT_COLOR;
+  s32 newR, newG, newB, defR, defG, defB;
-  s8 r, g, b;
+  u16 * palDataSrc = gPlttBufferUnfaded + palOffset;
-  struct PlttData *data2 = (struct PlttData *)&blendColor;
+  u16 * palDataDst = gPlttBufferFaded + palOffset;
-  struct PlttData *data3;
+  u32 defaultBlendColor = DEFAULT_LIGHT_COLOR;
-  struct PlttData *blendData;
+  u16 *palDataSrcEnd = palDataSrc + 16;
-  u16 altBlendIndices = 0;
+  u16 altBlendIndices = *palDataDst++ = *palDataSrc++; // color 0 is copied through unchanged
-  for (i = 0; i < numEntries; i++) {
+  u32 altBlendColor;
-    u16 index = i + palOffset;
+
-    struct PlttData *data1 = (struct PlttData *)&gPlttBufferUnfaded[index];
+  coeff *= 2;
-    if (i == 0) {
+  newR = (blendColor << 27) >> 27;
-      if (data1->unused_15) { // Color 0 is a bitmask for which colors to blend; color 15 is the alt blend color
+  newG = (blendColor << 22) >> 27;
-        gPlttBufferFaded[index] = gPlttBufferUnfaded[index];
+  newB = (blendColor << 17) >> 27;
-        altBlendIndices = gPlttBufferUnfaded[index] << 1; // bit 0 specifies color 1, etc.
+
-        data3 = (struct PlttData *)&gPlttBufferUnfaded[index+15];
+  if (altBlendIndices >> 15) { // High bit set; bitmask of which colors to alt-blend
-        if (!data3->unused_15) // use default blend color instead
+    // Note that bit 0 of altBlendIndices specifies color 1
-          data3 = (struct PlttData *)&defaultBlendColor;
+    altBlendColor = palDataSrc[14]; // color 15
-      }
+    if (altBlendColor >> 15) { // Set alternate blend color
-      continue;
+      defR = (altBlendColor << 27) >> 27;
+      defG = (altBlendColor << 22) >> 27;
+      defB = (altBlendColor << 17) >> 27;
+    } else { // Set default blend color
+      defR = (defaultBlendColor << 27) >> 27;
+      defG = (defaultBlendColor << 22) >> 27;
+      defB = (defaultBlendColor << 17) >> 27;
     }
-    r = data1->r;
+  } else {
-    g = data1->g;
+    altBlendIndices = 0;
-    b = data1->b;
+  }
-    blendData = (altBlendIndices && altBlendIndices & (1 << i)) ? data3 : data2;
+  while (palDataSrc != palDataSrcEnd) {
-    gPlttBufferFaded[index] = RGB(r + (((blendData->r - r) * coeff) >> 4),
+    u32 palDataSrcColor = *palDataSrc;
-                                  g + (((blendData->g - g) * coeff) >> 4),
+    s32 r = (palDataSrcColor << 27) >> 27;
-                                  b + (((blendData->b - b) * coeff) >> 4));
+    s32 g = (palDataSrcColor << 22) >> 27;
+    s32 b = (palDataSrcColor << 17) >> 27;
+
+    if (altBlendIndices & 1) {
+      *palDataDst = ((r + (((defR - r) * coeff) >> 5)) << 0)
+                  | ((g + (((defG - g) * coeff) >> 5)) << 5)
+                  | ((b + (((defB - b) * coeff) >> 5)) << 10);
+    } else { // Use provided blend color
+      *palDataDst = ((r + (((newR - r) * coeff) >> 5)) << 0)
+                  | ((g + (((newG - g) * coeff) >> 5)) << 5)
+                  | ((b + (((newB - b) * coeff) >> 5)) << 10);
+    }
+    palDataSrc++;
+    palDataDst++;
+    altBlendIndices >>= 1;
   }
 }
 
-// Apply time effect to a series of palettes
+void TimeBlendPalettes(u32 palettes, u32 coeff, u32 blendColor) {
-void TimeBlendPalettes(u32 palettes, u8 coeff, u16 color) {
+  s32 newR, newG, newB, defR, defG, defB, altR, altG, altB;
-  u16 paletteOffset;
+  u16 * palDataSrc;
-  for (paletteOffset = 0; palettes; paletteOffset += 16) {
+  u16 * palDataDst;
-    if (palettes & 1)
+  u32 defaultBlendColor = DEFAULT_LIGHT_COLOR;
-      TimeBlendPalette(paletteOffset, 16, coeff, color);
+
+  if (!palettes)
+    return;
+
+  coeff *= 2;
+  newR = (blendColor << 27) >> 27;
+  newG = (blendColor << 22) >> 27;
+  newB = (blendColor << 17) >> 27;
+  defR = (defaultBlendColor << 27) >> 27;
+  defG = (defaultBlendColor << 22) >> 27;
+  defB = (defaultBlendColor << 17) >> 27;
+  palDataSrc = gPlttBufferUnfaded;
+  palDataDst = gPlttBufferFaded;
+
+  do {
+    if (palettes & 1) {
+      u16 *palDataSrcEnd = palDataSrc + 16;
+      u16 altBlendIndices = *palDataDst++ = *palDataSrc++; // color 0 is copied through
+      u32 altBlendColor;
+      if (altBlendIndices >> 15) { // High bit set; bitmask of which colors to alt-blend
+        // Note that bit 0 of altBlendIndices specifies color 1
+        altBlendColor = palDataSrc[14]; // color 15
+        if (altBlendColor >> 15) { // Set alternate blend color
+          altR = (altBlendColor << 27) >> 27;
+          altG = (altBlendColor << 22) >> 27;
+          altB = (altBlendColor << 17) >> 27;
+        } else {
+          altBlendColor = 0;
+        }
+      } else {
+        altBlendIndices = 0;
+      }
+      while (palDataSrc != palDataSrcEnd) {
+        u32 palDataSrcColor = *palDataSrc;
+        s32 r = (palDataSrcColor << 27) >> 27;
+        s32 g = (palDataSrcColor << 22) >> 27;
+        s32 b = (palDataSrcColor << 17) >> 27;
+
+        if (altBlendIndices & 1) {
+          if (altBlendColor) { // Use alternate blend color
+            *palDataDst = ((r + (((altR - r) * coeff) >> 5)) << 0)
+                        | ((g + (((altG - g) * coeff) >> 5)) << 5)
+                        | ((b + (((altB - b) * coeff) >> 5)) << 10);
+          } else { // Use default blend color
+            *palDataDst = ((r + (((defR - r) * coeff) >> 5)) << 0)
+                        | ((g + (((defG - g) * coeff) >> 5)) << 5)
+                        | ((b + (((defB - b) * coeff) >> 5)) << 10);
+          }
+        } else { // Use provided blend color
+          *palDataDst = ((r + (((newR - r) * coeff) >> 5)) << 0)
+                      | ((g + (((newG - g) * coeff) >> 5)) << 5)
+                      | ((b + (((newB - b) * coeff) >> 5)) << 10);
+        }
+        palDataSrc++;
+        palDataDst++;
+        altBlendIndices >>= 1;
+      }
+    } else {
+      palDataSrc += 16;
+      palDataDst += 16;
+    }
     palettes >>= 1;
-  }
+  } while (palettes);
 }
 
 void BlendPalettesUnfaded(u32 selectedPalettes, u8 coeff, u16 color)