font_diskfont.c

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/*
 * Copyright 2008 - 2025 Chris Young <chris@unsatisfactorysoftware.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 "amiga/os3support.h"
 
#include <stdlib.h>
#include <string.h>
#include <proto/diskfont.h>
#include <proto/exec.h>
#include <proto/graphics.h>
#include <proto/utility.h>
 
#include <graphics/rpattr.h>
 
#include "utils/log.h"
#include "utils/utf8.h"
#include "utils/nsoption.h"
 
#include "amiga/font.h"
#include "amiga/font_diskfont.h"
#include "amiga/gui.h"
#include "amiga/plotters.h"
#include "amiga/utf8.h"
 
#define MAX_FONT_NAME_SIZE 33
 
static plot_font_style_t *prev_fstyle = NULL;
static struct TextFont *prev_font = NULL;
static struct RastPort *prev_rp = NULL;
static struct RastPort temp_rp;
static UBYTE style_set = 0;
 
static struct TextFont *ami_font_bm_open(struct RastPort *rp, const plot_font_style_t *fstyle)
{
        struct TextFont *bmfont = NULL;
        struct TextAttr tattr;
        char *fontname;
        char font[MAX_FONT_NAME_SIZE];
 
        if(rp == NULL) return NULL;
 
        tattr.ta_Flags = 0;
 
        switch(fstyle->family)
        {
                case PLOT_FONT_FAMILY_SANS_SERIF:
                        fontname = nsoption_charp(font_sans);
                break;
                case PLOT_FONT_FAMILY_SERIF:
                        fontname = nsoption_charp(font_serif);
                break;
                case PLOT_FONT_FAMILY_MONOSPACE:
                        fontname = nsoption_charp(font_mono);
                break;
                case PLOT_FONT_FAMILY_CURSIVE:
                        fontname = nsoption_charp(font_cursive);
                break;
                case PLOT_FONT_FAMILY_FANTASY:
                        fontname = nsoption_charp(font_fantasy);
                break;
                default:
                        return NULL;
                break;
        }
 
        tattr.ta_Style = FS_NORMAL;
 
        if (fstyle->flags & FONTF_OBLIQUE)
                tattr.ta_Style = FSF_ITALIC;
 
        if (fstyle->flags & FONTF_ITALIC)
                tattr.ta_Style = FSF_ITALIC;
 
        if (fstyle->weight >= 700)
                tattr.ta_Style |= FSF_BOLD;
 
        if((prev_fstyle != NULL) && (prev_font != NULL) &&
                (fstyle->family == prev_fstyle->family) &&
                (fstyle->size == prev_fstyle->size)) {
                         if(rp != prev_rp) {
                                 /* We have the correct font open, but it isn't set here */
                                 SetRPAttrs(rp, RPTAG_Font, prev_font, TAG_DONE);
                                 prev_rp = rp;
                         }
                        /* Current font is correct, just SoftStyle it */
                        NSLOG(netsurf, INFO, "Applying SoftStyle to current font");
                        SetSoftStyle(rp, tattr.ta_Style, style_set);
                        return prev_font;
        }
 
        snprintf(font, MAX_FONT_NAME_SIZE, "%s.font", fontname);
        tattr.ta_Name = font;
        tattr.ta_YSize = fstyle->size / PLOT_STYLE_SCALE;
        NSLOG(netsurf, INFO, "font: %s/%d", tattr.ta_Name, tattr.ta_YSize);
 
        if(prev_font != NULL) {
                CloseFont(prev_font);
                prev_font = NULL;
        }
 
        if((bmfont = OpenDiskFont(&tattr))) {
                SetRPAttrs(rp, RPTAG_Font, bmfont, TAG_DONE);
                style_set = AskSoftStyle(rp);
                prev_rp = rp;
                prev_font = bmfont;
 
                if(prev_fstyle != NULL) {
                        memcpy(prev_fstyle, fstyle, sizeof(plot_font_style_t));
                }
        }
 
        return bmfont;
}
 
static size_t ami_font_bm_convert_local_to_utf8_offset(const char *utf8string, size_t length, UWORD offset)
{
        size_t chr = 0;
 
        for(UWORD i = 0; i < offset; i++) {
                chr = utf8_next(utf8string, length, chr);
                if(chr > length) return length;
        }
        
        return chr;
}
 
 
static nserror amiga_bm_nsfont_width(const plot_font_style_t *fstyle,
                const char *string, size_t length,
                int *width)
{
        char *localtext = NULL;
 
        *width = length;
 
        struct TextFont *bmfont = ami_font_bm_open(&temp_rp, fstyle);
        if(bmfont == NULL) return NSERROR_INVALID;
 
        if(utf8_to_local_encoding(string, length, &localtext) != NSERROR_OK) {
                return NSERROR_INVALID;
        }
 
        *width = TextLength(&temp_rp, localtext, (UWORD)strlen(localtext));
        free(localtext);
 
        return NSERROR_OK;
}
 
/**
 * Find the position in a string where an x coordinate falls.
 *
 * \param  fstyle       style for this text
 * \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 nserror amiga_bm_nsfont_position_in_string(const plot_font_style_t *fstyle,
                const char *string, size_t length,
                int x, size_t *char_offset, int *actual_x)
{
        struct TextExtent extent;
        struct TextFont *bmfont;
        char *localtext = NULL;
        UWORD co = 0;
 
        bmfont = ami_font_bm_open(&temp_rp, fstyle);
        if(bmfont == NULL) return NSERROR_INVALID;
 
        if(utf8_to_local_encoding(string, length, &localtext) != NSERROR_OK) {
                return NSERROR_INVALID;
        }
 
        co = TextFit(&temp_rp, localtext, (UWORD)strlen(localtext),
                                                &extent, NULL, 1, x, 32767);
        *char_offset = ami_font_bm_convert_local_to_utf8_offset(string, length, co);
        *actual_x = extent.te_Extent.MaxX;
 
        free(localtext);
 
        return NSERROR_OK;
}
 
 
/**
 * Find where to split a string to make it fit a width.
 *
 * \param  fstyle       style for this text
 * \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, [1..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 indicates first character after split point.
 *
 * Note: char_offset of 0 should never be returned.
 *
 * Returns:
 * char_offset giving split point closest to x, where actual_x <= x
 * else
 * char_offset giving split point closest to x, where actual_x > x
 *
 * Returning char_offset == length means no split possible
 */
 
static nserror amiga_bm_nsfont_split(const plot_font_style_t *fstyle,
                const char *string, size_t length,
                int x, size_t *char_offset, int *actual_x)
{
        struct TextExtent extent;
        UWORD co, offset;
        char *charp;
        char *localtext;
 
        struct TextFont *bmfont = ami_font_bm_open(&temp_rp, fstyle);
        if(bmfont == NULL) return NSERROR_INVALID;
 
        if(utf8_to_local_encoding(string, length, &localtext) != NSERROR_OK) {
                return NSERROR_INVALID;
        }
 
        offset = TextFit(&temp_rp, localtext, (UWORD)strlen(localtext),
                                &extent, NULL, 1, (UWORD)x, 32767);
 
        co = offset;
        charp = localtext + co;
        
 
        while((*charp != ' ') && (co > 0)) {
                charp--;
                co--;
        }
 
        if(co == 0) {
                co = offset;
                charp = localtext + co;
                while((*charp != ' ') && (co < strlen(localtext))) {
                        charp++;
                        co++;
                }
        }
        
        if((co > 0) && (co < strlen(localtext))) {
                *actual_x = TextLength(&temp_rp, localtext, co);
                *char_offset = ami_font_bm_convert_local_to_utf8_offset(string, length, co);
        } else {
                *actual_x = x;
                *char_offset = length;
        }
 
        free(localtext);
 
        return NSERROR_OK;
}
 
static ULONG amiga_bm_nsfont_text(struct RastPort *rp, const char *string, ULONG length,
                        const plot_font_style_t *fstyle, ULONG dx, ULONG dy, bool aa)
{
        if(!string || string[0]=='\0') return 0;
        if(!length) return 0;
        if(rp == NULL) return 0;
 
        struct TextFont *bmfont = ami_font_bm_open(rp, fstyle);
        char *localtext = NULL;
        if(bmfont == NULL) return 0;
        if(utf8_to_local_encoding(string, length, &localtext) == NSERROR_OK) {
                Move(rp, dx, dy);
                Text(rp, localtext, (UWORD)strlen(localtext));
                free(localtext);
        }
 
        return 0;
}
 
const struct ami_font_functions ami_font_diskfont_table = {
        amiga_bm_nsfont_width,
        amiga_bm_nsfont_position_in_string,
        amiga_bm_nsfont_split,
        amiga_bm_nsfont_text
};
 
void ami_font_diskfont_init(void)
{
        /* Set up table */
        ami_nsfont = &ami_font_diskfont_table;
 
        /* Alloc space to hold currently open font - doesn't matter if this fails */
        prev_fstyle = calloc(1, sizeof(plot_font_style_t));
 
        /* Init temp RastPort */
        InitRastPort(&temp_rp);
}
 
void ami_font_diskfont_fini(void)
{
        if(prev_font != NULL) {
                CloseFont(prev_font);
                prev_font = NULL;
        }
 
        if(prev_fstyle != NULL) {
                free(prev_fstyle);
                prev_fstyle = NULL;
        }
}