// Copyright 2009 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include "VideoBackends/Software/TextureEncoder.h"

#include "Common/Align.h"
#include "Common/Assert.h"
#include "Common/CommonFuncs.h"
#include "Common/CommonTypes.h"
#include "Common/MsgHandler.h"
#include "Common/Swap.h"

#include "VideoBackends/Software/EfbInterface.h"
#include "VideoBackends/Software/SWTexture.h"

#include "VideoCommon/BPMemory.h"
#include "VideoCommon/LookUpTables.h"
#include "VideoCommon/TextureCacheBase.h"
#include "VideoCommon/TextureDecoder.h"

namespace TextureEncoder
{
static inline void RGBA_to_RGBA8(const u8* src, u8* r, u8* g, u8* b, u8* a)
{
  u32 srcColor = *(u32*)src;
  *a = Convert6To8(srcColor & 0x3f);
  *b = Convert6To8((srcColor >> 6) & 0x3f);
  *g = Convert6To8((srcColor >> 12) & 0x3f);
  *r = Convert6To8((srcColor >> 18) & 0x3f);
}

static inline void RGBA_to_RGB8(const u8* src, u8* r, u8* g, u8* b)
{
  u32 srcColor = *(u32*)src;
  *b = Convert6To8((srcColor >> 6) & 0x3f);
  *g = Convert6To8((srcColor >> 12) & 0x3f);
  *r = Convert6To8((srcColor >> 18) & 0x3f);
}

static inline u8 RGB8_to_I(u8 r, u8 g, u8 b)
{
  // values multiplied by 256 to keep math integer
  u16 val = 4096 + 66 * r + 129 * g + 25 * b;
  return val >> 8;
}

// box filter sampling averages 4 samples with the source texel being the top left of the box
// components are scaled to the range 0-255 after all samples are taken

static inline void BoxfilterRGBA_to_RGBA8(const u8* src, u8* r, u8* g, u8* b, u8* a)
{
  u16 r16 = 0, g16 = 0, b16 = 0, a16 = 0;

  for (int y = 0; y < 2; y++)
  {
    for (int x = 0; x < 2; x++)
    {
      u32 srcColor = *(u32*)src;

      a16 += srcColor & 0x3f;
      b16 += (srcColor >> 6) & 0x3f;
      g16 += (srcColor >> 12) & 0x3f;
      r16 += (srcColor >> 18) & 0x3f;

      src += 3;  // move to next pixel
    }
    src += (640 - 2) * 3;  // move to next line
  }

  *r = r16 + (r16 >> 6);
  *g = g16 + (g16 >> 6);
  *b = b16 + (b16 >> 6);
  *a = a16 + (a16 >> 6);
}

static inline void BoxfilterRGBA_to_RGB8(const u8* src, u8* r, u8* g, u8* b)
{
  u16 r16 = 0, g16 = 0, b16 = 0;

  for (int y = 0; y < 2; y++)
  {
    for (int x = 0; x < 2; x++)
    {
      u32 srcColor = *(u32*)src;

      b16 += (srcColor >> 6) & 0x3f;
      g16 += (srcColor >> 12) & 0x3f;
      r16 += (srcColor >> 18) & 0x3f;

      src += 3;  // move to next pixel
    }
    src += (640 - 2) * 3;  // move to next line
  }

  *r = r16 + (r16 >> 6);
  *g = g16 + (g16 >> 6);
  *b = b16 + (b16 >> 6);
}

static inline void BoxfilterRGBA_to_x8(const u8* src, u8* x8, int shift)
{
  u16 x16 = 0;

  for (int y = 0; y < 2; y++)
  {
    for (int x = 0; x < 2; x++)
    {
      u32 srcColor = *(u32*)src;

      x16 += (srcColor >> shift) & 0x3f;

      src += 3;  // move to next pixel
    }
    src += (640 - 2) * 3;  // move to next line
  }

  *x8 = x16 + (x16 >> 6);
}

static inline void BoxfilterRGBA_to_xx8(const u8* src, u8* x1, u8* x2, int shift1, int shift2)
{
  u16 x16_1 = 0;
  u16 x16_2 = 0;

  for (int y = 0; y < 2; y++)
  {
    for (int x = 0; x < 2; x++)
    {
      u32 srcColor = *(u32*)src;

      x16_1 += (srcColor >> shift1) & 0x3f;
      x16_2 += (srcColor >> shift2) & 0x3f;

      src += 3;  // move to next pixel
    }
    src += (640 - 2) * 3;  // move to next line
  }

  *x1 = x16_1 + (x16_1 >> 6);
  *x2 = x16_2 + (x16_2 >> 6);
}

static inline void BoxfilterRGB_to_RGB8(const u8* src, u8* r, u8* g, u8* b)
{
  u16 r16 = 0, g16 = 0, b16 = 0;

  for (int y = 0; y < 2; y++)
  {
    for (int x = 0; x < 2; x++)
    {
      b16 += src[0];
      g16 += src[1];
      r16 += src[2];

      src += 3;  // move to next pixel
    }
    src += (640 - 2) * 3;  // move to next line
  }

  *r = r16 >> 2;
  *g = g16 >> 2;
  *b = b16 >> 2;
}

static inline void BoxfilterRGB_to_x8(const u8* src, u8* x8, int comp)
{
  u16 x16 = 0;

  for (int y = 0; y < 2; y++)
  {
    for (int x = 0; x < 2; x++)
    {
      x16 += src[comp];

      src += 3;  // move to next pixel
    }
    src += (640 - 2) * 3;  // move to next line
  }

  *x8 = x16 >> 2;
}

static inline void BoxfilterRGB_to_xx8(const u8* src, u8* x1, u8* x2, int comp1, int comp2)
{
  u16 x16_1 = 0;
  u16 x16_2 = 0;

  for (int y = 0; y < 2; y++)
  {
    for (int x = 0; x < 2; x++)
    {
      x16_1 += src[comp1];
      x16_2 += src[comp2];

      src += 3;  // move to next pixel
    }
    src += (640 - 2) * 3;  // move to next line
  }

  *x1 = x16_1 >> 2;
  *x2 = x16_2 >> 2;
}

static void SetBlockDimensions(int blkWidthLog2, int blkHeightLog2, u16* sBlkCount, u16* tBlkCount,
                               u16* sBlkSize, u16* tBlkSize)
{
  // if half_scale is 1 then the size is cut in half
  u32 width = bpmem.copyTexSrcWH.x >> bpmem.triggerEFBCopy.half_scale;
  u32 height = bpmem.copyTexSrcWH.y >> bpmem.triggerEFBCopy.half_scale;

  *sBlkCount = (width >> blkWidthLog2) + 1;
  *tBlkCount = (height >> blkHeightLog2) + 1;

  *sBlkSize = 1 << blkWidthLog2;
  *tBlkSize = 1 << blkHeightLog2;
}

static void SetSpans(int sBlkSize, int tBlkSize, s32* tSpan, s32* sBlkSpan, s32* tBlkSpan,
                     s32* writeStride)
{
  // width is 1 less than the number of pixels of width
  u32 width = bpmem.copyTexSrcWH.x >> bpmem.triggerEFBCopy.half_scale;
  u32 alignedWidth = Common::AlignUp(width + 1, sBlkSize);

  u32 readStride = 3 << bpmem.triggerEFBCopy.half_scale;

  *tSpan = (640 - sBlkSize) *
           readStride;  // bytes to advance src pointer after each row of texels in a block
  *sBlkSpan =
      ((-640 * tBlkSize) + sBlkSize) * readStride;  // bytes to advance src pointer after each block
  *tBlkSpan = ((640 * tBlkSize) - alignedWidth) *
              readStride;  // bytes to advance src pointer after each row of blocks

  *writeStride = bpmem.copyDestStride << 5;
}

#define ENCODE_LOOP_BLOCKS                                                                         \
  for (int tBlk = 0; tBlk < tBlkCount; tBlk++)                                                     \
  {                                                                                                \
    dst = dstBlockStart;                                                                           \
    for (int sBlk = 0; sBlk < sBlkCount; sBlk++)                                                   \
    {                                                                                              \
      for (int t = 0; t < tBlkSize; t++)                                                           \
      {                                                                                            \
        for (int s = 0; s < sBlkSize; s++)                                                         \
        {
#define ENCODE_LOOP_SPANS                                                                          \
  }                                                                                                \
  src += tSpan;                                                                                    \
  }                                                                                                \
  src += sBlkSpan;                                                                                 \
  }                                                                                                \
  src += tBlkSpan;                                                                                 \
  dstBlockStart += writeStride;                                                                    \
  }

#define ENCODE_LOOP_SPANS2                                                                         \
  }                                                                                                \
  src += tSpan;                                                                                    \
  }                                                                                                \
  src += sBlkSpan;                                                                                 \
  dst += 32;                                                                                       \
  }                                                                                                \
  src += tBlkSpan;                                                                                 \
  dstBlockStart += writeStride;                                                                    \
  }

static void EncodeRGBA6(u8* dst, const u8* src, EFBCopyFormat format, bool yuv)
{
  u16 sBlkCount, tBlkCount, sBlkSize, tBlkSize;
  s32 tSpan, sBlkSpan, tBlkSpan, writeStride;
  u8 r, g, b, a;
  u32 readStride = 3;
  u8* dstBlockStart = dst;

  switch (format)
  {
  case EFBCopyFormat::R4:
    SetBlockDimensions(3, 3, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    sBlkSize /= 2;
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        RGBA_to_RGB8(src, &r, &g, &b);
        src += readStride;
        *dst = RGB8_to_I(r, g, b) & 0xf0;

        RGBA_to_RGB8(src, &r, &g, &b);
        src += readStride;
        *dst |= RGB8_to_I(r, g, b) >> 4;
        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        u32 srcColor = *(u32*)src;
        src += readStride;
        *dst = (srcColor >> 16) & 0xf0;

        srcColor = *(u32*)src;
        src += readStride;
        *dst |= (srcColor >> 20) & 0x0f;
        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::R8_0x1:
  case EFBCopyFormat::R8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        RGBA_to_RGB8(src, &r, &g, &b);
        src += readStride;
        *dst++ = RGB8_to_I(r, g, b);
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        u32 srcColor = *(u32*)src;
        *dst++ = Convert6To8((srcColor >> 18) & 0x3f);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA4:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        RGBA_to_RGBA8(src, &r, &g, &b, &a);
        src += readStride;
        *dst++ = (a & 0xf0) | (RGB8_to_I(r, g, b) >> 4);
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        u32 srcColor = *(u32*)src;
        src += readStride;
        *dst++ = ((srcColor << 2) & 0xf0) | ((srcColor >> 20) & 0x0f);
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        RGBA_to_RGBA8(src, &r, &g, &b, &a);
        src += readStride;
        *dst++ = a;
        *dst++ = RGB8_to_I(r, g, b);
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        u32 srcColor = *(u32*)src;
        src += readStride;
        *dst++ = Convert6To8(srcColor & 0x3f);
        *dst++ = Convert6To8((srcColor >> 18) & 0x3f);
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RGB565:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u32 srcColor = *(u32*)src;
      src += readStride;

      u16 val =
          ((srcColor >> 8) & 0xf800) | ((srcColor >> 7) & 0x07e0) | ((srcColor >> 7) & 0x001f);
      *(u16*)dst = Common::swap16(val);
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGB5A3:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u32 srcColor = *(u32*)src;
      src += readStride;

      u16 alpha = (srcColor << 9) & 0x7000;
      u16 val;
      if (alpha == 0x7000)  // 555
        val = 0x8000 | ((srcColor >> 9) & 0x7c00) | ((srcColor >> 8) & 0x03e0) |
              ((srcColor >> 7) & 0x001f);
      else  // 4443
        val = alpha | ((srcColor >> 12) & 0x0f00) | ((srcColor >> 10) & 0x00f0) |
              ((srcColor >> 8) & 0x000f);

      *(u16*)dst = Common::swap16(val);
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGBA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      RGBA_to_RGBA8(src, &dst[1], &dst[32], &dst[33], &dst[0]);
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS2
    break;

  case EFBCopyFormat::A8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u32 srcColor = *(u32*)src;
      *dst++ = Convert6To8(srcColor & 0x3f);
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::G8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u32 srcColor = *(u32*)src;
      *dst++ = Convert6To8((srcColor >> 12) & 0x3f);
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::B8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u32 srcColor = *(u32*)src;
      *dst++ = Convert6To8((srcColor >> 6) & 0x3f);
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RG8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u32 srcColor = *(u32*)src;
      src += readStride;
      *dst++ = Convert6To8((srcColor >> 12) & 0x3f);
      *dst++ = Convert6To8((srcColor >> 18) & 0x3f);
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::GB8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u32 srcColor = *(u32*)src;
      src += readStride;
      *dst++ = Convert6To8((srcColor >> 6) & 0x3f);
      *dst++ = Convert6To8((srcColor >> 12) & 0x3f);
    }
    ENCODE_LOOP_SPANS
    break;

  default:
    PanicAlertFmt("Unknown texture copy format: {}\n", format);
    break;
  }
}

static void EncodeRGBA6halfscale(u8* dst, const u8* src, EFBCopyFormat format, bool yuv)
{
  u16 sBlkCount, tBlkCount, sBlkSize, tBlkSize;
  s32 tSpan, sBlkSpan, tBlkSpan, writeStride;
  u8 r, g, b, a;
  u32 readStride = 6;
  u8* dstBlockStart = dst;

  switch (format)
  {
  case EFBCopyFormat::R4:
    SetBlockDimensions(3, 3, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    sBlkSize /= 2;
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_RGB8(src, &r, &g, &b);
        src += readStride;
        *dst = RGB8_to_I(r, g, b) & 0xf0;

        BoxfilterRGBA_to_RGB8(src, &r, &g, &b);
        src += readStride;
        *dst |= RGB8_to_I(r, g, b) >> 4;
        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_x8(src, &r, 18);
        src += readStride;
        *dst = r & 0xf0;

        BoxfilterRGBA_to_x8(src, &r, 18);
        src += readStride;
        *dst |= r >> 4;
        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::R8_0x1:
  case EFBCopyFormat::R8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_RGB8(src, &r, &g, &b);
        src += readStride;
        *dst++ = RGB8_to_I(r, g, b);
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_x8(src, &r, 18);
        *dst++ = r;
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA4:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_RGBA8(src, &r, &g, &b, &a);
        src += readStride;
        *dst++ = (a & 0xf0) | (RGB8_to_I(r, g, b) >> 4);
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_xx8(src, &r, &a, 18, 0);
        src += readStride;
        *dst++ = (a & 0xf0) | (r >> 4);
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_RGBA8(src, &r, &g, &b, &a);
        src += readStride;
        *dst++ = a;
        *dst++ = RGB8_to_I(r, g, b);
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGBA_to_xx8(src, &r, &a, 18, 0);
        src += readStride;
        *dst++ = a;
        *dst++ = r;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RGB565:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_RGB8(src, &r, &g, &b);
      src += readStride;

      u16 val = ((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | ((b >> 3) & 0x001f);
      *(u16*)dst = Common::swap16(val);
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGB5A3:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_RGBA8(src, &r, &g, &b, &a);
      src += readStride;

      u16 val;
      if (a >= 224)  // 5551
        val = 0x8000 | ((r << 7) & 0x7c00) | ((g << 2) & 0x03e0) | ((b >> 3) & 0x001f);
      else  // 4443
        val = ((a << 7) & 0x7000) | ((r << 4) & 0x0f00) | (g & 0x00f0) | ((b >> 4) & 0x000f);

      *(u16*)dst = Common::swap16(val);
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGBA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_RGBA8(src, &dst[1], &dst[32], &dst[33], &dst[0]);
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS2
    break;

  case EFBCopyFormat::A8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_x8(src, &a, 0);
      *dst++ = a;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::G8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_x8(src, &g, 12);
      *dst++ = g;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::B8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_x8(src, &b, 6);
      *dst++ = b;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RG8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_xx8(src, &r, &g, 18, 12);
      src += readStride;
      *dst++ = g;
      *dst++ = r;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::GB8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGBA_to_xx8(src, &g, &b, 12, 6);
      src += readStride;
      *dst++ = b;
      *dst++ = g;
    }
    ENCODE_LOOP_SPANS
    break;

  default:
    PanicAlertFmt("Unknown texture copy format: {}\n", format);
    break;
  }
}

static void EncodeRGB8(u8* dst, const u8* src, EFBCopyFormat format, bool yuv)
{
  u16 sBlkCount, tBlkCount, sBlkSize, tBlkSize;
  s32 tSpan, sBlkSpan, tBlkSpan, writeStride;
  u32 readStride = 3;
  u8* dstBlockStart = dst;

  switch (format)
  {
  case EFBCopyFormat::R4:
    SetBlockDimensions(3, 3, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    sBlkSize /= 2;
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst = RGB8_to_I(src[2], src[1], src[0]) & 0xf0;
        src += readStride;

        *dst |= RGB8_to_I(src[2], src[1], src[0]) >> 4;
        src += readStride;
        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst = src[2] & 0xf0;
        src += readStride;

        *dst |= src[2] >> 4;
        src += readStride;

        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::R8_0x1:
  case EFBCopyFormat::R8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst++ = RGB8_to_I(src[2], src[1], src[0]);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst++ = src[2];
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA4:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst++ = 0xf0 | (RGB8_to_I(src[2], src[1], src[0]) >> 4);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst++ = 0xf0 | (src[2] >> 4);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst++ = 0xff;
        *dst++ = RGB8_to_I(src[2], src[1], src[0]);

        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        *dst++ = 0xff;
        *dst++ = src[2];
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RGB565:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u16 val = ((src[2] << 8) & 0xf800) | ((src[1] << 3) & 0x07e0) | ((src[0] >> 3) & 0x001f);
      *(u16*)dst = Common::swap16(val);
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGB5A3:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      u16 val =
          0x8000 | ((src[2] << 7) & 0x7c00) | ((src[1] << 2) & 0x03e0) | ((src[0] >> 3) & 0x001f);
      *(u16*)dst = Common::swap16(val);
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGBA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      dst[0] = 0xff;
      dst[1] = src[2];
      dst[32] = src[1];
      dst[33] = src[0];
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS2
    break;

  case EFBCopyFormat::A8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS { *dst++ = 0xff; }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::G8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      *dst++ = src[1];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::B8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      *dst++ = src[0];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RG8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      // FIXME: is this backwards?
      *dst++ = src[1];
      *dst++ = src[2];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::GB8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      *dst++ = src[0];
      *dst++ = src[1];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  default:
    PanicAlertFmt("Unknown texture copy format: {}\n", format);
    break;
  }
}

static void EncodeRGB8halfscale(u8* dst, const u8* src, EFBCopyFormat format, bool yuv)
{
  u16 sBlkCount, tBlkCount, sBlkSize, tBlkSize;
  s32 tSpan, sBlkSpan, tBlkSpan, writeStride;
  u8 r, g, b;
  u32 readStride = 6;
  u8* dstBlockStart = dst;

  switch (format)
  {
  case EFBCopyFormat::R4:
    SetBlockDimensions(3, 3, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    sBlkSize /= 2;
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_RGB8(src, &r, &g, &b);
        *dst = RGB8_to_I(r, g, b) & 0xf0;
        src += readStride;

        BoxfilterRGB_to_RGB8(src, &r, &g, &b);
        *dst |= RGB8_to_I(r, g, b) >> 4;
        src += readStride;
        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_x8(src, &r, 2);
        *dst = r & 0xf0;
        src += readStride;

        BoxfilterRGB_to_x8(src, &r, 2);
        *dst |= r >> 4;
        src += readStride;

        dst++;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::R8_0x1:
  case EFBCopyFormat::R8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_RGB8(src, &r, &g, &b);
        *dst++ = RGB8_to_I(r, g, b);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_x8(src, &r, 2);
        *dst++ = r;
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA4:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_RGB8(src, &r, &g, &b);
        *dst++ = 0xf0 | (RGB8_to_I(r, g, b) >> 4);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_x8(src, &r, 2);
        *dst++ = 0xf0 | (r >> 4);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    if (yuv)
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_RGB8(src, &r, &g, &b);
        *dst++ = 0xff;
        *dst++ = RGB8_to_I(r, g, b);
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    else
    {
      ENCODE_LOOP_BLOCKS
      {
        BoxfilterRGB_to_x8(src, &r, 2);
        *dst++ = 0xff;
        *dst++ = r;
        src += readStride;
      }
      ENCODE_LOOP_SPANS
    }
    break;

  case EFBCopyFormat::RGB565:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_RGB8(src, &r, &g, &b);
      u16 val = ((r << 8) & 0xf800) | ((g << 3) & 0x07e0) | ((b >> 3) & 0x001f);
      *(u16*)dst = Common::swap16(val);
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGB5A3:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_RGB8(src, &r, &g, &b);
      u16 val = 0x8000 | ((r << 7) & 0x7c00) | ((g << 2) & 0x03e0) | ((b >> 3) & 0x001f);
      *(u16*)dst = Common::swap16(val);
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RGBA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_RGB8(src, &r, &g, &b);
      dst[0] = 0xff;
      dst[1] = r;
      dst[32] = g;
      dst[33] = b;
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS2
    break;

  case EFBCopyFormat::A8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS { *dst++ = 0xff; }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::G8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_x8(src, &g, 1);
      *dst++ = g;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::B8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_x8(src, &b, 0);
      *dst++ = b;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RG8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_xx8(src, &r, &g, 2, 1);
      *dst++ = g;
      *dst++ = r;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::GB8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_xx8(src, &g, &b, 1, 0);
      *dst++ = b;
      *dst++ = g;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  default:
    PanicAlertFmt("Unknown texture copy format: {}\n", format);
    break;
  }
}

static void EncodeZ24(u8* dst, const u8* src, EFBCopyFormat format)
{
  u16 sBlkCount, tBlkCount, sBlkSize, tBlkSize;
  s32 tSpan, sBlkSpan, tBlkSpan, writeStride;
  u32 readStride = 3;
  u8* dstBlockStart = dst;

  switch (format)
  {
  case EFBCopyFormat::R8_0x1:
  case EFBCopyFormat::R8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      *dst++ = src[2];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

    // FIXME: handle RA8?

  case EFBCopyFormat::RGBA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      dst[0] = 0xff;
      dst[1] = src[2];
      dst[32] = src[1];
      dst[33] = src[0];
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS2
    break;

  case EFBCopyFormat::R4:
    SetBlockDimensions(3, 3, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    sBlkSize /= 2;
    ENCODE_LOOP_BLOCKS
    {
      *dst = src[2] & 0xf0;
      src += readStride;

      *dst |= src[2] >> 4;
      src += readStride;

      dst++;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::G8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      *dst++ = src[1];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::B8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      *dst++ = src[0];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RG8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      // FIXME: should these be reversed?
      *dst++ = src[1];
      *dst++ = src[2];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::GB8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      *dst++ = src[0];
      *dst++ = src[1];
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  default:
    PanicAlertFmt("Unknown texture copy format: {}\n", format);
    break;
  }
}

static void EncodeZ24halfscale(u8* dst, const u8* src, EFBCopyFormat format)
{
  u16 sBlkCount, tBlkCount, sBlkSize, tBlkSize;
  s32 tSpan, sBlkSpan, tBlkSpan, writeStride;
  u32 readStride = 6;
  u8 r, g, b;
  u8* dstBlockStart = dst;

  switch (format)
  {
  case EFBCopyFormat::R8_0x1:
  case EFBCopyFormat::R8:
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_x8(src, &b, 2);
      *dst++ = b;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

    // FIXME: handle RA8?

  case EFBCopyFormat::RGBA8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_RGB8(src, &dst[33], &dst[32], &dst[1]);
      dst[0] = 255;
      src += readStride;
      dst += 2;
    }
    ENCODE_LOOP_SPANS2
    break;

  case EFBCopyFormat::R4:  // Z4
    SetBlockDimensions(3, 3, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    sBlkSize /= 2;
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_x8(src, &b, 2);
      *dst = b & 0xf0;
      src += readStride;

      BoxfilterRGB_to_x8(src, &b, 2);
      *dst |= b >> 4;
      src += readStride;

      dst++;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::G8:  // Z8M
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_x8(src, &g, 1);
      *dst++ = g;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::B8:  // Z8L
    SetBlockDimensions(3, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_x8(src, &r, 0);
      *dst++ = r;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::RG8:  // RG8
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_xx8(src, &r, &g, 0, 1);
      *dst++ = g;
      *dst++ = r;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  case EFBCopyFormat::GB8:
    SetBlockDimensions(2, 2, &sBlkCount, &tBlkCount, &sBlkSize, &tBlkSize);
    SetSpans(sBlkSize, tBlkSize, &tSpan, &sBlkSpan, &tBlkSpan, &writeStride);
    ENCODE_LOOP_BLOCKS
    {
      BoxfilterRGB_to_xx8(src, &g, &b, 1, 2);
      // FIXME: is this backwards?
      *dst++ = b;
      *dst++ = g;
      src += readStride;
    }
    ENCODE_LOOP_SPANS
    break;

  default:
    PanicAlertFmt("Unknown texture copy format: {}\n", format);
    break;
  }
}

namespace
{
void EncodeEfbCopy(u8* dst, const EFBCopyParams& params, u32 native_width, u32 bytes_per_row,
                   u32 num_blocks_y, u32 memory_stride, const MathUtil::Rectangle<int>& src_rect,
                   bool scale_by_half)
{
  const u8* src = EfbInterface::GetPixelPointer(src_rect.left, src_rect.top, params.depth);

  if (scale_by_half)
  {
    switch (params.efb_format)
    {
    case PixelFormat::RGBA6_Z24:
      EncodeRGBA6halfscale(dst, src, params.copy_format, params.yuv);
      break;
    case PixelFormat::RGB8_Z24:
      EncodeRGB8halfscale(dst, src, params.copy_format, params.yuv);
      break;
    case PixelFormat::RGB565_Z16:
      EncodeRGB8halfscale(dst, src, params.copy_format, params.yuv);
      break;
    case PixelFormat::Z24:
      EncodeZ24halfscale(dst, src, params.copy_format);
      break;
    default:
      break;
    }
  }
  else
  {
    switch (params.efb_format)
    {
    case PixelFormat::RGBA6_Z24:
      EncodeRGBA6(dst, src, params.copy_format, params.yuv);
      break;
    case PixelFormat::RGB8_Z24:
      EncodeRGB8(dst, src, params.copy_format, params.yuv);
      break;
    case PixelFormat::RGB565_Z16:
      EncodeRGB8(dst, src, params.copy_format, params.yuv);
      break;
    case PixelFormat::Z24:
      EncodeZ24(dst, src, params.copy_format);
      break;
    default:
      break;
    }
  }
}
}  // namespace

void Encode(AbstractStagingTexture* dst, const EFBCopyParams& params, u32 native_width,
            u32 bytes_per_row, u32 num_blocks_y, u32 memory_stride,
            const MathUtil::Rectangle<int>& src_rect, bool scale_by_half, float y_scale,
            float gamma)
{
  // HACK: Override the memory stride for this staging texture with new copy stride.
  // This is required because the texture encoder assumes that we're writing directly to memory,
  // and each row is tightly packed with no padding, whereas our encoding abstract texture has
  // a width of 2560. When we copy the texture back later on, it'll use the tightly packed stride.
  ASSERT(memory_stride <= (dst->GetConfig().width * dst->GetTexelSize()));
  static_cast<SW::SWStagingTexture*>(dst)->SetMapStride(memory_stride);

  if (params.copy_format == EFBCopyFormat::XFB)
  {
    EfbInterface::EncodeXFB(reinterpret_cast<u8*>(dst->GetMappedPointer()), native_width, src_rect,
                            y_scale, gamma);
  }
  else
  {
    EncodeEfbCopy(reinterpret_cast<u8*>(dst->GetMappedPointer()), params, native_width,
                  bytes_per_row, num_blocks_y, memory_stride, src_rect, scale_by_half);
  }
}
}  // namespace TextureEncoder