Author: des Date: Fri Jan 1 04:04:40 2016 New Revision: 293034 URL: https://svnweb.freebsd.org/changeset/base/293034
Log: 17 years and change after I wrote warp_saver, here's a simple plasma effect (currently only three circular patterns) which requires quite a bit of fixed-point arithmetic, including sqrt() and cos(). Happy New Year! Added: head/sys/dev/syscons/plasma/ head/sys/dev/syscons/plasma/fp16.c (contents, props changed) head/sys/dev/syscons/plasma/fp16.h (contents, props changed) head/sys/dev/syscons/plasma/plasma_saver.c (contents, props changed) head/sys/modules/syscons/plasma/ head/sys/modules/syscons/plasma/Makefile (contents, props changed) Modified: head/share/man/man4/splash.4 head/sys/modules/syscons/Makefile Modified: head/share/man/man4/splash.4 ============================================================================== --- head/share/man/man4/splash.4 Fri Jan 1 03:59:09 2016 (r293033) +++ head/share/man/man4/splash.4 Fri Jan 1 04:04:40 2016 (r293034) @@ -26,7 +26,7 @@ .\" .\" $FreeBSD$ .\" -.Dd November 29, 2010 +.Dd December 31, 2015 .Dt SPLASH 4 .Os .Sh NAME @@ -130,6 +130,8 @@ the screen will also be powered off. Animated graphical .Fx logo. +.It Pa plasma_saver.ko +Draws an animated interference pattern. .It Pa rain_saver.ko Draws a shower on the screen. .It Pa snake_saver.ko @@ -282,6 +284,14 @@ based on the code, with some additional inspiration from the .Pa daemon_saver code. +The +.Pa logo_saver , +.Pa plasma_saver , +.Pa rain_saver +and +.Pa warp_saver +modules were written by +.An Dag-Erling Sm\(/orgrav Aq Mt [email protected] . .Sh CAVEATS Both the splash screen and the screen saver work with .Xr syscons 4 Added: head/sys/dev/syscons/plasma/fp16.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/dev/syscons/plasma/fp16.c Fri Jan 1 04:04:40 2016 (r293034) @@ -0,0 +1,131 @@ +/*- + * Copyright (c) 2015 Dag-Erling Smørgrav + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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 AUTHOR 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 AUTHOR 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. + * + * $FreeBSD$ + */ + +#ifdef _KERNEL +#include <sys/libkern.h> +#else +#include <stdio.h> +#include <strings.h> +#endif + +#include "fp16.h" + +/* + * Compute the quare root of x, using Newton's method with 2^(log2(x)/2) + * as the initial estimate. + */ +fp16_t +fp16_sqrt(fp16_t x) +{ + fp16_t y, delta; + signed int log2x; + + /* special case */ + if (x == 0) + return (0); + + /* shift toward 0 by half the logarithm */ + log2x = flsl(x) - 1; + if (log2x >= 16) { + y = x >> (log2x - 16) / 2; + } else { +#if 0 + y = x << (16 - log2x) / 2; +#else + /* XXX for now, return 0 for anything < 1 */ + return (0); +#endif + } + while (y > 0) { + /* delta = y^2 / 2y */ + delta = fp16_div(fp16_sub(fp16_mul(y, y), x), y * 2); + if (delta == 0) + break; + y = fp16_sub(y, delta); + } + return (y); +} + +static fp16_t fp16_cos_table[256] = { + 65536, 65534, 65531, 65524, 65516, 65505, 65491, 65475, + 65457, 65436, 65412, 65386, 65358, 65327, 65294, 65258, + 65220, 65179, 65136, 65091, 65043, 64992, 64939, 64884, + 64826, 64766, 64703, 64638, 64571, 64501, 64428, 64353, + 64276, 64197, 64115, 64030, 63943, 63854, 63762, 63668, + 63571, 63473, 63371, 63268, 63162, 63053, 62942, 62829, + 62714, 62596, 62475, 62353, 62228, 62100, 61971, 61839, + 61705, 61568, 61429, 61288, 61144, 60998, 60850, 60700, + 60547, 60392, 60235, 60075, 59913, 59749, 59583, 59414, + 59243, 59070, 58895, 58718, 58538, 58356, 58172, 57986, + 57797, 57606, 57414, 57219, 57022, 56822, 56621, 56417, + 56212, 56004, 55794, 55582, 55368, 55152, 54933, 54713, + 54491, 54266, 54040, 53811, 53581, 53348, 53114, 52877, + 52639, 52398, 52155, 51911, 51665, 51416, 51166, 50914, + 50660, 50403, 50146, 49886, 49624, 49360, 49095, 48828, + 48558, 48288, 48015, 47740, 47464, 47186, 46906, 46624, + 46340, 46055, 45768, 45480, 45189, 44897, 44603, 44308, + 44011, 43712, 43412, 43110, 42806, 42501, 42194, 41885, + 41575, 41263, 40950, 40636, 40319, 40002, 39682, 39362, + 39039, 38716, 38390, 38064, 37736, 37406, 37075, 36743, + 36409, 36074, 35738, 35400, 35061, 34721, 34379, 34036, + 33692, 33346, 32999, 32651, 32302, 31952, 31600, 31247, + 30893, 30538, 30181, 29824, 29465, 29105, 28745, 28383, + 28020, 27656, 27291, 26925, 26557, 26189, 25820, 25450, + 25079, 24707, 24334, 23960, 23586, 23210, 22833, 22456, + 22078, 21699, 21319, 20938, 20557, 20175, 19792, 19408, + 19024, 18638, 18253, 17866, 17479, 17091, 16702, 16313, + 15923, 15533, 15142, 14751, 14359, 13966, 13573, 13179, + 12785, 12390, 11995, 11600, 11204, 10807, 10410, 10013, + 9616, 9218, 8819, 8421, 8022, 7623, 7223, 6823, + 6423, 6023, 5622, 5222, 4821, 4420, 4018, 3617, + 3215, 2814, 2412, 2010, 1608, 1206, 804, 402, +}; + +/* + * Compute the cosine of theta. + */ +fp16_t +fp16_cos(fp16_t theta) +{ + unsigned int i; + + i = 1024 * (theta % FP16_2PI) / FP16_2PI; + switch (i / 256) { + case 0: + return (fp16_cos_table[i % 256]); + case 1: + return (-fp16_cos_table[255 - i % 256]); + case 2: + return (-fp16_cos_table[i % 256]); + case 3: + return (fp16_cos_table[255 - i % 256]); + default: + /* inconceivable! */ + return (0); + } +} Added: head/sys/dev/syscons/plasma/fp16.h ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/dev/syscons/plasma/fp16.h Fri Jan 1 04:04:40 2016 (r293034) @@ -0,0 +1,84 @@ +/*- + * Copyright (c) 2015 Dag-Erling Smørgrav + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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 AUTHOR 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 AUTHOR 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. + * + * $FreeBSD$ + */ + +#ifndef FP16_H_INCLUDED +#define FP16_H_INCLUDED + +typedef signed long long fp16_t; + +#define ItoFP16(n) ((signed long long)(n) << 16) +#define FP16toI(n) ((signed long long)(n) >> 16) + +#ifndef _KERNEL +#define FP16toF(n) ((n) / 65536.0) +#endif + +/* add a and b */ +static inline fp16_t +fp16_add(fp16_t a, fp16_t b) +{ + + return (a + b); +} + +/* subtract b from a */ +static inline fp16_t +fp16_sub(fp16_t a, fp16_t b) +{ + + return (a - b); +} + +/* multiply a by b */ +static inline fp16_t +fp16_mul(fp16_t a, fp16_t b) +{ + + return (a * b >> 16); +} + +/* divide a by b */ +static inline fp16_t +fp16_div(fp16_t a, fp16_t b) +{ + + return ((a << 16) / b); +} + +/* square root */ +fp16_t fp16_sqrt(fp16_t); + +#define FP16_2PI 411774 +#define FP16_PI 205887 +#define FP16_PI_2 102943 +#define FP16_PI_4 51471 + +/* cosine */ +fp16_t fp16_cos(fp16_t); + +#endif Added: head/sys/dev/syscons/plasma/plasma_saver.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/dev/syscons/plasma/plasma_saver.c Fri Jan 1 04:04:40 2016 (r293034) @@ -0,0 +1,239 @@ +/*- + * Copyright (c) 2015 Dag-Erling Smørgrav + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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 AUTHOR 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 AUTHOR 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. + * + * $FreeBSD$ + * + * To CJA, in appreciation of Nighthawk brunches past and future. + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/syslog.h> +#include <sys/consio.h> +#include <sys/fbio.h> + +#include <dev/fb/fbreg.h> +#include <dev/fb/splashreg.h> +#include <dev/syscons/syscons.h> + +#define SAVER_NAME "plasma_saver" + +#include "fp16.h" + +/* + * Preferred video modes + */ +static int modes[] = { + M_VGA_CG640, + M_PC98_PEGC640x480, + M_PC98_PEGC640x400, + M_VGA_CG320, + -1 +}; + +/* + * Display parameters + */ +static unsigned char *vid; +static unsigned int banksize, scrmode, scrw, scrh; +static unsigned int blanked; + +/* + * List of foci + */ +#define FOCI 3 +static struct { + int x, y; /* coordinates */ + int vx, vy; /* velocity */ +} plasma_foci[FOCI]; + +/* + * Palette + */ +static struct { + unsigned char r, g, b; +} plasma_pal[256]; + +/* + * Draw a new frame + */ +static void +plasma_update(video_adapter_t *adp) +{ + unsigned int x, y; /* coordinates */ + signed int dx, dy; /* horizontal / vertical distance */ + fp16_t sqd, d; /* square of distance and distance */ + fp16_t m; /* magnitude */ + unsigned int org, off; /* origin and offset */ + unsigned int i; /* loop index */ + + /* switch to bank 0 */ + vidd_set_win_org(adp, 0); + /* for each scan line */ + for (y = org = off = 0; y < scrh; ++y) { + /* for each pixel on scan line */ + for (x = 0; x < scrw; ++x, ++off) { + /* for each focus */ + for (i = m = 0; i < FOCI; ++i) { + dx = x - plasma_foci[i].x; + dy = y - plasma_foci[i].y; + sqd = ItoFP16(dx * dx + dy * dy); + d = fp16_sqrt(sqd); + /* divide by 4 to stretch out the pattern */ + m = fp16_add(m, fp16_cos(d / 4)); + } + /* + * m is now in the range +/- FOCI, but we need a + * value between 0 and 255. We scale to +/- 127 + * and add 127, which moves it into the range [0, + * 254]. + */ + m = fp16_mul(m, ItoFP16(127)); + m = fp16_div(m, ItoFP16(FOCI)); + m = fp16_add(m, ItoFP16(127)); + /* switch banks if necessary */ + if (off > banksize) { + off -= banksize; + org += banksize; + vidd_set_win_org(adp, org); + } + /* plot */ + vid[off] = FP16toI(m); + } + } + /* now move the foci */ + for (i = 0; i < FOCI; ++i) { + plasma_foci[i].x += plasma_foci[i].vx; + if (plasma_foci[i].x < 0) { + /* bounce against left wall */ + plasma_foci[i].vx = -plasma_foci[i].vx; + plasma_foci[i].x = -plasma_foci[i].x; + } else if (plasma_foci[i].x >= scrw) { + /* bounce against right wall */ + plasma_foci[i].vx = -plasma_foci[i].vx; + plasma_foci[i].x = scrw - (plasma_foci[i].x - scrw); + } + plasma_foci[i].y += plasma_foci[i].vy; + if (plasma_foci[i].y < 0) { + /* bounce against ceiling */ + plasma_foci[i].vy = -plasma_foci[i].vy; + plasma_foci[i].y = -plasma_foci[i].y; + } else if (plasma_foci[i].y >= scrh) { + /* bounce against floor */ + plasma_foci[i].vy = -plasma_foci[i].vy; + plasma_foci[i].y = scrh - (plasma_foci[i].y - scrh); + } + } +} + +/* + * Start or stop the screensaver + */ +static int +plasma_saver(video_adapter_t *adp, int blank) +{ + int pl; + + if (blank) { + /* switch to graphics mode */ + if (blanked <= 0) { + pl = splhigh(); + vidd_set_mode(adp, scrmode); + vidd_load_palette(adp, (unsigned char *)plasma_pal); + vidd_set_border(adp, 0); + blanked++; + vid = (unsigned char *)adp->va_window; + banksize = adp->va_window_size; + splx(pl); + vidd_clear(adp); + } + /* update display */ + plasma_update(adp); + } else { + blanked = 0; + } + return (0); +} + +/* + * Initialize on module load + */ +static int +plasma_init(video_adapter_t *adp) +{ + video_info_t info; + int i; + + /* select video mode */ + for (i = 0; modes[i] >= 0; ++i) + if (vidd_get_info(adp, modes[i], &info) == 0) + break; + if (modes[i] < 0) { + log(LOG_NOTICE, "%s: no supported video modes\n", SAVER_NAME); + return (ENODEV); + } + scrmode = modes[i]; + scrw = info.vi_width; + scrh = info.vi_height; + + /* initialize the palette */ + for (i = 0; i < 256; ++i) + plasma_pal[i].r = plasma_pal[i].g = plasma_pal[i].b = i; + + /* randomize the foci */ + for (i = 0; i < FOCI; i++) { + plasma_foci[i].x = random() % scrw; + plasma_foci[i].y = random() % scrh; + plasma_foci[i].vx = random() % 5 - 2; + plasma_foci[i].vy = random() % 5 - 2; + } + + return (0); +} + +/* + * Clean up before module unload + */ +static int +plasma_term(video_adapter_t *adp) +{ + + return (0); +} + +/* + * Boilerplate + */ +static scrn_saver_t plasma_module = { + SAVER_NAME, + plasma_init, + plasma_term, + plasma_saver, + NULL +}; + +SAVER_MODULE(plasma_saver, plasma_module); Modified: head/sys/modules/syscons/Makefile ============================================================================== --- head/sys/modules/syscons/Makefile Fri Jan 1 03:59:09 2016 (r293033) +++ head/sys/modules/syscons/Makefile Fri Jan 1 04:04:40 2016 (r293034) @@ -9,6 +9,7 @@ SUBDIR= ${_apm} \ ${_fire} \ green \ ${_logo} \ + ${_plasma} \ ${_rain} \ ${_snake} \ ${_star} \ @@ -25,6 +26,7 @@ _daemon= daemon _dragon= dragon _fire= fire _logo= logo +_plasma= plasma _rain= rain _snake= snake _star= star Added: head/sys/modules/syscons/plasma/Makefile ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/modules/syscons/plasma/Makefile Fri Jan 1 04:04:40 2016 (r293034) @@ -0,0 +1,8 @@ +# $FreeBSD$ + +.PATH: ${.CURDIR}/../../../dev/syscons/plasma + +KMOD= plasma_saver +SRCS= fp16.c plasma_saver.c + +.include <bsd.kmod.mk> _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
