source: mainline/uspace/lib/draw/font.c@ de9992c

/*
 * Copyright (c) 2012 Petr Koupy
 * Copyright (c) 2014 Martin Sucha
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup draw
 * @{
 */
/**
 * @file
 */

#include <errno.h>
#include <stdlib.h>
#include <str.h>

#include <draw/font.h>
#include <draw/drawctx.h>

font_t *font_create(font_backend_t *backend, void *backend_data)
{
        font_t *font = malloc(sizeof(font_t));
        if (font == NULL)
                return NULL;

        font->backend = backend;
        font->backend_data = backend_data;

        return font;
}

void font_release(font_t *font)
{
        font->backend->release(font->backend_data);
}

errno_t font_get_metrics(font_t *font, font_metrics_t *metrics)
{
        return font->backend->get_font_metrics(font->backend_data, metrics);
}

errno_t font_resolve_glyph(font_t *font, char32_t c, glyph_id_t *glyph_id)
{
        return font->backend->resolve_glyph(font->backend_data, c, glyph_id);
}

errno_t font_get_glyph_metrics(font_t *font, glyph_id_t glyph_id,
    glyph_metrics_t *glyph_metrics)
{
        return font->backend->get_glyph_metrics(font->backend_data,
            glyph_id, glyph_metrics);
}

errno_t font_render_glyph(font_t *font, drawctx_t *context, source_t *source,
    sysarg_t x, sysarg_t y, glyph_id_t glyph_id)
{
        return font->backend->render_glyph(font->backend_data, context, source,
            x, y, glyph_id);
}

/* TODO this is bad interface */
errno_t font_get_box(font_t *font, char *text, sysarg_t *width, sysarg_t *height)
{
        font_metrics_t fm;
        errno_t rc = font_get_metrics(font, &fm);
        if (rc != EOK)
                return rc;

        native_t x = 0;

        size_t off = 0;
        while (true) {
                char32_t c = str_decode(text, &off, STR_NO_LIMIT);
                if (c == 0)
                        break;

                glyph_id_t glyph_id;
                rc = font_resolve_glyph(font, c, &glyph_id);
                if (rc != EOK) {
                        errno_t rc2 = font_resolve_glyph(font, U_SPECIAL, &glyph_id);
                        if (rc2 != EOK) {
                                return rc;
                        }
                }

                glyph_metrics_t glyph_metrics;
                rc = font_get_glyph_metrics(font, glyph_id, &glyph_metrics);
                if (rc != EOK)
                        return rc;

                x += glyph_metrics_get_advancement(&glyph_metrics);
        }

        *width = x;
        *height = fm.ascender + fm.descender;
        return EOK;
}

/* TODO this is bad interface */
errno_t font_draw_text(font_t *font, drawctx_t *context, source_t *source,
    const char *text, sysarg_t sx, sysarg_t sy)
{
        drawctx_save(context);
        drawctx_set_compose(context, compose_over);

        font_metrics_t fm;
        errno_t rc = font_get_metrics(font, &fm);
        if (rc != EOK)
                return rc;

        native_t baseline = sy + fm.ascender;
        native_t x = sx;

        size_t off = 0;
        while (true) {
                char32_t c = str_decode(text, &off, STR_NO_LIMIT);
                if (c == 0)
                        break;

                glyph_id_t glyph_id;
                rc = font_resolve_glyph(font, c, &glyph_id);
                if (rc != EOK) {
                        errno_t rc2 = font_resolve_glyph(font, U_SPECIAL, &glyph_id);
                        if (rc2 != EOK) {
                                return rc;
                        }
                }

                glyph_metrics_t glyph_metrics;
                rc = font_get_glyph_metrics(font, glyph_id, &glyph_metrics);
                if (rc != EOK)
                        return rc;

                rc = font_render_glyph(font, context, source, x, baseline,
                    glyph_id);
                if (rc != EOK)
                        return rc;

                x += glyph_metrics_get_advancement(&glyph_metrics);

        }

        drawctx_restore(context);
        source_set_mask(source, NULL, false);

        return EOK;
}

/** @}
 */