You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
101 lines
2.7 KiB
101 lines
2.7 KiB
12 years ago
|
/*
|
||
|
|
|
||
|
|
u8g_ellipse.c
|
||
|
|
|
||
|
|
Utility to draw empty and filled ellipses.
|
||
|
|
|
||
|
|
Universal 8bit Graphics Library
|
||
|
|
|
||
|
|
Copyright (c) 2011, bjthom@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.
|
||
|
|
|
||
|
|
Addition to the U8G Library as of 02/29/12
|
||
|
|
Adapted from Bresenham's Algorithm and the following websites:
|
||
|
|
http://free.pages.at/easyfilter/bresenham.html
|
||
|
|
http://homepage.smc.edu/kennedy_john/belipse.pdf
|
||
|
|
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "u8g.h"
|
||
|
|
|
||
|
|
|
||
|
|
#ifdef WORK_IN_PROGRESS
|
||
|
|
|
||
|
|
void u8g_DrawEllipseRect(u8g_t *u8g, u8g_uint_t x0, u8g_uint_t y0, u8g_uint_t x1, u8g_uint_t y1)
|
||
|
|
{
|
||
|
|
int a = abs(x1 - x0);
|
||
|
|
int b = abs(y1 - y0); //get diameters
|
||
|
|
int b1 = b&1;
|
||
|
|
long dx = 4*(1-a)*b*b;
|
||
|
|
long dy = 4*(b1+1)*a*a;
|
||
|
|
long err = dx+dy+b1*a*a;
|
||
|
|
long e2;
|
||
|
|
|
||
|
|
if (x0 > x1) { x0 = x1; x1 += a; }
|
||
|
|
if (y0 > y1) { y0 = y1; }
|
||
|
|
y0 += (b+1)/2;
|
||
|
|
y1 = y0-b1;
|
||
|
|
a *= 8*a;
|
||
|
|
b1 = 8*b*b;
|
||
|
|
|
||
|
|
do {
|
||
|
|
u8g_DrawPixel(u8g, x1, y0);
|
||
|
|
u8g_DrawPixel(u8g, x0, y0);
|
||
|
|
u8g_DrawPixel(u8g, x0, y1);
|
||
|
|
u8g_DrawPixel(u8g, x1, y1);
|
||
|
|
e2 = 2*err;
|
||
|
|
if (e2 >= dx) {
|
||
|
|
x0++;
|
||
|
|
x1--;
|
||
|
|
err += dx += b1;
|
||
|
|
}
|
||
|
|
if (e2 <= dy) {
|
||
|
|
y0++;
|
||
|
|
y1--;
|
||
|
|
err += dy += a;
|
||
|
|
}
|
||
|
|
} while (x0 <= x1);
|
||
|
|
|
||
|
|
while (y0-y1 < b) {
|
||
|
|
u8g_DrawPixel(u8g, x0-1, y0);
|
||
|
|
u8g_DrawPixel(u8g, x1+1, y0++);
|
||
|
|
u8g_DrawPixel(u8g, x0-1, y1);
|
||
|
|
u8g_DrawPixel(u8g, x1+1, y1--);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void u8g_DrawEllipse(u8g_t *u8g, u8g_uint_t x0, u8g_uint_t y0, u8g_uint_t xr, u8g_uint_t yr)
|
||
|
|
{
|
||
|
|
u8g_DrawPixel(u8g, x0, y0+yr);
|
||
|
|
u8g_DrawPixel(u8g, x0, y0-yr);
|
||
|
|
u8g_DrawPixel(u8g, x0+xr, y0);
|
||
|
|
u8g_DrawPixel(u8g, x0-xr, y0);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|