wiringPi_Blueberry/devLib/scrollPhat.c

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2023-08-11 15:53:17 +08:00
/*
* scrollPhat.c:
* Simple driver for the Pimoroni Scroll Phat device
*
* Copyright (c) 2015 Gordon Henderson.
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
*
* wiringPi is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* wiringPi 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <time.h>
#include <wiringPiI2C.h>
#include "scrollPhatFont.h"
#include "scrollPhat.h"
// Size
#define SP_WIDTH 11
#define SP_HEIGHT 5
// I2C
#define PHAT_I2C_ADDR 0x60
// Software copy of the framebuffer
// it's 8-bit deep although the display itself is only 1-bit deep.
static unsigned char frameBuffer [SP_WIDTH * SP_HEIGHT] ;
static int lastX, lastY ;
static int printDelayFactor ;
static int scrollPhatFd ;
static int putcharX ;
#undef DEBUG
/*
* delay:
* Wait for some number of milliseconds.
* This taken from wiringPi as there is no-need to include the whole of
* wiringPi just for the delay function.
*********************************************************************************
*/
static void delay (unsigned int howLong)
{
struct timespec sleeper, dummy ;
sleeper.tv_sec = (time_t)(howLong / 1000) ;
sleeper.tv_nsec = (long)(howLong % 1000) * 1000000 ;
nanosleep (&sleeper, &dummy) ;
}
/*
* scrollPhatUpdate:
* Copy our software version to the real display
*********************************************************************************
*/
void scrollPhatUpdate (void)
{
register int x, y ;
register unsigned char data, pixel ;
unsigned char pixels [SP_WIDTH] ;
#ifdef DEBUG
printf ("+-----------+\n") ;
for (y = 0 ; y < SP_HEIGHT ; ++y)
{
putchar ('|') ;
for (x = 0 ; x < SP_WIDTH ; ++x)
{
pixel = frameBuffer [x + y * SP_WIDTH] ;
putchar (pixel == 0 ? ' ' : '*') ;
}
printf ("|\n") ;
}
printf ("+-----------+\n") ;
#endif
for (x = 0 ; x < SP_WIDTH ; ++x)
{
data = 0 ;
for (y = 0 ; y < SP_HEIGHT ; ++y)
{
pixel = frameBuffer [x + y * SP_WIDTH] ;
data = (data << 1) | ((pixel == 0) ? 0 : 1) ;
}
pixels [x] = data ;
}
for (x = 0 ; x < SP_WIDTH ; ++x)
wiringPiI2CWriteReg8 (scrollPhatFd, 1 + x, pixels [x]) ;
wiringPiI2CWriteReg8 (scrollPhatFd, 0x0C, 0) ;
}
/*
*********************************************************************************
* Standard Graphical Functions
*********************************************************************************
*/
/*
* scrollPhatPoint:
* Plot a pixel. Crude clipping - speed is not the essence here.
*********************************************************************************
*/
void scrollPhatPoint (int x, int y, int colour)
{
lastX = x ;
lastY = y ;
if ((x < 0) || (x >= SP_WIDTH) || (y < 0) || (y >= SP_HEIGHT))
return ;
frameBuffer [x + y * SP_WIDTH] = colour ;
}
/*
* scrollPhatLine: scrollPhatLineTo:
* Classic Bressenham Line code - rely on the point function to do the
* clipping for us here.
*********************************************************************************
*/
void scrollPhatLine (int x0, int y0, int x1, int y1, int colour)
{
int dx, dy ;
int sx, sy ;
int err, e2 ;
lastX = x1 ;
lastY = y1 ;
dx = abs (x1 - x0) ;
dy = abs (y1 - y0) ;
sx = (x0 < x1) ? 1 : -1 ;
sy = (y0 < y1) ? 1 : -1 ;
err = dx - dy ;
for (;;)
{
scrollPhatPoint (x0, y0, colour) ;
if ((x0 == x1) && (y0 == y1))
break ;
e2 = 2 * err ;
if (e2 > -dy)
{
err -= dy ;
x0 += sx ;
}
if (e2 < dx)
{
err += dx ;
y0 += sy ;
}
}
}
void scrollPhatLineTo (int x, int y, int colour)
{
scrollPhatLine (lastX, lastY, x, y, colour) ;
}
/*
* scrollPhatRectangle:
* A rectangle is a spoilt days fishing
*********************************************************************************
*/
void scrollPhatRectangle (int x1, int y1, int x2, int y2, int colour, int filled)
{
register int x ;
if (filled)
{
/**/ if (x1 == x2)
scrollPhatLine (x1, y1, x2, y2, colour) ;
else if (x1 < x2)
for (x = x1 ; x <= x2 ; ++x)
scrollPhatLine (x, y1, x, y2, colour) ;
else
for (x = x2 ; x <= x1 ; ++x)
scrollPhatLine (x, y1, x, y2, colour) ;
}
else
{
scrollPhatLine (x1, y1, x2, y1, colour) ;
scrollPhatLineTo (x2, y2, colour) ;
scrollPhatLineTo (x1, y2, colour) ;
scrollPhatLineTo (x1, y1, colour) ;
}
}
/*
* scrollPhatPutchar:
* Print a single character to the screen then advance the pointer by an
* appropriate ammount (variable width font).
* We rely on the clipping done by the pixel plot function to keep us
* out of trouble.
* Return the width + space
*********************************************************************************
*/
int scrollPhatPutchar (int c)
{
register int x, y ;
unsigned char line ;
unsigned char *fontPtr ;
unsigned char *p2 ;
int lineWidth, width, mask ;
// The font is printable characters, uppercase only...
// and somewhat varaible width...
c &= 0x7F ;
if (c > 0x60)
c -= 64 ;
else
c -= 32 ;
fontPtr = scrollPhatFont + c * fontHeight ;
// Work out width of this character
// There probably is a more efficient way to do this, but...
p2 = fontPtr ;
width = 0 ;
for (y = 0 ; y < fontHeight ; ++y)
{
mask = 0x80 ;
for (lineWidth = 8 ; lineWidth > 0 ; --lineWidth)
{
if ((*p2 & mask) != 0)
break ;
mask >>= 1 ;
}
if (lineWidth > width)
width = lineWidth ;
++p2 ;
}
if (width == 0) // Likely to be a blank or space character
width = 3 ;
for (y = fontHeight - 1 ; y >= 0 ; --y)
{
x = 0 ;
line = *fontPtr++ ;
for (mask = 1 << (width - 1) ; mask != 0 ; mask >>= 1)
{
scrollPhatPoint (putcharX + x, y, (line & mask)) ;
++x ;
}
}
// make a line of space
for (y = fontHeight - 1 ; y >= 0 ; --y)
scrollPhatPoint (putcharX + width, y, 0) ;
putcharX = putcharX + width + 1 ;
return width + 1 ;
}
/*
* scrollPhatPuts:
* Send a string to the display - and scroll it across.
* This is somewhat of a hack in that we print the entire string to the
* display and let the point clipping take care of what's off-screen...
*********************************************************************************
*/
void scrollPhatPuts (const char *str)
{
int i ;
int movingX = 0 ;
const char *s ;
int pixelLen ;
// Print it once, then we know the width in pixels...
putcharX = 0 ;
s = str ;
while (*s)
scrollPhatPutchar (*s++) ;
pixelLen = putcharX ;
// Now scroll it by printing it and moving left one pixel
movingX = 0 ;
for (i = 0 ; i < pixelLen ; ++i)
{
putcharX = movingX ;
s = str ;
while (*s)
scrollPhatPutchar (*s++) ;
--movingX ;
scrollPhatUpdate () ;
delay (printDelayFactor) ;
}
}
/*
* scrollPhatPrintf:
* Does what it says
*********************************************************************************
*/
void scrollPhatPrintf (const char *message, ...)
{
va_list argp ;
char buffer [1024] ;
va_start (argp, message) ;
vsnprintf (buffer, 1023, message, argp) ;
va_end (argp) ;
scrollPhatPuts (buffer) ;
}
/*
* scrollPhatPrintSpeed:
* Change the print speed - mS per shift by 1 pixel
*********************************************************************************
*/
void scrollPhatPrintSpeed (const int pps)
{
if (pps < 0)
printDelayFactor = 0 ;
else
printDelayFactor = pps ;
}
/*
* scrollPhatClear:
* Clear the display
*********************************************************************************
*/
void scrollPhatClear (void)
{
register int i ;
register unsigned char *ptr = frameBuffer ;
for (i = 0 ; i < (SP_WIDTH * SP_HEIGHT) ; ++i)
*ptr++ = 0 ;
scrollPhatUpdate () ;
}
/*
* scrollPhatIntensity:
* Set the display brightness - percentage
*********************************************************************************
*/
void scrollPhatIntensity (const int percent)
{
wiringPiI2CWriteReg8 (scrollPhatFd, 0x19, (127 * percent) / 100) ;
}
/*
* scrollPhatSetup:
* Initialise the Scroll Phat display
*********************************************************************************
*/
int scrollPhatSetup (void)
{
if ((scrollPhatFd = wiringPiI2CSetup (PHAT_I2C_ADDR)) < 0)
return scrollPhatFd ;
wiringPiI2CWriteReg8 (scrollPhatFd, 0x00, 0x03) ; // Enable display, set to 5x11 mode
scrollPhatIntensity (10) ;
scrollPhatClear () ;
scrollPhatPrintSpeed (100) ;
return 0 ;
}