iforce2d Chris
Displays distance to start location on OLED screen.
Diff: u8g_ellipse.c
- Revision:
- 0:972874f31c98
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/u8g_ellipse.c Wed Mar 07 12:49:14 2018 +0000
@@ -0,0 +1,394 @@
+/*
+
+ 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
+
+#if defined(U8G_16BIT)
+typedef int32_t u8g_long_t;
+#else
+typedef int16_t u8g_long_t;
+#endif
+
+
+/*
+ Source:
+ ftp://pc.fk0.name/pub/books/programming/bezier-ellipse.pdf
+ Foley, Computer Graphics, p 90
+*/
+static void u8g_draw_ellipse_section(u8g_t *u8g, u8g_uint_t x, u8g_uint_t y, u8g_uint_t x0, u8g_uint_t y0, uint8_t option) U8G_NOINLINE;
+static void u8g_draw_ellipse_section(u8g_t *u8g, u8g_uint_t x, u8g_uint_t y, u8g_uint_t x0, u8g_uint_t y0, uint8_t option)
+{
+ /* upper right */
+ if ( option & U8G_DRAW_UPPER_RIGHT )
+ {
+ u8g_DrawPixel(u8g, x0 + x, y0 - y);
+ }
+
+ /* upper left */
+ if ( option & U8G_DRAW_UPPER_LEFT )
+ {
+ u8g_DrawPixel(u8g, x0 - x, y0 - y);
+ }
+
+ /* lower right */
+ if ( option & U8G_DRAW_LOWER_RIGHT )
+ {
+ u8g_DrawPixel(u8g, x0 + x, y0 + y);
+ }
+
+ /* lower left */
+ if ( option & U8G_DRAW_LOWER_LEFT )
+ {
+ u8g_DrawPixel(u8g, x0 - x, y0 + y);
+ }
+}
+
+void u8g_draw_ellipse(u8g_t *u8g, u8g_uint_t x0, u8g_uint_t y0, u8g_uint_t rx, u8g_uint_t ry, uint8_t option)
+{
+ u8g_uint_t x, y;
+ u8g_long_t xchg, ychg;
+ u8g_long_t err;
+ u8g_long_t rxrx2;
+ u8g_long_t ryry2;
+ u8g_long_t stopx, stopy;
+
+ rxrx2 = rx;
+ rxrx2 *= rx;
+ rxrx2 *= 2;
+
+ ryry2 = ry;
+ ryry2 *= ry;
+ ryry2 *= 2;
+
+ x = rx;
+ y = 0;
+
+ xchg = 1;
+ xchg -= rx;
+ xchg -= rx;
+ xchg *= ry;
+ xchg *= ry;
+
+ ychg = rx;
+ ychg *= rx;
+
+ err = 0;
+
+ stopx = ryry2;
+ stopx *= rx;
+ stopy = 0;
+
+ while( stopx >= stopy )
+ {
+ u8g_draw_ellipse_section(u8g, x, y, x0, y0, option);
+ y++;
+ stopy += rxrx2;
+ err += ychg;
+ ychg += rxrx2;
+ if ( 2*err+xchg > 0 )
+ {
+ x--;
+ stopx -= ryry2;
+ err += xchg;
+ xchg += ryry2;
+ }
+ }
+
+ x = 0;
+ y = ry;
+
+ xchg = ry;
+ xchg *= ry;
+
+ ychg = 1;
+ ychg -= ry;
+ ychg -= ry;
+ ychg *= rx;
+ ychg *= rx;
+
+ err = 0;
+
+ stopx = 0;
+
+ stopy = rxrx2;
+ stopy *= ry;
+
+
+ while( stopx <= stopy )
+ {
+ u8g_draw_ellipse_section(u8g, x, y, x0, y0, option);
+ x++;
+ stopx += ryry2;
+ err += xchg;
+ xchg += ryry2;
+ if ( 2*err+ychg > 0 )
+ {
+ y--;
+ stopy -= rxrx2;
+ err += ychg;
+ ychg += rxrx2;
+ }
+ }
+
+}
+
+void u8g_DrawEllipse(u8g_t *u8g, u8g_uint_t x0, u8g_uint_t y0, u8g_uint_t rx, u8g_uint_t ry, uint8_t option)
+{
+ /* check for bounding box */
+ {
+ u8g_uint_t rxp, rxp2;
+ u8g_uint_t ryp, ryp2;
+
+ rxp = rx;
+ rxp++;
+ rxp2 = rxp;
+ rxp2 *= 2;
+
+ ryp = ry;
+ ryp++;
+ ryp2 = ryp;
+ ryp2 *= 2;
+
+ if ( u8g_IsBBXIntersection(u8g, x0-rxp, y0-ryp, rxp2, ryp2) == 0)
+ return;
+ }
+
+ u8g_draw_ellipse(u8g, x0, y0, rx, ry, option);
+}
+
+static void u8g_draw_filled_ellipse_section(u8g_t *u8g, u8g_uint_t x, u8g_uint_t y, u8g_uint_t x0, u8g_uint_t y0, uint8_t option) U8G_NOINLINE;
+static void u8g_draw_filled_ellipse_section(u8g_t *u8g, u8g_uint_t x, u8g_uint_t y, u8g_uint_t x0, u8g_uint_t y0, uint8_t option)
+{
+ /* upper right */
+ if ( option & U8G_DRAW_UPPER_RIGHT )
+ {
+ u8g_DrawVLine(u8g, x0+x, y0-y, y+1);
+ }
+
+ /* upper left */
+ if ( option & U8G_DRAW_UPPER_LEFT )
+ {
+ u8g_DrawVLine(u8g, x0-x, y0-y, y+1);
+ }
+
+ /* lower right */
+ if ( option & U8G_DRAW_LOWER_RIGHT )
+ {
+ u8g_DrawVLine(u8g, x0+x, y0, y+1);
+ }
+
+ /* lower left */
+ if ( option & U8G_DRAW_LOWER_LEFT )
+ {
+ u8g_DrawVLine(u8g, x0-x, y0, y+1);
+ }
+}
+
+void u8g_draw_filled_ellipse(u8g_t *u8g, u8g_uint_t x0, u8g_uint_t y0, u8g_uint_t rx, u8g_uint_t ry, uint8_t option)
+{
+ u8g_uint_t x, y;
+ u8g_long_t xchg, ychg;
+ u8g_long_t err;
+ u8g_long_t rxrx2;
+ u8g_long_t ryry2;
+ u8g_long_t stopx, stopy;
+
+ rxrx2 = rx;
+ rxrx2 *= rx;
+ rxrx2 *= 2;
+
+ ryry2 = ry;
+ ryry2 *= ry;
+ ryry2 *= 2;
+
+ x = rx;
+ y = 0;
+
+ xchg = 1;
+ xchg -= rx;
+ xchg -= rx;
+ xchg *= ry;
+ xchg *= ry;
+
+ ychg = rx;
+ ychg *= rx;
+
+ err = 0;
+
+ stopx = ryry2;
+ stopx *= rx;
+ stopy = 0;
+
+ while( stopx >= stopy )
+ {
+ u8g_draw_filled_ellipse_section(u8g, x, y, x0, y0, option);
+ y++;
+ stopy += rxrx2;
+ err += ychg;
+ ychg += rxrx2;
+ if ( 2*err+xchg > 0 )
+ {
+ x--;
+ stopx -= ryry2;
+ err += xchg;
+ xchg += ryry2;
+ }
+ }
+
+ x = 0;
+ y = ry;
+
+ xchg = ry;
+ xchg *= ry;
+
+ ychg = 1;
+ ychg -= ry;
+ ychg -= ry;
+ ychg *= rx;
+ ychg *= rx;
+
+ err = 0;
+
+ stopx = 0;
+
+ stopy = rxrx2;
+ stopy *= ry;
+
+
+ while( stopx <= stopy )
+ {
+ u8g_draw_filled_ellipse_section(u8g, x, y, x0, y0, option);
+ x++;
+ stopx += ryry2;
+ err += xchg;
+ xchg += ryry2;
+ if ( 2*err+ychg > 0 )
+ {
+ y--;
+ stopy -= rxrx2;
+ err += ychg;
+ ychg += rxrx2;
+ }
+ }
+
+}
+
+void u8g_DrawFilledEllipse(u8g_t *u8g, u8g_uint_t x0, u8g_uint_t y0, u8g_uint_t rx, u8g_uint_t ry, uint8_t option)
+{
+ /* check for bounding box */
+ {
+ u8g_uint_t rxp, rxp2;
+ u8g_uint_t ryp, ryp2;
+
+ rxp = rx;
+ rxp++;
+ rxp2 = rxp;
+ rxp2 *= 2;
+
+ ryp = ry;
+ ryp++;
+ ryp2 = ryp;
+ ryp2 *= 2;
+
+ if ( u8g_IsBBXIntersection(u8g, x0-rxp, y0-ryp, rxp2, ryp2) == 0)
+ return;
+ }
+
+ u8g_draw_filled_ellipse(u8g, x0, y0, rx, ry, option);
+}
+