font_freetype.c

the embedded GUI for SamSung s3c2410 cpu based board.is microwindows0.90

/*
 * Copyright (c) 2000, 2002, 2003 Greg Haerr <[e-mail]>
 * Portions Copyright (c) 2002 by Koninklijke Philips Electronics N.V.
 *
 * Freetype TrueType routines originally contributed by Martin Jolicoeur
 * Heavily modified by Greg Haerr
 */
/*#define NDEBUG*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <dirent.h>
#include <freetype/freetype.h>
#include <freetype/ftxkern.h>
#include <freetype/ftnameid.h>
#include <freetype/ftxcmap.h>
#include <freetype/ftxwidth.h>
#include "device.h"
#include "devfont.h"

#if TT_FREETYPE_MAJOR != 1 || TT_FREETYPE_MINOR < 3
#error "You must link with freetype lib version 1.3.x +, and not freetype 2."
#endif

typedef struct MWFREETYPEFONT {
	PMWFONTPROCS	fontprocs;	/* common hdr*/
	MWCOORD		fontsize;
	int		fontrotation;
	int		fontattr;		

	TT_Face 	face;		/* freetype stuff*/
	TT_Instance	instance;
	TT_CharMap 	char_map;
	TT_Kerning 	directory;
	TT_Matrix 	matrix;
	TT_Glyph 	glyph;
	MWBOOL 		can_kern;
	short 		last_glyph_code;
	short 		last_pen_pos;
} MWFREETYPEFONT;

int  freetype_init(PSD psd);
PMWFREETYPEFONT freetype_createfont(const char *name, MWCOORD height, int attr);

static MWBOOL freetype_getfontinfo(PMWFONT pfont, PMWFONTINFO pfontinfo);
static void freetype_gettextsize(PMWFONT pfont, const void *text, int cc,
		MWTEXTFLAGS flags, MWCOORD *pwidth, MWCOORD *pheight,
		MWCOORD *pbase);
static void freetype_destroyfont(PMWFONT pfont);
static void freetype_drawtext(PMWFONT pfont, PSD psd, MWCOORD x, MWCOORD y,
		const void *text, int cc, MWTEXTFLAGS flags);
static void freetype_setfontsize(PMWFONT pfont, MWCOORD fontsize);
static void freetype_setfontrotation(PMWFONT pfont, int tenthdegrees);
		
/* handling routines for MWFREETYPEFONT*/
static MWFONTPROCS freetype_procs = {
	MWTF_UC16,			/* routines expect unicode 16*/
	freetype_getfontinfo,
	freetype_gettextsize,
	NULL,				/* gettextbits*/
	freetype_destroyfont,
	freetype_drawtext,
	freetype_setfontsize,
	freetype_setfontrotation,
	NULL,				/* setfontattr*/
	NULL,				/* duplicate not yet implemented */
};

static TT_Engine 	engine;		/* THE ONLY freetype engine */
static OUTPIXELVAL gray_palette[5];

/* temp extern decls*/
extern MWPIXELVAL gr_foreground;
extern MWPIXELVAL gr_background;
extern MWBOOL gr_usebg;

int
freetype_init(PSD psd)
{
	static int inited = 0;

	if (inited)
		return 1;
	
	/* Init freetype library */
	if (TT_Init_FreeType (&engine) != TT_Err_Ok) {
		return 0;
	}

	/* Init kerning extension */
	if (TT_Init_Kerning_Extension (engine) != TT_Err_Ok)
		return 0;

	inited = 1;
	return 1;
}

PMWFREETYPEFONT
freetype_createfont(const char *name, MWCOORD height, int attr)
{
	PMWFREETYPEFONT 	pf;
	unsigned short 		i, n;
	unsigned short 		platform, encoding;
	TT_Face_Properties 	properties;
	char *			p;
	char			fontname[128];

	/* check for pathname prefix*/
	if (strchr(name, '/') != NULL)
		strcpy(fontname, name);
	else {
		strcpy(fontname, FREETYPE_FONT_DIR);
		strcat(fontname, "/");
		strcat(fontname, name);
	}

	/* check for extension*/
	if ((p = strrchr(fontname, '.')) == NULL ||
	    strcmp(p, ".ttf") != 0) {
		strcat(fontname, ".ttf");
	}

	/* allocate font structure*/
	pf = (PMWFREETYPEFONT)calloc(sizeof(MWFREETYPEFONT), 1);
	if (!pf)
		return NULL;
	pf->fontprocs = &freetype_procs;

	/* Load face */
	if (TT_Open_Face (engine, fontname, &pf->face) != TT_Err_Ok)
		goto out;

	/* Load first kerning table */
	pf->can_kern = TRUE;
	if (TT_Load_Kerning_Table (pf->face, 0) != TT_Err_Ok)
		pf->can_kern = FALSE;
	else {
		if (TT_Get_Kerning_Directory (pf->face, &pf->directory)
		    != TT_Err_Ok)
			pf->can_kern = FALSE;
		else {
			/* Support only version 0 kerning table ... */
			if ((pf->directory.version != 0) ||
				(pf->directory.nTables <= 0) ||
				(pf->directory.tables->loaded != 1) ||
				(pf->directory.tables->version != 0) ||
				(pf->directory.tables->t.kern0.nPairs <= 0))
					pf->can_kern = FALSE;
		}
	}

	/* get face properties and allocate preload arrays */
	TT_Get_Face_Properties (pf->face, &properties);

#if 0
	/*
	 * Use header information for ascent and descent
	 * to compute scaled ascent/descent for current font height.
	 */
	h = properties.os2->sTypoAscender - properties.os2->sTypoDescender
		+ properties.os2->sTypoLineGap;
	ascent = properties.os2->sTypoAscender
		+ properties.os2->sTypoLineGap/2;
	pf->ascent = (ascent * height + h/2) / h;
	pf->descent = height - pf->ascent;
#endif
	/* Create a glyph container */
	if (TT_New_Glyph (pf->face, &pf->glyph) != TT_Err_Ok)
		goto out;

	/* create instance */
	if (TT_New_Instance (pf->face, &pf->instance) != TT_Err_Ok)
		goto out;

	/* Set the instance resolution */
	if (TT_Set_Instance_Resolutions (pf->instance, 96, 96) != TT_Err_Ok)
		goto out;

	/* Look for a Unicode charmap: Windows flavor of Apple flavor only */
	n = properties.num_CharMaps;

	for (i = 0; i < n; i++) {
		TT_Get_CharMap_ID (pf->face, i, &platform, &encoding);
		if (((platform == TT_PLATFORM_MICROSOFT) &&
			(encoding == TT_MS_ID_UNICODE_CS)) ||
				((platform == TT_PLATFORM_APPLE_UNICODE) &&
			 		(encoding == TT_APPLE_ID_DEFAULT)))
		{
			TT_Get_CharMap (pf->face, i, &pf->char_map);
			i = n + 1;
		}
	}
	if (i == n) {
		DPRINTF("freetype_createfont: no unicode map table\n");
		goto out;
	}
	
	GdSetFontSize((PMWFONT)pf, height);
	GdSetFontRotation((PMWFONT)pf, 0);
	GdSetFontAttr((PMWFONT)pf, attr, 0);

	return pf;

out:
	free(pf);
	return NULL;
}

static int
compute_kernval(PMWFREETYPEFONT pf, short current_glyph_code)
{
	int 		i = 0;
	int 		kernval;
	int 		nPairs = pf->directory.tables->t.kern0.nPairs;
	TT_Kern_0_Pair *pair = pf->directory.tables->t.kern0.pairs;

	if (pf->last_glyph_code != -1) {
		while ((pair->left != pf->last_glyph_code)
			&& (pair->right != current_glyph_code))
		{
			pair++;
			i++;
			if (i == nPairs)
			break;
		}

		if (i == nPairs)
			kernval = 0;
		else
			/* We round the value (hence the +32) */
			kernval = (pair->value + 32) & -64;
	} else
		kernval = 0;

	return kernval;
}

static TT_UShort
Get_Glyph_Width(PMWFREETYPEFONT pf, TT_UShort glyph_index)
{
	TT_Glyph_Metrics metrics;
	
    	if (TT_Load_Glyph ( pf->instance, pf->glyph,
		TT_Char_Index (pf->char_map,glyph_index),
		TTLOAD_SCALE_GLYPH|TTLOAD_HINT_GLYPH) != TT_Err_Ok)
    	{
		/* Try to load default glyph: index 0 */
		if (TT_Load_Glyph ( pf->instance, pf->glyph, 0,
			TTLOAD_SCALE_GLYPH|TTLOAD_HINT_GLYPH) != TT_Err_Ok)
		    return 0;
	}

	TT_Get_Glyph_Metrics (pf->glyph, &metrics);
	return((metrics.advance & 0xFFFFFFC0) >> 6);
}

/* Render a single glyph*/
static void
drawchar(PMWFREETYPEFONT pf, PSD psd, TT_Glyph glyph, int x_offset,
	int y_offset)
{
	TT_F26Dot6 	xmin, ymin, xmax, ymax, x, y, z;
	unsigned char 	*src, *srcptr;
	MWPIXELVAL 	*dst, *dstptr;
	MWPIXELVAL 	*bitmap;
	int 		size, width, height;
	TT_Outline 	outline;
	TT_BBox 	bbox;
	TT_Raster_Map 	Raster;
	TT_Error 	error;
	/*MWPIXELVAL 	save;*/

	/* we begin by grid-fitting the bounding box */
	TT_Get_Glyph_Outline (pf->glyph, &outline);
	TT_Get_Outline_BBox (&outline, &bbox);

	xmin = (bbox.xMin & -64) >> 6;
	ymin = (bbox.yMin & -64) >> 6;
	xmax = ((bbox.xMax + 63) & -64) >> 6;
	ymax = ((bbox.yMax + 63) & -64) >> 6;
	width = xmax - xmin;
	height = ymax - ymin;
	size = width * height;

	/* now re-allocate the raster bitmap */
	Raster.rows = height;
	Raster.width = width;

	if (pf->fontattr&MWTF_ANTIALIAS)
		Raster.cols = (Raster.width + 3) & -4;	/* pad to 32-bits */
	else
		Raster.cols = (Raster.width + 7) & -8;	/* pad to 64-bits ??? */

	Raster.flow = TT_Flow_Up;
	Raster.size = Raster.rows * Raster.cols;
	Raster.bitmap = malloc (Raster.size);

	memset (Raster.bitmap, 0, Raster.size);

	/* now render the glyph in the small pixmap */

	/* IMPORTANT NOTE: the offset parameters passed to the function     */
	/* TT_Get_Glyph_Bitmap() must be integer pixel values, i.e.,        */
	/* multiples of 64.  HINTING WILL BE RUINED IF THIS ISN'T THE CASE! */
	/* This is why we _did_ grid-fit the bounding box, especially xmin  */
	/* and ymin.                                                        */

	if (!(pf->fontattr&MWTF_ANTIALIAS))
		error = TT_Get_Glyph_Bitmap (pf->glyph, &Raster,
				-xmin * 64, -ymin * 64);
	else
		error = TT_Get_Glyph_Pixmap (pf->glyph, &Raster,
				-xmin * 64, -ymin * 64);

	if (error) {
		free (Raster.bitmap);
		return;
	}

	bitmap = malloc (size * sizeof (MWPIXELVAL));
	memset (bitmap, 0, size * sizeof (MWPIXELVAL));

	src = (char *) Raster.bitmap;
	dst = bitmap + (size - width);

	for (y = ymin; y < ymax; y++) {
		srcptr = src;
		dstptr = dst;

		for (x = xmin; x < xmax; x++) {
			if (pf->fontattr&MWTF_ANTIALIAS)
				*dstptr++ = gray_palette[(int) *srcptr];
			else {
				for(z=0;
				    z <= ((xmax-x-1) < 7 ? (xmax-x-1) : 7);
				    z++) {
					*dstptr++ = ((*srcptr << z) & 0x80)?
						gr_foreground: gr_background;
				}
				x += 7;
			}

			srcptr++;
		}

		src += Raster.cols;
		dst -= width;
	}

	/* FIXME - must clear background upstairs if not gr_usebg*/
	/* FIXME: GdArea problem if fg == bg*/
	/*save = gr_background;*/
	/*gr_background = gr_foreground + 1;*/

	/* Now draw the bitmap ... */
	GdArea(psd, x_offset + xmin, y_offset - (ymin + height), width, height,
		bitmap, MWPF_PIXELVAL);

	/*gr_background = save;*/

	free (bitmap);
	free (Raster.bitmap);
}

/*
 * Draw unicode 16 text string using FREETYPE type font
 */
static void
freetype_drawtext(PMWFONT pfont, PSD psd, MWCOORD ax, MWCOORD ay,
	const void *text, int cc, MWTEXTFLAGS flags)
{
	PMWFREETYPEFONT	pf = (PMWFREETYPEFONT)pfont;
	const unsigned short *	str = text;
	TT_F26Dot6 	x = ax, y = ay;
	TT_Pos 		vec_x, vec_y;
	int 		i;
	TT_F26Dot6	startx, starty;
	TT_Outline 	outline;
	TT_UShort 	curchar;
	TT_Glyph_Metrics metrics;
	TT_Face_Properties properties;
	TT_Instance_Metrics imetrics;
	TT_F26Dot6 ascent, descent;
	static unsigned char blend[5] = { 0x00, 0x44, 0x88, 0xcc, 0xff };
	static unsigned char virtual_palette[5] = { 0, 1, 2, 3, 4 };

	pf->last_glyph_code = -1;		/* reset kerning*/
	pf->last_pen_pos = -32767;

	/* 
	 * Compute instance ascent & descent values
	 * in fractional units (1/64th pixel)
	 */
	TT_Get_Face_Properties (pf->face, &properties);
	TT_Get_Instance_Metrics(pf->instance, &imetrics);	
  
	ascent = ((properties.horizontal->Ascender * imetrics.y_scale)/0x10000);
	descent = ((properties.horizontal->Descender*imetrics.y_scale)/0x10000);

	/* 
	 * Offset the starting point if necessary,
	 * FreeType always aligns at baseline
	 */
	if (flags&MWTF_BOTTOM) {
		vec_x = 0;
		vec_y = descent;
		TT_Transform_Vector(&vec_x, &vec_y,&pf->matrix);
		x -= vec_x / 64;
		y += vec_y / 64;
	} else if (flags&MWTF_TOP) {
		vec_x = 0;
		vec_y = ascent;
		TT_Transform_Vector(&vec_x, &vec_y,&pf->matrix);
		x -= vec_x / 64;
		y += vec_y / 64;
	}

	/* Set the "graylevels" */
	if (pf->fontattr&MWTF_ANTIALIAS) {
		TT_Set_Raster_Gray_Palette (engine, virtual_palette);

		alphablend(psd, gray_palette, gr_foreground, gr_background,
			blend, 5);
	}

	startx = x;
	starty = y;
	for (i = 0; i < cc; i++) {
		curchar = TT_Char_Index (pf->char_map, str[i]);

		if (TT_Load_Glyph (pf->instance, pf->glyph, curchar,
			TTLOAD_DEFAULT) != TT_Err_Ok)
				continue;

		if (pf->fontrotation) {
			TT_Get_Glyph_Outline (pf->glyph, &outline);
			TT_Transform_Outline (&outline, &pf->matrix);
		}

		TT_Get_Glyph_Metrics (pf->glyph, &metrics);

		if ((pf->fontattr&MWTF_KERNING) && pf->can_kern) {
			if (pf->fontrotation) {
				vec_x = compute_kernval(pf, curchar);
				vec_y = 0;
				TT_Transform_Vector(&vec_x, &vec_y,&pf->matrix);

				x += vec_x / 64;
				y -= vec_y / 64;
			} else
				x += compute_kernval(pf, curchar) / 64;
		}
			
		drawchar(pf, psd, pf->glyph, x, y);

		if (pf->fontrotation) {
			vec_x = metrics.advance;
			vec_y = 0;
			TT_Transform_Vector (&vec_x, &vec_y, &pf->matrix);

			x += vec_x / 64;
			y -= vec_y / 64;
		} else {
			x += metrics.advance / 64;