Fixed color scan problem.

backend/sceptre.c

@@ -49,7 +49,7 @@
 
 /*--------------------------------------------------------------------------*/
 
-#define BUILD 7			/* 2002-03-02 */
+#define BUILD 8			/* 2002-03-07 */
 #define BACKEND_NAME sceptre
 #define SCEPTRE_CONFIG_FILE "sceptre.conf"
 
@@ -1556,6 +1556,8 @@ sane_get_parameters (SANE_Handle handle, SANE_Parameters * params)
 
   if (!(dev->scanning))
     {
+      /* Prepare the parameters for the caller. */
+      memset (&dev->params, 0, sizeof (SANE_Parameters));
 
       if (dev->val[OPT_PREVIEW].w == SANE_TRUE)
 	{
@@ -1629,9 +1631,6 @@ sane_get_parameters (SANE_Handle handle, SANE_Parameters * params)
 	  break;
 	}
 
-      /* Prepare the parameters for the caller. */
-      memset (&dev->params, 0, sizeof (SANE_Parameters));
-
       /* this scanner does only one pass */
       dev->params.last_frame = SANE_TRUE;
       dev->params.depth = dev->depth;
@@ -1677,8 +1676,9 @@ sane_get_parameters (SANE_Handle handle, SANE_Parameters * params)
 		}
 	    }
 
-	  dev->params.bytes_per_line =
+	  dev->params.bytes_per_line = dev->params.pixels_per_line;
-	    dev->params.pixels_per_line * (dev->depth / 8);
+	  if (dev->scan_mode == SCEPTRE_COLOR)
+	    dev->params.bytes_per_line *= 3;
 
 	  /* lines number rounding rules:
 	   *   2n + [0.0 .. 2.0[  -> round to 2n
@@ -1825,14 +1825,18 @@ sane_read (SANE_Handle handle, SANE_Byte * buf, SANE_Int max_len,
   /* 
    * Try to read the maximum number of bytes.
    *
-   * The windows driver reads no more than 0xffff byte, I've tried 
+   * The windows driver reads no more than 0xffff bytes, I've tried 
    * some bigger values, but the scanner is losing data!!!
    */
-  size = data_left;
+  size = dev->bytes_left;
   if (size > dev->buffer_size)
     {
       size = dev->buffer_size;
     }
+  if (size > data_left)
+    {
+      size = data_left;
+    }
 
   /* If it is a preview, read only what we have been asked
    * for. Else, try to maximize the throughput. 
@@ -1878,7 +1882,7 @@ sane_read (SANE_Handle handle, SANE_Byte * buf, SANE_Int max_len,
 	  /* Still got some data. Send it. */
 	  if (size > (size_t) max_len)
 	    size = max_len;
-	  if (size > (size_t) dev->bytes_left)
+	  if (size > dev->bytes_left)
 	    size = dev->bytes_left;
 
 	  memcpy (buf, dev->image + dev->image_begin, size);

backend/sceptre.desc

@@ -10,7 +10,7 @@
 ;
 
 :backend "sceptre"
-:version "1.0-7"                  ; version of backend
+:version "1.0-8"                  ; version of backend
 :status :new                      ; :alpha, :beta, :stable, :new
 :manpage "sane-sceptre"           ; name of manpage
 :url "http://www.geocities.com/harikus2000/sane" ; backend's web page

backend/sceptre.h

@@ -345,7 +345,7 @@ typedef struct Sceptre_Scanner
   int depth;			/* depth per color */
   int halftone_param;		/* haltone number, valid for SCEPTRE_HALFTONE */
 
-  int bytes_left;		/* number of bytes promised to backend
+  size_t bytes_left;		/* number of bytes promised to backend
 				   * left to read. */
 
   int color_shift;		/* for color scan: number of lines to