/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
Copyright (C) 2006 Robert Beckebans <trebor_7@users.sourceforge.net>

This file is part of XreaL source code.

XreaL source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

XreaL source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with XreaL source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// tr_font.c
// 
//
// The font system uses FreeType 2.x to render TrueType fonts for use within the game.
// As of this writing ( Nov, 2000 ) Team Arena uses these fonts for all of the ui and 
// about 90% of the cgame presentation. A few areas of the CGAME were left uses the old 
// fonts since the code is shared with standard Q3A.
//
// If you include this font rendering code in a commercial product you MUST include the
// following somewhere with your product, see www.freetype.org for specifics or changes.
// The Freetype code also uses some hinting techniques that MIGHT infringe on patents 
// held by apple so be aware of that also.
//
// As of Q3A 1.25+ and Team Arena, we are shipping the game with the font rendering code
// disabled. This removes any potential patent issues and it keeps us from having to 
// distribute an actual TrueTrype font which is 1. expensive to do and 2. seems to require
// an act of god to accomplish. 
//
// What we did was pre-render the fonts using FreeType ( which is why we leave the FreeType
// credit in the credits ) and then saved off the glyph data and then hand touched up the 
// font bitmaps so they scale a bit better in GL.
//
// There are limitations in the way fonts are saved and reloaded in that it is based on 
// point size and not name. So if you pre-render Helvetica in 18 point and Impact in 18 point
// you will end up with a single 18 point data file and image set. Typically you will want to 
// choose 3 sizes to best approximate the scaling you will be doing in the ui scripting system
// 
// In the UI Scripting code, a scale of 1.0 is equal to a 48 point font. In Team Arena, we
// use three or four scales, most of them exactly equaling the specific rendered size. We 
// rendered three sizes in Team Arena, 12, 16, and 20. 
//
// To generate new font data you need to go through the following steps.
// 1. delete the fontImage_x_xx.tga files and fontImage_xx.dat files from the fonts path.
// 2. in a ui script, specificy a font, smallFont, and bigFont keyword with font name and 
//    point size. the original TrueType fonts must exist in fonts at this point.
// 3. run the game, you should see things normally.
// 4. Exit the game and there will be three dat files and at least three tga files. The 
//    tga's are in 256x256 pages so if it takes three images to render a 24 point font you 
//    will end up with fontImage_0_24.tga through fontImage_2_24.tga
// 5. In future runs of the game, the system looks for these images and data files when a
//    specific point sized font is rendered and loads them for use. 
// 6. Because of the original beta nature of the FreeType code you will probably want to hand
//    touch the font bitmaps.
// 
// Currently a define in the project turns on or off the FreeType code which is currently 
// defined out. To pre-render new fonts you need enable the define ( BUILD_FREETYPE ) and 
// uncheck the exclude from build check box in the FreeType2 area of the Renderer project. 

#include "tr_local.h"
#include "../qcommon/qcommon.h"

#ifdef BUILD_FREETYPE
//#include <freetype/fterrors.h>
#include <freetype/ftsystem.h>
#include <freetype/ftimage.h>
#include <freetype/freetype.h>
#include <freetype/ftoutln.h>

#define _FLOOR(x)  ((x) & -64)
#define _CEIL(x)   (((x)+63) & -64)
#define _TRUNC(x)  ((x) >> 6)

FT_Library      ftLibrary = NULL;
#endif

#define MAX_FONTS 16
static int      registeredFontCount = 0;
static fontInfo_t registeredFont[MAX_FONTS];

#ifdef BUILD_FREETYPE
void R_GetGlyphInfo(FT_GlyphSlot glyph, int *left, int *right, int *width, int *top, int *bottom, int *height, int *pitch)
{

	*left = _FLOOR(glyph->metrics.horiBearingX);
	*right = _CEIL(glyph->metrics.horiBearingX + glyph->metrics.width);
	*width = _TRUNC(*right - *left);

	*top = _CEIL(glyph->metrics.horiBearingY);
	*bottom = _FLOOR(glyph->metrics.horiBearingY - glyph->metrics.height);
	*height = _TRUNC(*top - *bottom);
	*pitch = (qtrue ? (*width + 3) & -4 : (*width + 7) >> 3);
}


FT_Bitmap      *R_RenderGlyph(FT_GlyphSlot glyph, glyphInfo_t * glyphOut)
{

	FT_Bitmap      *bit2;
	int             left, right, width, top, bottom, height, pitch, size;

	R_GetGlyphInfo(glyph, &left, &right, &width, &top, &bottom, &height, &pitch);

	if(glyph->format == ft_glyph_format_outline)
	{
		size = pitch * height;

		bit2 = Z_Malloc(sizeof(FT_Bitmap));

		bit2->width = width;
		bit2->rows = height;
		bit2->pitch = pitch;
		bit2->pixel_mode = ft_pixel_mode_grays;
		//bit2->pixel_mode = ft_pixel_mode_mono;
		bit2->buffer = Z_Malloc(pitch * height);
		bit2->num_grays = 256;

		Com_Memset(bit2->buffer, 0, size);

		FT_Outline_Translate(&glyph->outline, -left, -bottom);

		FT_Outline_Get_Bitmap(ftLibrary, &glyph->outline, bit2);

		glyphOut->height = height;
		glyphOut->pitch = pitch;
		glyphOut->top = (glyph->metrics.horiBearingY >> 6) + 1;
		glyphOut->bottom = bottom;

		return bit2;
	}
	else
	{
		ri.Printf(PRINT_ALL, "Non-outline fonts are not supported\n");
	}
	return NULL;
}

static void WriteTGA(char *filename, byte * data, int width, int height)
{
	byte           *buffer;
	int             i, c;

	buffer = Z_Malloc(width * height * 4 + 18);

	Com_Memset(buffer, 0, 18);
	buffer[2] = 2;				// uncompressed type
	buffer[12] = width & 255;
	buffer[13] = width >> 8;
	buffer[14] = height & 255;
	buffer[15] = height >> 8;
	buffer[16] = 32;			// pixel size

	// swap rgb to bgr
	c = 18 + width * height * 4;
	for(i = 18; i < c; i += 4)
	{
		buffer[i] = data[i - 18 + 2];	// blue
		buffer[i + 1] = data[i - 18 + 1];	// green
		buffer[i + 2] = data[i - 18 + 0];	// red
		buffer[i + 3] = data[i - 18 + 3];	// alpha
	}

	// Tr3B: flip upside down
	{
		int             row;
		unsigned char  *flip;
		unsigned char  *src, *dst;

		flip = (unsigned char *)malloc(width * 4);
		for(row = 0; row < height / 2; row++)
		{
			src = buffer + 18 + (row * 4 * width);
			dst = buffer + 18 + ((height - row - 1) * 4 * width);

			memcpy(flip, src, width * 4);
			memcpy(src, dst, width * 4);
			memcpy(dst, flip, width * 4);
		}
		free(flip);
	}

	ri.FS_WriteFile(filename, buffer, c);

	Z_Free(buffer);
}

static glyphInfo_t *RE_ConstructGlyphInfo(unsigned char *imageOut, int *xOut, int *yOut,
										  int *maxHeight, FT_Face face, const unsigned char c, qboolean calcHeight)
{
	int             i;
	static glyphInfo_t glyph;
	unsigned char  *src, *dst;
	float           scaled_width, scaled_height;
	FT_Bitmap      *bitmap = NULL;

	Com_Memset(&glyph, 0, sizeof(glyphInfo_t));
	// make sure everything is here
	if(face != NULL)
	{
		FT_Load_Glyph(face, FT_Get_Char_Index(face, c), FT_LOAD_DEFAULT);
		bitmap = R_RenderGlyph(face->glyph, &glyph);
		if(bitmap)
		{
			glyph.xSkip = (face->glyph->metrics.horiAdvance >> 6) + 1;
		}
		else
		{
			return &glyph;
		}

		if(glyph.height > *maxHeight)
		{
			*maxHeight = glyph.height;
		}

		if(calcHeight)
		{
			Z_Free(bitmap->buffer);
			Z_Free(bitmap);
			return &glyph;
		}

/*
    // need to convert to power of 2 sizes so we do not get 
    // any scaling from the gl upload
  	for (scaled_width = 1 ; scaled_width < glyph.pitch ; scaled_width<<=1)
	  	;
  	for (scaled_height = 1 ; scaled_height < glyph.height ; scaled_height<<=1)
	  	;
*/

		scaled_width = glyph.pitch;
		scaled_height = glyph.height;

		// we need to make sure we fit
		if(*xOut + scaled_width + 1 >= 255)
		{
			if(*yOut + *maxHeight + 1 >= 255)
			{
				*yOut = -1;
				*xOut = -1;
				Z_Free(bitmap->buffer);
				Z_Free(bitmap);
				return &glyph;
			}
			else
			{
				*xOut = 0;
				*yOut += *maxHeight + 1;
			}
		}
		else if(*yOut + *maxHeight + 1 >= 255)
		{
			*yOut = -1;
			*xOut = -1;
			Z_Free(bitmap->buffer);
			Z_Free(bitmap);
			return &glyph;
		}


		src = bitmap->buffer;
		dst = imageOut + (*yOut * 256) + *xOut;

		if(bitmap->pixel_mode == ft_pixel_mode_mono)
		{
			for(i = 0; i < glyph.height; i++)
			{
				int             j;
				unsigned char  *_src = src;
				unsigned char  *_dst = dst;
				unsigned char   mask = 0x80;
				unsigned char   val = *_src;

				for(j = 0; j < glyph.pitch; j++)
				{
					if(mask == 0x80)
					{
						val = *_src++;
					}
					if(val & mask)
					{
						*_dst = 0xff;
					}
					mask >>= 1;

					if(mask == 0)
					{
						mask = 0x80;
					}
					_dst++;
				}

				src += glyph.pitch;
				dst += 256;

			}
		}
		else
		{
			for(i = 0; i < glyph.height; i++)
			{
				Com_Memcpy(dst, src, glyph.pitch);
				src += glyph.pitch;
				dst += 256;
			}
		}

		// we now have an 8 bit per pixel grey scale bitmap 
		// that is width wide and pf->ftSize->metrics.y_ppem tall

		glyph.imageHeight = scaled_height;
		glyph.imageWidth = scaled_width;
		glyph.s = (float)*xOut / 256;
		glyph.t = (float)*yOut / 256;
		glyph.s2 = glyph.s + (float)scaled_width / 256;
		glyph.t2 = glyph.t + (float)scaled_height / 256;

		*xOut += scaled_width + 1;
	}

	Z_Free(bitmap->buffer);
	Z_Free(bitmap);

	return &glyph;
}
#endif

static int      fdOffset;
static byte    *fdFile;

int readInt()
{
	int             i =
		fdFile[fdOffset] + (fdFile[fdOffset + 1] << 8) + (fdFile[fdOffset + 2] << 16) + (fdFile[fdOffset + 3] << 24);
	fdOffset += 4;
	return i;
}

typedef union
{
	byte            fred[4];
	float           ffred;
} poor;

float readFloat()
{
	poor            me;

#if idppc
	me.fred[0] = fdFile[fdOffset + 3];
	me.fred[1] = fdFile[fdOffset + 2];
	me.fred[2] = fdFile[fdOffset + 1];
	me.fred[3] = fdFile[fdOffset + 0];
#else
	me.fred[0] = fdFile[fdOffset + 0];
	me.fred[1] = fdFile[fdOffset + 1];
	me.fred[2] = fdFile[fdOffset + 2];
	me.fred[3] = fdFile[fdOffset + 3];
#endif
	fdOffset += 4;
	return me.ffred;
}

void RE_RegisterFont(const char *fontName, int pointSize, fontInfo_t * font)
{
#ifdef BUILD_FREETYPE
	FT_Face         face;
	int             j, k, xOut, yOut, lastStart, imageNumber;
	int             scaledSize, newSize, maxHeight, left, satLevels;
	unsigned char  *out, *imageBuff;
	glyphInfo_t    *glyph;
	image_t        *image;
	qhandle_t       h;
	float           max;
#endif
	void           *faceData;
	int             i, len;
	char            fileName[MAX_QPATH];
	char            strippedName[MAX_QPATH];
	float           dpi = 72;
	float           glyphScale = 72.0f / dpi;	// change the scale to be relative to 1 based on 72 dpi ( so dpi of 144 means a scale of .5 )

	if(pointSize <= 0)
	{
		pointSize = 12;
	}
	// we also need to adjust the scale based on point size relative to 48 points as the ui scaling is based on a 48 point font
	glyphScale *= 48.0f / pointSize;

	// make sure the render thread is stopped
	R_SyncRenderThread();

	if(registeredFontCount >= MAX_FONTS)
	{
		ri.Printf(PRINT_ALL, "RE_RegisterFont: Too many fonts registered already.\n");
		return;
	}

	Com_StripExtension(fontName, strippedName, sizeof(strippedName));
	Com_sprintf(fileName, sizeof(fileName), "%s_%i.dat", strippedName, pointSize);
	for(i = 0; i < registeredFontCount; i++)
	{
		if(Q_stricmp(fileName, registeredFont[i].name) == 0)
		{
			Com_Memcpy(font, &registeredFont[i], sizeof(fontInfo_t));
			return;
		}
	}

	len = ri.FS_ReadFile(fileName, NULL);
	if(len == sizeof(fontInfo_t))
	{
		ri.FS_ReadFile(fileName, &faceData);
		fdOffset = 0;
		fdFile = faceData;
		for(i = 0; i < GLYPHS_PER_FONT; i++)
		{
			font->glyphs[i].height = readInt();
			font->glyphs[i].top = readInt();
			font->glyphs[i].bottom = readInt();
			font->glyphs[i].pitch = readInt();
			font->glyphs[i].xSkip = readInt();
			font->glyphs[i].imageWidth = readInt();
			font->glyphs[i].imageHeight = readInt();
			font->glyphs[i].s = readFloat();
			font->glyphs[i].t = readFloat();
			font->glyphs[i].s2 = readFloat();
			font->glyphs[i].t2 = readFloat();
			font->glyphs[i].glyph = readInt();
			Com_Memcpy(font->glyphs[i].shaderName, &fdFile[fdOffset], 32);
			fdOffset += 32;
		}
		font->glyphScale = readFloat();
		Com_Memcpy(font->name, &fdFile[fdOffset], 64);

//      Com_Memcpy(font, faceData, sizeof(fontInfo_t));
		Q_strncpyz(font->name, fileName, sizeof(font->name));
		for(i = GLYPH_START; i < GLYPH_END; i++)
		{
			font->glyphs[i].glyph = RE_RegisterShaderNoMip(font->glyphs[i].shaderName);
		}
		Com_Memcpy(&registeredFont[registeredFontCount++], font, sizeof(fontInfo_t));
		return;
	}

#ifndef BUILD_FREETYPE
	ri.Printf(PRINT_ALL, "RE_RegisterFont: FreeType code not available\n");
#else
	if(ftLibrary == NULL)
	{
		ri.Printf(PRINT_ALL, "RE_RegisterFont: FreeType not initialized.\n");
		return;
	}

	Com_sprintf(fileName, sizeof(fileName), "%s.ttf", strippedName);
	len = ri.FS_ReadFile(fileName, &faceData);
	if(len <= 0)
	{
		ri.Printf(PRINT_ALL, "RE_RegisterFont: Unable to read font file '%s'\n", fileName);
		return;
	}

	// allocate on the stack first in case we fail
	if(FT_New_Memory_Face(ftLibrary, faceData, len, 0, &face))
	{
		ri.Printf(PRINT_ALL, "RE_RegisterFont: FreeType2, unable to allocate new face.\n");
		return;
	}


	if(FT_Set_Char_Size(face, pointSize << 6, pointSize << 6, dpi, dpi))
	{
		ri.Printf(PRINT_ALL, "RE_RegisterFont: FreeType2, Unable to set face char size.\n");
		return;
	}

	// make a 256x256 image buffer, once it is full, register it, clean it and keep going 
	// until all glyphs are rendered

	out = Z_Malloc(1024 * 1024);
	if(out == NULL)
	{
		ri.Printf(PRINT_ALL, "RE_RegisterFont: Z_Malloc failure during output image creation.\n");
		return;
	}
	Com_Memset(out, 0, 1024 * 1024);

	maxHeight = 0;

	for(i = GLYPH_START; i < GLYPH_END; i++)
	{
		glyph = RE_ConstructGlyphInfo(out, &xOut, &yOut, &maxHeight, face, (unsigned char)i, qtrue);
	}

	xOut = 0;
	yOut = 0;
	i = GLYPH_START;
	lastStart = i;
	imageNumber = 0;

	while(i <= GLYPH_END)
	{
		glyph = RE_ConstructGlyphInfo(out, &xOut, &yOut, &maxHeight, face, (unsigned char)i, qfalse);

		if(xOut == -1 || yOut == -1 || i == GLYPH_END)
		{
			// ran out of room
			// we need to create an image from the bitmap, set all the handles in the glyphs to this point
			// 

			scaledSize = 256 * 256;
			newSize = scaledSize * 4;
			imageBuff = Z_Malloc(newSize);
			left = 0;
			max = 0;
			satLevels = 255;
			for(k = 0; k < (scaledSize); k++)
			{
				if(max < out[k])
				{
					max = out[k];
				}
			}

			if(max > 0)
			{
				max = 255 / max;
			}

			for(k = 0; k < (scaledSize); k++)
			{
				imageBuff[left++] = 255;
				imageBuff[left++] = 255;
				imageBuff[left++] = 255;

				imageBuff[left++] = ((float)out[k] * max);
			}

			Com_sprintf(fileName, sizeof(fileName), "%s_%i_%i.tga", strippedName, imageNumber++, pointSize);
			if(!ri.FS_FileExists(fileName))
			{
				WriteTGA(fileName, imageBuff, 256, 256);
			}

			image = R_CreateImage(fileName, imageBuff, 256, 256, qfalse, qfalse, WT_CLAMP);
			h = RE_RegisterShaderFromImage(fileName, image, qfalse);
			for(j = lastStart; j < i; j++)
			{
				font->glyphs[j].glyph = h;
				Q_strncpyz(font->glyphs[j].shaderName, fileName, sizeof(font->glyphs[j].shaderName));
			}
			lastStart = i;
			Com_Memset(out, 0, 1024 * 1024);
			xOut = 0;
			yOut = 0;
			Z_Free(imageBuff);
			i++;
		}
		else
		{
			Com_Memcpy(&font->glyphs[i], glyph, sizeof(glyphInfo_t));
			i++;
		}
	}

	registeredFont[registeredFontCount].glyphScale = glyphScale;
	font->glyphScale = glyphScale;
	Com_Memcpy(&registeredFont[registeredFontCount++], font, sizeof(fontInfo_t));

	Com_sprintf(fileName, sizeof(fileName), "%s_%i.dat", strippedName, pointSize);
	if(!ri.FS_FileExists(fileName))
	{
		ri.FS_WriteFile(fileName, font, sizeof(fontInfo_t));
	}

	Z_Free(out);

	ri.FS_FreeFile(faceData);
#endif
}



void R_InitFreeType()
{
#ifdef BUILD_FREETYPE
	if(FT_Init_FreeType(&ftLibrary))
	{
		ri.Printf(PRINT_ALL, "R_InitFreeType: Unable to initialize FreeType.\n");
	}
#endif
	registeredFontCount = 0;
}


void R_DoneFreeType()
{
#ifdef BUILD_FREETYPE
	if(ftLibrary)
	{
		FT_Done_FreeType(ftLibrary);
		ftLibrary = NULL;
	}
#endif
	registeredFontCount = 0;
}
