allow framebuffer port to use freetype2 library

svn path=/trunk/netsurf/; revision=6570

1 files changed, 260 insertions, 0 deletions

diff --git a/framebuffer/fb_font_freetype.c b/framebuffer/fb_font_freetype.c
new file mode 100644
index 000000000..36130fa55
--- /dev/null
+++ b/framebuffer/fb_font_freetype.c
@@ -0,0 +1,260 @@
+/*
+ * Copyright 2005 James Bursa <bursa@users.sourceforge.net>
+ *           2008 Vincent Sanders <vince@simtec.co.uk>
+ *
+ * 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 <inttypes.h>
+#include <assert.h>
+
+#include "css/css.h"
+#include "render/font.h"
+#include "desktop/options.h"
+#include "utils/utf8.h"
+#include "utils/log.h"
+
+#include "framebuffer/fb_gui.h"
+#include "framebuffer/fb_font.h"
+
+static FT_Library library; 
+static FT_Face face_sans_serif; 
+
+
+utf8_convert_ret utf8_to_local_encoding(const char *string, 
+				       size_t len,
+				       char **result)
+{
+	return utf8_to_enc(string, "UTF-8", len, result);
+}
+
+
+/* initialise font handling */
+bool fb_font_init(void)
+{
+        FT_Error error;
+
+        error = FT_Init_FreeType( &library ); 
+        if (error) {
+                LOG(("Freetype could not initialised (code %d)\n", error));
+                return false;
+        }
+
+        error = FT_New_Face(library, 
+                            "/usr/share/fonts/truetype/freefont/FreeSans.ttf", 
+                            0, 
+                            &face_sans_serif ); 
+        if (error) {
+                LOG(("Could not find default font (code %d)\n", error));
+                FT_Done_FreeType(library);
+                return false;
+        }
+ 
+        error = FT_Set_Pixel_Sizes(face_sans_serif, 0, 14 ); 
+        if (error) {
+                LOG(("Could not set pixel size (code %d)\n", error));
+                return false;
+        } 
+        
+        
+        return true;
+}
+
+bool fb_font_finalise(void)
+{
+        FT_Done_FreeType(library);
+        return true;
+}
+
+
+
+FT_Face 
+fb_get_face(const struct css_style *style)
+{
+        FT_Face face;
+        face = face_sans_serif;
+        FT_Error error;
+        int size;
+
+	if (style->font_size.value.length.unit == CSS_UNIT_PX) {
+		size = style->font_size.value.length.value;
+
+                error = FT_Set_Pixel_Sizes(face_sans_serif, 0, size ); 
+                if (error) {
+                        LOG(("Could not set pixel size (code %d)\n", error));
+                } 
+        } else {
+		size = css_len2pt(&style->font_size.value.length, style);
+                error = FT_Set_Char_Size( face, 0, size*64, 72, 72 );
+                if (error) {
+                        LOG(("Could not set pixel size (code %d)\n", error));
+                } 
+        }
+
+
+        return face;
+}
+
+/**
+ * Measure the width of a string.
+ *
+ * \param  style   css_style for this text, with style->font_size.size ==
+ *		   CSS_FONT_SIZE_LENGTH
+ * \param  string  UTF-8 string to measure
+ * \param  length  length of string
+ * \param  width   updated to width of string[0..length)
+ * \return  true on success, false on error and error reported
+ */
+static bool nsfont_width(const struct css_style *style,
+                         const char *string, size_t length,
+                         int *width)
+{
+        uint32_t ucs4;
+        size_t nxtchr = 0;
+        FT_UInt glyph_index; 
+        FT_Face face = fb_get_face(style);
+        FT_Error error;
+
+        *width = 0;
+        while (nxtchr < length) {
+                ucs4 = utf8_to_ucs4(string + nxtchr, length - nxtchr);
+                nxtchr = utf8_next(string, length, nxtchr);
+                glyph_index = FT_Get_Char_Index(face, ucs4);
+
+                error = FT_Load_Glyph(face, glyph_index, FT_LOAD_DEFAULT);
+                if (error) 
+                        continue;
+
+                *width += face->glyph->advance.x >> 6;
+        }
+
+	return true;
+}
+
+/**
+ * Find the position in a string where an x coordinate falls.
+ *
+ * \param  style        css_style for this text, with style->font_size.size ==
+ *                      CSS_FONT_SIZE_LENGTH
+ * \param  string       UTF-8 string to measure
+ * \param  length       length of string
+ * \param  x            x coordinate to search for
+ * \param  char_offset  updated to offset in string of actual_x, [0..length]
+ * \param  actual_x     updated to x coordinate of character closest to x
+ * \return  true on success, false on error and error reported
+ */
+
+static bool nsfont_position_in_string(const struct css_style *style,
+		const char *string, size_t length,
+		int x, size_t *char_offset, int *actual_x)
+{
+        uint32_t ucs4;
+        size_t nxtchr = 0;
+        FT_UInt glyph_index; 
+        FT_Face face = fb_get_face(style);
+        FT_Error error;
+
+        *actual_x = 0;
+        while (nxtchr < length) {
+                ucs4 = utf8_to_ucs4(string + nxtchr, length - nxtchr);
+                glyph_index = FT_Get_Char_Index(face, ucs4);
+
+                error = FT_Load_Glyph(face, glyph_index, FT_LOAD_DEFAULT);
+                if (error) 
+                        continue;
+
+                *actual_x += face->glyph->advance.x >> 6;
+                if (*actual_x > x)
+                        break;
+
+                nxtchr = utf8_next(string, length, nxtchr);
+        }
+
+        *char_offset = nxtchr;
+	return true;
+}
+
+
+/**
+ * Find where to split a string to make it fit a width.
+ *
+ * \param  style        css_style for this text, with style->font_size.size ==
+ *                      CSS_FONT_SIZE_LENGTH
+ * \param  string       UTF-8 string to measure
+ * \param  length       length of string
+ * \param  x            width available
+ * \param  char_offset  updated to offset in string of actual_x, [0..length]
+ * \param  actual_x     updated to x coordinate of character closest to x
+ * \return  true on success, false on error and error reported
+ *
+ * On exit, [char_offset == 0 ||
+ *           string[char_offset] == ' ' ||
+ *           char_offset == length]
+ */
+
+static bool nsfont_split(const struct css_style *style,
+		const char *string, size_t length,
+		int x, size_t *char_offset, int *actual_x)
+{
+        uint32_t ucs4;
+        size_t nxtchr = 0;
+        FT_UInt glyph_index; 
+        FT_Face face = fb_get_face(style);
+        FT_Error error;
+        int last_space_x = -1;
+        int last_space_idx = -1;
+
+        *actual_x = 0;
+        while (nxtchr < length) {
+                ucs4 = utf8_to_ucs4(string + nxtchr, length - nxtchr);
+
+                if (ucs4 == 0x20) {
+                        last_space_x = *actual_x;
+                        last_space_idx = nxtchr;
+                }
+
+                glyph_index = FT_Get_Char_Index(face, ucs4);
+
+                error = FT_Load_Glyph(face, glyph_index, FT_LOAD_DEFAULT);
+                if (error) 
+                        continue;
+
+                *actual_x += face->glyph->advance.x >> 6;
+                if (*actual_x > x)
+                        break;
+
+                nxtchr = utf8_next(string, length, nxtchr);
+        }
+
+        if (last_space_x == -1) {
+                *char_offset = nxtchr;
+        } else {
+                *actual_x = last_space_x;
+                *char_offset = last_space_idx;
+        }
+	return true;
+}
+
+const struct font_functions nsfont = {
+	nsfont_width,
+	nsfont_position_in_string,
+	nsfont_split
+};
+
+/*
+ * Local Variables:
+ * c-basic-offset:8
+ * End:
+ */