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authorreinelt <>2003-08-16 07:31:35 +0000
committerreinelt <>2003-08-16 07:31:35 +0000
commita8d642c8c2dcb10ebaf878b7b97c7da8f8c3062d (patch)
treeb96e57eecc9c13dbd925ef913e4fb19a9c39c13e /USBLCD.c
parent42e23909e0118d73b2657f9d4423cffd1a0ea3a0 (diff)
downloadlcd4linux-a8d642c8c2dcb10ebaf878b7b97c7da8f8c3062d.tar.gz
[lcd4linux @ 2003-08-16 07:31:35 by reinelt]
double buffering in all drivers
Diffstat (limited to 'USBLCD.c')
-rw-r--r--USBLCD.c91
1 files changed, 65 insertions, 26 deletions
diff --git a/USBLCD.c b/USBLCD.c
index 6d58c61..c9a0986 100644
--- a/USBLCD.c
+++ b/USBLCD.c
@@ -1,4 +1,4 @@
-/* $Id: USBLCD.c,v 1.10 2003/07/24 04:48:09 reinelt Exp $
+/* $Id: USBLCD.c,v 1.11 2003/08/16 07:31:35 reinelt Exp $
*
* Driver for USBLCD ( see http://www.usblcd.de )
* This Driver is based on HD44780.c
@@ -22,6 +22,9 @@
*
*
* $Log: USBLCD.c,v $
+ * Revision 1.11 2003/08/16 07:31:35 reinelt
+ * double buffering in all drivers
+ *
* Revision 1.10 2003/07/24 04:48:09 reinelt
* 'soft clear' needed for virtual rows
*
@@ -94,13 +97,13 @@
#define CHARS 8
static LCD Lcd;
-
-int usblcd_file;
-
static char *Port=NULL;
-static char Txt[4][40];
+static int usblcd_file;
+
+static char *FrameBuffer1=NULL;
+static char *FrameBuffer2=NULL;
-static unsigned char Buffer[1024];
+static unsigned char *Buffer;
static unsigned char *BufPtr;
static void USBLCD_send ()
@@ -195,19 +198,15 @@ static void USBLCD_define_char (int ascii, char *buffer)
int USBLCD_clear (int full)
{
- int row, col;
-
- for (row=0; row<Lcd.rows; row++) {
- for (col=0; col<Lcd.cols; col++) {
- Txt[row][col]='\t';
- }
- }
-
+
+ memset (FrameBuffer1, ' ', Lcd.rows*Lcd.cols*sizeof(char));
bar_clear();
- if (full)
+ if (full) {
+ memset (FrameBuffer2, ' ', Lcd.rows*Lcd.cols*sizeof(char));
USBLCD_command (0x01); // clear display
-
+ }
+
return 0;
}
@@ -248,6 +247,21 @@ int USBLCD_init (LCD *Self)
Self->cols=cols;
Lcd=*Self;
+ // Init the command buffer
+ Buffer = (char*)malloc(1024);
+ if (Buffer==NULL) {
+ error ("USBLCD: coommand buffer could not be allocated: malloc() failed");
+ return -1;
+ }
+
+ // Init the framebuffers
+ FrameBuffer1 = (char*)malloc(Lcd.cols*Lcd.rows*sizeof(char));
+ FrameBuffer2 = (char*)malloc(Lcd.cols*Lcd.rows*sizeof(char));
+ if (FrameBuffer1==NULL || FrameBuffer2==NULL) {
+ error ("USBLCD: framebuffer could not be allocated: malloc() failed");
+ return -1;
+ }
+
if (USBLCD_open()!=0)
return -1;
@@ -271,7 +285,7 @@ void USBLCD_goto (int row, int col)
int USBLCD_put (int row, int col, char *text)
{
- char *p=&Txt[row][col];
+ char *p=FrameBuffer1+row*Lcd.cols+col;
char *t=text;
while (*t && col++<=Lcd.cols) {
@@ -289,9 +303,8 @@ int USBLCD_bar (int type, int row, int col, int max, int len1, int len2)
int USBLCD_flush (void)
{
- char buffer[256];
- char *p;
- int c, row, col;
+ int row, col, pos1, pos2;
+ int c, equal;
bar_process(USBLCD_define_char);
@@ -299,31 +312,57 @@ int USBLCD_flush (void)
for (col=0; col<Lcd.cols; col++) {
c=bar_peek(row, col);
if (c!=-1) {
- Txt[row][col]=(char)c;
+ FrameBuffer1[row*Lcd.cols+col]=(char)c;
}
}
for (col=0; col<Lcd.cols; col++) {
- if (Txt[row][col]=='\t') continue;
+ if (FrameBuffer1[row*Lcd.cols+col]==FrameBuffer2[row*Lcd.cols+col]) continue;
USBLCD_goto (row, col);
- for (p=buffer; col<Lcd.cols; col++, p++) {
- if (Txt[row][col]=='\t') break;
- *p=Txt[row][col];
+ for (pos1=col++, pos2=pos1, equal=0; col<Lcd.cols; col++) {
+ if (FrameBuffer1[row*Lcd.cols+col]==FrameBuffer2[row*Lcd.cols+col]) {
+ // If we find just one equal byte, we don't break, because this
+ // would require a goto, which takes one byte, too.
+ if (++equal>2) break;
+ } else {
+ pos2=col;
+ equal=0;
+ }
}
- USBLCD_write (buffer, p-buffer);
+ USBLCD_write (FrameBuffer1+row*Lcd.cols+pos1, pos2-pos1+1);
}
}
USBLCD_send();
+ memcpy (FrameBuffer2, FrameBuffer1, Lcd.rows*Lcd.cols*sizeof(char));
+
return 0;
}
int USBLCD_quit (void)
{
+ info("USBLCD: shutting down.");
USBLCD_send();
+
debug ("closing port %s", Port);
close(usblcd_file);
+
+ if (Buffer) {
+ free(Buffer);
+ Buffer=NULL;
+ }
+
+ if (FrameBuffer1) {
+ free(FrameBuffer1);
+ FrameBuffer1=NULL;
+ }
+
+ if (FrameBuffer2) {
+ free(FrameBuffer2);
+ FrameBuffer2=NULL;
+ }
+
return 0;
}