WebSVN – Kolibri OS – Diff – /contrib/network/netsurf/netsurf/css/utils.c


/*
 * Copyright 2004 James Bursa 
 * Copyright 2009 John-Mark Bell 
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf 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; version 2 of the License.
 *
 * NetSurf 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 this program.  If not, see .
 */
 
#include 
 
#include "css/utils.h"
 
#include "desktop/options.h"
#include "utils/log.h"
 
/** Screen DPI in fixed point units: defaults to 90, which RISC OS uses */
css_fixed nscss_screen_dpi = F_90;
 
/**
 * Convert an absolute CSS length to points.
 *
 * \param  length  Length to convert
 * \param  unit    Corresponding unit
 * \return	   length in points
 */
css_fixed nscss_len2pt(css_fixed length, css_unit unit)
{
	/* Length must not be relative */
	assert(unit != CSS_UNIT_EM && unit != CSS_UNIT_EX);
 
	switch (unit) {
	/* We assume the screen and any other output has the same dpi */
	/* 1in = DPIpx => 1px = (72/DPI)pt */
	case CSS_UNIT_PX: return FDIV(FMUL(length, F_72), nscss_screen_dpi);
	/* 1in = 72pt */
	case CSS_UNIT_IN: return FMUL(length, F_72);
	/* 1in = 2.54cm => 1cm = (72/2.54)pt */
	case CSS_UNIT_CM: return FMUL(length, 
				FDIV(F_72, FLTTOFIX(2.54)));
	/* 1in = 25.4mm => 1mm = (72/25.4)pt */
	case CSS_UNIT_MM: return FMUL(length, 
				      FDIV(F_72, FLTTOFIX(25.4)));
	case CSS_UNIT_PT: return length;
	/* 1pc = 12pt */
	case CSS_UNIT_PC: return FMUL(length, INTTOFIX(12));
	default: break;
	}
 
	return 0;
}
 
 
/**
 * Convert a CSS length to pixels.
 *
 * \param  length  Length to convert
 * \param  unit    Corresponding unit
 * \param  style   Computed style applying to length. May be NULL if unit is 
 *                 neither em nor ex
 * \return	   length in pixels
 */
css_fixed nscss_len2px(css_fixed length, css_unit unit, 
		const css_computed_style *style)
{
	/* We assume the screen and ay other output has the same dpi */
	css_fixed px_per_unit;
 
	assert(style != NULL || (unit != CSS_UNIT_EM && unit != CSS_UNIT_EX));
 
	switch (unit) {
	case CSS_UNIT_EM:
	case CSS_UNIT_EX:
	{
		css_fixed font_size = 0;
		css_unit font_unit = CSS_UNIT_PT;
 
		css_computed_font_size(style, &font_size, &font_unit);
 
		/* Convert to points */
		font_size = nscss_len2pt(font_size, font_unit);
 
		/* Clamp to configured minimum */
		if (font_size < FDIV(INTTOFIX(nsoption_int(font_min_size)), F_10)) {
		  font_size = FDIV(INTTOFIX(nsoption_int(font_min_size)), F_10);
		}
 
		/* Convert to pixels (manually, to maximise precision) 
		 * 1in = 72pt => 1pt = (DPI/72)px */
		px_per_unit = FDIV(FMUL(font_size, nscss_screen_dpi), F_72);
 
		/* Scale ex units: we use a fixed ratio of 1ex = 0.6em */
		if (unit == CSS_UNIT_EX)
			px_per_unit = FMUL(px_per_unit, FLTTOFIX(0.6));
	}
		break;
	case CSS_UNIT_PX: 
		px_per_unit = F_1;
		break;
	/* 1in = DPIpx */
	case CSS_UNIT_IN: 
		px_per_unit = nscss_screen_dpi;
		break;
	/* 1in = 2.54cm => 1cm = (DPI/2.54)px */
	case CSS_UNIT_CM: 
		px_per_unit = FDIV(nscss_screen_dpi, FLTTOFIX(2.54));
		break;
	/* 1in = 25.4mm => 1mm = (DPI/25.4)px */
	case CSS_UNIT_MM: 
		px_per_unit = FDIV(nscss_screen_dpi, FLTTOFIX(25.4));
		break;
	/* 1in = 72pt => 1pt = (DPI/72)px */
	case CSS_UNIT_PT: 
		px_per_unit = FDIV(nscss_screen_dpi, F_72);
		break;
	/* 1pc = 12pt => 1in = 6pc => 1pc = (DPI/6)px */
	case CSS_UNIT_PC: 
		px_per_unit = FDIV(nscss_screen_dpi, INTTOFIX(6));
		break;
	default:
		px_per_unit = 0;
		break;
	}
 
	/* Ensure we round px_per_unit to the nearest whole number of pixels:
	 * the use of FIXTOINT() below will truncate. */
	px_per_unit += F_0_5;
 
	/* Calculate total number of pixels */
	return FMUL(length, TRUNCATEFIX(px_per_unit));
}

Rev 4364	Rev 5043
1	/*	1	/*
2	* Copyright 2004 James Bursa	2	* Copyright 2004 James Bursa
3	* Copyright 2009 John-Mark Bell	3	* Copyright 2009 John-Mark Bell
4	*	4	*
5	* This file is part of NetSurf, http://www.netsurf-browser.org/	5	* This file is part of NetSurf, http://www.netsurf-browser.org/
6	*	6	*
7	* NetSurf is free software; you can redistribute it and/or modify	7	* NetSurf is free software; you can redistribute it and/or modify
8	* it under the terms of the GNU General Public License as published by	8	* it under the terms of the GNU General Public License as published by
9	* the Free Software Foundation; version 2 of the License.	9	* the Free Software Foundation; version 2 of the License.
10	*	10	*
11	* NetSurf is distributed in the hope that it will be useful,	11	* NetSurf is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.	14	* GNU General Public License for more details.
15	*	15	*
16	* You should have received a copy of the GNU General Public License	16	* You should have received a copy of the GNU General Public License
17	* along with this program. If not, see .	17	* along with this program. If not, see .
18	*/	18	*/
19		19
20	#include	20	#include
21		21
22	#include "css/utils.h"	22	#include "css/utils.h"
23		23
24	#include "desktop/options.h"	24	#include "desktop/options.h"
25	#include "utils/log.h"	25	#include "utils/log.h"
26		26
27	/** Screen DPI in fixed point units: defaults to 90, which RISC OS uses */	27	/** Screen DPI in fixed point units: defaults to 90, which RISC OS uses */
28	css_fixed nscss_screen_dpi = F_90;	28	css_fixed nscss_screen_dpi = F_90;
29		29
30	/**	30	/**
31	* Convert an absolute CSS length to points.	31	* Convert an absolute CSS length to points.
32	*	32	*
33	* \param length Length to convert	33	* \param length Length to convert
34	* \param unit Corresponding unit	34	* \param unit Corresponding unit
35	* \return length in points	35	* \return length in points
36	*/	36	*/
37	css_fixed nscss_len2pt(css_fixed length, css_unit unit)	37	css_fixed nscss_len2pt(css_fixed length, css_unit unit)
38	{	38	{
39	/* Length must not be relative */	39	/* Length must not be relative */
40	assert(unit != CSS_UNIT_EM && unit != CSS_UNIT_EX);	40	assert(unit != CSS_UNIT_EM && unit != CSS_UNIT_EX);
41		41
42	switch (unit) {	42	switch (unit) {
43	/* We assume the screen and any other output has the same dpi */	43	/* We assume the screen and any other output has the same dpi */
44	/* 1in = DPIpx => 1px = (72/DPI)pt */	44	/* 1in = DPIpx => 1px = (72/DPI)pt */
45	case CSS_UNIT_PX: return FDIV(FMUL(length, F_72), nscss_screen_dpi);	45	case CSS_UNIT_PX: return FDIV(FMUL(length, F_72), nscss_screen_dpi);
46	/* 1in = 72pt */	46	/* 1in = 72pt */
47	case CSS_UNIT_IN: return FMUL(length, F_72);	47	case CSS_UNIT_IN: return FMUL(length, F_72);
48	/* 1in = 2.54cm => 1cm = (72/2.54)pt */	48	/* 1in = 2.54cm => 1cm = (72/2.54)pt */
49	case CSS_UNIT_CM: return FMUL(length,	49	case CSS_UNIT_CM: return FMUL(length,
50	FDIV(F_72, FLTTOFIX(2.54)));	50	FDIV(F_72, FLTTOFIX(2.54)));
51	/* 1in = 25.4mm => 1mm = (72/25.4)pt */	51	/* 1in = 25.4mm => 1mm = (72/25.4)pt */
52	case CSS_UNIT_MM: return FMUL(length,	52	case CSS_UNIT_MM: return FMUL(length,
53	FDIV(F_72, FLTTOFIX(25.4)));	53	FDIV(F_72, FLTTOFIX(25.4)));
54	case CSS_UNIT_PT: return length;	54	case CSS_UNIT_PT: return length;
55	/* 1pc = 12pt */	55	/* 1pc = 12pt */
56	case CSS_UNIT_PC: return FMUL(length, INTTOFIX(12));	56	case CSS_UNIT_PC: return FMUL(length, INTTOFIX(12));
57	default: break;	57	default: break;
58	}	58	}
59		59
60	return 0;	60	return 0;
61	}	61	}
62		62
63		63
64	/**	64	/**
65	* Convert a CSS length to pixels.	65	* Convert a CSS length to pixels.
66	*	66	*
67	* \param length Length to convert	67	* \param length Length to convert
68	* \param unit Corresponding unit	68	* \param unit Corresponding unit
69	* \param style Computed style applying to length. May be NULL if unit is	69	* \param style Computed style applying to length. May be NULL if unit is
70	* neither em nor ex	70	* neither em nor ex
71	* \return length in pixels	71	* \return length in pixels
72	*/	72	*/
73	css_fixed nscss_len2px(css_fixed length, css_unit unit,	73	css_fixed nscss_len2px(css_fixed length, css_unit unit,
74	const css_computed_style *style)	74	const css_computed_style *style)
75	{	75	{
76	/* We assume the screen and any other output has the same dpi */	76	/* We assume the screen and ay other output has the same dpi */
77	css_fixed px_per_unit;	77	css_fixed px_per_unit;
78		78
79	assert(style != NULL \|\| (unit != CSS_UNIT_EM && unit != CSS_UNIT_EX));	79	assert(style != NULL \|\| (unit != CSS_UNIT_EM && unit != CSS_UNIT_EX));
80		80
81	switch (unit) {	81	switch (unit) {
82	case CSS_UNIT_EM:	82	case CSS_UNIT_EM:
83	case CSS_UNIT_EX:	83	case CSS_UNIT_EX:
84	{	84	{
85	css_fixed font_size = 0;	85	css_fixed font_size = 0;
86	css_unit font_unit = CSS_UNIT_PT;	86	css_unit font_unit = CSS_UNIT_PT;
87		87
88	css_computed_font_size(style, &font_size, &font_unit);	88	css_computed_font_size(style, &font_size, &font_unit);
89		89
90	/* Convert to points */	90	/* Convert to points */
91	font_size = nscss_len2pt(font_size, font_unit);	91	font_size = nscss_len2pt(font_size, font_unit);
92		92
93	/* Clamp to configured minimum */	93	/* Clamp to configured minimum */
94	if (font_size < FDIV(INTTOFIX(nsoption_int(font_min_size)), F_10)) {	94	if (font_size < FDIV(INTTOFIX(nsoption_int(font_min_size)), F_10)) {
95	font_size = FDIV(INTTOFIX(nsoption_int(font_min_size)), F_10);	95	font_size = FDIV(INTTOFIX(nsoption_int(font_min_size)), F_10);
96	}	96	}
97		97
98	/* Convert to pixels (manually, to maximise precision)	98	/* Convert to pixels (manually, to maximise precision)
99	* 1in = 72pt => 1pt = (DPI/72)px */	99	* 1in = 72pt => 1pt = (DPI/72)px */
100	px_per_unit = FDIV(FMUL(font_size, nscss_screen_dpi), F_72);	100	px_per_unit = FDIV(FMUL(font_size, nscss_screen_dpi), F_72);
101		101
102	/* Scale ex units: we use a fixed ratio of 1ex = 0.6em */	102	/* Scale ex units: we use a fixed ratio of 1ex = 0.6em */
103	if (unit == CSS_UNIT_EX)	103	if (unit == CSS_UNIT_EX)
104	px_per_unit = FMUL(px_per_unit, FLTTOFIX(0.6));	104	px_per_unit = FMUL(px_per_unit, FLTTOFIX(0.6));
105	}	105	}
106	break;	106	break;
107	case CSS_UNIT_PX:	107	case CSS_UNIT_PX:
108	px_per_unit = F_1;	108	px_per_unit = F_1;
109	break;	109	break;
110	/* 1in = DPIpx */	110	/* 1in = DPIpx */
111	case CSS_UNIT_IN:	111	case CSS_UNIT_IN:
112	px_per_unit = nscss_screen_dpi;	112	px_per_unit = nscss_screen_dpi;
113	break;	113	break;
114	/* 1in = 2.54cm => 1cm = (DPI/2.54)px */	114	/* 1in = 2.54cm => 1cm = (DPI/2.54)px */
115	case CSS_UNIT_CM:	115	case CSS_UNIT_CM:
116	px_per_unit = FDIV(nscss_screen_dpi, FLTTOFIX(2.54));	116	px_per_unit = FDIV(nscss_screen_dpi, FLTTOFIX(2.54));
117	break;	117	break;
118	/* 1in = 25.4mm => 1mm = (DPI/25.4)px */	118	/* 1in = 25.4mm => 1mm = (DPI/25.4)px */
119	case CSS_UNIT_MM:	119	case CSS_UNIT_MM:
120	px_per_unit = FDIV(nscss_screen_dpi, FLTTOFIX(25.4));	120	px_per_unit = FDIV(nscss_screen_dpi, FLTTOFIX(25.4));
121	break;	121	break;
122	/* 1in = 72pt => 1pt = (DPI/72)px */	122	/* 1in = 72pt => 1pt = (DPI/72)px */
123	case CSS_UNIT_PT:	123	case CSS_UNIT_PT:
124	px_per_unit = FDIV(nscss_screen_dpi, F_72);	124	px_per_unit = FDIV(nscss_screen_dpi, F_72);
125	break;	125	break;
126	/* 1pc = 12pt => 1in = 6pc => 1pc = (DPI/6)px */	126	/* 1pc = 12pt => 1in = 6pc => 1pc = (DPI/6)px */
127	case CSS_UNIT_PC:	127	case CSS_UNIT_PC:
128	px_per_unit = FDIV(nscss_screen_dpi, INTTOFIX(6));	128	px_per_unit = FDIV(nscss_screen_dpi, INTTOFIX(6));
129	break;	129	break;
130	default:	130	default:
131	px_per_unit = 0;	131	px_per_unit = 0;
132	break;	132	break;
133	}	133	}
134		134
135	/* Ensure we round px_per_unit to the nearest whole number of pixels:	135	/* Ensure we round px_per_unit to the nearest whole number of pixels:
136	* the use of FIXTOINT() below will truncate. */	136	* the use of FIXTOINT() below will truncate. */
137	px_per_unit += F_0_5;	137	px_per_unit += F_0_5;
138		138
139	/* Calculate total number of pixels */	139	/* Calculate total number of pixels */
140	return FMUL(length, TRUNCATEFIX(px_per_unit));	140	return FMUL(length, TRUNCATEFIX(px_per_unit));
141	}	141	}

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(root)/contrib/network/netsurf/netsurf/css/utils.c – Rev 4364 → 5043