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- /*
- u8g2_box.c
- Universal 8bit Graphics Library (https://github.com/olikraus/u8g2/)
- Copyright (c) 2016, 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 "u8g2.h"
- void u8g2_DrawLine(u8g2_t *u8g2, u8g2_uint_t x1, u8g2_uint_t y1, u8g2_uint_t x2, u8g2_uint_t y2)
- {
- u8g2_uint_t tmp;
- u8g2_uint_t x,y;
- u8g2_uint_t dx, dy;
- u8g2_int_t err;
- u8g2_int_t ystep;
- uint8_t swapxy = 0;
-
- /* no intersection check at the moment, should be added... */
- if ( x1 > x2 ) dx = x1-x2; else dx = x2-x1;
- if ( y1 > y2 ) dy = y1-y2; else dy = y2-y1;
- if ( dy > dx )
- {
- swapxy = 1;
- tmp = dx; dx =dy; dy = tmp;
- tmp = x1; x1 =y1; y1 = tmp;
- tmp = x2; x2 =y2; y2 = tmp;
- }
- if ( x1 > x2 )
- {
- tmp = x1; x1 =x2; x2 = tmp;
- tmp = y1; y1 =y2; y2 = tmp;
- }
- err = dx >> 1;
- if ( y2 > y1 ) ystep = 1; else ystep = -1;
- y = y1;
- #ifndef U8G2_16BIT
- if ( x2 == 255 )
- x2--;
- #else
- if ( x2 == 0xffff )
- x2--;
- #endif
- for( x = x1; x <= x2; x++ )
- {
- if ( swapxy == 0 )
- u8g2_DrawPixel(u8g2, x, y);
- else
- u8g2_DrawPixel(u8g2, y, x);
- err -= (uint8_t)dy;
- if ( err < 0 )
- {
- y += (u8g2_uint_t)ystep;
- err += (u8g2_uint_t)dx;
- }
- }
- }
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