cairo-atsui-font.c

按照官方的说法：Cairo is a vector graphics library with cross-device output support. 翻译过来

/* cairo - a vector graphics library with display and print output
 *
 * Copyright © 2004 Calum Robinson
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 *
 * The Original Code is the cairo graphics library.
 *
 * The Initial Developer of the Original Code is Calum Robinson
 *
 * Contributor(s):
 *  Calum Robinson <[e-mail]>
 */

#include <stdlib.h>
#include <math.h>
#include "cairo-atsui.h"
#include "cairoint.h"
#include "cairo.h"
#include "cairo-quartz-private.h"

/*
 * FixedToFloat/FloatToFixed are 10.3+ SDK items - include definitions
 * here so we can use older SDKs.
 */
#ifndef FixedToFloat
#define fixed1              ((Fixed) 0x00010000L)
#define FixedToFloat(a)     ((float)(a) / fixed1)
#define FloatToFixed(a)     ((Fixed)((float)(a) * fixed1))
#endif

/* If this isn't defined, we must be building on non-intel,
 * hence it will be 0.
 */
#ifndef kCGBitmapByteOrder32Host
#define kCGBitmapByteOrder32Host 0
#endif

typedef struct _cairo_atsui_font_face cairo_atsui_font_face_t;
typedef struct _cairo_atsui_font cairo_atsui_font_t;

static cairo_status_t _cairo_atsui_font_create_scaled (cairo_font_face_t *font_face,
						       ATSUFontID font_id,
						       ATSUStyle style,
						       const cairo_matrix_t *font_matrix,
						       const cairo_matrix_t *ctm,
						       const cairo_font_options_t *options,
						       cairo_scaled_font_t **font_out);

struct _cairo_atsui_font {
    cairo_scaled_font_t base;

    ATSUStyle style;
    ATSUStyle unscaled_style;
    ATSUFontID fontID;
};

struct _cairo_atsui_font_face {
  cairo_font_face_t base;
  ATSUFontID font_id;
};

static void
_cairo_atsui_font_face_destroy (void *abstract_face)
{
}

static cairo_status_t
_cairo_atsui_font_face_scaled_font_create (void	*abstract_face,
					   const cairo_matrix_t	*font_matrix,
					   const cairo_matrix_t	*ctm,
					   const cairo_font_options_t *options,
					   cairo_scaled_font_t **font)
{
    cairo_atsui_font_face_t *font_face = abstract_face;
    OSStatus err;
    ATSUAttributeTag styleTags[] = { kATSUFontTag };
    ATSUAttributeValuePtr styleValues[] = { &font_face->font_id };
    ByteCount styleSizes[] = {  sizeof(ATSUFontID) };
    ATSUStyle style;

    err = ATSUCreateStyle (&style);
    err = ATSUSetAttributes(style,
                            sizeof(styleTags) / sizeof(styleTags[0]),
                            styleTags, styleSizes, styleValues);

    return _cairo_atsui_font_create_scaled (&font_face->base, font_face->font_id, style,
					    font_matrix, ctm, options, font);
}

static const cairo_font_face_backend_t _cairo_atsui_font_face_backend = {
    CAIRO_FONT_TYPE_ATSUI,
    _cairo_atsui_font_face_destroy,
    _cairo_atsui_font_face_scaled_font_create
};

cairo_font_face_t *
cairo_atsui_font_face_create_for_atsu_font_id (ATSUFontID font_id)
{
  cairo_atsui_font_face_t *font_face;

  font_face = malloc (sizeof (cairo_atsui_font_face_t));
  if (!font_face) {
    _cairo_error (CAIRO_STATUS_NO_MEMORY);
    return (cairo_font_face_t *)&_cairo_font_face_nil;
  }

  font_face->font_id = font_id;

    _cairo_font_face_init (&font_face->base, &_cairo_atsui_font_face_backend);

    return &font_face->base;
}

static CGAffineTransform
CGAffineTransformMakeWithCairoFontScale(const cairo_matrix_t *scale)
{
    return CGAffineTransformMake(scale->xx, scale->yx,
                                 scale->xy, scale->yy,
                                 0, 0);
}

static ATSUStyle
CreateSizedCopyOfStyle(ATSUStyle inStyle, const cairo_matrix_t *scale)
{
    ATSUStyle style;
    OSStatus err;

    /* Set the style's size */
    CGAffineTransform theTransform =
        CGAffineTransformMakeWithCairoFontScale(scale);
    Fixed theSize =
        FloatToFixed(CGSizeApplyAffineTransform
                     (CGSizeMake(1.0, 1.0), theTransform).height);
    const ATSUAttributeTag theFontStyleTags[] = { kATSUSizeTag };
    const ByteCount theFontStyleSizes[] = { sizeof(Fixed) };
    ATSUAttributeValuePtr theFontStyleValues[] = { &theSize };

    err = ATSUCreateAndCopyStyle(inStyle, &style);

    err = ATSUSetAttributes(style,
                            sizeof(theFontStyleTags) /
                            sizeof(ATSUAttributeTag), theFontStyleTags,
                            theFontStyleSizes, theFontStyleValues);

    return style;
}

static cairo_status_t
_cairo_atsui_font_set_metrics (cairo_atsui_font_t *font)
{
    ATSFontRef atsFont;
    ATSFontMetrics metrics;
    OSStatus err;

    atsFont = FMGetATSFontRefFromFont(font->fontID);

    if (atsFont) {
        err =
            ATSFontGetHorizontalMetrics(atsFont, kATSOptionFlagsDefault,
                                        &metrics);

        if (err == noErr) {
	    	cairo_font_extents_t extents;

            extents.ascent = metrics.ascent;
            extents.descent = -metrics.descent;
            extents.height = metrics.capHeight;
            extents.max_x_advance = metrics.maxAdvanceWidth;

            /* The FT backend doesn't handle max_y_advance either, so we'll ignore it for now. */
            extents.max_y_advance = 0.0;

	    	_cairo_scaled_font_set_metrics (&font->base, &extents);

            return CAIRO_STATUS_SUCCESS;
        }
    }

    return CAIRO_STATUS_NULL_POINTER;
}

static cairo_status_t
_cairo_atsui_font_create_scaled (cairo_font_face_t *font_face,
				 ATSUFontID font_id,
				 ATSUStyle style,
				 const cairo_matrix_t *font_matrix,
				 const cairo_matrix_t *ctm,
				 const cairo_font_options_t *options,
				 cairo_scaled_font_t **font_out)
{
    cairo_atsui_font_t *font = NULL;
    OSStatus err;
    cairo_status_t status;

    font = malloc(sizeof(cairo_atsui_font_t));
    if (font == NULL)
	return CAIRO_STATUS_NO_MEMORY;

    _cairo_scaled_font_init(&font->base, font_face, font_matrix, ctm, options,
			    &cairo_atsui_scaled_font_backend);

    font->style = CreateSizedCopyOfStyle(style, &font->base.scale);

    Fixed theSize = FloatToFixed(1.0);
    const ATSUAttributeTag theFontStyleTags[] = { kATSUSizeTag };
    const ByteCount theFontStyleSizes[] = { sizeof(Fixed) };
    ATSUAttributeValuePtr theFontStyleValues[] = { &theSize };
    err = ATSUSetAttributes(style,
                            sizeof(theFontStyleTags) /
                            sizeof(ATSUAttributeTag), theFontStyleTags,
                            theFontStyleSizes, theFontStyleValues);

    font->unscaled_style = style;

    font->fontID = font_id;

    *font_out = &font->base;

    status = _cairo_atsui_font_set_metrics (font);
    if (status) {
	cairo_scaled_font_destroy (&font->base);
	return status;
    }

    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_atsui_font_create_toy(cairo_toy_font_face_t *toy_face,
			     const cairo_matrix_t *font_matrix,
			     const cairo_matrix_t *ctm,
			     const cairo_font_options_t *options,
			     cairo_scaled_font_t **font_out)
{
    ATSUStyle style;
    ATSUFontID fontID;
    OSStatus err;
    Boolean isItalic, isBold;
    const char *family = toy_face->family;

    err = ATSUCreateStyle(&style);

    switch (toy_face->weight) {
    case CAIRO_FONT_WEIGHT_BOLD:
        isBold = true;
        break;
    case CAIRO_FONT_WEIGHT_NORMAL:
    default:
        isBold = false;
        break;
    }

    switch (toy_face->slant) {
    case CAIRO_FONT_SLANT_ITALIC:
        isItalic = true;
        break;
    case CAIRO_FONT_SLANT_OBLIQUE:
        isItalic = false;
        break;
    case CAIRO_FONT_SLANT_NORMAL:
    default:
        isItalic = false;
        break;
    }

    err = ATSUFindFontFromName(family, strlen(family),
                               kFontFamilyName,
                               kFontNoPlatformCode,
                               kFontRomanScript,
                               kFontNoLanguageCode, &fontID);

    if (err != noErr) {
	/* couldn't get the font - remap css names and try again */

	if (!strcmp(family, "serif"))
	    family = "Times";
	else if (!strcmp(family, "sans-serif"))
	    family = "Helvetica";
	else if (!strcmp(family, "cursive"))
	    family = "Apple Chancery";
	else if (!strcmp(family, "fantasy"))
	    family = "Gadget";
	else if (!strcmp(family, "monospace"))
	    family = "Courier";
	else /* anything else - return error instead? */
	    family = "Courier";

	err = ATSUFindFontFromName(family, strlen(family),
				   kFontFamilyName,
				   kFontNoPlatformCode,
				   kFontRomanScript,
				   kFontNoLanguageCode, &fontID);
    }

    ATSUAttributeTag styleTags[] =
        { kATSUQDItalicTag, kATSUQDBoldfaceTag, kATSUFontTag };
    ATSUAttributeValuePtr styleValues[] = { &isItalic, &isBold, &fontID };
    ByteCount styleSizes[] =
        { sizeof(Boolean), sizeof(Boolean), sizeof(ATSUFontID) };

    err = ATSUSetAttributes(style,
                            sizeof(styleTags) / sizeof(styleTags[0]),
                            styleTags, styleSizes, styleValues);

    return _cairo_atsui_font_create_scaled (&toy_face->base, fontID, style,
					    font_matrix, ctm, options, font_out);
}

static void
_cairo_atsui_font_fini(void *abstract_font)
{
    cairo_atsui_font_t *font = abstract_font;

    if (font == NULL)
        return;

    if (font->style)
        ATSUDisposeStyle(font->style);
    if (font->unscaled_style)
        ATSUDisposeStyle(font->unscaled_style);
}

static cairo_status_t
_cairo_atsui_font_init_glyph_metrics (cairo_atsui_font_t *font,
				      cairo_scaled_glyph_t *scaled_glyph)
{
   cairo_text_extents_t extents;
   OSStatus err;
   GlyphID theGlyph = _cairo_scaled_glyph_index (scaled_glyph);
   ATSGlyphIdealMetrics metricsH, metricsV;
   ATSUStyle style;
   ATSUVerticalCharacterType verticalType = kATSUStronglyVertical;
   const ATSUAttributeTag theTag[] = { kATSUVerticalCharacterTag };
   const ByteCount theSizes[] = { sizeof(verticalType) };
   ATSUAttributeValuePtr theValues[] = { &verticalType };