Merge pull request #105 from jiangzhengwenjz/palette

palette

1 files changed, 989 insertions, 0 deletions

diff --git a/src/palette.c b/src/palette.c
new file mode 100644
index 000000000..6609c9baa
--- /dev/null
+++ b/src/palette.c
@@ -0,0 +1,989 @@
+#include "global.h"
+#include "palette.h"
+#include "util.h"
+#include "decompress.h"
+#include "gpu_regs.h"
+#include "task.h"
+
+enum
+{
+    NORMAL_FADE,
+    FAST_FADE,
+    HARDWARE_FADE,
+};
+
+#define NUM_PALETTE_STRUCTS 16
+
+// unused palette struct
+struct PaletteStructTemplate
+{
+    u16 uid;
+    u16 *src;
+    u16 pst_field_8_0:1;
+    u16 pst_field_8_1:9;
+    u16 size:5;
+    u16 pst_field_9_7:1;
+    u8 pst_field_A;
+    u8 srcCount:5;
+    u8 pst_field_B_5:3;
+    u8 pst_field_C;
+};
+
+struct PaletteStruct
+{
+    const struct PaletteStructTemplate *base;
+    u32 ps_field_4_0:1;
+    u16 ps_field_4_1:1;
+    u32 baseDestOffset:9;
+    u16 destOffset:10;
+    u16 srcIndex:7;
+    u8 ps_field_8;
+    u8 ps_field_9;
+};
+
+static void sub_8070790(struct PaletteStruct *, u32 *);
+static void sub_80708F4(struct PaletteStruct *, u32 *);
+static void sub_80709B4(struct PaletteStruct *);
+static u8 GetPaletteNumByUid(u16);
+static u8 UpdateNormalPaletteFade(void);
+static void BeginFastPaletteFadeInternal(u8);
+static u8 UpdateFastPaletteFade(void);
+static u8 UpdateHardwarePaletteFade(void);
+static void UpdateBlendRegisters(void);
+static bool8 IsSoftwarePaletteFadeFinishing(void);
+static void sub_80718B8(u8 taskId);
+
+ALIGNED(4) EWRAM_DATA u16 gPlttBufferUnfaded[PLTT_BUFFER_SIZE] = {0};
+ALIGNED(4) EWRAM_DATA u16 gPlttBufferFaded[PLTT_BUFFER_SIZE] = {0};
+static EWRAM_DATA struct PaletteStruct sPaletteStructs[NUM_PALETTE_STRUCTS] = {0};
+EWRAM_DATA struct PaletteFadeControl gPaletteFade = {0};
+static EWRAM_DATA u32 sPlttBufferTransferPending = 0;
+EWRAM_DATA u8 gPaletteDecompressionBuffer[PLTT_DECOMP_BUFFER_SIZE] = {0};
+
+static const struct PaletteStructTemplate gDummyPaletteStructTemplate =
+{
+    .uid = 0xFFFF,
+    .pst_field_B_5 = 1
+};
+
+static const u8 sRoundedDownGrayscaleMap[] =
+{
+     0,  0,  0,  0,  0,
+     5,  5,  5,  5,  5,
+    11, 11, 11, 11, 11,
+    16, 16, 16, 16, 16,
+    21, 21, 21, 21, 21,
+    27, 27, 27, 27, 27,
+    31, 31
+};
+
+void LoadCompressedPalette(const u32 *src, u16 offset, u16 size)
+{
+    LZDecompressWram(src, gPaletteDecompressionBuffer);
+    CpuCopy16(gPaletteDecompressionBuffer, gPlttBufferUnfaded + offset, size);
+    CpuCopy16(gPaletteDecompressionBuffer, gPlttBufferFaded + offset, size);
+}
+
+void LoadPalette(const void *src, u16 offset, u16 size)
+{
+    CpuCopy16(src, gPlttBufferUnfaded + offset, size);
+    CpuCopy16(src, gPlttBufferFaded + offset, size);
+}
+
+void FillPalette(u16 value, u16 offset, u16 size)
+{
+    CpuFill16(value, gPlttBufferUnfaded + offset, size);
+    CpuFill16(value, gPlttBufferFaded + offset, size);
+}
+
+void TransferPlttBuffer(void)
+{
+    if (!gPaletteFade.bufferTransferDisabled)
+    {
+        void *src = gPlttBufferFaded;
+        void *dest = (void *)PLTT;
+        DmaCopy16(3, src, dest, PLTT_SIZE);
+        sPlttBufferTransferPending = 0;
+        if (gPaletteFade.mode == HARDWARE_FADE && gPaletteFade.active)
+            UpdateBlendRegisters();
+    }
+}
+
+u8 UpdatePaletteFade(void)
+{
+    u8 result;
+    u8 dummy = 0;
+
+    if (sPlttBufferTransferPending)
+        return PALETTE_FADE_STATUS_LOADING;
+    if (gPaletteFade.mode == NORMAL_FADE)
+        result = UpdateNormalPaletteFade();
+    else if (gPaletteFade.mode == FAST_FADE)
+        result = UpdateFastPaletteFade();
+    else
+        result = UpdateHardwarePaletteFade();
+    sPlttBufferTransferPending = gPaletteFade.multipurpose1 | dummy;
+    return result;
+}
+
+void ResetPaletteFade(void)
+{
+    u8 i;
+
+    for (i = 0; i < 16; ++i)
+        ResetPaletteStruct(i);
+    ResetPaletteFadeControl();
+}
+
+void ReadPlttIntoBuffers(void)
+{
+    u16 i;
+    u16 *pltt = (u16 *)PLTT;
+
+    for (i = 0; i < PLTT_SIZE / 2; ++i)
+    {
+        gPlttBufferUnfaded[i] = pltt[i];
+        gPlttBufferFaded[i] = pltt[i];
+    }
+}
+
+bool8 BeginNormalPaletteFade(u32 selectedPalettes, s8 delay, u8 startY, u8 targetY, u16 blendColor)
+{
+    u8 temp;
+    u16 color = blendColor;
+
+    if (gPaletteFade.active)
+    {
+        return FALSE;
+    }
+    else
+    {
+        gPaletteFade.deltaY = 2;
+        if (delay < 0)
+        {
+            gPaletteFade.deltaY += (delay * -1);
+            delay = 0;
+        }
+        gPaletteFade_selectedPalettes = selectedPalettes;
+        gPaletteFade.delayCounter = delay;
+        gPaletteFade_delay = delay;
+        gPaletteFade.y = startY;
+        gPaletteFade.targetY = targetY;
+        gPaletteFade.blendColor = color;
+        gPaletteFade.active = TRUE;
+        gPaletteFade.mode = NORMAL_FADE;
+        if (startY < targetY)
+            gPaletteFade.yDec = FALSE;
+        else
+            gPaletteFade.yDec = TRUE;
+        UpdatePaletteFade();
+        temp = gPaletteFade.bufferTransferDisabled;
+        gPaletteFade.bufferTransferDisabled = FALSE;
+        CpuCopy32(gPlttBufferFaded, (void *)PLTT, PLTT_SIZE);
+        sPlttBufferTransferPending = 0;
+        if (gPaletteFade.mode == HARDWARE_FADE && gPaletteFade.active)
+            UpdateBlendRegisters();
+        gPaletteFade.bufferTransferDisabled = temp;
+        return TRUE;
+    }
+}
+
+// not used
+static bool8 sub_80706D0(u32 a1, u8 a2, u8 a3, u8 a4, u16 a5)
+{
+    ReadPlttIntoBuffers();
+    return BeginNormalPaletteFade(a1, a2, a3, a4, a5);
+}
+
+// not used
+static void sub_8070718(u8 a1, u32 *a2)
+{
+    u8 i;
+
+    for (i = 0; i < NUM_PALETTE_STRUCTS; ++i)
+    {
+        struct PaletteStruct *palstruct = &sPaletteStructs[i];
+
+        if (palstruct->ps_field_4_0)
+        {
+            if (palstruct->base->pst_field_8_0 == a1)
+            {
+                u8 val1 = palstruct->srcIndex;
+                u8 val2 = palstruct->base->srcCount;
+
+                if (val1 == val2)
+                {
+                    sub_80709B4(palstruct);
+                    if (!palstruct->ps_field_4_0)
+                        continue;
+                }
+                if (palstruct->ps_field_8 == 0)
+                    sub_8070790(palstruct, a2);
+                else
+                    --palstruct->ps_field_8;
+                sub_80708F4(palstruct, a2);
+            }
+        }
+    }
+}
+
+// not used
+static void sub_8070790(struct PaletteStruct *a1, u32 *a2)
+{
+    s32 srcIndex;
+    s32 srcCount;
+    u8 i = 0;
+    u16 srcOffset = a1->srcIndex * a1->base->size;
+
+    if (!a1->base->pst_field_8_0)
+    {
+        while (i < a1->base->size)
+        {
+            gPlttBufferUnfaded[a1->destOffset] = a1->base->src[srcOffset];
+            gPlttBufferFaded[a1->destOffset] = a1->base->src[srcOffset];
+            ++i;
+            ++a1->destOffset;
+            ++srcOffset;
+        }
+    }
+    else
+    {
+        while (i < a1->base->size)
+        {
+            gPlttBufferFaded[a1->destOffset] = a1->base->src[srcOffset];
+            ++i;
+            ++a1->destOffset;
+            ++srcOffset;
+        }
+    }
+    a1->destOffset = a1->baseDestOffset;
+    a1->ps_field_8 = a1->base->pst_field_A;
+    ++a1->srcIndex;
+    srcIndex = a1->srcIndex;
+    srcCount = a1->base->srcCount;
+    if (srcIndex >= srcCount)
+    {
+        if (a1->ps_field_9)
+            --a1->ps_field_9;
+        a1->srcIndex = 0;
+    }
+    *a2 |= 1 << (a1->baseDestOffset >> 4);
+}
+
+// not used
+static void sub_80708F4(struct PaletteStruct *a1, u32 *a2)
+{
+    if (gPaletteFade.active && ((1 << (a1->baseDestOffset >> 4)) & gPaletteFade_selectedPalettes))
+    {
+        if (!a1->base->pst_field_8_0)
+        {
+            if (gPaletteFade.delayCounter != gPaletteFade_delay)
+                BlendPalette(a1->baseDestOffset,
+                             a1->base->size,
+                             gPaletteFade.y,
+                             gPaletteFade.blendColor);
+        }
+        else
+        {
+            if (!gPaletteFade.delayCounter)
+            {
+                if (a1->ps_field_8 != a1->base->pst_field_A)
+                {
+                    u32 srcOffset = a1->srcIndex * a1->base->size;
+                    u8 i;
+
+                    for (i = 0; i < a1->base->size; ++i)
+                        gPlttBufferFaded[a1->baseDestOffset + i] = a1->base->src[srcOffset + i];
+                }
+            }
+        }
+    }
+}
+
+// not used
+static void sub_80709B4(struct PaletteStruct *a1)
+{
+    if (!a1->ps_field_9)
+    {
+        s32 val = a1->base->pst_field_B_5;
+
+        if (!val)
+        {
+            a1->srcIndex = 0;
+            a1->ps_field_8 = a1->base->pst_field_A;
+            a1->ps_field_9 = a1->base->pst_field_C;
+            a1->destOffset = a1->baseDestOffset;
+        }
+        else
+        {
+            if (val < 0)
+                return;
+            if (val > 2)
+                return;
+            ResetPaletteStructByUid(a1->base->uid);
+        }
+    }
+    else
+    {
+        --a1->ps_field_9;
+    }
+}
+
+void ResetPaletteStructByUid(u16 a1)
+{
+    u8 paletteNum = GetPaletteNumByUid(a1);
+    if (paletteNum != 16)
+        ResetPaletteStruct(paletteNum);
+}
+
+void ResetPaletteStruct(u8 paletteNum)
+{
+    sPaletteStructs[paletteNum].base = &gDummyPaletteStructTemplate;
+    sPaletteStructs[paletteNum].ps_field_4_0 = 0;
+    sPaletteStructs[paletteNum].baseDestOffset = 0;
+    sPaletteStructs[paletteNum].destOffset = 0;
+    sPaletteStructs[paletteNum].srcIndex = 0;
+    sPaletteStructs[paletteNum].ps_field_4_1 = 0;
+    sPaletteStructs[paletteNum].ps_field_8 = 0;
+    sPaletteStructs[paletteNum].ps_field_9 = 0;
+}
+
+void ResetPaletteFadeControl(void)
+{
+    gPaletteFade.multipurpose1 = 0;
+    gPaletteFade.multipurpose2 = 0;
+    gPaletteFade.delayCounter = 0;
+    gPaletteFade.y = 0;
+    gPaletteFade.targetY = 0;
+    gPaletteFade.blendColor = 0;
+    gPaletteFade.active = FALSE;
+    gPaletteFade.multipurpose2 = 0; // assign same value twice
+    gPaletteFade.yDec = FALSE;
+    gPaletteFade.bufferTransferDisabled = FALSE;
+    gPaletteFade.shouldResetBlendRegisters = FALSE;
+    gPaletteFade.hardwareFadeFinishing = FALSE;
+    gPaletteFade.softwareFadeFinishing = FALSE;
+    gPaletteFade.softwareFadeFinishingCounter = 0;
+    gPaletteFade.objPaletteToggle = 0;
+    gPaletteFade.deltaY = 2;
+}
+
+// not used
+static void sub_8070AFC(u16 uid)
+{
+    u8 paletteNum = GetPaletteNumByUid(uid);
+    if (paletteNum != 16)
+        sPaletteStructs[paletteNum].ps_field_4_1 = 1;
+}
+
+// not used
+static void sub_8070B28(u16 uid)
+{
+    u8 paletteNum = GetPaletteNumByUid(uid);
+    if (paletteNum != 16)
+        sPaletteStructs[paletteNum].ps_field_4_1 = 0;
+}
+
+// not used
+static u8 GetPaletteNumByUid(u16 uid)
+{
+    u8 i;
+
+    for (i = 0; i < NUM_PALETTE_STRUCTS; ++i)
+        if (sPaletteStructs[i].base->uid == uid)
+            return i;
+    return 16;
+}
+
+static u8 UpdateNormalPaletteFade(void)
+{
+    u16 paletteOffset;
+    u16 selectedPalettes;
+
+    if (!gPaletteFade.active)
+        return PALETTE_FADE_STATUS_DONE;
+    if (IsSoftwarePaletteFadeFinishing())
+    {
+        return gPaletteFade.active ? PALETTE_FADE_STATUS_ACTIVE : PALETTE_FADE_STATUS_DONE;
+    }
+    else
+    {
+        if (!gPaletteFade.objPaletteToggle)
+        {
+            if (gPaletteFade.delayCounter < gPaletteFade_delay)
+            {
+                ++gPaletteFade.delayCounter;
+                return 2;
+            }
+            gPaletteFade.delayCounter = 0;
+        }
+        paletteOffset = 0;
+        if (!gPaletteFade.objPaletteToggle)
+        {
+            selectedPalettes = gPaletteFade_selectedPalettes;
+        }
+        else
+        {
+            selectedPalettes = gPaletteFade_selectedPalettes >> 16;
+            paletteOffset = 256;
+        }
+        while (selectedPalettes)
+        {
+            if (selectedPalettes & 1)
+                BlendPalette(paletteOffset,
+                             16,
+                             gPaletteFade.y,
+                             gPaletteFade.blendColor);
+            selectedPalettes >>= 1;
+            paletteOffset += 16;
+        }
+        gPaletteFade.objPaletteToggle ^= 1;
+        if (!gPaletteFade.objPaletteToggle)
+        {
+            if (gPaletteFade.y == gPaletteFade.targetY)
+            {
+                gPaletteFade_selectedPalettes = 0;
+                gPaletteFade.softwareFadeFinishing = TRUE;
+            }
+            else
+            {
+                s8 val;
+
+                if (!gPaletteFade.yDec)
+                {
+                    val = gPaletteFade.y;
+                    val += gPaletteFade.deltaY;
+                    if (val > gPaletteFade.targetY)
+                        val = gPaletteFade.targetY;
+                    gPaletteFade.y = val;
+                }
+                else
+                {
+                    val = gPaletteFade.y;
+                    val -= gPaletteFade.deltaY;
+                    if (val < gPaletteFade.targetY)
+                        val = gPaletteFade.targetY;
+                    gPaletteFade.y = val;
+                }
+            }
+        }
+        // gPaletteFade.active cannot change since the last time it was checked. So this
+        // is equivalent to `return PALETTE_FADE_STATUS_ACTIVE;`
+        return gPaletteFade.active ? PALETTE_FADE_STATUS_ACTIVE : PALETTE_FADE_STATUS_DONE;
+    }
+}
+
+void InvertPlttBuffer(u32 selectedPalettes)
+{
+    u16 paletteOffset = 0;
+
+    while (selectedPalettes)
+    {
+        if (selectedPalettes & 1)
+        {
+            u8 i;
+
+            for (i = 0; i < 16; ++i)
+                gPlttBufferFaded[paletteOffset + i] = ~gPlttBufferFaded[paletteOffset + i];
+        }
+        selectedPalettes >>= 1;
+        paletteOffset += 16;
+    }
+}
+
+void TintPlttBuffer(u32 selectedPalettes, s8 r, s8 g, s8 b)
+{
+    u16 paletteOffset = 0;
+
+    while (selectedPalettes)
+    {
+        if (selectedPalettes & 1)
+        {
+            u8 i;
+
+            for (i = 0; i < 16; ++i)
+            {
+                struct PlttData *data = (struct PlttData *)&gPlttBufferFaded[paletteOffset + i];
+                
+                data->r += r;
+                data->g += g;
+                data->b += b;
+            }
+        }
+        selectedPalettes >>= 1;
+        paletteOffset += 16;
+    }
+}
+
+void UnfadePlttBuffer(u32 selectedPalettes)
+{
+    u16 paletteOffset = 0;
+
+    while (selectedPalettes)
+    {
+        if (selectedPalettes & 1)
+        {
+            u8 i;
+
+            for (i = 0; i < 16; ++i)
+                gPlttBufferFaded[paletteOffset + i] = gPlttBufferUnfaded[paletteOffset + i];
+        }
+        selectedPalettes >>= 1;
+        paletteOffset += 16;
+    }
+}
+
+void BeginFastPaletteFade(u8 submode)
+{
+    gPaletteFade.deltaY = 2;
+    BeginFastPaletteFadeInternal(submode);
+}
+
+static void BeginFastPaletteFadeInternal(u8 submode)
+{
+    gPaletteFade.y = 31;
+    gPaletteFade_submode = submode & 0x3F;
+    gPaletteFade.active = TRUE;
+    gPaletteFade.mode = FAST_FADE;
+    if (submode == FAST_FADE_IN_FROM_BLACK)
+        CpuFill16(RGB_BLACK, gPlttBufferFaded, PLTT_SIZE);
+    if (submode == FAST_FADE_IN_FROM_WHITE)
+        CpuFill16(RGB_WHITE, gPlttBufferFaded, PLTT_SIZE);
+    UpdatePaletteFade();
+}
+
+static u8 UpdateFastPaletteFade(void)
+{
+    u16 i;
+    u16 paletteOffsetStart, paletteOffsetEnd;
+    s8 r0, g0, b0, r, g, b;
+
+    if (!gPaletteFade.active)
+        return PALETTE_FADE_STATUS_DONE;
+    if (IsSoftwarePaletteFadeFinishing())
+        return gPaletteFade.active ? PALETTE_FADE_STATUS_ACTIVE : PALETTE_FADE_STATUS_DONE;
+    if (gPaletteFade.objPaletteToggle)
+    {
+        paletteOffsetStart = 256;
+        paletteOffsetEnd = 512;
+    }
+    else
+    {
+        paletteOffsetStart = 0;
+        paletteOffsetEnd = 256;
+    }
+    switch (gPaletteFade_submode)
+    {
+    case FAST_FADE_IN_FROM_WHITE:
+        for (i = paletteOffsetStart; i < paletteOffsetEnd; ++i)
+        {
+            struct PlttData *unfaded;
+            struct PlttData *faded;
+
+            unfaded = (struct PlttData *)&gPlttBufferUnfaded[i];
+            r0 = unfaded->r;
+            g0 = unfaded->g;
+            b0 = unfaded->b;
+            faded = (struct PlttData *)&gPlttBufferFaded[i];
+            r = faded->r - 2;
+            g = faded->g - 2;
+            b = faded->b - 2;
+            if (r < r0)
+                r = r0;
+            if (g < g0)
+                g = g0;
+            if (b < b0)
+                b = b0;
+            gPlttBufferFaded[i] = r | (g << 5) | (b << 10);
+        }
+        break;
+    case FAST_FADE_OUT_TO_WHITE:
+        for (i = paletteOffsetStart; i < paletteOffsetEnd; ++i)
+        {
+            struct PlttData *data = (struct PlttData *)&gPlttBufferFaded[i];
+
+            r = data->r + 2;
+            g = data->g + 2;
+            b = data->b + 2;
+            if (r > 31)
+                r = 31;
+            if (g > 31)
+                g = 31;
+            if (b > 31)
+                b = 31;
+            gPlttBufferFaded[i] = r | (g << 5) | (b << 10);
+        }
+        break;
+    case FAST_FADE_IN_FROM_BLACK:
+        for (i = paletteOffsetStart; i < paletteOffsetEnd; ++i)
+        {
+            struct PlttData *unfaded;
+            struct PlttData *faded;
+
+            unfaded = (struct PlttData *)&gPlttBufferUnfaded[i];
+            r0 = unfaded->r;
+            g0 = unfaded->g;
+            b0 = unfaded->b;
+            faded = (struct PlttData *)&gPlttBufferFaded[i];
+            r = faded->r + 2;
+            g = faded->g + 2;
+            b = faded->b + 2;
+            if (r > r0)
+                r = r0;
+            if (g > g0)
+                g = g0;
+            if (b > b0)
+                b = b0;
+            gPlttBufferFaded[i] = r | (g << 5) | (b << 10);
+        }
+        break;
+    case FAST_FADE_OUT_TO_BLACK:
+        for (i = paletteOffsetStart; i < paletteOffsetEnd; ++i)
+        {
+            struct PlttData *data = (struct PlttData *)&gPlttBufferFaded[i];
+
+            r = data->r - 2;
+            g = data->g - 2;
+            b = data->b - 2;
+            if (r < 0)
+                r = 0;
+            if (g < 0)
+                g = 0;
+            if (b < 0)
+                b = 0;
+            gPlttBufferFaded[i] = r | (g << 5) | (b << 10);
+        }
+    }
+    gPaletteFade.objPaletteToggle ^= 1;
+    if (gPaletteFade.objPaletteToggle)
+        // gPaletteFade.active cannot change since the last time it was checked. So this
+        // is equivalent to `return PALETTE_FADE_STATUS_ACTIVE;`
+        return gPaletteFade.active ? PALETTE_FADE_STATUS_ACTIVE : PALETTE_FADE_STATUS_DONE;
+    if (gPaletteFade.y - gPaletteFade.deltaY < 0)
+        gPaletteFade.y = 0;
+    else
+        gPaletteFade.y -= gPaletteFade.deltaY;
+    if (gPaletteFade.y == 0)
+    {
+        switch (gPaletteFade_submode)
+        {
+        case FAST_FADE_IN_FROM_WHITE:
+        case FAST_FADE_IN_FROM_BLACK:
+            CpuCopy32(gPlttBufferUnfaded, gPlttBufferFaded, PLTT_SIZE);
+            break;
+        case FAST_FADE_OUT_TO_WHITE:
+            CpuFill32(0xFFFFFFFF, gPlttBufferFaded, PLTT_SIZE);
+            break;
+        case FAST_FADE_OUT_TO_BLACK:
+            CpuFill32(0x00000000, gPlttBufferFaded, PLTT_SIZE);
+            break;
+        }
+        gPaletteFade.mode = NORMAL_FADE;
+        gPaletteFade.softwareFadeFinishing = TRUE;
+    }
+    // gPaletteFade.active cannot change since the last time it was checked. So this
+    // is equivalent to `return PALETTE_FADE_STATUS_ACTIVE;`
+    return gPaletteFade.active ? PALETTE_FADE_STATUS_ACTIVE : PALETTE_FADE_STATUS_DONE;
+}
+
+void BeginHardwarePaletteFade(u8 blendCnt, u8 delay, u8 y, u8 targetY, u8 shouldResetBlendRegisters)
+{
+    gPaletteFade_blendCnt = blendCnt;
+    gPaletteFade.delayCounter = delay;
+    gPaletteFade_delay = delay;
+    gPaletteFade.y = y;
+    gPaletteFade.targetY = targetY;
+    gPaletteFade.active = TRUE;
+    gPaletteFade.mode = HARDWARE_FADE;
+    gPaletteFade.shouldResetBlendRegisters = shouldResetBlendRegisters & 1;
+    gPaletteFade.hardwareFadeFinishing = FALSE;
+    if (y < targetY)
+        gPaletteFade.yDec = FALSE;
+    else
+        gPaletteFade.yDec = TRUE;
+}
+
+static u8 UpdateHardwarePaletteFade(void)
+{
+    if (!gPaletteFade.active)
+        return PALETTE_FADE_STATUS_DONE;
+    if (gPaletteFade.delayCounter < gPaletteFade_delay)
+    {
+        ++gPaletteFade.delayCounter;
+        return PALETTE_FADE_STATUS_DELAY;
+    }
+    gPaletteFade.delayCounter = 0;
+    if (!gPaletteFade.yDec)
+    {
+        ++gPaletteFade.y;
+        if (gPaletteFade.y > gPaletteFade.targetY)
+        {
+            ++gPaletteFade.hardwareFadeFinishing;
+            --gPaletteFade.y;
+        }
+    }
+    else
+    {
+        if (gPaletteFade.y-- - 1 < gPaletteFade.targetY)
+        {
+            ++gPaletteFade.hardwareFadeFinishing;
+            ++gPaletteFade.y;
+        }
+    }
+
+    if (gPaletteFade.hardwareFadeFinishing)
+    {
+        if (gPaletteFade.shouldResetBlendRegisters)
+        {
+            gPaletteFade_blendCnt = 0;
+            gPaletteFade.y = 0;
+        }
+        gPaletteFade.shouldResetBlendRegisters = FALSE;
+    }
+    // gPaletteFade.active cannot change since the last time it was checked. So this
+    // is equivalent to `return PALETTE_FADE_STATUS_ACTIVE;`
+    return gPaletteFade.active ? PALETTE_FADE_STATUS_ACTIVE : PALETTE_FADE_STATUS_DONE;
+}
+
+static void UpdateBlendRegisters(void)
+{
+    SetGpuReg(REG_OFFSET_BLDCNT, (u16)gPaletteFade_blendCnt);
+    SetGpuReg(REG_OFFSET_BLDY, gPaletteFade.y);
+    if (gPaletteFade.hardwareFadeFinishing)
+    {
+        gPaletteFade.hardwareFadeFinishing = FALSE;
+        gPaletteFade.mode = 0;
+        gPaletteFade_blendCnt = 0;
+        gPaletteFade.y = 0;
+        gPaletteFade.active = FALSE;
+    }
+}
+
+static bool8 IsSoftwarePaletteFadeFinishing(void)
+{
+    if (gPaletteFade.softwareFadeFinishing)
+    {
+        if (gPaletteFade.softwareFadeFinishingCounter == 4)
+        {
+            gPaletteFade.active = FALSE;
+            gPaletteFade.softwareFadeFinishing = FALSE;
+            gPaletteFade.softwareFadeFinishingCounter = 0;
+        }
+        else
+        {
+            ++gPaletteFade.softwareFadeFinishingCounter;
+        }
+        return TRUE;
+    }
+    else
+    {
+        return FALSE;
+    }
+}
+
+void BlendPalettes(u32 selectedPalettes, u8 coeff, u16 color)
+{
+    u16 paletteOffset;
+
+    for (paletteOffset = 0; selectedPalettes; paletteOffset += 16)
+    {
+        if (selectedPalettes & 1)
+            BlendPalette(paletteOffset, 16, coeff, color);
+        selectedPalettes >>= 1;
+    }
+}
+
+void BlendPalettesUnfaded(u32 selectedPalettes, u8 coeff, u16 color)
+{
+    // This copy is done via DMA in both RUBY and EMERALD
+    CpuFastCopy(gPlttBufferUnfaded, gPlttBufferFaded, 0x400);
+    BlendPalettes(selectedPalettes, coeff, color);
+}
+
+void TintPalette_GrayScale(u16 *palette, u16 count)
+{
+    s32 r, g, b, i;
+    u32 gray;
+
+    for (i = 0; i < count; ++i)
+    {
+        r = (*palette >>  0) & 0x1F;
+        g = (*palette >>  5) & 0x1F;
+        b = (*palette >> 10) & 0x1F;
+        gray = (r * Q_8_8(0.3) + g * Q_8_8(0.59) + b * Q_8_8(0.1133)) >> 8;
+        *palette++ = (gray << 10) | (gray << 5) | (gray << 0);
+    }
+}
+
+void TintPalette_GrayScale2(u16 *palette, u16 count)
+{
+    s32 r, g, b, i;
+    u32 gray;
+
+    for (i = 0; i < count; ++i)
+    {
+        r = (*palette >>  0) & 0x1F;
+        g = (*palette >>  5) & 0x1F;
+        b = (*palette >> 10) & 0x1F;
+        gray = (r * Q_8_8(0.3) + g * Q_8_8(0.59) + b * Q_8_8(0.1133)) >> 8;
+
+        if (gray > 0x1F)
+            gray = 0x1F;
+        gray = sRoundedDownGrayscaleMap[gray];
+        *palette++ = (gray << 10) | (gray << 5) | (gray << 0);
+    }
+}
+
+void TintPalette_SepiaTone(u16 *palette, u16 count)
+{
+    s32 r, g, b, i;
+    u32 gray;
+
+    for (i = 0; i < count; ++i)
+    {
+        r = (*palette >>  0) & 0x1F;
+        g = (*palette >>  5) & 0x1F;
+        b = (*palette >> 10) & 0x1F;
+        gray = (r * Q_8_8(0.3) + g * Q_8_8(0.59) + b * Q_8_8(0.1133)) >> 8;
+        r = (u16)((Q_8_8(1.2) * gray)) >> 8;
+        g = (u16)((Q_8_8(1.0) * gray)) >> 8;
+        b = (u16)((Q_8_8(0.94) * gray)) >> 8;
+        if (r > 31)
+            r = 31;
+        *palette++ = (b << 10) | (g << 5) | (r << 0);
+    }
+}
+
+void TintPalette_CustomTone(u16 *palette, u16 count, u16 rTone, u16 gTone, u16 bTone)
+{
+    s32 r, g, b, i;
+    u32 gray;
+
+    for (i = 0; i < count; ++i)
+    {
+        r = (*palette >>  0) & 0x1F;
+        g = (*palette >>  5) & 0x1F;
+        b = (*palette >> 10) & 0x1F;
+        gray = (r * Q_8_8(0.3) + g * Q_8_8(0.59) + b * Q_8_8(0.1133)) >> 8;
+        r = (u16)((rTone * gray)) >> 8;
+        g = (u16)((gTone * gray)) >> 8;
+        b = (u16)((bTone * gray)) >> 8;
+        if (r > 31)
+            r = 31;
+        if (g > 31)
+            g = 31;
+        if (b > 31)
+            b = 31;
+        *palette++ = (b << 10) | (g << 5) | (r << 0);
+    }
+}
+
+void sub_80716F8(const u16 *src, u16 *dst, u16 count, u8 a4)
+{
+    s32 r, g, b, i;
+    u32 gray;
+
+    if (!a4)
+    {
+        for (i = 0; i < count; ++i)
+            *dst++ = *src++;
+    }
+    else
+    {
+        for (i = 0; i < count; ++src, ++dst, ++i)
+        {
+            r = (*src >>  0) & 0x1F;
+            g = (*src >>  5) & 0x1F;
+            b = (*src >> 10) & 0x1F;
+            gray = (r * Q_8_8(0.3) + g * Q_8_8(0.59) + b * Q_8_8(0.1133)) >> 8;
+            r += (a4 * (gray - r) >> 4);
+            g += (a4 * (gray - g) >> 4);
+            b += (a4 * (gray - b) >> 4);
+            *dst = (b << 10) | (g << 5) | (r << 0);
+        }
+    }
+}
+
+void sub_80717A8(u32 a1, s8 a2, u8 a3, u8 a4, u16 a5, u8 a6, u8 a7)
+{
+    u8 taskId;
+
+    taskId = CreateTask(sub_80718B8, a6);
+    gTasks[taskId].data[0] = a3;
+    gTasks[taskId].data[1] = a4;
+    if (a2 >= 0)
+    {
+        gTasks[taskId].data[3] = a2;
+        gTasks[taskId].data[2] = 1;
+    }
+    else
+    {
+        gTasks[taskId].data[3] = 0;
+        gTasks[taskId].data[2] = -a2 + 1;
+    }
+    if (a4 < a3)
+        gTasks[taskId].data[2] *= -1;
+    SetWordTaskArg(taskId, 5, a1);
+    gTasks[taskId].data[7] = a5;
+    gTasks[taskId].data[8] = a7;
+    gTasks[taskId].func(taskId);
+}
+
+bool32 sub_807185C(u8 var)
+{
+    s32 i;
+
+    for (i = 0; i < NUM_TASKS; ++i)
+        if (gTasks[i].isActive == TRUE
+         && gTasks[i].func == sub_80718B8
+         && gTasks[i].data[8] == var)
+            return TRUE;
+    return FALSE;
+}
+
+void sub_8071898(void)
+{
+    u8 taskId;
+
+    while (TRUE)
+    {
+        taskId = FindTaskIdByFunc(sub_80718B8);
+        if (taskId == TASK_NONE)
+            break;
+        DestroyTask(taskId);
+    }
+}
+
+static void sub_80718B8(u8 taskId)
+{
+    u32 wordVar;
+    s16 *data;
+    s16 temp;
+
+    data = gTasks[taskId].data;
+    wordVar = GetWordTaskArg(taskId, 5);
+    if (++data[4] > data[3])
+    {
+        data[4] = 0;
+        BlendPalettes(wordVar, data[0], data[7]);
+        temp = data[1];
+        if (data[0] == temp)
+        {
+            DestroyTask(taskId);
+        }
+        else
+        {
+            data[0] += data[2];
+            if (data[2] >= 0)
+            {
+                if (data[0] < temp)
+                    return;
+            }
+            else if (data[0] > temp)
+            {
+                return;
+            }
+            data[0] = temp;
+        }
+    }
+}