diff --git a/Libraries/u8glib/u8g_ellipse.c b/Libraries/u8glib/u8g_ellipse.c new file mode 100644 --- /dev/null +++ b/Libraries/u8glib/u8g_ellipse.c @@ -0,0 +1,393 @@ +/* + + 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); +}