// ==========================================================
// Bitmap conversion routines
//
// Design and implementation by
// - Floris van den Berg (flvdberg@wxs.nl)
// - Hervé Drolon (drolon@infonie.fr)
// - Jani Kajala (janik@remedy.fi)
// - Detlev Vendt (detlev.vendt@brillit.de)
//
// 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 32 bits
// ----------------------------------------------------------

void DLL_CALLCONV
FreeImage_ConvertLine1To32(BYTE *target, BYTE *source, int width_in_pixels, RGBQUAD *palette) {
	for (int cols = 0; cols < width_in_pixels; cols++) {
		int 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[FI_RGBA_ALPHA]	= 0xFF;
		target += 4;
	}	
}

void DLL_CALLCONV
FreeImage_ConvertLine4To32(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[FI_RGBA_ALPHA] = 0xFF;
		target += 4;
	}
}

void DLL_CALLCONV
FreeImage_ConvertLine8To32(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[FI_RGBA_ALPHA]	= 0xFF;
		target += 4;
	}
}

void DLL_CALLCONV
FreeImage_ConvertLine16To32_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[FI_RGBA_ALPHA] = 0xFF;
		target += 4;
	}
}

void DLL_CALLCONV
FreeImage_ConvertLine16To32_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[FI_RGBA_ALPHA] = 0xFF;
		target += 4;
	}
}
/*
void DLL_CALLCONV
FreeImage_ConvertLine24To32(BYTE *target, BYTE *source, int width_in_pixels) {
	for (int cols = 0; cols < width_in_pixels; cols++) {
		*(DWORD *)target = (*(DWORD *) source & FI_RGBA_RGB_MASK) | FI_RGBA_ALPHA_MASK;
		target += 4;
		source += 3;
	}
}
*/
/**
This unoptimized version of the conversion function avoid an undetermined bug with VC++ SP6. 
The bug occurs in release mode only, when the image height is equal to 537 
(try e.g. a size of 432x537 to reproduce the bug with the optimized function).
*/
void DLL_CALLCONV
FreeImage_ConvertLine24To32(BYTE *target, BYTE *source, int width_in_pixels) {
	for (int cols = 0; cols < width_in_pixels; cols++) {
		target[FI_RGBA_RED]   = source[FI_RGBA_RED];
		target[FI_RGBA_GREEN] = source[FI_RGBA_GREEN];
		target[FI_RGBA_BLUE]  = source[FI_RGBA_BLUE];
		target[FI_RGBA_ALPHA] = 0xFF;
		target += 4;
		source += 3;
	}
}

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

inline void 
FreeImage_ConvertLine1To32MapTransparency(BYTE *target, BYTE *source, int width_in_pixels, RGBQUAD *palette, BYTE *table, int transparent_pixels) {
	for (int cols = 0; cols < width_in_pixels; cols++) {
		int 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[FI_RGBA_ALPHA] = (index < transparent_pixels) ? table[index] : 255;		
		target += 4;
	}	
}

inline void 
FreeImage_ConvertLine4To32MapTransparency(BYTE *target, BYTE *source, int width_in_pixels, RGBQUAD *palette, BYTE *table, int transparent_pixels) {
	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;
			target[FI_RGBA_ALPHA]	= (LOWNIBBLE(source[x]) < transparent_pixels) ? table[LOWNIBBLE(source[x])] : 255;

			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;
			target[FI_RGBA_ALPHA]	= (HINIBBLE(source[x] >> 4) < transparent_pixels) ? table[HINIBBLE(source[x]) >> 4] : 255;
		}

		low_nibble = !low_nibble;
				
		target += 4;
	}
}

inline void 
FreeImage_ConvertLine8To32MapTransparency(BYTE *target, BYTE *source, int width_in_pixels, RGBQUAD *palette, BYTE *table, int transparent_pixels) {
	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[FI_RGBA_ALPHA] = (source[cols] < transparent_pixels) ? table[source[cols]] : 255;
		target += 4;		
	}
}

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

FIBITMAP * DLL_CALLCONV
FreeImage_ConvertTo32Bits(FIBITMAP *dib) {
	if(!FreeImage_HasPixels(dib)) return NULL;

	const int 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 == 32) {
			return FreeImage_Clone(dib);
		}

		FIBITMAP *new_dib = FreeImage_Allocate(width, height, 32, 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);

		BOOL bIsTransparent = FreeImage_IsTransparent(dib);

		switch(bpp) {
			case 1:
			{
				if(bIsTransparent) {
					for (int rows = 0; rows < height; rows++) {
						FreeImage_ConvertLine1To32MapTransparency(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib), FreeImage_GetTransparencyTable(dib), FreeImage_GetTransparencyCount(dib));
					}
				} else {
					for (int rows = 0; rows < height; rows++) {
						FreeImage_ConvertLine1To32(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib));
					}					
				}

				return new_dib;
			}

			case 4:
			{
				if(bIsTransparent) {
					for (int rows = 0; rows < height; rows++) {
						FreeImage_ConvertLine4To32MapTransparency(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib), FreeImage_GetTransparencyTable(dib), FreeImage_GetTransparencyCount(dib));
					}
				} else {
					for (int rows = 0; rows < height; rows++) {
						FreeImage_ConvertLine4To32(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib));
					}					
				}

				return new_dib;
			}
				
			case 8:
			{
				if(bIsTransparent) {
					for (int rows = 0; rows < height; rows++) {
						FreeImage_ConvertLine8To32MapTransparency(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width, FreeImage_GetPalette(dib), FreeImage_GetTransparencyTable(dib), FreeImage_GetTransparencyCount(dib));
					}
				} else {
					for (int rows = 0; rows < height; rows++) {
						FreeImage_ConvertLine8To32(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_ConvertLine16To32_565(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width);
					} else {
						// includes case where all the masks are 0
						FreeImage_ConvertLine16To32_555(FreeImage_GetScanLine(new_dib, rows), FreeImage_GetScanLine(dib, rows), width);
					}
				}

				return new_dib;
			}

			case 24:
			{
				for (int rows = 0; rows < height; rows++) {
					FreeImage_ConvertLine24To32(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, 32, 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;
			RGBQUAD *dst_pixel = (RGBQUAD*)dst_bits;
			for(int cols = 0; cols < width; cols++) {
				dst_pixel[cols].rgbRed		= (BYTE)(src_pixel[cols].red   >> 8);
				dst_pixel[cols].rgbGreen	= (BYTE)(src_pixel[cols].green >> 8);
				dst_pixel[cols].rgbBlue		= (BYTE)(src_pixel[cols].blue  >> 8);
				dst_pixel[cols].rgbReserved = (BYTE)0xFF;
			}
			src_bits += src_pitch;
			dst_bits += dst_pitch;
		}

		return new_dib;

	} else if(image_type == FIT_RGBA16) {
		FIBITMAP *new_dib = FreeImage_Allocate(width, height, 32, 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;
			RGBQUAD *dst_pixel = (RGBQUAD*)dst_bits;
			for(int cols = 0; cols < width; cols++) {
				dst_pixel[cols].rgbRed		= (BYTE)(src_pixel[cols].red   >> 8);
				dst_pixel[cols].rgbGreen	= (BYTE)(src_pixel[cols].green >> 8);
				dst_pixel[cols].rgbBlue		= (BYTE)(src_pixel[cols].blue  >> 8);
				dst_pixel[cols].rgbReserved = (BYTE)(src_pixel[cols].alpha >> 8);
			}
			src_bits += src_pitch;
			dst_bits += dst_pitch;
		}		

		return new_dib;
	}
	
	return NULL;
}