gp_text.h

// SPDX-License-Identifier: LGPL-2.1-or-later
/*
 * Copyright (C) 2009-2011 Jiri "BlueBear" Dluhos
 *                         <jiri.bluebear.dluhos@gmail.com>
 *
 * Copyright (C) 2009-2023 Cyril Hrubis <metan@ucw.cz>
 */
 
#ifndef TEXT_GP_TEXT_H
#define TEXT_GP_TEXT_H
 
#include <stdarg.h>
 
#include <core/gp_types.h>
#include <text/gp_text_style.h>
#include <text/gp_text_metric.h>
#include <text/gp_fonts.h>
 
/* How the rendered text should be aligned.
 * For gp_text(), the alignment is relative to the specified point:
 *
 *   - GP_ALIGN_LEFT draws the text to the left of the point,
 *   - GP_ALIGN_CENTER centers it at the point horizontally,
 *   - GP_ALIGN_RIGHT draws the text to the right of the point
 *   - GP_TEXT_BEARING apply bearing at the start of the string
 *   - GP_VALIGN_ABOVE (or TOP) draws the text above the point
 *   - GP_VALIGN_CENTER centers the text vertically at the point
 *   - GP_VALIGN_BASELINE places the text baseline at the point
 *   - GP_VALIGN_BELOW (or BOTTOM) draws the text below the point
 *   - GP_TEXT_NOBG mix the alpha pixels with data read from the pixmap
 *                  rather than mixing them with bg_color
 *                  (which is slightly slower)
 */
typedef enum gp_text_attr {
        GP_ALIGN_LEFT = 0x01,
        GP_ALIGN_CENTER = 0x02,
        GP_ALIGN_RIGHT = 0x03,
        GP_ALIGN_HORIZ = 0x03,
        GP_TEXT_BEARING = 0x04,
        GP_VALIGN_ABOVE = 0x10,
        GP_VALIGN_TOP = GP_VALIGN_ABOVE,
        GP_VALIGN_CENTER = 0x20,
        GP_VALIGN_BASELINE = 0x30,
        GP_VALIGN_BELOW = 0x40,
        GP_VALIGN_BOTTOM = GP_VALIGN_BELOW,
        GP_TEXT_NOBG = 0x80,
} gp_text_attr;
 
/*
 * Raw version, doesn't use Text aligment.
 *
 * If flags are set to GP_TEXT_NOBG the the bg_color is ignored and
 * the pixmap pixels are used for alpha mixing.
 */
gp_size gp_text_raw(gp_pixmap *pixmap, const gp_text_style *style,
                    gp_coord x, gp_coord y, uint8_t flags,
                    gp_pixel fg_color, gp_pixel bg_color,
                    const char *str, size_t max_chars);
 
/*
 * Draws a string.
 *
 * The string is rendered to pixmap (horizontally) with defined text style.
 * The x and y coordinates determines point defined by aligment flags.
 *
 * The background color is ignored for 1bpp font formats.
 */
gp_size gp_text(gp_pixmap *pixmap, const gp_text_style *style,
                gp_coord x, gp_coord y, int align,
                gp_pixel fg_color, gp_pixel bg_color, const char *str);
 
gp_size gp_glyph_draw(gp_pixmap *pixmap, const gp_text_style *style,
                      gp_coord x, gp_coord y, int flags,
                      gp_pixel fg_color, gp_pixel bg_color,
                      uint32_t glyph);
 
/*
 * Aligns a string between x1 and x2 based ond horizontal aligment flags. The
 * caller must make sure that the string will fit horizontally between x1 and x2.
 */
static inline gp_size gp_text_xxy(gp_pixmap *pixmap, const gp_text_style *style,
                                  gp_coord x1, gp_coord x2, gp_coord y, int align,
                                  gp_pixel fg_color, gp_pixel bg_color, const char *str)
{
        gp_coord x, len;
 
        if (x1 < x2) {
                x = x1;
                len = x2 - x1;
        } else {
                x = x2;
                len = x1 - x2;
        }
 
        int halign = align & GP_ALIGN_HORIZ;
 
        align &= ~GP_ALIGN_HORIZ;
 
        switch (halign) {
        case GP_ALIGN_LEFT:
                align |= GP_ALIGN_RIGHT;
        break;
        case GP_ALIGN_CENTER:
                x += len/2;
                align |= GP_ALIGN_CENTER;
        break;
        case GP_ALIGN_RIGHT:
                x += len;
                align |= GP_ALIGN_LEFT;
        break;
        }
 
        return gp_text(pixmap, style, x, y, align, fg_color, bg_color, str);
}
 
/*
 * Same as the gp_text() but the number of characters can be limited.
 */
gp_size gp_text_ext(gp_pixmap *pixmap, const gp_text_style *style,
                    gp_coord x, gp_coord y, int align,
                    gp_pixel fg_color, gp_pixel bg_color,
                    const char *str, size_t max_chars);
 
/*
 * Same as above, but printf like and returns text width in pixels.
 */
gp_size gp_print(gp_pixmap *pixmap, const gp_text_style *style,
                 gp_coord x, gp_coord y, int align,
                 gp_pixel fg_color, gp_pixel bg_color, const char *fmt, ...)
                 __attribute__ ((format (printf, 8, 9)));
 
 
gp_size gp_vprint(gp_pixmap *pixmap, const gp_text_style *style,
                  gp_coord x, gp_coord y, int align,
                  gp_pixel fg_color, gp_pixel bg_color,
                  const char *fmt, va_list va);
 
__attribute__ ((format (printf, 9, 10)))
static inline gp_size gp_print_xxy(gp_pixmap *pixmap, const gp_text_style *style,
                                   gp_coord x1, gp_coord x2, gp_coord y, int align,
                                   gp_pixel fg_color, gp_pixel bg_color, const char *fmt, ...)
{
        gp_coord x, len;
        gp_size ret;
        va_list va;
 
        if (x1 < x2) {
                x = x1;
                len = x2 - x1;
        } else {
                x = x2;
                len = x1 - x2;
        }
 
        int halign = align & GP_ALIGN_HORIZ;
 
        align &= ~GP_ALIGN_HORIZ;
 
        switch (halign) {
        case GP_ALIGN_LEFT:
                align |= GP_ALIGN_RIGHT;
        break;
        case GP_ALIGN_CENTER:
                x += len/2;
                align |= GP_ALIGN_CENTER;
        break;
        case GP_ALIGN_RIGHT:
                x += len;
                align |= GP_ALIGN_LEFT;
        break;
        }
 
        va_start(va, fmt);
        ret = gp_vprint(pixmap, style, x, y, align, fg_color, bg_color, fmt, va);
        va_end(va);
 
        return ret;
}
 
/*
 * Clears rectangle that would be used to draw text of size pixels.
 */
void gp_text_clear(gp_pixmap *pixmap, const gp_text_style *style,
                   gp_coord x, gp_coord y, int align,
                   gp_pixel bg_color, gp_size size);
 
/*
 * Dtto, but with string.
 */
void gp_text_clear_str(gp_pixmap *pixmap, const gp_text_style *style,
                       gp_coord x, gp_coord y, int align,
                       gp_pixel bg_color, const char *str);
 
#endif /* TEXT_GP_TEXT_H */