//---------------------------------------------------------------------------
// 
// MechCommander 2
//
// TGA file Specifics
//
//---------------------------------------------------------------------------//
// Copyright (C) Microsoft Corporation. All rights reserved.                 //
//===========================================================================//

#ifndef TGAINFO_H
#include "tgainfo.h"
#endif

#include "EString.h"

#include <string.h>
#include <gameos.hpp>
//---------------------------------------------------------------------------
typedef struct _RGB
{
	unsigned char r;
	unsigned char g;
	unsigned char b;
} RGB;

//---------------------------------------------------------------------------
void tgaDecomp(MemoryPtr dest, MemoryPtr source, TGAFileHeader *tga_header)
{
	//---------------------------------------------------------------------
	// Display Image based on Format 10 (0x0a).  RLE true color.

	//----------------------------------------------
	// Parse RLE data -- Check for RLE/RAW byte
	MemoryPtr data_offset = source;
	long currentHeight = 0;
	long currentWidth = 0;
	while (currentHeight != tga_header->height)
	{
		while (currentWidth != tga_header->width)
		{
			byte rep_count = *data_offset;
			data_offset++;
			RGB rgb;
				
			//----------------------------------------------------------
			// Only an RLE packet if MSbit is 1
			if (rep_count >= 128)
			{
				rep_count ^= 0x80;

				rgb.b = *data_offset;
				data_offset++;
				rgb.g = *data_offset;
				data_offset++;
				rgb.r = *data_offset;
				data_offset++;
		
				//-------------------------
				// One more for Alpha Data
				// Use later for aliasing
				byte alpha = 0;
				if (tga_header->pixel_depth == 32)
				{
					alpha = *data_offset;
					data_offset++;
				}
						
				for (long i=0;i<rep_count+1;i++)
				{
					*dest = rgb.b;
					dest++;
					*dest = rgb.g;
					dest++;
					*dest = rgb.r;
					dest++;
					
					if (tga_header->pixel_depth == 32)
					{
						*dest = alpha;
						dest++;
					}
					else
					{
						//---------------------
						// Assume a color key.
						// r 0xff, g 0x00, b 0xff is alpha 0 (Hot Pink)
						// all else is alpha 0xff
						if ((rgb.r == 0xff) && (rgb.g == 0x0) && (rgb.b == 0xff))
							*dest = 0x0;
						else
							*dest = 0xff;

						dest++;
					}
						
					currentWidth++;
				}
			}
			else
			{
				for (int i=0;i<rep_count+1;i++)
				{
					rgb.b = *data_offset;
					data_offset++;
					rgb.g = *data_offset;
					data_offset++;
					rgb.r = *data_offset;
					data_offset++;
					
					//-------------------------
					// One more for Alpha Data
					// Use later for aliasing
					byte alpha = 0;
					if (tga_header->pixel_depth == 32)
					{
						alpha = *data_offset;
						data_offset++;
					}
					
					*dest = rgb.b;
					dest++;
					*dest = rgb.g;
					dest++;
					*dest = rgb.r;
					dest++;
					
					if (tga_header->pixel_depth == 32)
					{
						*dest = alpha;
						dest++;
					}
					else
					{
						//---------------------
						// Assume a color key.
						// r 0xff, g 0x00, b 0xff is alpha 0 (Hot Pink)
						// all else is alpha 0xff
						if ((rgb.r == 0xff) && (rgb.g == 0x0) && (rgb.b == 0xff))
							*dest = 0x0;
						else
							*dest = 0xff;

						dest++;
					}
						
					currentWidth++;
				}
			}
		}

		currentWidth = 0;
		currentHeight++;
	}
}	

//---------------------------------------------------------------------------
void flipTopToBottom (MemoryPtr buffer, BYTE depth, long width, long height)
{
	//-----------------------------------------------------------
	// ScanLine by Scanline
	MemoryPtr tmpBuffer = (MemoryPtr)malloc(width * height * (depth>>3));
	MemoryPtr tmpPointer = tmpBuffer;

	//----------------------------------
	// Point to last scanline.
	long pixelWidth = width * (depth >> 3);
	MemoryPtr workBuffer = buffer + ((height - 1) * pixelWidth);
	
	for (long i=0;i<height;i++)
	{
		memcpy(tmpBuffer,workBuffer,pixelWidth);

		workBuffer -= pixelWidth;
		tmpBuffer += pixelWidth;
	}

	memcpy(buffer,tmpPointer,width * height * (depth>>3));

	free(tmpPointer);
}
	
//---------------------------------------------------------------------------
void tgaCopy (MemoryPtr dest, MemoryPtr src, long size)
{
	long numCopied = 0;
	while (numCopied != size)
	{
		*dest = *src;
		dest++;
		src++;

		*dest = *src;
		dest++;
		src++;

		*dest = *src;
		dest++;
		src++;

		*dest = 0xff;
		dest++;
		numCopied++;
	}
}

//---------------------------------------------------------------------------
static const int g_textureCache_BufferSize = 16384/*64*64*sizeof(DWORD)*/;
static BYTE g_textureCache_Buffer[g_textureCache_BufferSize];
EString *g_textureCache_FilenameOfLastLoadedTexture = NULL;/*This is an (EString *) instead of an EString because apparently gos memory management has a problem with global static allocation of EStrings.*/
static int g_textureCache_WidthOfLastLoadedTexture = 0;/*just to be sure*/
static int g_textureCache_HeightOfLastLoadedTexture = 0;/*just to be sure*/
static int g_textureCache_NumberOfConsecutiveLoads = 0;
static bool g_textureCache_LastTextureIsCached = false;

void loadTGATexture (FilePtr tgaFile, MemoryPtr ourRAM, long width, long height)
{
	if (!g_textureCache_FilenameOfLastLoadedTexture)
		g_textureCache_FilenameOfLastLoadedTexture = new EString;

	if (width * height * sizeof(DWORD) <= g_textureCache_BufferSize)
	{
		if ((g_textureCache_FilenameOfLastLoadedTexture->Data())
			&& (0 == strcmp(tgaFile->getFilename(), g_textureCache_FilenameOfLastLoadedTexture->Data()))
			&& ((const int)width == g_textureCache_WidthOfLastLoadedTexture)
			&& ((const int)height == g_textureCache_HeightOfLastLoadedTexture)
			)
		{
			if (g_textureCache_LastTextureIsCached)
			{
				g_textureCache_NumberOfConsecutiveLoads += 1;
				memcpy(ourRAM, g_textureCache_Buffer, width*height*sizeof(DWORD));
				return;
			}
		}
	}

	MemoryPtr tgaBuffer = (MemoryPtr)malloc(tgaFile->fileSize());

	tgaFile->read(tgaBuffer,tgaFile->fileSize());

	//---------------------------------------
	// Parse out TGAHeader.
	TGAFileHeader *header = (TGAFileHeader *)tgaBuffer;

	gosASSERT(header->width == width);
	gosASSERT(header->height == height);

	switch (header->image_type)
	{
		case UNC_PAL:
		{
			//------------------------------------------------
			// If palette, use entries to create 24Bit image.
		}
		break;

		case UNC_TRUE:
		{
			//------------------------------------------------
			// This is just a bitmap.  Copy it into ourRAM.
			MemoryPtr image = tgaBuffer + sizeof(TGAFileHeader);

			if (header->pixel_depth == 32)
				memcpy(ourRAM,image,width * height * 4);
			else
				tgaCopy(ourRAM,image,width * height);

			//------------------------------------------------------------------------
			// Must check image_descriptor to see if we need to un upside down image.
			bool left = (header->image_descriptor & 16) != 0;
			bool top = (header->image_descriptor & 32) != 0;

			if (!top && !left)
			{
				//--------------------------------
				// Image is Upside down.
				flipTopToBottom(ourRAM,32,width,height);
			}
			else if (!top && left)
			{
				//flipTopToBottom(ourRAM,header->pixel_depth,width,height);
				//flipRightToLeft(ourRAM,header->pixel_depth,width,height);
			}
			else if (top && left)
			{
				//flipRightToLeft(ourRAM,header->pixel_depth,width,height);
			}
		}
		break;

		case RLE_PAL:
		{
			//------------------------------------------------
			// If palette, use entries to create 24Bit image.
		}
		break;

		case RLE_TRUE:
		{
			MemoryPtr image = tgaBuffer + sizeof(TGAFileHeader);
			tgaDecomp(ourRAM,image,header);

			//------------------------------------------------------------------------
			// Must check image_descriptor to see if we need to un upside down image.
			bool left = (header->image_descriptor & 16) != 0;
			bool top = (header->image_descriptor & 32) != 0;

			if (!top && !left)
			{
				//--------------------------------
				// Image is Upside down.
				flipTopToBottom(ourRAM,32,width,height);
			}
			else if (!top && left)
			{
				//flipTopToBottom(ourRAM,header->pixel_depth,width,height);
				//flipRightToLeft(ourRAM,header->pixel_depth,width,height);
			}
			else if (top && left)
			{
				//flipRightToLeft(ourRAM,header->pixel_depth,width,height);
			}
		}
		break;
	}

	free(tgaBuffer);

	if (width * height * sizeof(DWORD) <= g_textureCache_BufferSize)
	{
		if ((g_textureCache_FilenameOfLastLoadedTexture->Data())
			&& (0 == strcmp(tgaFile->getFilename(), g_textureCache_FilenameOfLastLoadedTexture->Data()))
			&& ((const int)width == g_textureCache_WidthOfLastLoadedTexture)
			&& ((const int)height == g_textureCache_HeightOfLastLoadedTexture)
			)
		{
			g_textureCache_NumberOfConsecutiveLoads += 1;
			if (2 == g_textureCache_NumberOfConsecutiveLoads )
			{
				memcpy(g_textureCache_Buffer, ourRAM, width*height*sizeof(DWORD));
				(*g_textureCache_FilenameOfLastLoadedTexture) = tgaFile->getFilename();
				g_textureCache_WidthOfLastLoadedTexture = width;
				g_textureCache_HeightOfLastLoadedTexture = height;
				g_textureCache_LastTextureIsCached = true;
			}
		}
		else
		{
			(*g_textureCache_FilenameOfLastLoadedTexture) = tgaFile->getFilename();
			g_textureCache_WidthOfLastLoadedTexture = width;
			g_textureCache_HeightOfLastLoadedTexture = height;
			g_textureCache_NumberOfConsecutiveLoads = 1;
			g_textureCache_LastTextureIsCached = false;
		}
	}
}	

void loadTGAMask (FilePtr tgaFile, MemoryPtr ourRAM, long width, long height)
{
	MemoryPtr tgaBuffer = (MemoryPtr)malloc(tgaFile->fileSize());

	tgaFile->read(tgaBuffer,tgaFile->fileSize());

	//---------------------------------------
	// Parse out TGAHeader.
	TGAFileHeader *header = (TGAFileHeader *)tgaBuffer;

	gosASSERT(header->width == width);
	gosASSERT(header->height == height);
	gosASSERT(header->image_type != UNC_TRUE);
	gosASSERT(header->image_type != RLE_TRUE);
	gosASSERT(header->image_type != RLE_PAL);

	switch (header->image_type)
	{
		case UNC_PAL:
		case UNC_GRAY:
		{
			//------------------------------------------------
			// This is just a bitmap.  Copy it into ourRAM.
			MemoryPtr image = tgaBuffer + sizeof(TGAFileHeader);
			if (header->color_map)
				image += header->cm_length * (header->cm_entry_size>>3);

			memcpy(ourRAM,image,width * height);

			//------------------------------------------------------------------------
			// Must check image_descriptor to see if we need to un upside down image.
			bool left = (header->image_descriptor & 16) != 0;
			bool top = (header->image_descriptor & 32) != 0;

			if (!top && !left)
			{
				//--------------------------------
				// Image is Upside down.
				flipTopToBottom(ourRAM,header->pixel_depth,width,height);
			}
			else if (!top && left)
			{
				flipTopToBottom(ourRAM,header->pixel_depth,width,height);
				//flipRightToLeft(ourRAM,header->pixel_depth,width,height);
			}
			else if (top && left)
			{
				//flipRightToLeft(ourRAM,header->pixel_depth,width,height);
			}
		}
		break;

		case RLE_PAL:
		{
		}
		break;
	}

	free(tgaBuffer);
}	

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