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diff --git a/src/select/unit.c b/src/select/unit.c
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+/*
+ * This file is part of LibCSS
+ * Licensed under the MIT License,
+ * http://www.opensource.org/licenses/mit-license.php
+ *
+ * Copyright 2021 Michael Drake <tlsa@netsurf-browser.org>
+ */
+
+#include <libcss/stylesheet.h>
+
+#include "utils/utils.h"
+
+#include "propget.h"
+#include "unit.h"
+
+/**
+ * Map viewport-relative length units to either vh or vw.
+ *
+ * Non-viewport-relative units are unchanged.
+ *
+ * \param[in] style Reference style.
+ * \param[in] viewport_height Viewport height in px.
+ * \param[in] viewport_width Viewport width in px.
+ * \param[in] unit Unit to map.
+ * \return the mapped unit.
+ */
+static inline css_unit css_unit__map_viewport_units(
+ const css_computed_style *style,
+ const css_fixed viewport_height,
+ const css_fixed viewport_width,
+ const css_unit unit)
+{
+ switch (unit) {
+ case CSS_UNIT_VI:
+ return (style != NULL && get_writing_mode(style) !=
+ CSS_WRITING_MODE_HORIZONTAL_TB) ?
+ CSS_UNIT_VH : CSS_UNIT_VW;
+
+ case CSS_UNIT_VB:
+ return (style != NULL && get_writing_mode(style) !=
+ CSS_WRITING_MODE_HORIZONTAL_TB) ?
+ CSS_UNIT_VW : CSS_UNIT_VH;
+
+ case CSS_UNIT_VMIN:
+ return (viewport_height < viewport_width) ?
+ CSS_UNIT_VH : CSS_UNIT_VW;
+
+ case CSS_UNIT_VMAX:
+ return (viewport_height > viewport_width) ?
+ CSS_UNIT_VH : CSS_UNIT_VW;
+
+ default:
+ return unit;
+ }
+}
+
+/**
+ * Convert an absolute length to points (pt).
+ *
+ * \param[in] style Style to get font-size from, or NULL.
+ * \param[in] viewport_height Client viewport height.
+ * \param[in] viewport_width Client viewport width.
+ * \param[in] length Length to convert.
+ * \param[in] unit Current unit of length.
+ * \return length in points (pt).
+ */
+static inline css_fixed css_unit__absolute_len2pt(
+ const css_computed_style *style,
+ const css_fixed viewport_height,
+ const css_fixed viewport_width,
+ const css_fixed length,
+ const 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);
+
+ switch (css_unit__map_viewport_units(style,
+ viewport_height,
+ viewport_width,
+ unit)) {
+ case CSS_UNIT_PX:
+ return FDIV(FMUL(length, F_72), F_96);
+
+ case CSS_UNIT_IN:
+ return FMUL(length, F_72);
+
+ case CSS_UNIT_CM:
+ return FMUL(length, FDIV(F_72, FLTTOFIX(2.54)));
+
+ case CSS_UNIT_MM:
+ return FMUL(length, FDIV(F_72, FLTTOFIX(25.4)));
+
+ case CSS_UNIT_Q:
+ return FMUL(length, FDIV(F_72, FLTTOFIX(101.6)));
+
+ case CSS_UNIT_PT:
+ return length;
+
+ case CSS_UNIT_PC:
+ return FMUL(length, INTTOFIX(12));
+
+ case CSS_UNIT_VH:
+ return FDIV(FMUL(FDIV(FMUL(length, viewport_height), F_100),
+ F_72), F_96);
+
+ case CSS_UNIT_VW:
+ return FDIV(FMUL(FDIV(FMUL(length, viewport_width), F_100),
+ F_72), F_96);
+
+ default:
+ return 0;
+ }
+}
+
+/* Exported function, documented in unit.h. */
+css_fixed css_unit_font_size_len2pt(
+ const css_unit_len_ctx *ctx,
+ const css_fixed length,
+ const css_unit unit)
+{
+ return css_unit__absolute_len2pt(
+ ctx->ref_style,
+ ctx->viewport_height,
+ ctx->viewport_width,
+ length,
+ unit);
+}
+
+/**
+ * Get font size from a style in CSS pixels.
+ *
+ * The style should have font size in absolute units.
+ *
+ * \param[in] style Style to get font-size from, or NULL.
+ * \param[in] font_size_default Client font size for NULL style.
+ * \param[in] font_size_minimum Client minimum font size clamp.
+ * \param[in] viewport_height Client viewport height.
+ * \param[in] viewport_width Client viewport width.
+ * \return font-size in CSS pixels.
+ */
+static inline css_fixed css_unit__font_size_px(
+ const css_computed_style *style,
+ const css_fixed font_size_default,
+ const css_fixed font_size_minimum,
+ const css_fixed viewport_height,
+ const css_fixed viewport_width)
+{
+ css_fixed font_length = 0;
+ css_unit font_unit = CSS_UNIT_PT;
+
+ if (style == NULL) {
+ return font_size_default;
+ }
+
+ get_font_size(style, &font_length, &font_unit);
+
+ if (font_unit != CSS_UNIT_PX) {
+ font_length = css_unit__absolute_len2pt(style,
+ viewport_height,
+ viewport_width,
+ font_length,
+ font_unit);
+
+ /* Convert from pt to CSS pixels.*/
+ font_length = FDIV(FMUL(font_length, F_96), F_72);
+ }
+
+ /* Clamp to configured minimum */
+ if (font_length < font_size_minimum) {
+ font_length = font_size_minimum;
+ }
+
+ return font_length;
+}
+
+/**
+ * Get the number of CSS pixels for a given unit.
+ *
+ * \param[in] measure Client callback for font measuring.
+ * \param[in] ref_style Reference style. (Element or parent, or NULL).
+ * \param[in] root_style Root element style or NULL.
+ * \param[in] font_size_default Client default font size in CSS pixels.
+ * \param[in] font_size_minimum Client minimum font size in CSS pixels.
+ * \param[in] viewport_height Viewport height in CSS pixels.
+ * \param[in] viewport_width Viewport width in CSS pixels.
+ * \param[in] unit The unit to convert from.
+ * \param[in] pw Client private word for measure callback.
+ * \return Number of CSS pixels equivalent to the given unit.
+ */
+static inline css_fixed css_unit__px_per_unit(
+ const css_unit_len_measure measure,
+ const css_computed_style *ref_style,
+ const css_computed_style *root_style,
+ const css_fixed font_size_default,
+ const css_fixed font_size_minimum,
+ const css_fixed viewport_height,
+ const css_fixed viewport_width,
+ const css_unit unit,
+ void *pw)
+{
+ switch (css_unit__map_viewport_units(
+ ref_style,
+ viewport_height,
+ viewport_width,
+ unit)) {
+ case CSS_UNIT_EM:
+ return css_unit__font_size_px(
+ ref_style,
+ font_size_default,
+ font_size_minimum,
+ viewport_height,
+ viewport_width);
+
+ case CSS_UNIT_EX:
+ if (measure != NULL) {
+ return measure(pw, ref_style, CSS_UNIT_EX);
+ }
+ return FMUL(css_unit__font_size_px(
+ ref_style,
+ font_size_default,
+ font_size_minimum,
+ viewport_height,
+ viewport_width), FLTTOFIX(0.6));
+
+ case CSS_UNIT_CH:
+ if (measure != NULL) {
+ return measure(pw, ref_style, CSS_UNIT_CH);
+ }
+ return FMUL(css_unit__font_size_px(
+ ref_style,
+ font_size_default,
+ font_size_minimum,
+ viewport_height,
+ viewport_width), FLTTOFIX(0.4));
+
+ case CSS_UNIT_PX:
+ return F_1;
+
+ case CSS_UNIT_IN:
+ return F_96;
+
+ case CSS_UNIT_CM:
+ return FDIV(F_96, FLTTOFIX(2.54));
+
+ case CSS_UNIT_MM:
+ return FDIV(F_96, FLTTOFIX(25.4));
+
+ case CSS_UNIT_Q:
+ return FDIV(F_96, FLTTOFIX(101.6));
+
+ case CSS_UNIT_PT:
+ return FDIV(F_96, F_72);
+
+ case CSS_UNIT_PC:
+ return FDIV(F_96, INTTOFIX(6));
+
+ case CSS_UNIT_REM:
+ return css_unit__font_size_px(
+ root_style,
+ font_size_default,
+ font_size_minimum,
+ viewport_height,
+ viewport_width);
+
+ case CSS_UNIT_VH:
+ return FDIV(viewport_width, F_100);
+
+ case CSS_UNIT_VW:
+ return FDIV(viewport_height, F_100);
+
+ default:
+ return 0;
+ }
+}
+
+/* Exported function, documented in unit.h. */
+css_fixed css_unit_len2px_mq(
+ const css_media *media,
+ const css_fixed length,
+ const css_unit unit)
+{
+ /* In the media query context there is no reference or root element
+ * style, so these are hardcoded to NULL. */
+ css_fixed px_per_unit = css_unit__px_per_unit(
+ NULL,
+ NULL,
+ NULL,
+ media->client_font_size,
+ INTTOFIX(0),
+ media->height,
+ media->width,
+ unit,
+ NULL);
+
+ /* 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));
+}
+
+/* Exported function, documented in unit.h. */
+css_fixed css_unit_len2css_px(
+ const css_unit_len_ctx *ctx,
+ const css_fixed length,
+ const css_unit unit)
+{
+ css_fixed px_per_unit = css_unit__px_per_unit(
+ ctx->measure,
+ ctx->ref_style,
+ ctx->root_style,
+ ctx->font_size_default,
+ ctx->font_size_minimum,
+ ctx->viewport_height,
+ ctx->viewport_width,
+ unit,
+ ctx->pw);
+
+ /* 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));
+}
+
+/* Exported function, documented in unit.h. */
+css_fixed css_unit_len2device_px(
+ const css_unit_len_ctx *ctx,
+ const css_fixed length,
+ const css_unit unit)
+{
+ css_fixed px_per_unit = css_unit__px_per_unit(
+ ctx->measure,
+ ctx->ref_style,
+ ctx->root_style,
+ ctx->font_size_default,
+ ctx->font_size_minimum,
+ ctx->viewport_height,
+ ctx->viewport_width,
+ unit,
+ ctx->pw);
+
+ px_per_unit = css_unit_css2device_px(px_per_unit, ctx->device_dpi);
+
+ /* 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));
+}
+
+/**
+ * Get font size from a computed style.
+ *
+ * The computed style will have font-size with an absolute unit.
+ * If no computed style is given, the client default font-size will be returned.
+ *
+ * \param[in] ctx Length unit conversion context.
+ * \param[in] style The style to get the font-size for, or NULL.
+ * \return The font size in absolute units.
+ */
+static inline css_hint_length css_unit__get_font_size(
+ const css_unit_len_ctx *ctx,
+ const css_computed_style *style)
+{
+ css_hint_length size;
+
+ if (style == NULL) {
+ size.value = ctx->font_size_default;
+ size.unit = CSS_UNIT_PX;
+ } else {
+ enum css_font_size_e status = get_font_size(
+ style, &size.value, &size.unit);
+
+ UNUSED(status);
+
+ assert(status == CSS_FONT_SIZE_DIMENSION);
+ assert(size.unit != CSS_UNIT_EM);
+ assert(size.unit != CSS_UNIT_EX);
+ assert(size.unit != CSS_UNIT_PCT);
+ }
+
+ return size;
+}
+
+/* Exported function, documented in unit.h. */
+css_error css_unit_compute_absolute_font_size(
+ const css_unit_len_ctx *ctx,
+ css_hint *size)
+{
+ css_hint_length ref_len;
+
+ assert(size->status != CSS_FONT_SIZE_INHERIT);
+
+ switch (size->status) {
+ case CSS_FONT_SIZE_XX_SMALL: /* Fall-through. */
+ case CSS_FONT_SIZE_X_SMALL: /* Fall-through. */
+ case CSS_FONT_SIZE_SMALL: /* Fall-through. */
+ case CSS_FONT_SIZE_MEDIUM: /* Fall-through. */
+ case CSS_FONT_SIZE_LARGE: /* Fall-through. */
+ case CSS_FONT_SIZE_X_LARGE: /* Fall-through. */
+ case CSS_FONT_SIZE_XX_LARGE:
+ {
+ static const css_fixed factors[CSS_FONT_SIZE_XX_LARGE] = {
+ [CSS_FONT_SIZE_XX_SMALL - 1] = FLTTOFIX(0.5625),
+ [CSS_FONT_SIZE_X_SMALL - 1] = FLTTOFIX(0.6250),
+ [CSS_FONT_SIZE_SMALL - 1] = FLTTOFIX(0.8125),
+ [CSS_FONT_SIZE_MEDIUM - 1] = FLTTOFIX(1.0000),
+ [CSS_FONT_SIZE_LARGE - 1] = FLTTOFIX(1.1250),
+ [CSS_FONT_SIZE_X_LARGE - 1] = FLTTOFIX(1.5000),
+ [CSS_FONT_SIZE_XX_LARGE - 1] = FLTTOFIX(2.0000),
+ };
+ assert(CSS_FONT_SIZE_INHERIT == 0);
+ assert(CSS_FONT_SIZE_XX_SMALL == 1);
+
+ size->data.length.value = FMUL(factors[size->status - 1],
+ ctx->font_size_default);
+ size->data.length.unit = CSS_UNIT_PX;
+ size->status = CSS_FONT_SIZE_DIMENSION;
+ break;
+ }
+ case CSS_FONT_SIZE_LARGER:
+ ref_len = css_unit__get_font_size(ctx, ctx->ref_style);
+ size->data.length.value = FMUL(ref_len.value, FLTTOFIX(1.2));
+ size->data.length.unit = ref_len.unit;
+ size->status = CSS_FONT_SIZE_DIMENSION;
+ break;
+
+ case CSS_FONT_SIZE_SMALLER:
+ ref_len = css_unit__get_font_size(ctx, ctx->ref_style);
+ size->data.length.value = FDIV(ref_len.value, FLTTOFIX(1.2));
+ size->data.length.unit = ref_len.unit;
+ size->status = CSS_FONT_SIZE_DIMENSION;
+ break;
+
+ case CSS_FONT_SIZE_DIMENSION:
+ /* Convert any relative units to absolute. */
+ switch (size->data.length.unit) {
+ case CSS_UNIT_PCT:
+ ref_len = css_unit__get_font_size(ctx, ctx->ref_style);
+ size->data.length.value = FDIV(
+ FMUL(size->data.length.value,
+ ref_len.value), INTTOFIX(100));
+ size->data.length.unit = ref_len.unit;
+ break;
+
+ case CSS_UNIT_EM: /* Fall-through */
+ case CSS_UNIT_EX: /* Fall-through */
+ case CSS_UNIT_CH:
+ /* Parent relative units. */
+ ref_len = css_unit__get_font_size(ctx, ctx->ref_style);
+
+ size->data.length.unit = ref_len.unit;
+ size->data.length.value = FMUL(size->data.length.value,
+ ref_len.value);
+
+ switch (size->data.length.unit) {
+ case CSS_UNIT_EX:
+ size->data.length.value = FMUL(
+ size->data.length.value,
+ FLTTOFIX(0.6));
+ break;
+
+ case CSS_UNIT_CH:
+ size->data.length.value = FMUL(
+ size->data.length.value,
+ FLTTOFIX(0.4));
+ break;
+
+ default:
+ break;
+ }
+ break;
+
+ case CSS_UNIT_REM:
+ /* Root element relative units. */
+ ref_len = css_unit__get_font_size(ctx, ctx->root_style);
+
+ size->data.length.unit = ref_len.unit;
+ size->data.length.value = FMUL(size->data.length.value,
+ ref_len.value);
+ break;
+
+ default:
+ break;
+ }
+ default:
+ break;
+ }
+
+ return CSS_OK;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-27 01:24:11 +0000