[project @ 2005-01-08 21:02:32 by bursa]

Initial version of RISC OS Unicode font library. Require Unicode (RO5) Font Manager.

svn path=/import/rufl/; revision=2443

1 files changed, 255 insertions, 0 deletions

diff --git a/rufl_paint.c b/rufl_paint.c
new file mode 100644
index 0000000..9014d96
--- /dev/null
+++ b/rufl_paint.c
@@ -0,0 +1,255 @@
+/*
+ * This file is part of RUfl
+ * Licensed under the MIT License,
+ *                http://www.opensource.org/licenses/mit-license
+ * Copyright 2005 James Bursa <james@semichrome.net>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "oslib/font.h"
+#include "rufl_internal.h"
+
+
+static int rufl_family_list_cmp(const void *keyval, const void *datum);
+static rufl_code rufl_paint_span(unsigned short *s, unsigned int n,
+		unsigned int font, unsigned int font_size, int *x, int y);
+static rufl_code rufl_paint_not_available(unsigned short *s, unsigned int n,
+		unsigned int font_size, int *x, int y);
+static rufl_code rufl_place_in_cache(unsigned int font, unsigned int font_size,
+		font_f f);
+
+
+/**
+ * Render Unicode text.
+ */
+
+rufl_code rufl_paint(const char *font_family, rufl_style font_style,
+		 unsigned int font_size,
+		const char *string, size_t length,
+		int x, int y)
+{
+	unsigned short s[80];
+	unsigned int font;
+	unsigned int font0, font1;
+	unsigned int n;
+	unsigned int u;
+	char **family;
+	struct rufl_character_set *charset;
+	rufl_code code;
+
+	if (length == 0)
+		return rufl_OK;
+
+	family = bsearch(font_family, rufl_family_list,
+			rufl_family_list_entries,
+			sizeof rufl_family_list[0], rufl_family_list_cmp);
+	if (!family)
+		return rufl_FONT_NOT_FOUND;
+	font = rufl_family_map[rufl_STYLES * (family - rufl_family_list) +
+			font_style];
+	charset = rufl_font_list[font].charset;
+
+	rufl_utf8_read(string, length, u);
+	if (rufl_character_set_test(charset, u))
+		font1 = font;
+	else
+		font1 = rufl_substitution_lookup(u);
+	do {
+		s[0] = u;
+		n = 1;
+		font0 = font1;
+		/* invariant: s[0..n) is in font font0 */
+		while (0 < length && n < 70 && font1 == font0) {
+			rufl_utf8_read(string, length, u);
+			s[n] = u;
+			if (rufl_character_set_test(charset, u))
+				font1 = font;
+			else
+				font1 = rufl_substitution_lookup(u);
+			if (font1 == font0)
+				n++;
+		}
+		s[n] = 0;
+
+		if (font0 == NOT_AVAILABLE)
+			code = rufl_paint_not_available(s, n, font_size, &x, y);
+		else
+			code = rufl_paint_span(s, n, font0, font_size, &x, y);
+
+		if (code != rufl_OK)
+			return code;
+
+	} while (!(length == 0 && font1 == font0));
+
+	return rufl_OK;
+}
+
+
+int rufl_family_list_cmp(const void *keyval, const void *datum)
+{
+	const char *key = keyval;
+	const char * const *entry = datum;
+	return strcmp(key, *entry);
+}
+
+
+/**
+ * Render a string of characters from a single RISC OS font.
+ */
+
+rufl_code rufl_paint_span(unsigned short *s, unsigned int n,
+		unsigned int font, unsigned int font_size, int *x, int y)
+{
+	char font_name[80];
+	int x_out, y_out;
+	unsigned int i;
+	font_f f;
+	rufl_code code;
+
+	/* search cache */
+	for (i = 0; i != rufl_CACHE_SIZE; i++) {
+		if (rufl_cache[i].font == font &&
+				rufl_cache[i].size == font_size)
+			break;
+	}
+	if (i != rufl_CACHE_SIZE) {
+		/* found in cache */
+		f = rufl_cache[i].f;
+		rufl_cache[i].last_used = rufl_cache_time++;
+	} else {
+		/* not found */
+		snprintf(font_name, sizeof font_name, "%s\\EUTF8",
+				rufl_font_list[font].identifier);
+		rufl_fm_error = xfont_find_font(font_name,
+				font_size, font_size, 0, 0, &f, 0, 0);
+		if (rufl_fm_error)
+			return rufl_FONT_MANAGER_ERROR;
+		/* place in cache */
+		code = rufl_place_in_cache(font, font_size, f);
+		if (code != rufl_OK)
+			return code;
+	}
+
+	/* paint span */
+	rufl_fm_error = xfont_paint(f, (const char *) s, font_OS_UNITS |
+			font_GIVEN_LENGTH | font_GIVEN_FONT | font_KERN |
+			font_GIVEN16_BIT,
+			*x, y, 0, 0, n * 2);
+	if (rufl_fm_error) {
+		xfont_lose_font(f);
+		return rufl_FONT_MANAGER_ERROR;
+	}
+
+	/* increment x by width of span */
+	rufl_fm_error = xfont_scan_string(f, (const char *) s,
+			font_GIVEN_LENGTH | font_GIVEN_FONT | font_KERN |
+			font_GIVEN16_BIT,
+			0x7fffffff, 0x7fffffff, 0, 0, n * 2,
+			0, &x_out, &y_out, 0);
+	if (rufl_fm_error) {
+		xfont_lose_font(f);
+		return rufl_FONT_MANAGER_ERROR;
+	}
+	*x += x_out / 400;
+
+	return rufl_OK;
+}
+
+
+/**
+ * Render a string of characters not available in any font as their hex code.
+ */
+
+rufl_code rufl_paint_not_available(unsigned short *s, unsigned int n,
+		unsigned int font_size, int *x, int y)
+{
+	char missing[] = "0000";
+	unsigned int i;
+	font_f f;
+	rufl_code code;
+
+	/* search cache */
+	for (i = 0; i != rufl_CACHE_SIZE; i++) {
+		if (rufl_cache[i].font == rufl_CACHE_CORPUS &&
+				rufl_cache[i].size == font_size)
+			break;
+	}
+	if (i != rufl_CACHE_SIZE) {
+		/* found in cache */
+		f = rufl_cache[i].f;
+		rufl_cache[i].last_used = rufl_cache_time++;
+	} else {
+		/* not found */
+		rufl_fm_error = xfont_find_font("Corpus.Medium\\EUTF8",
+				font_size / 2, font_size / 2, 0, 0,
+				&f, 0, 0);
+		if (rufl_fm_error)
+			return rufl_FONT_MANAGER_ERROR;
+		/* place in cache */
+		code = rufl_place_in_cache(rufl_CACHE_CORPUS, font_size, f);
+		if (code != rufl_OK)
+			return code;
+	}
+
+	for (i = 0; i != n; i++) {
+		missing[0] = "0123456789abcdef"[(s[i] >> 12) & 0xf];
+		missing[1] = "0123456789abcdef"[(s[i] >> 8) & 0xf];
+		missing[2] = "0123456789abcdef"[(s[i] >> 4) & 0xf];
+		missing[3] = "0123456789abcdef"[(s[i] >> 0) & 0xf];
+
+		/* first two characters in top row */
+		rufl_fm_error = xfont_paint(f, missing, font_OS_UNITS |
+				font_GIVEN_LENGTH | font_GIVEN_FONT | font_KERN,
+				*x, y + 5 * font_size / 64,
+				0, 0, 2);
+		if (rufl_fm_error)
+			return rufl_FONT_MANAGER_ERROR;
+
+		/* last two characters underneath */
+		rufl_fm_error = xfont_paint(f, missing + 2, font_OS_UNITS |
+				font_GIVEN_LENGTH | font_GIVEN_FONT | font_KERN,
+				*x, y, 0, 0, 2);
+		if (rufl_fm_error)
+			return rufl_FONT_MANAGER_ERROR;
+
+		*x += 7 * font_size / 64;
+	}
+
+	return rufl_OK;
+}
+
+
+/**
+ * Place a font into the recent-use cache, making space if necessary.
+ */
+
+rufl_code rufl_place_in_cache(unsigned int font, unsigned int font_size,
+		font_f f)
+{
+	unsigned int i;
+	unsigned int max_age = 0;
+	unsigned int evict = 0;
+
+	for (i = 0; i != rufl_CACHE_SIZE; i++) {
+		if (rufl_cache[i].font == rufl_CACHE_NONE) {
+			evict = i;
+			break;
+		} else if (max_age < rufl_cache_time -
+				rufl_cache[i].last_used) {
+			max_age = rufl_cache_time -
+					rufl_cache[i].last_used;
+			evict = i;
+		}
+	}
+	rufl_fm_error = xfont_lose_font(rufl_cache[evict].f);
+	if (rufl_fm_error)
+		return rufl_FONT_MANAGER_ERROR;
+	rufl_cache[evict].font = font;
+	rufl_cache[evict].size = font_size;
+	rufl_cache[evict].f = f;
+	rufl_cache[evict].last_used = rufl_cache_time++;
+
+	return rufl_OK;
+}