Switch to new libcss API for unit conversion.

6 files changed, 21 insertions, 447 deletions

diff --git a/content/handlers/css/Makefile b/content/handlers/css/Makefile
index bbfc8d7b4..d5cf16647 100644
--- a/content/handlers/css/Makefile
+++ b/content/handlers/css/Makefile
@@ -1,4 +1,4 @@
 # CSS sources
 
-S_CSS := css.c dump.c internal.c hints.c select.c utils.c
+S_CSS := css.c dump.c internal.c hints.c select.c
 
diff --git a/content/handlers/css/css.c b/content/handlers/css/css.c
index be945fb97..f9197ddfe 100644
--- a/content/handlers/css/css.c
+++ b/content/handlers/css/css.c
@@ -40,6 +40,9 @@
 /* Define to trace import fetches */
 #undef NSCSS_IMPORT_TRACE
 
+/** Screen DPI in fixed point units: defaults to 90, which RISC OS uses */
+css_fixed nscss_screen_dpi = F_90;
+
 struct content_css_data;
 
 /**
diff --git a/content/handlers/css/select.c b/content/handlers/css/select.c
index cfefb2a08..6dc1d9b6f 100644
--- a/content/handlers/css/select.c
+++ b/content/handlers/css/select.c
@@ -91,10 +91,6 @@ static css_error set_libcss_node_data(void *pw, void *node,
 static css_error get_libcss_node_data(void *pw, void *node,
 		void **libcss_node_data);
 
-static css_error nscss_compute_font_size(void *pw, const css_hint *parent,
-		css_hint *size);
-
-
 /**
  * Selection callback table for libcss
  */
@@ -135,9 +131,8 @@ static css_select_handler selection_handler = {
 	node_is_lang,
 	node_presentational_hint,
 	ua_default_for_property,
-	nscss_compute_font_size,
 	set_libcss_node_data,
-	get_libcss_node_data
+	get_libcss_node_data,
 };
 
 /**
@@ -250,12 +245,15 @@ static void nscss_dom_user_data_handler(dom_node_operation operation,
  * \param ctx             CSS selection context
  * \param n               Element to select for
  * \param media           Permitted media types
+ * \param unit_unit_len_ctx    Unit length conversion context
  * \param inline_style    Inline style associated with element, or NULL
  * \return Pointer to selection results (containing computed styles),
  *         or NULL on failure
  */
 css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
-		const css_media *media, const css_stylesheet *inline_style)
+		const css_media *media,
+		const css_unit_ctx *unit_len_ctx,
+		const css_stylesheet *inline_style)
 {
 	css_computed_style *composed;
 	css_select_results *styles;
@@ -263,7 +261,7 @@ css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
 	css_error error;
 
 	/* Select style for node */
-	error = css_select_style(ctx->ctx, n, media, inline_style,
+	error = css_select_style(ctx->ctx, n, unit_len_ctx, media, inline_style,
 			&selection_handler, ctx, &styles);
 
 	if (error != CSS_OK || styles == NULL) {
@@ -278,8 +276,7 @@ css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
 		 * element's style */
 		error = css_computed_style_compose(ctx->parent_style,
 				styles->styles[CSS_PSEUDO_ELEMENT_NONE],
-				nscss_compute_font_size, ctx,
-				&composed);
+				unit_len_ctx, &composed);
 		if (error != CSS_OK) {
 			css_select_results_destroy(styles);
 			return NULL;
@@ -310,8 +307,7 @@ css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
 		error = css_computed_style_compose(
 				styles->styles[CSS_PSEUDO_ELEMENT_NONE],
 				styles->styles[pseudo_element],
-				nscss_compute_font_size, ctx,
-				&composed);
+				unit_len_ctx, &composed);
 		if (error != CSS_OK) {
 			/* TODO: perhaps this shouldn't be quite so
 			 * catastrophic? */
@@ -330,11 +326,13 @@ css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
 /**
  * Get a blank style
  *
- * \param ctx     CSS selection context
- * \param parent  Parent style to cascade inherited properties from
+ * \param ctx           CSS selection context
+ * \param unit_unit_len_ctx  Unit length conversion context
+ * \param parent        Parent style to cascade inherited properties from
  * \return Pointer to blank style, or NULL on failure
  */
 css_computed_style *nscss_get_blank_style(nscss_select_ctx *ctx,
+		const css_unit_ctx *unit_len_ctx,
 		const css_computed_style *parent)
 {
 	css_computed_style *partial, *composed;
@@ -349,7 +347,7 @@ css_computed_style *nscss_get_blank_style(nscss_select_ctx *ctx,
 	/* TODO: Do we really need to compose?  Initial style shouldn't
 	 * have any inherited properties. */
 	error = css_computed_style_compose(parent, partial,
-			nscss_compute_font_size, ctx, &composed);
+			unit_len_ctx, &composed);
 	css_computed_style_destroy(partial);
 	if (error != CSS_OK) {
 		css_computed_style_destroy(composed);
@@ -359,115 +357,6 @@ css_computed_style *nscss_get_blank_style(nscss_select_ctx *ctx,
 	return composed;
 }
 
-/**
- * Font size computation callback for libcss
- *
- * \param pw      Computation context
- * \param parent  Parent font size (absolute)
- * \param size    Font size to compute
- * \return CSS_OK on success
- *
- * \post \a size will be an absolute font size
- */
-css_error nscss_compute_font_size(void *pw, const css_hint *parent,
-		css_hint *size)
-{
-	/**
-	 * Table of font-size keyword scale factors
-	 *
-	 * These are multiplied by the configured default font size
-	 * to produce an absolute size for the relevant keyword
-	 */
-	static const css_fixed factors[] = {
-		FLTTOFIX(0.5625), /* xx-small */
-		FLTTOFIX(0.6250), /* x-small */
-		FLTTOFIX(0.8125), /* small */
-		FLTTOFIX(1.0000), /* medium */
-		FLTTOFIX(1.1250), /* large */
-		FLTTOFIX(1.5000), /* x-large */
-		FLTTOFIX(2.0000)  /* xx-large */
-	};
-	css_hint_length parent_size;
-
-	/* Grab parent size, defaulting to medium if none */
-	if (parent == NULL) {
-		parent_size.value = FDIV(FMUL(factors[CSS_FONT_SIZE_MEDIUM - 1],
-				INTTOFIX(nsoption_int(font_size))),
-				INTTOFIX(10));
-		parent_size.unit = CSS_UNIT_PT;
-	} else {
-		assert(parent->status == CSS_FONT_SIZE_DIMENSION);
-		assert(parent->data.length.unit != CSS_UNIT_EM);
-		assert(parent->data.length.unit != CSS_UNIT_EX);
-		assert(parent->data.length.unit != CSS_UNIT_PCT);
-
-		parent_size = parent->data.length;
-	}
-
-	assert(size->status != CSS_FONT_SIZE_INHERIT);
-
-	if (size->status < CSS_FONT_SIZE_LARGER) {
-		/* Keyword -- simple */
-		size->data.length.value = FDIV(FMUL(factors[size->status - 1],
-				INTTOFIX(nsoption_int(font_size))), F_10);
-		size->data.length.unit = CSS_UNIT_PT;
-	} else if (size->status == CSS_FONT_SIZE_LARGER) {
-		/** \todo Step within table, if appropriate */
-		size->data.length.value =
-				FMUL(parent_size.value, FLTTOFIX(1.2));
-		size->data.length.unit = parent_size.unit;
-	} else if (size->status == CSS_FONT_SIZE_SMALLER) {
-		/** \todo Step within table, if appropriate */
-		size->data.length.value =
-				FDIV(parent_size.value, FLTTOFIX(1.2));
-		size->data.length.unit = parent_size.unit;
-	} else if (size->data.length.unit == CSS_UNIT_EM ||
-			size->data.length.unit == CSS_UNIT_EX ||
-			size->data.length.unit == CSS_UNIT_CH) {
-		size->data.length.value =
-			FMUL(size->data.length.value, parent_size.value);
-
-		switch (size->data.length.unit) {
-		case CSS_UNIT_EX:
-			/* 1ex = 0.6em in NetSurf */
-			size->data.length.value = FMUL(size->data.length.value,
-					FLTTOFIX(0.6));
-			break;
-		case CSS_UNIT_CH:
-			/* Width of '0'.  1ch = 0.4em in NetSurf. */
-			size->data.length.value = FMUL(size->data.length.value,
-					FLTTOFIX(0.4));
-			break;
-		default:
-			/* No scaling required for EM. */
-			break;
-		}
-
-		size->data.length.unit = parent_size.unit;
-	} else if (size->data.length.unit == CSS_UNIT_PCT) {
-		size->data.length.value = FDIV(FMUL(size->data.length.value,
-				parent_size.value), INTTOFIX(100));
-		size->data.length.unit = parent_size.unit;
-	} else if (size->data.length.unit == CSS_UNIT_REM) {
-		nscss_select_ctx *ctx = pw;
-		if (parent == NULL) {
-			size->data.length.value = parent_size.value;
-			size->data.length.unit = parent_size.unit;
-		} else {
-			css_computed_font_size(ctx->root_style,
-					&parent_size.value,
-					&size->data.length.unit);
-			size->data.length.value = FMUL(
-					size->data.length.value,
-					parent_size.value);
-		}
-	}
-
-	size->status = CSS_FONT_SIZE_DIMENSION;
-
-	return CSS_OK;
-}
-
 /******************************************************************************
  * Style selection callbacks                                                  *
  ******************************************************************************/
diff --git a/content/handlers/css/select.h b/content/handlers/css/select.h
index b45d1ed3c..c17caadcb 100644
--- a/content/handlers/css/select.h
+++ b/content/handlers/css/select.h
@@ -45,9 +45,12 @@ css_stylesheet *nscss_create_inline_style(const uint8_t *data, size_t len,
 		const char *charset, const char *url, bool allow_quirks);
 
 css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
-		const css_media *media, const css_stylesheet *inline_style);
+		const css_media *media,
+		const css_unit_ctx *unit_len_ctx,
+		const css_stylesheet *inline_style);
 
 css_computed_style *nscss_get_blank_style(nscss_select_ctx *ctx,
+		const css_unit_ctx *unit_len_ctx,
 		const css_computed_style *parent);
 
 
diff --git a/content/handlers/css/utils.c b/content/handlers/css/utils.c
deleted file mode 100644
index 24ba44387..000000000
--- a/content/handlers/css/utils.c
+++ /dev/null
@@ -1,242 +0,0 @@
-/*
- * Copyright 2004 James Bursa <james@netsurf-browser.org>
- * Copyright 2009 John-Mark Bell <jmb@netsurf-browser.org>
- *
- * 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 <http://www.gnu.org/licenses/>.
- */
-
-#include <assert.h>
-
-#include "utils/nsoption.h"
-#include "utils/log.h"
-
-#include "css/utils.h"
-
-/** Screen DPI in fixed point units: defaults to 90, which RISC OS uses */
-css_fixed nscss_screen_dpi = F_90;
-
-/** Medium screen density for device viewing distance. */
-css_fixed nscss_baseline_pixel_density = F_96;
-
-/**
- * Map viewport-relative length units to either vh or vw.
- *
- * Non-viewport-relative units are unchanged.
- *
- * \param[in] ctx   Length conversion context.
- * \param[in] unit  Unit to map.
- * \return the mapped unit.
- */
-static inline css_unit css_utils__fudge_viewport_units(
-		const nscss_len_ctx *ctx,
-		css_unit unit)
-{
-	switch (unit) {
-	case CSS_UNIT_VI:
-		assert(ctx->root_style != NULL);
-		if (css_computed_writing_mode(ctx->root_style) ==
-				CSS_WRITING_MODE_HORIZONTAL_TB) {
-			unit = CSS_UNIT_VW;
-		} else {
-			unit = CSS_UNIT_VH;
-		}
-		break;
-	case CSS_UNIT_VB:
-		assert(ctx->root_style != NULL);
-		if (css_computed_writing_mode(ctx->root_style) ==
-				CSS_WRITING_MODE_HORIZONTAL_TB) {
-			unit = CSS_UNIT_VH;
-		} else {
-			unit = CSS_UNIT_VW;
-		}
-		break;
-	case CSS_UNIT_VMIN:
-		if (ctx->vh < ctx->vw) {
-			unit = CSS_UNIT_VH;
-		} else {
-			unit = CSS_UNIT_VW;
-		}
-		break;
-	case CSS_UNIT_VMAX:
-		if (ctx->vh > ctx->vw) {
-			unit = CSS_UNIT_VH;
-		} else {
-			unit = CSS_UNIT_VW;
-		}
-		break;
-	default: break;
-	}
-
-	return unit;
-}
-
-/* exported interface documented in content/handlers/css/utils.h */
-css_fixed nscss_len2pt(
-		const nscss_len_ctx *ctx,
-		css_fixed length,
-		css_unit unit)
-{
-	/* Length must not be relative */
-	assert(unit != CSS_UNIT_EM &&
-			unit != CSS_UNIT_EX &&
-			unit != CSS_UNIT_CH &&
-			unit != CSS_UNIT_REM);
-
-	unit = css_utils__fudge_viewport_units(ctx, unit);
-
-	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), F_96);
-	/* 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)));
-	/* 1in = 101.6q => 1mm = (72/101.6)pt */
-	case CSS_UNIT_Q: return FMUL(length,
-				      FDIV(F_72, FLTTOFIX(101.6)));
-	case CSS_UNIT_PT: return length;
-	/* 1pc = 12pt */
-	case CSS_UNIT_PC: return FMUL(length, INTTOFIX(12));
-	case CSS_UNIT_VH: return FDIV(FMUL(FDIV(FMUL(length, ctx->vh), F_100), F_72), F_96);
-	case CSS_UNIT_VW: return FDIV(FMUL(FDIV(FMUL(length,ctx->vw), F_100), F_72), F_96);
-	default: break;
-	}
-
-	return 0;
-}
-
-/* exported interface documented in content/handlers/css/utils.h */
-css_fixed nscss_len2px(
-		const nscss_len_ctx *ctx,
-		css_fixed length,
-		css_unit unit,
-		const css_computed_style *style)
-{
-	/* We assume the screen and any other output has the same dpi */
-	css_fixed px_per_unit;
-
-	unit = css_utils__fudge_viewport_units(ctx, unit);
-
-	switch (unit) {
-	case CSS_UNIT_EM:
-	case CSS_UNIT_EX:
-	case CSS_UNIT_CH:
-	{
-		css_fixed font_size = 0;
-		css_unit font_unit = CSS_UNIT_PT;
-
-		assert(style != NULL);
-
-		css_computed_font_size(style, &font_size, &font_unit);
-
-		/* Convert to points */
-		font_size = nscss_len2pt(ctx, 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, F_96), F_72);
-
-		/* Scale non-em units to em.  We have fixed ratios. */
-		switch (unit) {
-		case CSS_UNIT_EX:
-			px_per_unit = FMUL(px_per_unit, FLTTOFIX(0.6));
-			break;
-		case CSS_UNIT_CH:
-			px_per_unit = FMUL(px_per_unit, FLTTOFIX(0.4));
-			break;
-		default: break;
-		}
-	}
-		break;
-	case CSS_UNIT_PX:
-		px_per_unit = F_1;
-		break;
-	/* 1in = 96 CSS pixels */
-	case CSS_UNIT_IN:
-		px_per_unit = F_96;
-		break;
-	/* 1in = 2.54cm => 1cm = (DPI/2.54)px */
-	case CSS_UNIT_CM:
-		px_per_unit = FDIV(F_96, FLTTOFIX(2.54));
-		break;
-	/* 1in = 25.4mm => 1mm = (DPI/25.4)px */
-	case CSS_UNIT_MM:
-		px_per_unit = FDIV(F_96, FLTTOFIX(25.4));
-		break;
-	/* 1in = 101.6q => 1q = (DPI/101.6)px */
-	case CSS_UNIT_Q:
-		px_per_unit = FDIV(F_96, FLTTOFIX(101.6));
-		break;
-	/* 1in = 72pt => 1pt = (DPI/72)px */
-	case CSS_UNIT_PT:
-		px_per_unit = FDIV(F_96, F_72);
-		break;
-	/* 1pc = 12pt => 1in = 6pc => 1pc = (DPI/6)px */
-	case CSS_UNIT_PC:
-		px_per_unit = FDIV(F_96, INTTOFIX(6));
-		break;
-	case CSS_UNIT_REM:
-	{
-		css_fixed font_size = 0;
-		css_unit font_unit = CSS_UNIT_PT;
-
-		assert(ctx->root_style != NULL);
-
-		css_computed_font_size(ctx->root_style,
-				&font_size, &font_unit);
-
-		/* Convert to points */
-		font_size = nscss_len2pt(ctx, 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, F_96), F_72);
-		break;
-	}
-	case CSS_UNIT_VH:
-		px_per_unit = FDIV(ctx->vh, F_100);
-		break;
-	case CSS_UNIT_VW:
-		px_per_unit = FDIV(ctx->vw, F_100);
-		break;
-	default:
-		px_per_unit = 0;
-		break;
-	}
-
-	px_per_unit = nscss_pixels_css_to_physical(px_per_unit);
-
-	/* 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));
-}
diff --git a/content/handlers/css/utils.h b/content/handlers/css/utils.h
index e35a6605b..541677a3a 100644
--- a/content/handlers/css/utils.h
+++ b/content/handlers/css/utils.h
@@ -26,85 +26,6 @@
 /** DPI of the screen, in fixed point units */
 extern css_fixed nscss_screen_dpi;
 
-/** Medium screen density for device viewing distance. */
-extern css_fixed nscss_baseline_pixel_density;
-
-/**
- * Length conversion context data.
- */
-typedef struct nscss_len_ctx {
-	/**
-	 * Viewport width in px.
-	 * Only used if unit is vh, vw, vi, vb, vmin, or vmax.
-	 */
-	int vw;
-	/**
-	 * Viewport height in px.
-	 * Only used if unit is vh, vw, vi, vb, vmin, or vmax.
-	 */
-	int vh;
-	/**
-	 * Computed style for the document root element.
-	 * May be NULL if unit is not rem, or rlh.
-	 */
-	const css_computed_style *root_style;
-} nscss_len_ctx;
-
-/**
- * Convert an absolute CSS length to points.
- *
- * \param[in] ctx     Length conversion context.
- * \param[in] length  Absolute CSS length.
- * \param[in] unit    Unit of the length.
- * \return length in points
- */
-css_fixed nscss_len2pt(
-		const nscss_len_ctx *ctx,
-		css_fixed length,
-		css_unit unit);
-
-/**
- * Convert a CSS length to pixels.
- *
- * \param[in] ctx     Length conversion context.
- * \param[in] length  Length to convert.
- * \param[in] unit    Corresponding unit.
- * \param[in] style   Computed style applying to length.
- *                    May be NULL if unit is not em, ex, cap, ch, or ic.
- * \return length in pixels
- */
-css_fixed nscss_len2px(
-		const nscss_len_ctx *ctx,
-		css_fixed length,
-		css_unit unit,
-		const css_computed_style *style);
-
-/**
- * Convert css pixels to physical pixels.
- *
- * \param[in] css_pixels  Length in css pixels.
- * \return length in physical pixels
- */
-static inline css_fixed nscss_pixels_css_to_physical(
-		css_fixed css_pixels)
-{
-	return FDIV(FMUL(css_pixels, nscss_screen_dpi),
-			nscss_baseline_pixel_density);
-}
-
-/**
- * Convert physical pixels to css pixels.
- *
- * \param[in] physical_pixels  Length in physical pixels.
- * \return length in css pixels
- */
-static inline css_fixed nscss_pixels_physical_to_css(
-		css_fixed physical_pixels)
-{
-	return FDIV(FMUL(physical_pixels, nscss_baseline_pixel_density),
-			nscss_screen_dpi);
-}
-
 /**
  * Temporary helper wrappers for for libcss computed style getter, while
  * we don't support flexbox related property values.