squeezelite-esp32/components/display/core/gds_text.c

/* 
 *  (c) 2004,2006 Richard Titmuss for SlimProtoLib 
 *  (c) Philippe G. 2019, philippe_44@outlook.com
 *
 * This program 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, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 <string.h>
#include <ctype.h>
#include <stdint.h>
#include <arpa/inet.h>
#include "esp_log.h"
#include "gds.h"
#include "gds_draw.h"
#include "gds_text.h"
#include "gds_private.h"

#define max(a,b) (((a) > (b)) ? (a) : (b))

static char TAG[] = "gds";

/****************************************************************************************
 *  Set fonts for each line in text mode
 */
static const struct GDS_FontDef *GuessFont( struct GDS_Device *Device, int FontType) {
	switch(FontType) {
	case GDS_FONT_LINE_1:	
		return &Font_line_1;
	case GDS_FONT_LINE_2:	
		return &Font_line_2;
	case GDS_FONT_SMALL:	
		return &Font_droid_sans_fallback_11x13;	
	case GDS_FONT_MEDIUM:			
	default:		
		return &Font_droid_sans_fallback_15x17;	
	case GDS_FONT_LARGE:	
		return &Font_droid_sans_fallback_24x28;
		break;		
	case GDS_FONT_SEGMENT:			
		if (Device->Height == 32) return &Font_Tarable7Seg_16x32;
		else return &Font_Tarable7Seg_32x64;
	}
}


/****************************************************************************************
 *  Set fonts for each line in text mode
 */
bool GDS_TextSetFontAuto(struct GDS_Device* Device, int N, int FontType, int Space) {
	const struct GDS_FontDef *Font = GuessFont( Device, FontType );
	return GDS_TextSetFont( Device, N, Font, Space );
}

/****************************************************************************************
 *  Set fonts for each line in text mode
 */
bool GDS_TextSetFont(struct GDS_Device* Device, int N, const struct GDS_FontDef *Font, int Space) {
	if (--N >= MAX_LINES) return false;

	Device->Lines[N].Font = Font;
	
	// re-calculate lines absolute position
	Device->Lines[N].Space = Space;
	Device->Lines[0].Y = Device->Lines[0].Space;
	for (int i = 1; i <= N; i++) Device->Lines[i].Y = Device->Lines[i-1].Y + Device->Lines[i-1].Font->Height + Device->Lines[i].Space;
		
	ESP_LOGI(TAG, "Adding line %u at %d (height:%u)", N + 1, Device->Lines[N].Y, Device->Lines[N].Font->Height);
	
	if (Device->Lines[N].Y + Device->Lines[N].Font->Height > Device->Height) {
		ESP_LOGW(TAG, "line does not fit display");
		return false;
	}
	
	return true;
}

/****************************************************************************************
 * 
 */
bool GDS_TextLine(struct GDS_Device* Device, int N, int Pos, int Attr, char *Text) {
	int Width, X = Pos;

	// counting 1..n
	N--;
	
	GDS_SetFont( Device, Device->Lines[N].Font );	
	if (Attr & GDS_TEXT_MONOSPACE) GDS_FontForceMonospace( Device, true );
	
	Width = GDS_FontMeasureString( Device, Text );
	
	// adjusting position, erase only EoL for rigth-justified
	if (Pos == GDS_TEXT_RIGHT) X = Device->Width - Width - 1;
	else if (Pos == GDS_TEXT_CENTER) X = (Device->Width - Width) / 2;
	
	// erase if requested
	if (Attr & GDS_TEXT_CLEAR) {
		int Y_min = max(0, Device->Lines[N].Y), Y_max = max(0, Device->Lines[N].Y + Device->Lines[N].Font->Height);
		for (int c = (Attr & GDS_TEXT_CLEAR_EOL) ? X : 0; c < Device->Width; c++) 
			for (int y = Y_min; y < Y_max; y++)
				Device->DrawPixelFast( Device, c, y, GDS_COLOR_BLACK );
	}
		
	GDS_FontDrawString( Device, X, Device->Lines[N].Y, Text, GDS_COLOR_WHITE );
	
	ESP_LOGD(TAG, "displaying %s line %u (x:%d, attr:%u)", Text, N+1, X, Attr);
	
	// update whole display if requested
	Device->Dirty = true;
	if (Attr & GDS_TEXT_UPDATE) GDS_Update( Device );
		
	return Width + X < Device->Width;
}

/****************************************************************************************
 * Try to align string for better scrolling visual. there is probably much better to do
 */
int GDS_TextStretch(struct GDS_Device* Device, int N, char *String, int Max) {
	char Space[] = "     ";
	int Len = strlen(String), Extra = 0, Boundary;
	
	N--;
	
	// we might already fit
	GDS_SetFont( Device, Device->Lines[N].Font );	
	if (GDS_FontMeasureString( Device, String ) <= Device->Width) return 0;
		
	// add some space for better visual 
	strncat(String, Space, Max-Len);
	String[Max] = '\0';
	Len = strlen(String);
	
	// mark the end of the extended string
	Boundary = GDS_FontMeasureString( Device, String );
			
	// add a full display width	
	while (Len < Max && GDS_FontMeasureString( Device, String ) - Boundary < Device->Width) {
		String[Len++] = String[Extra++];
		String[Len] = '\0';
	}
		
	return Boundary;
}

/****************************************************************************************
 * 
 */
void GDS_TextPos(struct GDS_Device* Device, int FontType, int Where, int Attr, char *Text, ...) {
	va_list args;

	TextAnchor Anchor = TextAnchor_Center;	
	
	if (Attr & GDS_TEXT_CLEAR) GDS_Clear( Device, GDS_COLOR_BLACK );
	
	if (!Text) return;
	
	va_start(args, Text);
	
	switch(Where) {
	case GDS_TEXT_TOP_LEFT: 
	default:
		Anchor = TextAnchor_NorthWest; 
		break;
	case GDS_TEXT_MIDDLE_LEFT:
		Anchor = TextAnchor_West;
		break;
	case GDS_TEXT_BOTTOM_LEFT:
		Anchor = TextAnchor_SouthWest;
		break;
	case GDS_TEXT_CENTERED:
		Anchor = TextAnchor_Center;
		break;
	}	
	
	ESP_LOGD(TAG, "Displaying %s at %u with attribute %u", Text, Anchor, Attr);
	
	GDS_SetFont( Device, GuessFont( Device, FontType ) );	
	GDS_FontDrawAnchoredString( Device, Anchor, Text, GDS_COLOR_WHITE );
	
	Device->Dirty = true;
	if (Attr & GDS_TEXT_UPDATE) GDS_Update( Device );
	
	va_end(args);
}