What is the best way to draw 4bpp 2D tiles with multiple palettes?

I'm creating a generic SNES tilemap editor (similar to NES Screen Tool), meaning I'm drawing a lot of 4bpp tiles. However, my graphics loop takes too long to run, even with CachedBitmaps, which can't have their palettes changed, of which I may need to switch between 8. I can deal with the SNES format and size of things, but am struggling with the Windows side.

// basically the entire graphics drawing routine  case(WM_PAINT):{      PAINTSTRUCT ps;      HDC hdc = BeginPaint(hwnd, &ps);            Gdiplus::Graphics graphics(hdc);      graphics.Clear(ARGB1555toARGB8888(CGRAM[0]));   // convert 1st 15-bit CGRAM color to 32-bit & clear bkgd            // tileset2[i]->SetPalette(colorpalette); // called in tileset loading to test 1 palette      for(uint16_t i = 0; i < 1024; i++){          tilesetX[i] = new Gdiplus::CachedBitmap(tileset2[i], &graphics);      }            /* struct SNES_Tile{          uint16_t tileIndex: 10,          uint16_t palette: 3,          uint16_t priority: 1, // (irrelevant for this project)          uint16_t horzFlip: 1,          uint16_t vertFlip: 1,      }*/      // I can see each individual tile being drawn      for(int y = 0; y < 32; y++){          for(int x = 0; x < 32; x++){              // assume tilemap is set to 32x32, and not 64x32 or 32x64 or 64x64              graphics.DrawCachedBitmap(tilesetX[BG2[y * 32 + x] & 0x03FF], x * BG2CHRSize, y * BG2CHRSize);              // BG2[y * 32 + x]  & 0x03FF    : get tile index from VRAM and strip attributes              // tilesetX[...]                : get CachedBitmap to draw          }      }            EndPaint(hwnd, &ps);      break;  }  

I am early enough in my program that rewriting the entire graphics routine wouldn't be too much of a hassle.

Should I give up on GDI+ and switch to Direct2D or something else? Is there a faster way to draw 4bpp bitmaps without having to create a copy for each palette?

EDIT:

The reason my graphics drawing routine was so slow was because I was drawing directly to the screen. It is much faster to draw to a separate bitmap as a buffer, then draw the buffer to the screen. Updating the tile's palette when drawing to the buffer results in perfectly reasonably speeds. https://stackoverflow.com/questions/65880077/what-is-the-best-way-to-draw-4bpp-2d-tiles-with-multiple-palettes January 25, 2021 at 02:46PM