path: root/bitmap.c

/**
 * \file bitmap.c
 * \brief Bitmap manipulation support
 *
 * \subsection Copyright
 * Copyright (c) 2013 Michael Buesch <m@bues.ch>
 *
 * \subsection License
 * Licensed under the terms of the GNU General Public License version 2.
 */

#include "bitmap.h"
#include "font.h"

#include <avr/pgmspace.h>


/** \brief	Gibt die Breite eines Bitmaps zurueck.
 *		Beruecksichtigt die Rotation.
 */
uint8_t bitmap_width(struct bitmap *bitmap)
{
	if (bitmap->rotation == BITMAP_ROT_0DEG ||
	    bitmap->rotation == BITMAP_ROT_180DEG)
		return bitmap->width;
	return bitmap->height;
}

/** \brief	Gibt die Hoehe eines Bitmaps zurueck.
 *		Beruecksichtigt die Rotation.
 */
uint8_t bitmap_height(struct bitmap *bitmap)
{
	if (bitmap->rotation == BITMAP_ROT_0DEG ||
	    bitmap->rotation == BITMAP_ROT_180DEG)
		return bitmap->height;
	return bitmap->width;
}

/** \brief	Pixel in Bitmap beschreiben.
 *
 * \param bitmap	Das Bitmap.
 *
 * \param x		X Koordinate des Pixels.
 *
 * \param y		Y Koordinate des Pixels.
 *
 * \param on		Der neue Pixelwert. (1/0)
 */
void bitmap_pixel_write(struct bitmap *bitmap,
			uint8_t x, uint8_t y, bool on)
{
	uint8_t y_bit, *b, tmp_x, mask;

	/* Koordinaten nach Rotation uebersetzen. */
	switch (bitmap->rotation) {
	case BITMAP_ROT_0DEG:
	default:
		break;
	case BITMAP_ROT_90DEG:
		tmp_x = x;
		x = bitmap->width - y - 1;
		y = tmp_x;
		break;
	case BITMAP_ROT_180DEG:
		x = bitmap->width - x - 1;
		y = bitmap->height - y - 1;
		break;
	case BITMAP_ROT_270DEG:
		tmp_x = x;
		x = y;
		y = bitmap->height - tmp_x - 1;
		break;
	}

	/* Zeiger auf Byte auswaehlen. */
	y_bit = y % 8;
	b = bitmap_column_byte(bitmap, x, y);

	/* Pixel-Bit setzen oder loeschen. */
	mask = BITMASK8(y_bit);
	if (on)
		*b |= mask;
	else
		*b &= ~mask;
}

/** \brief	Rechteckigen Bereich im Bitmap fuellen.
 *
 * \param bitmap	Das Bitmap.
 *
 * \param area_x	X Koordinate des Bereichs.
 *
 * \param area_y	Y Koordinate des Bereichs.
 *
 * \param area_width	Breite des Bereichs.
 *
 * \param area_height	Hoehe des Bereichs.
 *
 * \param black		1 -> Schwarz zeichnen. 0 -> Weiss zeichnen.
 */
void bitmap_area_fill(struct bitmap *bitmap,
		      uint8_t area_x, uint8_t area_y,
		      uint8_t area_width, uint8_t area_height,
		      bool black)
{
	uint8_t x, y, tmp_x, tmp_width;
	uint8_t *b;

	/* Koordinaten nach Rotation uebersetzen. */
	switch (bitmap->rotation) {
	case BITMAP_ROT_0DEG:
	default:
		break;
	case BITMAP_ROT_90DEG:
		tmp_x = x;
		x = bitmap->width - y - 1;
		y = tmp_x;
		tmp_width = area_width;
		area_width = area_height;
		area_height = tmp_width;
		break;
	case BITMAP_ROT_180DEG:
		x = bitmap->width - x - 1;
		y = bitmap->height - y - 1;
		break;
	case BITMAP_ROT_270DEG:
		tmp_x = x;
		x = y;
		y = bitmap->height - tmp_x - 1;
		tmp_width = area_width;
		area_width = area_height;
		area_height = tmp_width;
		break;
	}

	y = area_y;

	if (y % 8) {
		/* TODO: Spezialbehandlung wenn area_y kein Vielfaches von 8 ist.
		 *	Kommt in diesem Projekt nicht vor.
		 */
	}
	/* Y-Bereich durchlaufen. */
	while (area_height >= 8) {
		/* X-Bereich durchlaufen. */
		for (x = area_x; x < area_x + area_width; x++) {
			b = bitmap_column_byte(bitmap, x, y);
			/* Pixel-Bits loeschen oder setzen. */
			if (black)
				*b = 0xFF;
			else
				*b = 0;
		}
		area_height -= 8;
		y += 8;
	}
	if (area_height) {
		/* TODO: Spezialbehandlung wenn area_height kein Vielfaches von 8 ist.
		 *	Kommt in diesem Projekt nicht vor.
		 */
	}
}

/** \brief	Linie in Bitmap zeichnen.
 *
 * \param bitmap	Das Bitmap.
 *
 * \param x_from	X Startkoordinate der Linie.
 *
 * \param y_from	Y Startkoordinate der Linie.
 *
 * \param x_to		X Endkoordinate der Linie.
 *
 * \param y_to		Y Endkoordinate der Linie.
 *
 * \param black		1 -> Schwarz zeichnen. 0 -> Weiss zeichnen.
 */
void bitmap_draw_line(struct bitmap *bitmap,
		      uint8_t x_from, uint8_t y_from,
		      uint8_t x_to, uint8_t y_to,
		      bool black)
{
	uint8_t x, y, error = 0;
	uint8_t dist_x, dist_y;
	int8_t x_inc, y_inc;

	/* Richtung und Distanz ermitteln. */
	if (x_to < x_from) {
		dist_x = x_from - x_to;
		x_inc = -1;
	} else {
		dist_x = x_to - x_from;
		x_inc = 1;
	}
	if (y_to < y_from) {
		dist_y = y_from - y_to;
		y_inc = -1;
	} else {
		dist_y = y_to - y_from;
		y_inc = 1;
	}
	x = x_from;
	y = y_from;

	/* Erstes Pixel schreiben. */
	bitmap_pixel_write(bitmap, x, y, black);

	/* Richtung abfragen. */
	if (dist_x >= dist_y) {
		/* Alle Pixel zeichnen. */
		while (x != x_to) {
			x += x_inc;
			error += dist_y * 2;
			if (error > dist_x) {
				y += y_inc;
				error -= dist_x * 2;
			}
			bitmap_pixel_write(bitmap, x, y, black);
		}
	} else {
		/* Alle Pixel zeichnen. */
		while (y != y_to) {
			y += y_inc;
			error += dist_x * 2;
			if (error > dist_y) {
				x += x_inc;
				error -= dist_y * 2;
			}
			bitmap_pixel_write(bitmap, x, y, black);
		}
	}
}

/** \brief	XBM in Bitmap zeichnen.
 *
 * \param bitmap	Das Bitmap.
 *
 * \param x_pos		X Zielkoordinate.
 *
 * \param y_pos		Y Zielkoordinate.
 *
 * \param xbm		Das XBM Bitmap.
 *
 * \param xbm_width	Breite des XBM Bitmaps.
 *
 * \param xbm_height	Hoehe des XBM Bitmaps.
 */
void bitmap_draw_xbm(struct bitmap *bitmap,
		     uint8_t x_pos, uint8_t y_pos,
		     const uint8_t __flash *xbm,
		     unsigned int xbm_width, unsigned int xbm_height)
{
	uint8_t x, y, mask;
	uint8_t bm_width = bitmap_width(bitmap);
	uint8_t bm_height = bitmap_height(bitmap);

	if (x_pos >= bm_width ||
	    y_pos >= bm_height ||
	    x_pos + xbm_width > bm_width ||
	    y_pos + xbm_height > bm_height) {
		/* Ungueltige Koordinaten. */
		return;
	}

	/* Das XBM Pixelweise durchlaufen und Pixel zeichnen. */
	for (y = 0; y < xbm_height; y++) {
		mask = 0x01;
		for (x = 0; x < xbm_width; x++) {
			bitmap_pixel_write(bitmap,
					   x_pos + x, y_pos + y,
					   !!(*xbm & mask));
			mask <<= 1;
			if (!mask) {
				mask = 0x01;
				xbm++;
			}
		}
		if (mask != 0x01)
			xbm++;
	}
}

/** \brief	ASCII Zeichen in Bitmap zeichnen.
 *
 * \param bitmap	Das Bitmap.
 *
 * \param x_pos		X Zielkoordinate.
 *
 * \param y_pos		Y Zielkoordinate.
 *
 * \param font_desc	Der Font der zum Zeichnen verwendet werden soll.
 *
 * \param ascii		Das ASCII Zeichen das gezeichnet werden soll.
 */
void bitmap_draw_char(struct bitmap *bitmap,
		      uint8_t x_pos, uint8_t y_pos,
		      const struct font_descriptor __flash *font_desc,
		      char ascii)
{
	const uint8_t __flash *xbm;
	uint8_t font_width, font_height, font_xbm_size;

	font_width = font_get_width(font_desc);
	font_height = font_get_height(font_desc);
	font_xbm_size = font_height * (div_round_up(font_width, 8));

	/* ASCII Zeichensatz auswaehlen. */
	if (ascii >= '0' && ascii <= '9') {
		xbm = font_get_numbers(font_desc);
		xbm += font_xbm_size * (ascii - '0');
	} else if (ascii >= 'a' && ascii <= 'z') {
		xbm = font_get_lowercase(font_desc);
		xbm += font_xbm_size * (ascii - 'a');
	} else if (ascii >= 'A' && ascii <= 'Z') {
		xbm = font_get_uppercase(font_desc);
		xbm += font_xbm_size * (ascii - 'A');
	} else
		return;

	/* Zeichen in Bitmap zeichnen. */
	bitmap_draw_xbm(bitmap, x_pos, y_pos, xbm, font_width, font_height);
}

/** \brief	ASCII String in Bitmap zeichnen.
 *
 * \param bitmap	Das Bitmap.
 *
 * \param x_pos		X Zielkoordinate.
 *
 * \param y_pos		Y Zielkoordinate.
 *
 * \param font_desc	Der Font der zum Zeichnen verwendet werden soll.
 *
 * \param string	Der NUL-terminierte String, der gezeichnet werden soll.
 */
void bitmap_draw_string(struct bitmap *bitmap,
			uint8_t x_pos, uint8_t y_pos,
			const struct font_descriptor __flash *font_desc,
			const char __memx *string)
{
	uint8_t x = 0, y = 0, font_width, font_height;
	char c;
	uint8_t bm_width = bitmap_width(bitmap);
	uint8_t bm_height = bitmap_height(bitmap);

	font_width = font_get_width(font_desc);
	font_height = font_get_height(font_desc);

	/* Jedes Zeichen im Bitmap zeichnen. */
	while (1) {
		c = *string;
		if (!c) {
			/* Stringende. */
			break;
		}
		/* Das ASCII Zeichen zeichnen. */
		bitmap_draw_char(bitmap, x_pos + x, y_pos + y,
				 font_desc, c);
		string++;
		/* Spalte inkrementieren. */
		x += font_width + 2;
		/* Zeilenumbruch? */
		if (x + font_width > bm_width) {
			x = 0;
			/* Zeile Inkrementieren. */
			y += font_height + 2;
			if (y + font_height > bm_height)
				break;
		}
	}
}