Diff: u8g_pb.c

Revision:

0:972874f31c98

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/u8g_pb.c	Wed Mar 07 12:49:14 2018 +0000
@@ -0,0 +1,192 @@
+/*
+
+  u8g_pb.c
+  
+  common procedures for the page buffer
+
+  Universal 8bit Graphics Library
+  
+  Copyright (c) 2011, olikraus@gmail.com
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without modification, 
+  are permitted provided that the following conditions are met:
+
+  * Redistributions of source code must retain the above copyright notice, this list 
+    of conditions and the following disclaimer.
+    
+  * Redistributions in binary form must reproduce the above copyright notice, this 
+    list of conditions and the following disclaimer in the documentation and/or other 
+    materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
+  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
+  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
+  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
+  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
+  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
+  
+  
+*/
+
+#include "u8g.h"
+
+void u8g_pb_Clear(u8g_pb_t *b)
+{
+  uint8_t *ptr = (uint8_t *)b->buf;
+  uint8_t *end_ptr = ptr;
+  end_ptr += b->width;
+  do
+  {
+    *ptr++ = 0;
+  } while( ptr != end_ptr );
+}
+
+/* the following procedure does not work. why? Can be checked with descpic */
+/*
+void u8g_pb_Clear(u8g_pb_t *b)
+{
+  uint8_t *ptr = (uint8_t *)b->buf;
+  uint8_t cnt = b->width;
+  do
+  {
+    *ptr++ = 0;
+    cnt--;
+  } while( cnt != 0 );
+}
+*/
+
+/*
+  intersection assumptions:
+    a1 <= a2 is always true    
+*/
+  /*
+    minimized version
+    ---1----0 1             b1 <= a2 && b1 > b2
+    -----1--0 1             b2 >= a1 && b1 > b2
+    ---1-1--- 1             b1 <= a2 && b2 >= a1
+  */
+/*
+uint8_t u8g_pb8v1_IsYIntersection___Old(u8g_pb_t *b, u8g_uint_t v0, u8g_uint_t v1)
+{
+  uint8_t c0, c1, c;
+  c0 = v0 <= b->p.page_y1;
+  c1 = v1 >= b->p.page_y0;
+  c = v0 > v1;
+  if ( c0 && c1 ) return 1;
+  if ( c0 && c ) return 1;
+  if ( c1 && c ) return 1;
+  return 0;
+}
+*/
+
+uint8_t u8g_pb_IsYIntersection(u8g_pb_t *pb, u8g_uint_t v0, u8g_uint_t v1)
+{
+  uint8_t c1, c2, c3, tmp;
+  c1 = v0 <= pb->p.page_y1;
+  c2 = v1 >= pb->p.page_y0;
+  c3 = v0 > v1;
+  /*
+  if ( c1 && c2 )
+    return 1;
+  if ( c1 && c3 )
+    return 1;
+  if ( c2 && c3 )
+    return 1;
+  return 0;
+  */
+  
+  tmp = c1;
+  c1 &= c2;
+  c2 &= c3;
+  c3 &= tmp;
+  c1 |= c2;
+  c1 |= c3;
+  return c1 & 1;
+}
+
+
+uint8_t u8g_pb_IsXIntersection(u8g_pb_t *b, u8g_uint_t v0, u8g_uint_t v1)
+{
+  uint8_t /*c0, c1, */ c2, c3;
+  /*
+    conditions: b->p.page_y0 < b->p.page_y1
+    there are no restriction on v0 and v1. If v0 > v1, then warp around unsigned is assumed
+  */
+  /*
+  c0 = v0 < 0;
+  c1 = v1 < 0;
+  */
+  c2 = v0 > b->width;
+  c3 = v1 > b->width;
+  /*if ( c0 && c1 ) return 0;*/
+  if ( c2 && c3 ) return 0;
+  /*if ( c1 && c2 ) return 0;*/
+  return 1;
+}
+
+uint8_t u8g_pb_IsIntersection(u8g_pb_t *pb, u8g_dev_arg_bbx_t *bbx)
+{
+  u8g_uint_t tmp;
+
+  tmp = bbx->y;
+  tmp += bbx->h;
+  tmp--;
+  
+  if ( u8g_pb_IsYIntersection(pb, bbx->y, tmp) == 0 )
+    return 0;
+  
+  /* maybe this one can be skiped... probability is very high to have an intersection, so it would be ok to always return 1 */
+  tmp = bbx->x;
+  tmp += bbx->w;
+  tmp--;
+    
+  return u8g_pb_IsXIntersection(pb, bbx->x, tmp);
+}
+
+void u8g_pb_GetPageBox(u8g_pb_t *pb, u8g_box_t *box)
+{
+  box->x0 = 0;
+  box->y0 = pb->p.page_y0;
+  box->x1 = pb->width;
+  box->x1--;
+  box->y1 = pb->p.page_y1;
+}
+
+
+uint8_t u8g_pb_Is8PixelVisible(u8g_pb_t *b, u8g_dev_arg_pixel_t *arg_pixel)
+{
+  u8g_uint_t v0, v1;
+  v0 = arg_pixel->y;
+  v1 = v0;
+  switch( arg_pixel->dir )
+  {
+    case 0:
+      break;
+    case 1:  
+      v1 += 8;          /* this is independent from the page height */
+      break;
+    case 2:  
+      break;
+    case 3: 
+      v0 -= 8;
+      break;
+  }
+  return u8g_pb_IsYIntersection(b, v0, v1);
+}
+
+
+
+uint8_t u8g_pb_WriteBuffer(u8g_pb_t *b, u8g_t *u8g, u8g_dev_t *dev)
+{
+  return u8g_WriteSequence(u8g, dev, b->width, b->buf);  
+}
+
+