diff --git a/Libraries/u8glib/u8g_line.c b/Libraries/u8glib/u8g_line.c new file mode 100644 --- /dev/null +++ b/Libraries/u8glib/u8g_line.c @@ -0,0 +1,81 @@ +/* + + u8g_line.h + + Universal 8bit Graphics Library + + Copyright (c) 2012, 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_DrawLine(u8g_t *u8g, u8g_uint_t x1, u8g_uint_t y1, u8g_uint_t x2, u8g_uint_t y2) +{ + u8g_uint_t tmp; + u8g_uint_t x,y; + u8g_uint_t dx, dy; + u8g_int_t err; + u8g_int_t ystep; + + uint8_t swapxy = 0; + + /* no BBX 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; + for( x = x1; x <= x2; x++ ) + { + if ( swapxy == 0 ) + u8g_DrawPixel(u8g, x, y); + else + u8g_DrawPixel(u8g, y, x); + err -= (uint8_t)dy; + if ( err < 0 ) + { + y += (u8g_uint_t)ystep; + err += (u8g_uint_t)dx; + } + } +}