// ==========================================================

// Bitmap conversion routines

//

// Design and implementation by

// - Floris van den Berg (flvdberg@wxs.nl)

// - Dale Larson (dlarson@norsesoft.com)

// - Hervé Drolon (drolon@infonie.fr)

// - Jani Kajala (janik@remedy.fi)

//

// This file is part of FreeImage 3

//

// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY

// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES

// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE

// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED

// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT

// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY

// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL

// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER

// THIS DISCLAIMER.

//

// Use at your own risk!

// ==========================================================

#include "FreeImage.h"

#include "Utilities.h"

// ----------------------------------------------------------

//  internal conversions X to 24 bits

// ----------------------------------------------------------

void DLL_CALLCONV

FreeImage_ConvertLine1To24(BYTE *target, BYTE *source, int width_in_pixels, RGBQUAD *palette) {

  for (int cols = 0; cols < width_in_pixels; cols++) {

    BYTE index = (source[cols >> 3] & (0x80 >> (cols & 0x07))) != 0 ? 1 : 0;

    target[FI_RGBA_BLUE] = palette[index].rgbBlue;

    target[FI_RGBA_GREEN] = palette[index].rgbGreen;

    target[FI_RGBA_RED] = palette[index].rgbRed;

    target += 3;

  }

}

void DLL_CALLCONV

FreeImage_ConvertLine4To24(BYTE *target, BYTE *source, int width_in_pixels, RGBQUAD *palette) {

  BOOL low_nibble = FALSE;

  int x = 0;

  for (int cols = 0; cols < width_in_pixels; ++cols ) {

    if (low_nibble) {

      target[FI_RGBA_BLUE] = palette[LOWNIBBLE(source[x])].rgbBlue;

      target[FI_RGBA_GREEN] = palette[LOWNIBBLE(source[x])].rgbGreen;

      target[FI_RGBA_RED] = palette[LOWNIBBLE(source[x])].rgbRed;

      x++;

    } else {

      target[FI_RGBA_BLUE] = palette[HINIBBLE(source[x]) >> 4].rgbBlue;

      target[FI_RGBA_GREEN] = palette[HINIBBLE(source[x]) >> 4].rgbGreen;

      target[FI_RGBA_RED] = palette[HINIBBLE(source[x]) >> 4].rgbRed;

    }

    low_nibble = !low_nibble;

    target += 3;

  }

}

void DLL_CALLCONV

FreeImage_ConvertLine8To24(BYTE *target, BYTE *source, int width_in_pixels, RGBQUAD *palette) {

  for (int cols = 0; cols < width_in_pixels; cols++) {

    target[FI_RGBA_BLUE] = palette[source[cols]].rgbBlue;

    target[FI_RGBA_GREEN] = palette[source[cols]].rgbGreen;

    target[FI_RGBA_RED] = palette[source[cols]].rgbRed;

    target += 3;

  }

}

void DLL_CALLCONV

FreeImage_ConvertLine16To24_555(BYTE *target, BYTE *source, int width_in_pixels) {

  WORD *bits = (WORD *)source;

  for (int cols = 0; cols < width_in_pixels; cols++) {

    target[FI_RGBA_RED]   = (BYTE)((((bits[cols] & FI16_555_RED_MASK) >> FI16_555_RED_SHIFT) * 0xFF) / 0x1F);

    target[FI_RGBA_GREEN] = (BYTE)((((bits[cols] & FI16_555_GREEN_MASK) >> FI16_555_GREEN_SHIFT) * 0xFF) / 0x1F);

    target[FI_RGBA_BLUE]  = (BYTE)((((bits[cols] & FI16_555_BLUE_MASK) >> FI16_555_BLUE_SHIFT) * 0xFF) / 0x1F);

    target += 3;

  }

}

void DLL_CALLCONV

FreeImage_ConvertLine16To24_565(BYTE *target, BYTE *source, int width_in_pixels) {

  WORD *bits = (WORD *)source;

  for (int cols = 0; cols < width_in_pixels; cols++) {

    target[FI_RGBA_RED]   = (BYTE)((((bits[cols] & FI16_565_RED_MASK) >> FI16_565_RED_SHIFT) * 0xFF) / 0x1F);

    target[FI_RGBA_GREEN] = (BYTE)((((bits[cols] & FI16_565_GREEN_MASK) >> FI16_565_GREEN_SHIFT) * 0xFF) / 0x3F);

    target[FI_RGBA_BLUE]  = (BYTE)((((bits[cols] & FI16_565_BLUE_MASK) >> FI16_565_BLUE_SHIFT) * 0xFF) / 0x1F);

    target += 3;

  }

}

void DLL_CALLCONV

FreeImage_ConvertLine32To24(BYTE *target, BYTE *source, int width_in_pixels) {

  for (int cols = 0; cols < width_in_pixels; cols++) {

    target[FI_RGBA_BLUE] = source[FI_RGBA_BLUE];

    target[FI_RGBA_GREEN] = source[FI_RGBA_GREEN];

    target[FI_RGBA_RED] = source[FI_RGBA_RED];

    target += 3;

    source += 4;

  }

}

// ----------------------------------------------------------

//   smart convert X to 24 bits

// ----------------------------------------------------------

FIBITMAP * DLL_CALLCONV

FreeImage_ConvertTo24Bits(FIBITMAP *dib) {

  if(!FreeImage_HasPixels(dib)) return NULL;

  const unsigned bpp = FreeImage_GetBPP(dib);

  const FREE_IMAGE_TYPE image_type = FreeImage_GetImageType(dib);

  if((image_type != FIT_BITMAP) && (image_type != FIT_RGB16) && (image_type != FIT_RGBA16)) {

    return NULL;

  }

  const int width = FreeImage_GetWidth(dib);

  const int height = FreeImage_GetHeight(dib);

  if(image_type == FIT_BITMAP) {

    if(bpp == 24) {

      return FreeImage_Clone(dib);

    }

    FIBITMAP *new_dib = FreeImage_Allocate(width, height, 24, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);

    if(new_dib == NULL) {

      return NULL;

    }

    // copy metadata from src to dst

    FreeImage_CloneMetadata(new_dib, dib);

    switch(bpp) {

      case 1 :

      {

        for (int rows = 0; rows < height; rows++) {

          FreeImage_ConvertLine1To24(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib));         

        }

        return new_dib;

      }

      case 4 :

      {

        for (int rows = 0; rows < height; rows++) {

          FreeImage_ConvertLine4To24(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib));

        }

        return new_dib;

      }

      case 8 :

      {

        for (int rows = 0; rows < height; rows++) {

          FreeImage_ConvertLine8To24(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib));

        }

        return new_dib;

      }

      case 16 :

      {

        for (int rows = 0; rows < height; rows++) {

          if ((FreeImage_GetRedMask(dib) == FI16_565_RED_MASK) && (FreeImage_GetGreenMask(dib) == FI16_565_GREEN_MASK) && (FreeImage_GetBlueMask(dib) == FI16_565_BLUE_MASK)) {

            FreeImage_ConvertLine16To24_565(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width);

          } else {

            // includes case where all the masks are 0

            FreeImage_ConvertLine16To24_555(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width);

          }

        }

        return new_dib;

      }

      case 32 :

      {

        for (int rows = 0; rows < height; rows++) {

          FreeImage_ConvertLine32To24(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width);

        }

        return new_dib;

      }

    }

  } else if(image_type == FIT_RGB16) {

    FIBITMAP *new_dib = FreeImage_Allocate(width, height, 24, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);

    if(new_dib == NULL) {

      return NULL;

    }

    // copy metadata from src to dst

    FreeImage_CloneMetadata(new_dib, dib);

    const unsigned src_pitch = FreeImage_GetPitch(dib);

    const unsigned dst_pitch = FreeImage_GetPitch(new_dib);

    const BYTE *src_bits = FreeImage_GetBits(dib);

    BYTE *dst_bits = FreeImage_GetBits(new_dib);

    for (int rows = 0; rows < height; rows++) {

      const FIRGB16 *src_pixel = (FIRGB16*)src_bits;

      RGBTRIPLE *dst_pixel = (RGBTRIPLE*)dst_bits;

      for(int cols = 0; cols < width; cols++) {

        dst_pixel[cols].rgbtRed   = (BYTE)(src_pixel[cols].red   >> 8);

        dst_pixel[cols].rgbtGreen = (BYTE)(src_pixel[cols].green >> 8);

        dst_pixel[cols].rgbtBlue  = (BYTE)(src_pixel[cols].blue  >> 8);

      }

      src_bits += src_pitch;

      dst_bits += dst_pitch;

    }

    return new_dib;

  } else if(image_type == FIT_RGBA16) {

    FIBITMAP *new_dib = FreeImage_Allocate(width, height, 24, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);

    if(new_dib == NULL) {

      return NULL;

    }

    // copy metadata from src to dst

    FreeImage_CloneMetadata(new_dib, dib);

    const unsigned src_pitch = FreeImage_GetPitch(dib);

    const unsigned dst_pitch = FreeImage_GetPitch(new_dib);

    const BYTE *src_bits = FreeImage_GetBits(dib);

    BYTE *dst_bits = FreeImage_GetBits(new_dib);

    for (int rows = 0; rows < height; rows++) {

      const FIRGBA16 *src_pixel = (FIRGBA16*)src_bits;

      RGBTRIPLE *dst_pixel = (RGBTRIPLE*)dst_bits;

      for(int cols = 0; cols < width; cols++) {

        dst_pixel[cols].rgbtRed   = (BYTE)(src_pixel[cols].red   >> 8);

        dst_pixel[cols].rgbtGreen = (BYTE)(src_pixel[cols].green >> 8);

        dst_pixel[cols].rgbtBlue  = (BYTE)(src_pixel[cols].blue  >> 8);

      }

      src_bits += src_pitch;

      dst_bits += dst_pitch;

    }   

    return new_dib;

  }

  return NULL;

}